REVIEW | doi:10.20944/preprints202307.2148.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: autoimmune inflamation with antibodies,; anti-NMDAR antibodies,; anti-AMPAR antibodies,; anti-GQ1b antibodies,; anti-DPPX antibodies,; anti-CASPR2 antibodies,; anti-LGI1 antibodies,; encephalitis,; psychoses
Online: 1 August 2023 (11:37:28 CEST)
Encephalitis is a condition with a variety of etiologies, clinical presentations and degrees of severity. The causes of these disorders include both neuroinfections and autoimmune diseases in which host antibodies are pathologically directed against self antigens. In autoimmune encephalitis, autoantibodies are expressed in the central nervous system. The incidence of this disease is approximately 4% of all reported cases of encephalitis. Autoimmune encephalitis can be induced by antibodies against neuronal surface antigens such as N-methyl-D-aspartate-activated glutamate receptors (NMDAR), ⍺-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPAR) or gangliosides GQ1b, DPPX, CASPR2, LGI1, as well as by antibodies against neuronal intracellular antigens. The paper presents a number of both mental and neurological symptoms of autoimmune encephalitis. Moreover, the coexistence of psychoses, neoplastic diseases and the methods of diagnosing autoimmune encephalitis are discussed. Attention was also drawn to the fact that early diagnosis, as well as early initiation of targeted treatment, increases the chance of a successful course of the therapeutic process.
REVIEW | doi:10.20944/preprints202311.0307.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: monoclonal antibodies; variants resistance; bispecific antibodies; engineered antibodies; antiviral therapy
Online: 6 November 2023 (10:38:14 CET)
Monoclonal antibody (mAb) therapy has revolutionized the treatment of various diseases, including cancer and autoimmune disorders. However, the emergence of SARS-CoV-2 variants, as well as other pathogenic variants, poses challenges in maintaining the therapeutic efficacy of mAbs. In this mini review article, we aim to explore the strategies to overcome variants resistance in mAb therapy against viral infections. Firstly, we discuss the mechanisms through which variants can evade the neutralizing effects of mAbs. Understanding these mechanisms is crucial in developing targeted approaches to combat resistance. Next, we delve into the strategies being pursued to address variants resistance. These include developing new mAbs or antibody cocktails that target multiple epitopes, engineering mAbs with improved binding affinities or enhanced neutralizing capabilities, and exploring alternative therapeutic modalities such as bispecific antibodies or antibody-drug conjugates. Furthermore, we highlight the role of computational modeling and artificial intelligence in predicting variant escape mutations and aiding in the design of more effective mAbs. Additionally, we examine the importance of continuous surveillance and monitoring of emerging variants to inform treatment strategies. This article emphasizes the urgent need for proactive approaches to tackle variants resistance in mAb therapy. By combining innovative design strategies, computational modeling, and vigilant surveillance, we can maintain the therapeutic effectiveness of mAbs and stay ahead in the battle against evolving pathogens and viral infections.
ARTICLE | doi:10.20944/preprints202012.0055.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: IgA vasculitis; antiphospholipid antibodies; lupus anticoagulant; anticardiolipin antibodies; anti-b2 glycoprotein antibodies
Online: 2 December 2020 (10:36:58 CET)
IgA vasculitis is a hypersensitivity vasculitis, which is usually self-limiting. Renal involvement is the most damaging long-term complication of IgA vasculitis, happening in 20% - 100% of cases. Some factors have been reported to be associated with renal involvement in IgA vasculitis; however, no biomarker has been proved as a risk factor for renal involvement and its severity yet. We followed 48 patients with a confirmed diagnosis of IgA vasculitis for six months. We checked these patients for renal involvement by microscopic urine examination. We checked aPL antibodies in all patients on admission and 12 weeks later. Urinalysis showed renal involvement in 14 of 48 patients with IgA vasculitis (29.16%). Antiphospholipid antibodies were positive in 9 patients with IgA vasculitis and renal involvement (9 out of 14, 64.28%), while they were positive in only six patients with IgA vasculitis without renal involvement (6 out of 34, 17.64%), showing a moderate correlation between positive aLP and renal involvement in patients with IgA vasculitis, with a kappa index of 0.457. Serum aPL antibodies, as a tool to predict renal involvement in IgA vasculitis, show a sensitivity of 64.3%, a specificity of 82.4%, PPV of 60.0%, and NPV of 84.8%, demonstrating that a positive serum aPL antibody can be used to positively predict the renal involvement, while a negative result is not strong enough to rule out future renal involvement.
ARTICLE | doi:10.20944/preprints202307.0313.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: COVID-19; Sinopharm vaccine; neutralizing antibodies; anti-S1 IgG antibodies; anti-RBD IgM antibodies; anti-N IgM antibodies; anti-N IgG antibodies; interferon γ.
Online: 5 July 2023 (12:31:08 CEST)
Several vaccines against COVID -19 have been developed and licenced to enhance the immune response against SARS-CoV-2. Similarly, infection with SARS-CoV-2 before vaccination has been shown to provide significant protection against severe infection and hospitalisation. The aim of this study was to investigate the effect of three doses of Sinopharm vaccine and SARS-CoV-2 infection on the specific immune response in 103 volunteers, measuring neutralizing antibodies, anti-S1 IgG, anti-RBD IgM, anti-N IgM, anti-N IgG antibodies and interferon γ. Our results showed that the presence of cardiovascular diseases increased the level of anti-N-IgG antibodies, while endocrinological diseases decreased the level of neutralizing antibodies and anti-N-IgG antibodies, suggesting that these diseases alter the effect of vaccine immunity. In addition, there was a significant decrease in anti-S1 IgG levels 6 months and in anti-N IgG levels 18 months post-infection, while neutralizing antibody and interferon γ levels were constant at 3, 6 and 18 months post-infection. Therefore, our results confirm the importance of hybrid immunity as the strongest and most durable compared to exclusively natural or vaccine-induced immunity. Significant positive correlations were found between humoral and cellular immunity markers: neutralizing antibodies, anti-S1 IgG, anti-N IgG and interferon γ, indicating a unique coordinated response specific to COVID-19.
REVIEW | doi:10.20944/preprints202309.1136.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Immunotherapy; autoimmune diseases; monoclonal antibodies; bispecific antibodies; CAR-T cells
Online: 18 September 2023 (07:17:18 CEST)
Systemic autoimmune diseases (SAIDs) such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and rheumatoid arthritis (RA) are fully related to the unregulated innate and adaptive immune systems involved in their pathogenesis. They have similar pathogenic characteristics including the interferon signature, loss of tolerance to self-nuclear antigens, and enhanced tissue damage like necrosis and fibrosis. Glucocorticoids and immunosuppressants, which have limited specificity and are prone to tolerance, are used as the first-line therapy. A plethora of novel immunotherapies have been developed including monoclonal and bispecific antibodies, and other biological agents to target cellular and soluble factors involved in disease pathogenesis such as B cells, co-stimulatory molecules, cytokines or their receptors, and signalling molecules. Many of these have shown encouraging results in clinical trials. CAR-T cell therapy is considered the most promising technique for curing autoimmune diseases, with recent successes in the treatment of SLE and SSc.
ARTICLE | doi:10.20944/preprints202308.0991.v1
Subject: Medicine And Pharmacology, Internal Medicine Keywords: COVID-19; antiphospholipid syndrome; vascular thrombosis; antiphospholipid antibodies; anticardiolipin antibodies (aCLA); anti-β2-glycoprotein I antibodies (anti-β2GPI); anti phosphatidylserine-prothrombin (aPS/PT) antibodies
Online: 14 August 2023 (10:22:52 CEST)
Background: Antiphospholipid antibodies (aPL) are a laboratory criterion for the classification of antiphospholipid syndrome (APS), and are known to cause clinical symptoms: vascular thrombosis or obstetric complications. It is suggested that aPL may be associated with thromboembolism in severe COVID-19 cases. Aim: to combine clinical data with aPL findings at 4 time points (admission, worsening, discharge, 3-month follow-up) in patients hospitalized with COVID-19 pneumonia. Methods: current and past history of thrombosis and obstetric complications; aPL determined at 4 time points: anticardiolipin (aCL), anti-β2-glycoprotein I (anti- β2GPI) and antiphosphatidylserine/prothrombin (aPS/PT) of the IgM, IgG or IgA isotypes. Results: 111 patients with COVID-19 pneumonia were enrolled. During hospitalization, 7 patients died, 3 of them due to pulmonary artery thromboembolism (none was aPL positive). Only one of the five who developed pulmonary artery thrombosis was aPL positive. Of 9/101 patients with a history of thrombosis, 5 had arterial thrombosis and none was aPL positive at admission and follow-up; 4 had venous thrombosis and one was aPL positive at all time points (newly diagnosed APS). Of these 9/101 patients, 55.6% were transiently aPL positive at discharge only, compared to 26.1% without history of thrombosis (p=0.05). Conclusions: aPL were not associated with fatal outcomes and vascular thrombosis; aPL were transiently positive in more than half of patients with a history of thrombosis.
REVIEW | doi:10.20944/preprints202006.0350.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Antibodies engineering; Computational approach; Novel drugs; Synthetic immunology; Next generation antibodies
Online: 28 June 2020 (20:24:49 CEST)
In the pre era of synthetic antibodies, pharmaceutical companies depend on finding novel drugs from medicinal plants and other traditional resources; while in present, technological advances in biology, computer and robotics give the researchers the ability to rewrite and edit DNA in order to synthesize very large sets of drug candidates; these novel and improved candidates serves the basis for creating another library of drug candidates and so on until we find the right biomolecule for the disease of interest. all these technologies combined together to synthesize therapeutic antibodies for many types of cancer, autoimmune diseases, and infectious diseases, that can address diseases much more readily to very rapidly get therapeutics into patients so that we can potentially have an impact on disease. The antibodies mechanism is recognize and bind to disease cells and pinpoint the immune system to attack those cells effectively. Now a days, they dependent on computational approach to guide and accelerate the process of antibodies engineering by combination of selection system and use of high-throughput data acquisition and analysis to build and construct populations of next generation antibodies that are thermo-stable, non-immunogenic as possible, and to be administered to many humans as possible. In this review, I will discuss the latest in silico methods for antibodies engineering.
ARTICLE | doi:10.20944/preprints202310.0336.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: systemic lupus erythematosus; autoimmune thyroid disease; hypothyroidism; hyperthyroidism; thyroid peroxidase antibodies; thyroglobulin antibodies
Online: 6 October 2023 (12:29:21 CEST)
Background and Objectives: Thyroid disease has been associated with autoimmune disorders. As systemic lupus erythematosus (SLE) is a systemic autoimmune disease with diverse manifestations spanning across all organ systems, the relationship of SLE with thyroid disorders needs investigation. In particular, the relationship of SLE with autoimmune thyroid disease has attracted the interest of the research community. The aim was to evaluate the relationship of SLE with autoimmune thyroid disease. Materials and Methods: A cohort of 45 consecutive patients, mean age 47,97 years (range 21-79 years) and 45 age and sex-matched controls were prospectively studied over a period of 12 months for the presence of thyroid disease and the prevalence of antithyroid antibodies. Results: Four patients (8.9%) were found to suffer from primary hypothyroidism, 5 (11.11%) from subclinical hypothyroidism and 1 (2.22%) from hyperthyroidism, whereas 1 (2.22%) of the controls had primary hypothyroidism and 1 (2.22%) had hyperthyroidism. Five patients (11.11%) had a thyroid hormone profile compatible with the presence of euthyroid sick syndrome. Thyroid peroxidase (TPOab) and thyroglobulin (Tgab) antibodies were detected in 20/45 and 15/45 of the SLE population and in 7/45 and 5/45 of the controls, respectively (p<0.05, chi square test). Conclusions: In conclusion, the incidence of clinical thyroid disease is greater amongst SLE patients than in a control population and in a significant number of these patients antithyroid antibodies are detectable. Thus, a subset of lupus patients appears to be predisposed to the development of thyroid disease and this should be considered when evaluating patients with SLE.
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: Meta-analysis; p53 wild type antibodies; p53 mutant antibodies; cancer survival prognostic factor.
Online: 24 September 2021 (12:46:26 CEST)
Importance: p53 is an unequivocal tumor suppressor altered in half cancers. The immune system produces systemic p53 autoantibodies (p53 Abs) in many cancer patients. Objective: The focus of this systemic review and meta-analysis is on the prognostic value of p53 Abs expressed in the serum of patients with solid tumors. Data Sources: All the clinical investigations were searched on PubMed, MBase and Cochrane from 1993 reporting the first study until May 2021. Study Selection: Studies were included that met the following criteria: 1) participants with cancer; 2) outcome results expressed in relation to the presence of a p53 antibody; 3) a primary outcome (disease free survival, overall survival or progression free survival) expressed as hazard ratio (HR). The following exclusion criteria were used: 1) insufficient data available to evaluate outcomes; 2) animal studies; 3) studies with less than 10 participants. 1333 potentially relevant articles; studies as duplicates, non-patients studies or reviews were excluded. After viewing the titles and abstracts of the 52 remaining studies, the full texts of 34 studies were retrieved and 12 studies were included in the analysis. Data Extraction and Synthesis: PRISMA guidelines were used for abstracting and assessing data quality and validity by three independent observers. The summary estimates were generated using a fixed-effect model (Mantel–Haenszel method) or a random-effect model (DerSimonian–Laird-method) depending on the absence or presence of heterogeneity (I2). Main Outcome(s) and Measure(s): The primary study outcome was to determine the prognostic value of p53 Abs from a large population size of patients with solid tumors, as determined before data collection. Results: In total 12 clinical studies and of which 2094 patients were included and it was determined that p53-wt Abs expression in the serum significantly correlated with a worse survival of cancer patients (95% CI 1.48 [1.24, 1.77]; p<0.00001). On the contrary, data from literature indicated that there was a potential association between p53-mut Abs antibodies with better survival. Conclusions and Relevance: This is the first meta-analysis proving the diagnostic utility of p53-Abs for cancer patients, predicting a worse outcome. The serum-p53 value (s-p53-value) could be useful for future theranostics.
ARTICLE | doi:10.20944/preprints202305.0747.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: antibodies; bioinformatics; immunoinflammation; Nicotiana tabacum
Online: 10 May 2023 (11:17:21 CEST)
Here, one hundred patients (50 smokers and 50 non-smokers) clinically diagnosed with COVID-19 were studied. Yet, bioinformatics was used to predict epitopes on Tobacco mosaic virus coat protein (TMV-CP) to produce antibodies towards SARS-CoV-2. Death was three times higher in non-smokers than in smokers. However, biochemical parameters did not separate the groups. Bioinformatics analysis predicted the presence of B-cell epitopes in TMV-CP, suggesting the production of antibodies anti-TMV-CP in smoker patients. Smokers may develop severe forms of COVID-19, but survival was superior in the evaluated group than in non-smokers. Anti-TMV-CP antibodies, potentially present in smokers, might act as a pro-immune agent against SARS-CoV-2 at earlier stages of infection. These data are helpful for future studies assessing COVID-19 in smokers.
ARTICLE | doi:10.20944/preprints202301.0359.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: monoclonal antibodies; tixagevimab/cilgavimab; immunocompromised
Online: 19 January 2023 (12:00:57 CET)
Objectives: Monoclonal antibodies (mAbs) have proven to be a valuable tool against COVID-19, mostly among subjects with risk factors for progression to severe illness. Tixagevimab/cilgavimab (TIX/CIL), a combination of two Fc-modified human monoclonal antibodies, has been recently approved to be employed as early treatment. Methods: Two groups of immunocompromised patients exposed to different early treatments (i.e., TIX/CIL vs. other mAbs [casirivimab/imdevimab, bamlanivimab/etesevimab, sotrovimab]) were compared in terms of clinical outcomes (hospitalization and mortality within 14 days from administration) and time to the negativity of nasal swabs. We used either Pearson’s chi-square or Fisher’s exact test for categorical variables, whereas the Wilcoxon rank–sum test was employed for continuous ones. Kaplan–Meier curves were produced to compare the time to nasopharyngeal swab negativity. Results: Early treatment with TIX/CIL was administered to 19 immunocompromised patients, while 89 patients received other mAbs. Most of them were solid organ transplant recipients or suffering from hematologic or solid malignancies. Overall, no significant difference was observed between the two groups in terms of clinical outcomes. In the TIX/CIL group, one patient (1/19, 5.3%), who was admitted to the emergency room within the first 14 days from treatment and was hospitalised due to COVID-19 progression, died. Regarding the time to nasal swab negativity, no significant difference (p=0.088) emerged. Conclusions: Early treatment of SARS-CoV-2 infection with TIX/CIL shows favourable outcomes in a small group of immunocompromised patients, reporting no significant difference when compared to similar patients treated with other mAbs.
ARTICLE | doi:10.20944/preprints201807.0503.v1
Subject: Biology And Life Sciences, Virology Keywords: cytomegalovirus; cell culture; antibodies; adaptation
Online: 26 July 2018 (04:31:39 CEST)
Propagation of human cytomegalovirus (CMV) in cultured cells results in genetic adaptations that confer improved growth in vitro and significant attenuation in vivo. Mutations in RL13 arise quickly during cell culture passage, while mutations in the UL128-131A locus emerge later during fibroblast passage and disrupt expression of a glycoprotein complex that is important for entry into epithelial and endothelial cells. As in vivo CMV replicates in the context of host antibodies, we reasoned that antibodies might mitigate the accumulation of adaptive mutations during cell culture passage. To test this, CMV in infant urine was used to infect replicate fibroblast cultures. One lineage was passaged in the absence of CMV-hyperimmuneglobulin (HIG) while the other was passaged with HIG in the culture medium. The former lost epithelial tropism and aquired mutations disrupting RL13 and UL131A expression, whereas the latter retained epithelial tropism and both gene loci remained intact after 22 passages. An epitheliotropic RL13+/ UL131A+ virus was isolated by limiting-dilution in the presence of HIG and expanded to produce a working stock sufficient to conduct cell tropism experiments. Thus, culture in the presence of antibodies may facilitate in vitro experiments using viruses that are genetically more authentic than has been previously possible.
ARTICLE | doi:10.20944/preprints201811.0246.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: monoclonal antibodies; polyclonal antibodies; triazines; enzyme immunoassay; quantitative structure-activity relationship analysis; 3D-QSAR; atrazine
Online: 9 November 2018 (11:36:02 CET)
A common task in the immunodetection of structurally close compounds is to analyze the selectivity of immune recognition: it is required to understand the regularities of immune recognition and to elucidate the basic structural elements which provide it. Triazines are compounds of particular interest for such a research due to their high variability and the necessity of their monitoring to provide safety of agricultural products and foodstuffs. We evaluated the binding of 20 triazines with polyclonal (pAb) and monoclonal (mAb) antibodies obtained using atrazine as the immunogenic hapten. A total of >3000 descriptors was used in QSAR analysis of binding activities (pIC50). Comparison of the two enzyme immunoassay systems showed that the system with pAb is much easier to describe using 2D QSAR methodology, while the system with mAb can be described using the 3D QSAR COMFA. Thus, for the 3D QSAR model of the polyclonal antibodies, the main statistical parameter q2 (‘leave-many-out’) is equal 0.498, and for monoclonal antibodies q2 is equal 0.566. Obviously, in the case of pAb, we deal with several targets, while in the case of mAb the target is one, and therefore it is easier to describe it using specific fields of molecular interactions distributed in space.
ARTICLE | doi:10.20944/preprints202309.1919.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: influenza; vaccines; antibodies; neuraminidase-inhibition; persistence.
Online: 28 September 2023 (17:59:45 CEST)
Neuraminidase (NA)-based immunity could reduce the harmful impact of novel antigenic variants of influenza viruses. Detection of neuraminidase-inhibiting (NI) antibodies in parallel with anti-hemagglutinin (HA) antibodies may enhance research of immunogenicity and duration of antibody response to influenza vaccines. To assess anti-NA antibodies after vaccination with seasonal inactivated influenza vaccines, we used the enzyme-linked lectin assay, and anti-HA antibodies were detected in hemagglutination inhibition assay. The dynamics of anti-NA antibody response differed depending on the virus subtype: antibodies to A/H3N2 virus neuraminidase increased later than antibodies to A/H1N1pdm09 subtype neuraminidase, and persisted longer. In contrast to HA antibodies, the fold increase in antibody titers to NA after vaccination poorly depended on the preexisting level. At the same time, NA antibody level after vaccination directly correlated with titers before vaccination. Difference was found in response to NA antigen between split and subunit adjuvanted vaccines and in NA functional activity in the vaccine formulations.
ARTICLE | doi:10.20944/preprints202303.0094.v1
Subject: Biology And Life Sciences, Virology Keywords: Antibodies; HCV; Prevalence; Febrile Patients; Nigeria
Online: 6 March 2023 (06:34:18 CET)
This study was to determine the prevalence of hepatitis C virus (HCV) among febrile patients attending a General Hospital in Emohua LGA, Rivers State, Nigeria. Eighty-nine patients, including 31 males and 58 females, aged 2 to 60 years, were recruited for this study. Blood samples were screened for antibodies to hepatitis C virus (HCV) using a commercially available anti-HCV-Ab enzyme-linked immunosorbent assay (ELISA) based kits following the manufacturer's description. The results showed an overall prevalence of 5.6%. Higher prevalence of HCV was observed among females (6.9%), age groups >41 years (11.1%), singles (7.9%) and patients with primary education (33.3%). Among all the variables evaluated, only education (p = 0.007) was significantly associated with the prevalence of HCV. Age (p = 0.21), sex (p = 0.47) and marital status (p = 0.42) were not associated with the prevalence of HCV among the studied population. This study showed a prevalence rate (5.6%) that is slightly alarmingly well above several other studies done in the past in Nigeria. The seropositivity of HCV among febrile patients remains a great danger to public health. Therefore, HCV screening by ELISA methods in all patients is recommended. Planned prevention, screening and treatment are needed to reduce further transmission.
ARTICLE | doi:10.20944/preprints202207.0335.v1
Online: 22 July 2022 (09:57:40 CEST)
The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), etiological agent of the novel coronavirus disease 2019 (COVID-19), has spread since December 2019, resulting in massive health and economic crisis worldwide. While efforts to stop the pandemic are crucial, collecting epidemiological data to help manage current and future pandemics will be important. In addition to humans, serological and molecular based studies have demonstrated SARS CoV-2 exposure in several wild, domestic and farmed animals. For examples Shriner and the team showed serologically an exposure of 40% to the white deer living in close proximity to urban centers. Additional reports have also emerged of susceptibility of animal’s species like cats, ferrets, raccoon dogs, cynomolgus macaques, rhesus macaques, white-tailed deer, rabbits, Egyptian fruit bats, and Syrian hamsters to SARS-CoV-2 infection.. It’s worth emphasizing that these reports are based on experimental data mostly derived from Europe, USA, South America and parts of Asia. In limited instances natural infections of SARS-CoV-2 have been reported in pet dogs, cats, tigers, lions, snow leopards, pumas, gorillas at zoos and farmed mink and ferrets. The presence of the virus in animal species and an understanding of whether these are natural or recent human to animal transmissions is important. It’s possible that such transmission could passage the virus or subject the virus to a different immunological pressure thereby helping with the development of viral variants in addition to being a host for future reservoirs of the virus. In Kenya SARS-CoV-2 was first detected on March 12th 2020 from imported human cases of persons who had travelled from the United States. This was followed by detection of imported cases majorly from China, Sweden and United Kingdom. Later infections were confirmed in Nairobi and Mombasa suggesting further cases of disease importations through the major ports of entry. However, no comparable data on animal exposure have hitherto been generated in Kenya. To address this key concern, we focused on three objectives; 1) development of a robust antibody ELISA based on crude SARS-CoV-2 lysate. 2) SARS-CoV-2 serology of domestic animals in Kenya. 3) Corroboration of the crude lysate based seroprevalence data and a commercial ELISA kit based on the Spike receptor binding domain (RBD) antigen. Our sample set included camel sera (both pre- & post outbreak sera), as well as sera from cats and dogs collected at the peak of the pandemic. Our results using the ELISA based on crude SARS-CoV-2 lysate indicated SARS-CoV-2 antibodies in camels (71%, N=145), cats 11% (N=16) and dogs (81%, N=36) with varying titer levels. These findings were comparable to those obtained using the commercial ELISA kit based on the spike RBD antigens. In summary, the data warrants two key conclusions: (i) we have demonstrated that the crude lysate ELISA allows for SARS-CoV-2 antibody detection, and given its potential to offer robust detection could be applied for initial mass screening (ii) although the current study cannot disentangle the relative contributions of antigenic cross-reactivity, pre-pandemic exposure to SARS-CoV-2 or human-animal transmission, it nonetheless demonstrates for the first time the prevalence of SARS-CoV-2 like antibodies in domestic and wild animals in Kenya. Our findings set the scene for further research into the prevalence of SARS-CoV-2 in domestic and wild animals to understand their potential epidemiological implications.
REVIEW | doi:10.20944/preprints202306.0011.v1
Subject: Medicine And Pharmacology, Transplantation Keywords: Desensitization; Donor specific antibodies; HLA system; antibodies identification; B cells; Plasma cells; Complement; New drugs; Desensitization; Donor specific antibodies; HLA system; B cells; Plasma cells; Complemennt; New drugs
Online: 1 June 2023 (03:17:00 CEST)
Abstract: Presence in a recipient of antibodies directed against donor specific antigens represent a major obstacle in transplanting such patients. Removal of these antibodies represents a challenge for physicians dealing with kidney transplantation. Several strategies, techniques and old and new drugs are to date used to desensitize these patients. Desensitization may occur before transplantation or at the time of transplantation or after transplantation according whether physicians deal with living or deceased donors. Different techniques may be used to reveal the presence of antibodies in the recipients; each technique has different sensitivity and specificity, different advantages and disadvantages. The target of the drugs used to desensitize are B cells, Plasma cells, the antibodies themselves and finally, the complement that is the final actor causing tissue disruption. If B cells are relatively easy to be targeted, more difficult are the plasma cell. Indeed, several new drugs are used in randomized trials also to defeat plasma cells. Antibodies may be removed rather easily, but often their removal is followed by a rebound. Complement is not easy to be defeated and new drugs are to date used to be successful in this action. However is to date possible to desensitize many patients and to obtain successful transplantation.
ARTICLE | doi:10.20944/preprints202307.0375.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: SARS-CoV-2; pandemic; animals; antibodies; seroprevalence
Online: 6 July 2023 (07:17:54 CEST)
The COVID-19 pandemic has become the largest public health crisis since the 1918 influenza pandemic. Despite the extensive research conducted on the SARS-CoV-2 virus in humans, little is still known about animal-related transmission and its consequences. Therefore, this study contributed to a better understanding of this issue by focusing on the serological survey of SARS-CoV-2 in samples from the serum bank of the Bovine Virology Laboratory at the Biological Institute of São Paulo, as well as horses and dogs from the Military Police of the State of São Paulo, and tapirs and bats from the states of Mato Grosso do Sul and São Paulo. To achieve this, the possible presence of anti-SARS-CoV-2 antibodies in domestic and wild animal species was evaluated using the ID Screen® "SARS-CoV-2 Double Antigen Multi Species" ELISA test (ID-Vet.®), following the manufacturer's recommendations. The findings of this study demonstrate a higher occurrence of anti-SARS-CoV-2 antibodies in domestic animals compared to wild animals, as well as different antibody profiles among the species analyzed, with horses showing a wide range of seroconversion comparable to humans.
REVIEW | doi:10.20944/preprints202306.1623.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Thyroid; autoimmunity; antibodies; thyrotropin; receptor; thyroglobulin; peroxidase
Online: 22 June 2023 (12:25:56 CEST)
Autoimmune thyroid disease refers to a spectrum of various diseases, with two extremes of clinical presentation, hypo-thyroidism (Hashimoto's thyroiditis), and hyperthyroidism (Graves-Basedow disease). Both conditions are character-ized by presenting a cellular and humoral autoimmune reaction, with an increase in the synthesis and secretion of an-tibodies directed towards various thyroid antigens, together with a phenomenon of thyrocyte necrosis and apoptosis (in Hashimoto's thyroiditis) and a persistent thyrotropin-receptor stimulation (in Graves-Basedow disease). The diagnosis of both entities is based on the clinical, laboratory and imaging findings. In this review, the usefulness of thyroid antibodies in the diagnostic approach to autoimmune thyroid disease is de-scribed.
ARTICLE | doi:10.20944/preprints202305.1096.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Malaria; Plasmodium enolase; Band 3; antibodies; hRBCghosts
Online: 16 May 2023 (05:17:02 CEST)
The antibodies targeting invasive proteins of Plasmodium falciparum (Pf) merozoites is a clever strategy against malaria parasite. The recent finding that Plasmodium merozoites surface enolase is a target for growth neutralizing antibodies has generated interest in identifying its re-ceptor (s) on erythrocytes. In the present study, several biochemical experiments were undertaken involving recombinant Pf enolase and antibody against it to search for its cognate receptor. The binding of rPfeno to erythrocytes was selectively sensitive to trypsin but resistant to neuramini-dase. Failure of yeast enolase binding to human red blood cells under similar conditions indicat-ed high specificity of parasite Pfeno. The mass spectrometric and immunological analyses of pro-teins obtained in pull downs and co-immunoprecipitation samples led to identification of band 3 as an interactor/receptor for Plasmodium enolase. Structural characterization of sequences of band 3 - rPfeno interacting regions revealed C-terminal exocytic regions of band 3 to be binding to Pfeno. Similarly, band 3 binding regions of rPfeno were also identified. Identification of receptor-ligand (band 3: Pfeno) pair paves the way for antimalarial anti-Pf enolase-based vaccine, anti-Pf enolase antibodies as drug and also for developing novel small molecule-based invasion inhibi-tory therapeutics including peptidomimetics that could disrupt the band 3: Pfeno protein-protein interactions.
ARTICLE | doi:10.20944/preprints202212.0218.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Monoclonal antibodies; Variable dosing; Fixed dosing; Oncology
Online: 13 December 2022 (02:25:03 CET)
Oncological patients need the proper doses of medications to facilitate their recovery. The two basic approaches used in dosing Monoclonal Antibodies (mAbs) are fixed-dose combination and variable dosing. In Fixed-Dose Combination Drugs (FDCs), two or more active components are combined in a single formulation at a predetermined dose. Variable dosage, which has long been the industry standard, is the polar opposite of this approach. The body changes over time; the Body Surface Area (BSA) in square meters is often used as a Measure (m2). This study uses a systematic review. Most mAbs used in oncology are predominantly given as cytotoxic anticancer drugs using body-size-based (variable) regimens. Despite the benefits of fixed-dose, variable dosing has become the industry standard, despite being criticized for ineffectiveness. While variable dosing has some advantages, the prevalent view is that continuous dosing has significant advantages based on the balance of probabilities. After assessing each alternative, including its benefits and drawbacks, history of use, and suitability in the current context, fixed dosing emerges as a viable option.
ARTICLE | doi:10.20944/preprints202210.0471.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: children; seroprevalence; antibodies; SARS-CoV-2; Vietnam
Online: 31 October 2022 (07:37:55 CET)
Background: The robustness of sero-surveillence has delineated the high burden of SARS-CoV-2 infection in children; however, these existing data showed wide variation. This study aimed to identify the serostatus of antibodies against SARS-CoV-2 and associated factors among children following the fourth pandemic wave in Vietnam. Methods: A cross-sectional study was conducted at Vietnam National Children’s Hospital (VNCH) between March 13 and April 3, 2022. 4,032 eligible children seeking medical care for any medical condition not related to acute Covid-19 infections was tested for IgG SARS-CoV-2 Antibodies by ADVIA Centaur® SARS-CoV-2 IgG (sCOVG) assay using the residuals of routine blood samples. Results: The median age of enrolled children was 39 (IQR=14-82) months. The overall seropositive prevalence was 59.2%, and the median antibody titer was 4.78 [IQR 2.38-9.57] UI/mL. The risk of seropositivity and the median antibody titer was not related to gender (58.6% versus 60.1%, 4.9 versus 4.6 UI/mL, all p>0.05). Among age groups, the highest seroprevalence was reported in the children aged 13 to <36 months old. Children aged ≤12 months were likely to be seropositive compared to children aged 36 to <60 months (59.2% versus 57.5%, p=0.49) and those aged ≥144 months (59.2% versus 65.5%, p=0.16). Children aged ≥144 months exhibited a significantly higher titer of protective COVID-19 antibodies than other age groups (p <0.001). In multivariate logistic regression, we observed independent factors associated with SARS-CoV-2 seropositivity, including the age 13 to <36 months (OR=1.29, 95%CI=1.06-1.56, p=0.01), 60 to <144 months (OR=79, 95%CI=0.67-0.95, p=0.01), ≥144 months (OR=1.84, 95%CI=1.21-2.8, p=0.005), the presence of infected household members (OR=2.36, 95%CI=2.06–2.70, p<0.001), participants from Hanoi (OR=1.54, 95%CI=1.34-1.77, p<0.001), underlying conditions (OR=0.71, 95%CI=0.60-0.85, p<=0.001), and using corticosteroids or immunosuppressants (OR=0.64, 95%CI=0.48-0.86, p=0.003). Conclusions: This study highlights a high seroprevalence of antibodies against SARS-CoV-2 among children seeking medical care for non-COVID-19-related conditions in a tertiary children’s hospital in Hanoi, Vietnam. In the context of reopening in-person schools and future emerged COVID-19 variants, this point will also be a key message about the necessity of “rush-out” immunization coverage for children, especially those under the age of three years.
ARTICLE | doi:10.20944/preprints202104.0619.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: monoclonal antibodies; ARDS; cytokine storm syndrome; inflammation
Online: 22 April 2021 (20:58:22 CEST)
Background: Cytokine storm in COVID-19 is heterogenous. There are at least three subtypes: cytokine release syndrome (CRS), macrophage activation syndrome (MAS), and sepsis. Methods: A retrospective study comprising 276 patients with SARS-CoV-2 pneumonia. All patients were tested for ferritin, interleukin-6, D-Dimer, fibrinogen, calcitonin, and C-reactive protein. According to the diagnostic criteria, three groups of patients with different subtypes of cytokine storm syndrome were identified: MAS, CRS or sepsis. In each group, treatment results were assessed depending on whether or not tocilizumab was used. Results: MAS was diagnosed in 9.1% of the patients examined, CRS in 81.8%, and sepsis in 9.1%. Median serum ferritin in patients with MAS was significantly higher (5894 vs. 984 vs. 957 ng/ml, p <0.001) than in those with CRS or sepsis. Hypofibrinogenemia and pancytopenia were also observed in MAS patients. In CRS patients, a higher mortality rate was observed among those who received tocilizumab, 21 vs. 10 patients (p=0.043), RR = 2.1 (95% CI 1.0-4.3). In MAS patients, tocilizumab decreased the mortality, 13 vs. 6 patients (p=0.013), RR = 0.50 (95% CI 0.25-0.99). Сonclusions: Tocilizumab therapy in patients with COVID-19 and CRS was associated with increased mortality, while in MAS patients it contributed to reduced mortality.
ARTICLE | doi:10.20944/preprints201705.0023.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: gluten; celiac disease; antibodies; Ménière’s disease; vertigo
Online: 2 May 2017 (05:49:26 CEST)
Background: Meniere's disease (MD) has been recently linked to gluten assumption. Approximately 75% of MD patients show positive skin test to food and about 50% of the positive responses are specific to the gliadin acid extract fraction. Aim of this study was to investigate the humoral immune responses to wheat antigens and related autoantigens in MD patients. Methods. We assessed the reactivity of sera from 28 patients with definite MD and 100 healthy controls against a repertoire of 51 antigens usually associated with immune reaction to gluten. Results. MD patients showed an increase of anti-wheat IgA, anti-cerebellar peptide IgA and anti-glutamic acid decarboxylase (GAD) 65 IgM compared to healthy controls. In particular, the increase of anti-wheat IgA and GAD 65 IgM has been confirmed in a subgroup of MD patients symptomatically responding to a gluten free diet (GFD). Conclusion. In MD patients, an increase of the antibody production against gluten biomarkers was observed; in particular, anti-wheat IgA seems to be associated to clinical response to GFD.
ARTICLE | doi:10.20944/preprints202311.1604.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: Antibodies; dog; Ehrlichia canis; Portugal; Rickettsia conorii; shelter
Online: 27 November 2023 (03:11:44 CET)
A cross-sectional study was conducted to gain insight into the epidemiology of canine ehrlichiosis and rickettsiosis in northern Portugal. Specific IgG antibodies to Ehrlichia canis were analysed using a commercial indirect ELISA test, and antibodies to Rickettsia conorii using a commercial IFAT. A total of 113 dogs from two different shelters were sampled, and seroprevalence values of 0.9% (95% confidence [CI]: 0.2–4.8%) for E. canis and 9.7 (95% CI: 5.5–16.6%) for R. conorii were found. Univariable models investigated risk factors for seropositivity. The odds ratios (OR) of R. conorii seropositivity were higher for female dogs (OR = 2.32; 95% CI: 1.58–3.39) and for dogs belonging to Shelter 2 (OR = 3.0; 95% CI: 2.28–3.95). Seropositive dogs for co-infection (E. canis + R. conorii) were more frequently observed in females (OR = 2.4; CI 95%: 1.66–3.47) and in Shelter 2 (OR = 2.72; 95% CI: 1.97–3.76). These findings show that shelter dogs in northern Portugal are exposed to E. canis and R. conorii, which can affect both canines and humans. It is imperative to adopt a One Health approach to educate the public about the hazards of canine zoonoses and develop legislation and procedures to control their spread and preserve public health.
REVIEW | doi:10.20944/preprints202306.2210.v1
Subject: Biology And Life Sciences, Other Keywords: aquaporins; AQP4; AQP1; antibodies; autoimmunity; CNS demyelination; NMOSD
Online: 30 June 2023 (10:16:07 CEST)
Aquaporins (AQPs; AQP0-AQP12) are water channels expressed in many and diverse cell types, participating in various functions of cells, tissues and systems, including the central nervous system (CNS). AQP dysfunction and autoimmunity to AQPs are implicated in several diseases. The best-known example of autoimmunity against AQPs is the antibodies to AQP4 which are involved in the pathogenesis of Neuromyelitis Optica spectrum disorder (NMOSD), a demyelinating disease of the CNS. The present review focuses on the discovery and the potential role of antibodies against AQP1 in the CNS, and their potential involvement in CNS demyelination and specifically in NMOSD. We describe (a) the several techniques developed for the detection of the AQP1-antibodies, with emphasis on methods that specifically identify antibodies targeting the extracellular domain of AQP1, i.e., those of potential pathogenic role, and (b) the available evidence supporting the pathogenic relevance of AQP1-antibodies.
ARTICLE | doi:10.20944/preprints202306.1156.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: measles; seroprevalence; immunity; anti-measles IgG antibodies; Greece
Online: 15 June 2023 (14:40:55 CEST)
Accurate data on susceptibility rates against measles in general population of Greece are scarce. Many studies estimate the vaccination coverage but none has calculated the nationwide immunity rate, involving all age groups, against measles virus. The purpose of our study was to determine the immunity status to measles, especially after the latest outbreak in 2017-2018. In total, 3,972 leftover blood samples were collected from a nationwide laboratory network using a geograph-ically stratified sampling strategy and were tested for the presence of measles specific IgG anti-bodies. The overall crude seroprevalence was calculated 89.6% and the adjusted 89.8% (95% CI: 88.8% - 90.8%). There was no statistically significant difference in seropositivity among sexes (p=0.783). Higher immunity rates and antibody titer were found in older age groups ≥ 41 years old (94.9%, 95% CI: 93.7% - 95.9%, and 730.0 IU/l) in comparison to younger individuals 1-40 years old (83.4%, 95% CI: 81.6% - 85.7%, and 616.5 IU/l). ). Comparing the seroprevalence among Nomenclature of Territorial Units for Statistics (NUTS 2), a statistically significant difference was estimated among them (<0.001). The two regions where higher measles incidence was observed during the 2017-2018 outbreak, Eastern Macedonia and Thrace and Western Greece, were among the four regions with the lower seropositivity (84.6%, 95% CI: 79.9% -89.4% and 85.9%, 95% CI: 81.4% - 90.4%, respectively). Our study showed a measles immunity gap that affects younger age groups and makes a new measles outbreak likely. Enforcement of vaccination campaigns and ad-dressing vaccine hesitancy could bridge it and achieve the required target for herd immunity.
ARTICLE | doi:10.20944/preprints202207.0223.v1
Subject: Biology And Life Sciences, Virology Keywords: Monoclonal antibodies; Sotrovimab; COVID-19; Omicron; BA.2
Online: 14 July 2022 (12:22:21 CEST)
Coronavirus disease 19 (COVID-19) continues to spread worldwide as a severe pandemic. The Omicron BA.2 became the predominant variant and the protagonist of the ongoing surge. As the virus continues to mutate, using of approved drugs or developing new therapeutic or prophylactic therapies against COVID-19 could be more complex. Sotrovimab is a monoclonal antibody (mAb) targeting the conserved epitope on the spike protein receptor; the most recent studies observed that it has substantially decreased in vitro activity against the Omicron BA.2 subvariant, but real-life data are still scarce. We describe the outcome of a case series of outpatients with BA.1 or BA.2 infection treated with sotrovimab. We conducted a retrospective observational study including all non-hospitalized adult patients treated with sotrovimab, for which a Sanger sequencing of SARS-CoV-2 was performed within a regional genomic surveillance program. Eleven (50%) patients with BA.1 infection and eleven (50%) with BA.2 infection were considered. Most patients were immunocompromised. During the follow-up period, no patient died and only one with BA.1 infection was hospitalized for severe COVID-19 pneumonia onset. One month after treatment, 90.9% of patients were completely asymptomatic in each group. We demonstrated that patients carrying the BA.2 variant treated with sotrovimab did not evolve to severe COVID-19, showing a similar outcome to BA.1 infected patients. Further studies are needed to prove that vaccination or the presumably high doses of mAbs used can protect this group of patients at high risk of progression.
ARTICLE | doi:10.20944/preprints202203.0101.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; CoronaVac; Vaccines; Antibodies
Online: 7 March 2022 (14:03:11 CET)
The COVID-19 pandemic is the biggest public health threat facing the globe today. Multiple vaccines have been approved, however the emergence of viral variants such as the recent Omicron, raises the possibility of booster doses to achieve adequate protection. In Brazil, the CoronaVac (Sinovac) vaccine was used, however it’s important to assess the immune response to this vaccine over time. This study aimed to monitor the anti-SARS-CoV-2 antibody responses in those immunized with CoronaVac and SARS-CoV-2 infected individuals. Samples were collected between August 2020 and August 2021. Within the vaccinated cohort, some individuals had history of infection by SARS-CoV-2 prior to immunization and others not. We analyzed RBD-specific and neutralizing- antibodies. Anti-RBD antibodies were detected in both cohorts, with a peak between 45-90 days post infection or vaccination, followed by a steady decline over time. In those with previous history of COVID-19, a higher, longer, more persistent response was observed. This trend was mirrored in the neutralization assays, where infection followed by immunization resulted in higher, longer lasting responses which were conditioned on the presence of levels of RBD antibodies right before the vaccination. This supports the necessity of booster doses of CoronaVac in due course to prevent serious disease.
REVIEW | doi:10.20944/preprints202004.0377.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; immune response; antibodies
Online: 21 April 2020 (06:56:12 CEST)
SARS-CoV-2 is a novel coronavirus that is the causative agent of Coronavirus infectious disease 2019 (COVD-19). As of the 17th April 2020, it has infected 2 114 269 people resulting in 145 144 deaths. The timing, magnitude and longevity of humoral immunity is not yet understood for SARS-CoV-2. Nevertheless, understanding this is urgently required to inform the likely future dynamics of the pandemic, to guide strategies to allow relaxation of social distancing measures and to understand how to deploy limiting vaccine doses when they become available to achieve maximum impact. SARS-CoV-2 is the seventh human coronavirus to be described. Four human coronaviruses circulate seasonally and cause common colds. Two other coronaviruses, SARS and MERS, have crossed from animal sources into humans but have not become endemic. Here we review what is known about the human humoral immune response to epidemic SARS CoV and MERS CoV and to the seasonal, endemic coronaviruses. Then we summarize recent, mostly non-peer reviewed studies into SARS-CoV-2 serology and reinfection in humans and non-human primates and summarize current pressing research needs.
BRIEF REPORT | doi:10.20944/preprints202003.0221.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: COVID-19; 2019-nCoV; diagnostics; antibodies; structural vaccinology
Online: 12 March 2020 (15:02:49 CET)
The appearance of the novel betacoronavirus 2019-nCoV represents a major threat to human health, and its diffusion around the world is predicted to have dramatic economic consequences. The knowledge of the 3D structures of 2019-nCoV proteins can facilitate the development of diagnostic and therapeutic molecules. Herein, we apply our energy-based method for the prediction of potential epitopes on viral proteins to design peptide-based molecules that can subsequently be used in diagnostic and therapeutic applications. We discuss these aspects in the paper.The designs have not been tested. Our aim is to share information that can be useful in the development of novel biomolecules with potential interesting activities against 2019-nCoV.
ARTICLE | doi:10.20944/preprints202311.1555.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: SARS-CoV-2 antibodies, ELISA, salivary samples, children, adults
Online: 24 November 2023 (05:37:48 CET)
Saliva is a promising matrix with several purposes. Our aim is to verify if salivary anti-SARS-CoV-2 antibody determination is suitable for monitoring immune response. One-hundred eighty-seven subjects were enrolled at University-Hospital Padova: 105 females (56.1%) and 82 males (43.9%), 95 (50.8%) children and 92 (49.2%) adults. Subjects self-collected saliva using Salivette; nineteen subjects collected three different samples within the day. A serum sample was obtained for all individuals. The N/S anti-SARS-CoV-2 salivary IgG (sal-IgG) and serum anti-SARS-CoV-2 S-RBD IgG (ser-IgG) were used for determining anti-SARS-CoV-2 antibodies. The mean (min-max) of age was 9.0 (1–18) for children and 42.5 (20–61) for adults. Of 187 samples, 63 were negative for sal-IgG (33.7%), while 7 were negative for ser-IgG (3.7%). Spearman’s correlation was 0.56 (p<0.001). Sal-IgG and ser-IgG levels were correlated with age, but not with gender, comorbidities, prolonged therapy, previous SARS-CoV-2 infection or time from last COVID-19 infection/vaccination. The repeatability ranged from 23.8% (7.4kAU/L) to 4.0% (3.77kAU/L). Linearity of the assay missed in 4/6 samples. No significant intra-subject differences were observed in sal-IgG across samples collected at different time points. Sal-IgG have a good agreement with ser-IgG. Non-invasive saliva collection represents an alternative method for antibody measurement, especially in children.
REVIEW | doi:10.20944/preprints202310.1503.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Lambert-Eaton; Paraneoplastic Syndrome; Tumor; SCLC; Antibodies; COVID-19
Online: 24 October 2023 (08:39:18 CEST)
Lambert-Eaton myasthenic syndrome is a primary autoimmune or paraneoplastic neuromuscular disorder, which causes muscle weakness, areflexia and autonomic disorders through the production of antibodies to voltage-gated calcium channels. Diagnosis may be challenging, yet at the same time extremely important, allowing the detection of a possible underlying malignancy, in cases of paraneoplastic presentation. Some antibodies have good sensitivity and specificity for malignancy and are also discussed. Although most of times being correlated to small cell lung cancer, other types of tumors may be also found in the paraneoplastic syndrome. Misdiagnosis with Myasthenia Gravis may occur and differences between these two disorders are discussed. Therapy choice may vary from each patient depending on drug response and the situation in which the patient is encounter. Overall, the present paper brings a review of Lambert-Eaton, involving the diagnosis, as well as, the pathophysiology, differential diagnosis, tumor investigation and treatment. Also, a brief overview through guidance on therapy during the Corona Virus Disease 2019 pandemic is analyzed.
ARTICLE | doi:10.20944/preprints202310.0185.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: monoclonal antibodies; myasthenia gravis; bioinformatics; mechanism of action; IMGT
Online: 4 October 2023 (03:54:47 CEST)
Background: Myasthenia Gravis (MG) is a rare autoimmune disease presenting with au-to-antibodies that affect the neuromuscular junction. Aside from symptomatic treatment options, novel therapeutics include monoclonal antibodies (mAbs). IMGT®, the international ImMunoGe-neTics information system® (https://www.imgt.org), extends the characterization of therapeutic antibodies with a systematic description of their mechanisms of action (MOA) and makes them available through its database for mAbs and fusion proteins, IMGT/mAb-DB. Methods: Using the available literature data combined with the amino acid sequence analyses from mAbs managed in IMGT/2Dstructure-DB, the IMGT® protein database, biocuration allowed to define in a standardized way descriptions of MOA of mAbs that target molecules towards MG treatment. Results: New therapeutic targets include FcRn and molecules such as CD38, CD40, CD19, MS4A1 and interleukin-6 receptor. A standardized graphical representation of the MOA of selected mAbs was created and integrated within IMGT/mAb-DB. The main mechanisms involved in these mAbs are either blocking or neutralizing. Therapies directed to B cell depletion and plasma cells have a blocking MOA with an immunosuppressant effect along with Fc-effector function (MS4A1, CD38) or FcγRIIb engager effect (CD19). Monoclonal antibodies targeting the complement also have blocking MOA with a complement inhibitor effect and treatments targeting T cells have a blocking MOA with an immunosuppressant effect (CD40) and Fc-effector function (IL6R). On the other hand, FcRn antagonists present a neutralizing MOA with an FcRn inhibitor effect. Conclusion: The MOA of each new mAb needs to be considered in association with the immuno-pathogenesis of each of the subtypes of MG in order to integrate the new mAbs as a viable and safe option in the therapy decision process. In IMGT/mAb-DB, mAbs for MG are characterized by their sequence, domains, chains and their MOA is described.
ARTICLE | doi:10.20944/preprints202009.0270.v2
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: caprine arthritis-encephalitis virus; goat; antigens; antibodies; proviral DNA
Online: 21 January 2021 (12:46:50 CET)
Aim: The aim of this study was to use a multi target approach to testing with both serological tests and an in-house real-time molecular test to investigate the prevalence of the caprine arthritis-encephalitis virus (CAEV) in goats from three hobbyist farms in the Republic of Tatarstan, Russia. Materials and Methods: We have approached the detection of using a multi target approach testing with both ELISA and an in-house real-time PCR test to investigate the prevalence of CAEV in goats. Animals from three hobbyist farms were used in this study. The animals from two farms (n=13 for F1 and n=8 for F2) had clinical signs of arthritis and mastitis. In the third farm (n=15 for F3), all goats were homebred and had no contact with imported animals. Results: CAEV antibodies (ELISA targets TM env and gag genes) were detected in serum samples from two farms (F1 and F2), indicating a seroprevalence 87.50-92.31%. Specific CAEV antibodies were also detected in milk samples. CAEV proviral DNA was detected in 53.85-62.50%. Results from all tests performed in the third farm (F3) were negative, indicting all tests were 100% specific.Conclusion: Results of this work show that CAEV is circulating and present in small hobbyist goat farms in Russia. Serological and molecular tests could be of importance for CAEV control and eradication programs in Russia for hobbyist goat farms.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: COVID-19; SARS-CoV-2; vaccine; coronavirus; monoclonal antibodies
Online: 3 December 2020 (09:20:35 CET)
Knowing the “point of view” of the immune system is essential to understand the characteristic of a pandemic, such as that generated by the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2, responsible for the Coronavirus Disease (COVID)-19. In this review, we will discuss the general host/pathogen interactions dictating protective immune response or immunopathology, addressing the role of immunity or immunopathology in influencing the clinical infection outcome, and debate the potential immunoprophylactic and immunotherapy strategies required to fight the virus infection.
REVIEW | doi:10.20944/preprints202005.0316.v1
Subject: Biology And Life Sciences, Virology Keywords: RT-PCR; seroconversion; serum biomarkers; SARS-CoV2; neutralizing antibodies
Online: 20 May 2020 (04:10:24 CEST)
The progression of the recent COVID-19 pandemic surprised political authorities as well as scientists. The possibility to design powerful strategies for health care and preserving economic and social activities strongly relies on the capacity to monitor correctly the virus spreading and the immune response in the symptomatic and asymptomatic population. The available data relative to the first pandemic months indicate that the test reliability was progressively improved but also that the extremely variable methodologies used in the diagnostic studies generated data that are often not comparable. This condition prevents a simple metadata analysis for the identification of reliable diagnostics guidelines. Nevertheless, there are converging evidences that combinations of complementary approaches may enable more precise identification of virus infection. Furthermore, it appears that the similarities between SARS-CoV2 and the related types SARS-CoV1 and MERS that caused outbreaks in the last 20 years can be exploited to infer some information for which no direct evidence is still available
REVIEW | doi:10.20944/preprints202004.0326.v1
Subject: Biology And Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; neutralizing antibodies; immunotherapy; vaccine
Online: 19 April 2020 (04:52:17 CEST)
We review aspects of the antibody response to SARS-CoV-2, the causative agent of the COVID- 19 pandemic. The topics we cover are relevant to immunotherapy with plasma from recovered patients and with monoclonal antibodies against the viral S-protein. The development of vaccines against SARS-CoV-2, an essential public health tool, will also be informed by an understanding of the antibody response in infected patients. Although virus-neutralizing antibodies are likely to protect, antibodies could potentially trigger immunopathogenic events in SARS-CoV-2-infected patients or enhance infection. An awareness of these possibilities may benefit clinicians and the developers of antibody-based therapies and vaccines.
ARTICLE | doi:10.20944/preprints201904.0118.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Receptor-specific antibodies; targeting; nanoparticles; dendritic cells; cross-presentation
Online: 10 April 2019 (07:46:18 CEST)
Abstract Optimal targeting of nanoparticles (NP) to dendritic cells (DCs) receptors to deliver cancer-specific antigens is key to an efficient induction of anti-tumor immune responses. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles containing tètanus toxoid and gp100 melanoma-associated antigen, toll-like receptor adjuvants were targeted to the DC-SIGN receptor in DCs by specific humanized antibodies or by ICAM3-Fc fusion proteins mimicking natural ligand. Despite higher binding and uptake efficacy of anti-DC-SIGN antibody-targeted NP vaccines than ICAM3-Fc ligand, no difference were observed in DC activation markers CD80, CD83, CD86 and CCR7 induced. DCs loaded with NP coated with ICAM3-Fc appeared more potent in activating T cells via cross-presentation than antibody-coated NP vaccines. This fact could be very crucial in the design of new cancer vaccines.
ARTICLE | doi:10.20944/preprints202311.0688.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: melanoma; metastasis; overall survival; progression-free survival; side effects; Nivolumab; Ipilimumab; anti-programmed death-1 antibodies; anti-cytotoxic T-lymphocyte antigen-4 antibodies.
Online: 10 November 2023 (11:05:56 CET)
Background: This study retrospective evaluates patients with stage IV melanoma treated with Nivolumab and Ipilimumab combination therapy from two regional oncology centers from Romania between the years of 2019 up to the end of 2022. Methods: The data were analyzed in SAS for Windows, V9.4. The survival curves were estimated using the Kaplan-Meier method, and survival distributions were compared with log-rank test. The effects of the main clinical and pathological variables on OS and PFS were investigated with Cox regression. Results: Kaplan-Meier curve of OS in all evaluable patients enrolled in the study resulted in a median OS of 346 days (95% CI: 150-NA) and a median PFS of 211 days (95% CI: 113-430). 45.3% of the patients experienced adverse events during the Nivolumab + Ipilimumab treatment with some of them having multiple organ systems involved. Discussion: The OS values were lower than that reported in approval clinical trials, but the results show a marked improvement when comparing to results obtained by chemotherapy regimens previously used in these scenarios. Conclusion: This study provides real-world insights into the survival data and safety profiles of combination therapy with anti-PD-1 antibodies and anti-CTLA-4 antibodies.
REVIEW | doi:10.20944/preprints202310.1583.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: nanobody; therapeutic nanobody; production; imaging; diagnosis; single-domain antibodies; VHHs
Online: 25 October 2023 (12:11:05 CEST)
Recently, nanobodies have taken center stage in research on drug discovery and development. Several therapeutic possibilities using nanobodies are presently undergoing clinical trials and waiting for FDA approval. The goal of this study was to emphasize the potential of nanobodies as therapeutic agents by concentrating on the most recent published studies that examined their properties, manufacturing, and possible applications. This article demonstrates that the unique properties of nanobodies in comparison to conventional antibodies, which are based on their small size and offer a number of benefits, make them seem to have a promising future. These advantages include the ability to access complex or hidden target sites that may be elusive to their larger antibody counterparts, and increased resilience against extreme conditions like tempera-ture changes and pH variations. As a result, nanobodies seem to have a bright future as adaptable tools for imaging in cancer and non-malignant diseases, as well as for in vitro and in vivo diagnostic and therapeutic potential for a variety of conditions, including oncology, infectious, metabolic, neurological, and other conditions like ophthalmologic, immune-mediated, and genetic disorders. More research is required to determine their effectiveness and safety in clinical applications. The current analysis offers a thorough overview of the therapeutic uses for nanobody products that are either on the market or undergoing clinical trials.
REVIEW | doi:10.20944/preprints202309.1180.v1
Subject: Medicine And Pharmacology, Hematology Keywords: myeloma; daratumumab; bispecific antibodies; chimeric antigen receptor T-cells; immunotherapy
Online: 19 September 2023 (05:28:58 CEST)
The landscape of therapeutic measures to treat multiple myeloma has undergone a seismic shift since the dawn of the current century. This has been driven largely by the introduction of new classes of small molecules, such as proteasome blockers (e.g., bortezomib) and immunomodulators (e.g., lenalidomide), as well as by immunotherapeutic agents starting with the anti-CD38 monoclonal antibody daratumumab in 2015. Recently, other immunotherapies have been added to the armamentarium of drugs available to fight this malignancy. These include the bispecifics teclistamab, talquetamab, and elranatamab, and the chimeric antigen receptor (CAR) T-cell products idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel). While the accumulated benefits of these newer agents have resulted in a more than doubling of the disease’s five-year survival rate to nearly 60% and improved quality of life, the disease remains incurable, as patients become refractory to the drugs and experience relapse. This review covers the current scope of anti-myeloma immunotherapeutic agents, both those in clinical use and in development. Included in the discussion are additional monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), bi- and multi-targeted mAbs, and CAR T-cells and emerging natural killer (NK) cells, including products intended for “off-the-shelf” (allogeneic) applications. Emphasis is placed on the benefits of each along with the challenges that need to be surmounted if MM is to be cured.
ARTICLE | doi:10.20944/preprints202309.0842.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: BNT162b2; efficacy; safety; neutralizing IgG antibodies; 25–hydroxyl vitamin D
Online: 13 September 2023 (05:33:42 CEST)
Background: BNT162b2 represents the authorized mRNA vaccine against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS–CoV–2) causing Covid–19. Methods: We conducted a prospective, single–center observational study with 273 employees of a medical facility to determine the efficacy and safety of the BNT162b2 third dose in relation to sex and BMI, and explore the possible determinants of neutralizing IgG and 25–hydroxy (25–OH) vitamin D levels. Results: At the median follow–up of 4.7 months, 38 of the participants had Covid–19 following vaccination. The incidence of adverse events (AEs) was significantly higher in females vs. males (p < 0.0108) and subjects with a high BMI of ≥ 30 kg/m2 vs. low BMI (p < 0.0117). The values of IgG were significantly enhanced in males vs. females (p < 0.0004), participants with high BMI vs. low BMI (p < 0.0003), a high number of ≥3 AEs vs. low number of AEs (p < 0.0003), and following infection with Covid–19 vs. without Covid–19 (p < 0.0005). Multivariate analysis (MVA) showed sex, BMI, number of AEs, and Covid-19 to be of predictive significance. On the contrary, 25–OH vitamin D concentrations in individuals with high vs. low BMI were significantly reduced (p < 0.0144) but this was not evident in MVA. Conclusions: This study confirmed the high efficacy of BNT162b2 in real–world scenario and revealed that its safety was affected by sex and BMI. Higher IgG levels suggesting better protection against infection were present in males, participants with high BMI, a high frequency of AEs, and those who overcame Covid-19 following vaccination.
ARTICLE | doi:10.20944/preprints202309.0576.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; variants; equine sera; neutralizing antibodies; immune escape; evolution
Online: 8 September 2023 (09:37:59 CEST)
The Receptor Binding Domain (RBD) of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is the functional region of the viral Spike protein (S), which is involved in cell attachment to target cells. The virus has accumulated progressively mutations in its genome, particularly in the RBD region, many of them associated with immune evasion to the host neutralizing antibodies. Some of the viral lineages derived from this evolution, have been classified as Variant of Interest (VOI) or Concern (VOC). The neutralizing capacity of a F(ab’)2 preparation from sera of horses immunized with viral RBD was evaluated, by lytic plaque reduction assay, against different SARS-CoV-2 variants. A F(ab’)2 preparation of an hyperimmune serum with 15 immunizations with RBD, exhibited a high titer of neutralizing antibodies against the ancestral-like strain (1/18,528). A reduction in the title of the F(ab’)2 preparation was observed against the different variants tested. The highest reduction was observed for the Omicron VOC (4.7 fold), followed by the Mu VOI (2.6), Delta VOC (1.8 fold) and Gamma VOC (1.5). Even if a progressive reduction in the neutralizing antibodies titer against the different variants evaluated was observed, the serum still exhibited a significant neutralizing titer, against the Mu VOI and the Omicron VOC (1/7113 and 1/3918 respectively), the strains evaluated most resistant to neutralization.
REVIEW | doi:10.20944/preprints202012.0645.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: immune complex; antibodies; Fab; Fc; HIV-1; vaccine; steric; allosteric
Online: 25 December 2020 (07:46:51 CET)
Immune complexes (ICs) made of antibody-bound antigens exhibit immunomodulatory activities exploitable in a vaccination strategy to optimize vaccine efficacy. The modulatory effects of ICs are typically attributed to the Fc fragments of the antibody components, which engage Fc receptors, complement and complement receptors on various immune cells. These Fc-mediated functions facilitate the critical interplay between innate and adaptive immune systems to impact the quality and quantity of the elicited adaptive responses. In addition to the Fc contribution, the Fab fragment also plays an immunoregulation role. The antigen-binding domains of the Fab fragment can bind their specific epitopes at high affinity to sterically occlude these antigenic sites from recognition by other antibodies. Moreover, the Fab-mediated binding have been demonstrated to induce allosteric alterations at nearby or distant antigenic sites. In this review article, we survey published studies to illuminate how the immunomodulatory functions of ICs have been investigated or utilized in a vaccination strategy to fight against an array of infectious pathogens, culminating with IC vaccine designs aimed at preventing HIV-1 infection. In particular, we highlight IC vaccine candidates that exploit Fab-mediated steric and allosteric effects to direct antibody responses away or toward the V1V2 domain, the V3 loop, and other antigenic sites on the HIV-1 envelope gp120 glycoprotein. Like other HIV-1 vaccine approaches, the path for IC-based vaccines to reach the clinic faces major hurdles yet to be overcome; however, investigations into this vaccine strategy have provided insights into the multifaceted activities of antibodies beyond their conventional roles in the host defense against HIV-1 and other microbial pathogens.
REVIEW | doi:10.20944/preprints201810.0675.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: surface plasmon resonance; cancer markers; biosensors; receptor immobilization; antibodies; nanoparticles
Online: 29 October 2018 (11:31:10 CET)
Almost 50 papers on surface plasmon resonance biosensors, published between 2016 and mid-2018, are reviewed. Papers concerning the determination of large particles such as vesicles, exosomes, cancer cells, living cells, stem cells and microRNA are excluded, as these are covered by a very recent review. The reviewed papers are categorized into five groups, depending on the degree of maturity of the reported solution: ranging from simple marker detection to clinical application of a previously developed biosensor. Instrumental solutions and details of biosensor construction are analyzed, including the chips, receptors and linkers used, as well as calibration strategies. Biosensors with a sandwich structure containing different nanoparticles are considered separately, as are SPR applications for investigating the interactions of biomolecules. An analysis is also made of the markers determined using the biosensors. Concluding, there is shown to be a growing number of SPR applications in the solution of real clinical problems.
ARTICLE | doi:10.20944/preprints202308.0488.v2
Subject: Medicine And Pharmacology, Tropical Medicine Keywords: COVID-19; Receptor binding domain (RBD); natural infection; vaccination; neutralizing antibodies
Online: 8 August 2023 (07:11:22 CEST)
(1) Background: To fight for COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also vaccination. Controversies exist about the effect of COVID-19 vaccination on previously infected persons; (2) Methods: A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons--with and without COVID-19 pre-infection. The sera were analyzed for the anti-Receptor Binding Domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays; (3) Results; Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection (Spearman correlation coefficient (r) = -0.8558; 95% CI, -0.9259 to -0.7288), p <0.0001 vs -0. 581; 95% CI, -0.7679 to -0.3028; p = 0.0002, respectively), indicating the capacity to neutralize the virus is better among the unvaccinated individuals. (4) Conclusions: Vaccines induced anti-RBD titers as high as the natural infection with lower neutralization capacity, and it did not boost the immunity in pre-infected persons.
REVIEW | doi:10.20944/preprints202304.0506.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: antiviral therapy; antiviral antibodies; antibody combination therapy; antibody potency; potency assays
Online: 18 April 2023 (08:30:07 CEST)
Viral diseases represent a major public health concern and an ever-present risk for developing into a future pandemic. Antiviral antibody therapeutics, either alone or in combination with other therapies, have emerged as valuable preventative and treatment options, including during a global emergency. Here we will discuss polyclonal and monoclonal antiviral antibody therapies, focusing on the unique biochemical and physiological properties that make them well suited as therapeutic agents. We will describe the methods of antibody characterization and potency assessment throughout development, highlighting similarities and differences between polyclonal and monoclonal products as appropriate. In addition, we will consider the benefits and challenges of antiviral antibodies when used in combination with other antibodies or other types of antiviral therapeutics. Lastly, we will discuss novel approaches to the characterization and development of antiviral antibodies and identify areas that would benefit from additional research.
ARTICLE | doi:10.20944/preprints202102.0075.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: bat; monoclonal antibodies; lyssaviruses; neutralization; glycoprotein; ABLV; rabies; RABV; phage display
Online: 2 February 2021 (08:27:58 CET)
Australian bat lyssavirus (ABLV) is a rhabdovirus that circulates in four species of pteropid bats (ABLVp) and the yellow-bellied sheath-tailed bat (ABLVs) in mainland Australia. In the three confirmed human cases of ABLV, rabies illness preceded fatality. As with rabies virus (RABV), post-exposure prophylaxis (PEP) for potential ABLV infections consists of wound cleansing, ad-ministration of the rabies vaccine and injection of rabies immunoglobulin (RIG) proximal to the wound. Despite the efficacy of PEP, the inaccessibility of human RIG (HRIG) in the developing world and the high immunogenicity of equine RIG (ERIG) has led to consideration of human monoclonal antibodies (hmAbs) as a passive immunization option that offers enhanced safety and specificity. Using a recombinant vesicular stomatitis virus (rVSV) expressing the glycoprotein (G) protein of ABLVs and phage display, we identified two hmAbs, A6 and F11, which completely neutralize ABLVs/ABLVp, and RABV at concentrations ranging from 0.19-3.12 µg/mL and 0.39-6.25 µg/mL respectively. A6 and F11 recognize overlapping epitopes in the lyssavirus G protein, ef-fectively neutralizing phylogroup 1 lyssaviruses, while having little effect on phylogroup 2 and non-grouped diverse lyssaviruses. These results suggest A6 and F11 could be effective therapeutic and diagnostic tools for phylogroup 1 lyssavirus infections.
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: SARS-CoV-2; S-protein; RBD; COVID-19; neutralizing antibodies; serology; vaccines; animal models; Warp Speed
Online: 21 June 2020 (15:44:06 CEST)
In this review, we address issues that relate to the rapid “Warp Speed” development of vaccines to counter the COVID-19 pandemic. We review the antibody response that is triggered by SARS-CoV-2 infection of humans, and how it may inform vaccine research. The isolation and properties of neutralizing monoclonal antibodies from COVID-19 patients provide additional information on what vaccines should try to elicit. The nature and longevity of the antibody response to coronaviruses are relevant to the potency and duration of vaccine-induced immunity. We summarize the immunogenicity of leading vaccine candidates tested to date in animals and humans, and discuss the outcome and interpretation of virus-challenge experiments in animals. By far the most immunogenic vaccine candidates for antibody responses are recombinant proteins, which are not included in the initial wave of “Warp Speed” immunogens. A substantial concern for SARS-CoV-2 vaccines is adverse events, which we review by considering what was seen in studies of SARS-CoV-1 and MERS-CoV vaccines. We conclude by outlining the possible outcomes of the “Warp Speed” vaccine program, which range from the hoped-for rapid success to a catastrophic adverse influence on vaccine uptake generally.
REVIEW | doi:10.20944/preprints202308.0567.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Pancreatic Ductal Adenocarcinoma; secretome; cell signaling; tumor microenvironment; small molecules; monoclonal antibodies.
Online: 7 August 2023 (12:12:00 CEST)
Pancreatic ductal adenocarcinoma (PDAC) is a ravaging disease whose poor prognosis requires a more detailed understanding of its biology to foster the development of effective therapies. The unsatisfactory results of treatments targeting cell proliferation and its related mechanisms suggested to rather focus on the inflammatory tumor microenvironment (TME). Here, we discuss the role of cancer secreted proteins in the complex TME tumor-stroma crosstalk, to sched lights on druggable molecular targets for the development of innovative, safer and more efficient therapeutic strategies.
REVIEW | doi:10.20944/preprints202307.1094.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: non-specific effects of vaccines; tolerance; immune training; excess deaths; IgG4 antibodies.
Online: 17 July 2023 (09:59:57 CEST)
Contrary to the long-held belief that the effects of vaccines are specific for the disease they were created; compelling evidence has demonstrated that vaccines can exert positive or deleterious non-specific effects (NSEs). In this review, we compiled research reports from the last 40 years, showing that live vaccines induce positive NSEs, whereas non-live vaccines induce several negative NSEs, including increased female mortality associated with enhanced susceptibility to other infectious diseases, especially in developing countries. These negative NSEs are determined by the vaccination sequence, the antigen concentration in vaccines, the type of vaccine used (live vs. non-live), and also by repeated vaccination. We do not recommend stopping using non-live vaccines, as they have demonstrated to protect against their target disease, so the suggestion is that their detrimental NSEs can be minimized simply by changing the current vaccination sequence. High IgG4 antibody levels generated in response to repeated inoculation with mRNA COVID-19 vaccines could be associated with a higher mortality rate from unrelated diseases and infections by suppressing the immune system. Since most COVID-19 vaccinated countries are reporting high percentages of excess mortality not directly attributable to deaths from such disease, the NSEs of mRNA vaccines on overall mortality should be studied in depth.
REVIEW | doi:10.20944/preprints202306.0770.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: Clostridium botulinum; botulism; neurotoxin; BoNT; therapeutic; antibodies; horse; dog; cat; farm animals
Online: 12 June 2023 (05:23:03 CEST)
Botulinum neurotoxins (BoNTs) are emerging as multipurpose therapeutic compounds for the treatment of several different syndromes involving peripheral and central nervous systems, and muscular and musculoskeletal disorders both in human and veterinary medicine. Therefore, the studies of BoNTs are rapidly developing and identifying newly produced BoNT variants. Efforts should be made to clarify the biological and pharmacological characteristics of these novel BoNTs as well as the natural ones. The high potential of BoNTs as a therapeutic compound for medical syndromes lies on its ability to reach a specific cell type bypassing other cells, thus having mild or no side effects. In this paper the recent developments on BoNTs are reviewed with the aim to analyze the current knowledge on BoNTs biological mechanisms of action, immunogenicity, formulations, and therapeutic applications in the veterinary field, highlighting advantages and drawbacks and identifying the gaps to be filled in order to address research priorities.
ARTICLE | doi:10.20944/preprints202212.0386.v1
Subject: Biology And Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; seroprevalence; antibodies; vaccine; natural infection; French Polynesia
Online: 21 December 2022 (04:56:44 CET)
In French Polynesia, Wuhan, Delta and Omicron SARS-CoV-2 variants-of-concern (VOCs) caused epidemics with variable severities. We assessed the prevalence and titers of anti-SARS-CoV-2 antibodies related to natural infection and/or vaccination, from a representative sample (N=673) of the adult population of Tahiti recruited during November-December 2021 (after the Delta outbreak and just before the Omicron epidemic). Of the 673 participants tested, 644 (95.7%) had detectable antibodies against SARS-CoV-2-S and/or -N proteins resulting from natural infection and/or vaccination, and 388 (57.7%) were positive only for the detection of anti-N antibodies indicating natural infection. SARS-CoV-2 seroprevalence extrapolated to the adult population of Tahiti was estimated at 95.9%. Concentrations of anti-SARS-CoV-2-S antibodies significantly increased with age, number of self-reported SARS-CoV-2 infections (0 or ≥1), and number of COVID-19 vaccine doses (0, 1, 2, or 3) received by the participants. Elderly people, who are at higher risk of severe outcomes, had received more vaccine doses than younger individuals both in our sample and in the general population. The high level of antibody responses related to past infections and vaccination, especially booster doses, has likely contributed to reducing the severity of the Omicron outbreak in French Polynesia.
REVIEW | doi:10.20944/preprints202102.0210.v1
Subject: Biology And Life Sciences, Virology Keywords: HIV-1; HIV envelope; glycosylation; signal peptide; PNGs; broadly neutralizing antibodies; vaccine
Online: 8 February 2021 (13:09:28 CET)
The RV144 trial represents the only vaccine trial to demonstrate any protective effect against HIV-1 infection. While the reason(s) for this protection are still being evaluated, it serves as justification for widespread efforts aimed at developing new, more effective HIV-1 vaccines. Advances in our knowledge of HIV-1 immunogens and host antibody responses to these immunogens are crucial to informing vaccine design. While the envelope (Env) protein is the only viral protein present on the surface of virions, it exists in a complex trimeric conformation and is decorated with an array of variable N-linked glycans, making it an important but difficult target for vaccine design. Thus far, efforts to elicit a protective humoral immune response using structural mimics of native Env trimers have been unsuccessful. Notably, the aforementioned N-linked glycans serve as a component of many of the epitopes crucial for the induction of potentially protective broadly neutralizing antibodies (bnAbs). Thus, a greater understanding of Env structural determinants, most critically Env glycosylation, will no doubt be of importance in generating effective immunogens. Recent studies have identified the HIV-1 Env signal peptide (SP) as an important contributor to Env glycosylation. Further investigation into the mechanisms by which the SP directs glycosylation will be important, both in the context of understanding HIV-1 biology and in order to inform HIV-1 vaccine design.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: autoimmune diseases; antinuclear antibodies; antinuclear factor; functional autoantibodies; natural autoantibodies; physiological autoimmunity
Online: 8 January 2021 (14:01:32 CET)
Incidence of autoimmune diseases increases. Antinuclear antibodies (ANA) testing is a critical tool for their diagnosis. However, ANA prevalence in health increased over last decades, especially among young people. ANA in health occur in low concentrations, with prevalence up to 50% in some populations, which demands a cutoff revision. The review deals with origin and probable physiological or compensatory function of ANA in health, according to the concept of immunological clearance, theory of autoimmune regulation of cell functions and the concept of functional autoantibodies. Considering ANA titers ≤1:320 as a serological marker of autoimmune diseases seems inappropriate. The role of anti-DFS70/LEDGFp75 autoantibodies is highlighted as possible anti-risk biomarker for autoimmune rheumatic disorders. ANA prevalence in health is different in various regions due to several underlying causes discussed in the review, all influencing in additive combinations according to the concept of the mosaic of autoimmunity. Not only titer, but the HEp-2 IFA staining patterns, like AC-2, is also important. Accepting autoantibodies as a kind of bioregulators, not only upper, but also lower borders of their normal range should be determined. Not only their excess, but also lack of them or “autoimmunodeficiency” could be a reason of disorders.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: antibodies; COVID-19; glycans; immunoglobulin M; SARS-CoV-2; pneumonia; prediction; protection
Online: 24 April 2020 (10:25:27 CEST)
The natural history of COVID-19 caused by SARS-CoV-2 is extremely variable, ranging from asymptomatic infection, to pneumonia, and to complications eventually fatal. We propose here the first model, explaining how the outcome of first, crucial 10-15 days after infection, hangs on the balance between the cumulative dose of viral exposure and the efficacy of the local innate immune response (natural IgA and IgM antibodies, MBL). If SARS-CoV-2 runs the blockade of this innate immunity and spreads from the upper airways to the alveoli in the early phases of the infections, it can replicate with no local resistance, causing pneumonia and releasing high amounts of antigens. The delayed and strong adaptive immune response (high affinity IgM and IgG antibodies) that follows, causes severe inflammation and triggers mediator cascades (complement, coagulation, and cytokine storm) leading to complications often requiring intensive therapy and being, in some patients, fatal. Strenuous exercise and high flow air in the incubation days and early stages of COVID-19, facilitates direct penetration of the virus to the lower airways and the alveoli, without impacting on the airway’s mucosae covered by neutralizing antibodies. This allows the virus to bypass the efficient immune barrier of the upper airways mucosa in young and healthy athletes. In conclusion, whether the virus or the adaptative immune response reach the lungs first, is a crucial factor deciding the fate of the patient. This “quantitative and time-sequence dependent” model has several implications for prevention, diagnosis, and therapy of COVID-19.
REVIEW | doi:10.20944/preprints202311.1607.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: COVID-19; SARS-COV2; rational vaccine design; coronavirus; epitope prediction; antibodies; RNA vaccines
Online: 27 November 2023 (07:20:43 CET)
The COVID-19 pandemic has significantly impacted global health and economies, necessitating the development of effective vaccines against the novel virus. Understanding the structure and function of SARS-CoV-2 is crucial for rational vaccine design. The virus consists of several key proteins, including the spike protein, envelope protein, membrane protein, and nucleocapsid protein. The spike protein plays a crucial role in host cell entry by binding to the angiotensin-converting enzyme 2 (ACE2) receptor on human cells. The replication of the virus within host cells is facilitated by various viral proteins, such as the RNA-dependent RNA polymerase (RdRp) and the main protease (Mpro). Rational vaccine design strategies for SARS-CoV-2 primarily focus on targeting the spike protein due to its role in host cell entry. However, developing vaccines against this protein is challenging due to its highly mutable nature and potential conformational changes. Alternative strategies involve using other viral proteins, such as the nucleocapsid protein, which is conserved and essential for viral replication. Considering T-cell responses in vaccine design is also vital as they play a vital role in controlling viral infections. Vaccines that elicit both antibody and T-cell responses are more likely to provide robust and durable immunity against SARS-CoV-2. Advancements in rational vaccine design for SARS-CoV-2 include mRNA-based vaccines, viral vector-based vaccines, and protein subunit vaccines. However, challenges remain in developing a universally effective vaccine, including the emergence of new SARS-CoV-2 variants and mutations that may affect the efficacy of existing vaccines. In conclusion, rational vaccine design for SARS-CoV-2 requires a comprehensive understanding of the virus's structure and function, targeting key viral proteins, and considering T-cell responses.
ARTICLE | doi:10.20944/preprints202311.1372.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: COVID-19; SARS-CoV-2 antibodies; sero-epidemiological survey; Polytechnic High School; Senegal
Online: 24 November 2023 (04:12:01 CET)
Cross-sectional survey was conducted to capture the true extent of COVID-19 exposure among students and staff of Polytechnic High School (PHS). Random cluster sampling was carried out between May 19 and August 18, 2022, after the fourth wave of COVID-19 transmission. IgM and IgG SARS-CoV-2 antibodies were screened using WANTAI SARS-CoV-2 ELISA assays. Seroprevalence and descriptive statistics were calculated. Moreo-ver, the association between seropositivity and different factors (age, gender, preventive measures comorbidity, and symptoms, etc.) was determined using Logistic Regression. The overall IgG and IgM seroprevalence were 92% and 6.91% respectively. We found a higher IgM seroprevalence in men than women (9.4% vs. 5.6%) and a lower IgM seroprevalence in (18-25) age group compared to (55-65) years. Low compliance with preventive measures was found with a significant IgM seroprevalence depending on non-respect of social distancing (p = 0.008). A total of 70% of participants presented symptoms linked to COVID-19 at the moment of the survey. Results revealed a significant difference according to IgG seroprevalence among participants who declared fa-tigue symptoms 92.06% compared to those who did not 80.39% (p = 0.0027). IgM seropositivity was associated with Body Mass Indice (BMI) categorized (O.R. 0.238, p = 0.043), ethnic group (O.R. 0.723, p = 0.046) and marital status (O.R. 2.399, p = 0.021). Moreover, IgG seropositivity was associated with Chronic sinusitis comorbidity (O.R. 0.238, p = 0.043) and vaccination status (O.R. 4.741, p < 0.001). The majority of students and staff have al-ready been exposed to SARS-CoV-2 and confirm the circulation of SARS-CoV-2 in PHS at the time of the survey. Our results underline the importance of sero-epidemiological surveys to estimate the real impact of the COVID-19 pandemic in a community and to monitor disparities in antibody response in the population.
ARTICLE | doi:10.20944/preprints202310.0666.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: inflammatory bowel disease; anti-pancreatic antibodies; cell based assay; Crohn’s disease; diagnostic biomarker
Online: 11 October 2023 (14:23:46 CEST)
Introduction: The serological support to early diagnosis and differential diagnosis of inflammatory bowel diseases (IBD) is actually very limited. In this study we evaluated the performance of a promising multiparametric method including either well established and newly developed biomarkers. Methods: This multicenter retrospective observational study finally enrolled 156 patients with IBD, 100 affected by Crohn’s disease (CD) and 56 by ulcerative colitis (UC) recruited at the Gastroenterology Units of Udine (Italy), Rijeka (Croatia) and Belgrade (Serbia). Twently age-sex matched blood donors (BD) were included as controls. Autoantibody profiles were determined using a mosaic cell and tissue-based indirect immunofluorescence (IIF) method simultaneously investigating: anti-saccharomyces cerevisiae antibodies (ASCA), anti-atypical perinuclear neutrophilic antibodies (P-ANCA), anti-pancreatic antigens antibodies (PAB) and anti-goblet cells antibodies (GAB). Results: PAB (anti-CUZD1 and/or anti-GP2 antibodies) were present in 24 CD patients versus none of UC patients or BD (24% sensitivity, 100% specificity). As regards CD patients, combined positivity of PAB and ASCA (sensitivity 84%, specificity 71.4%) performed better than ASCA alone. Colon involvement (87.5% vs. 60.5%; p=0.014), deep mucosal lesions (58.3% vs. 25.0%; p=0.002) and need for biologic therapies (79.2% vs. 46.1%; p=0.005) were significantly more prevalent in PAB-positive than in PAB-negative CD patients. Multivariate analysis identified PAB positivity (OR=3.67; 95%CI=1.29-10.46) and anti-CUZD1 in particular (OR=3.54; 95%CI=1.08-11.63) as significant risk factors for deep mucosal lesions development in CD. Conclusion: A multiparametric diagnostic approach appears very useful to better characterize IBD patients. PAB, isolated or combined with other autoantibodies, may support both differential diagnosis and selection of CD patients at risk for more severe disease.
ARTICLE | doi:10.20944/preprints202310.0515.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: SARS-CoV-2; healthcare workers; vaccine; COVID-19; neutralizing antibodies; variants of concern
Online: 10 October 2023 (02:50:24 CEST)
Although the anti-COVID-19 vaccination has proved to be an effective preventive tool, "break-through infections" have been documented in patients with complete primary vaccination course. Most of the SARS-CoV-2 neutralizing antibodies pro-duced after SARS-CoV-2 infection target the spike protein receptor-binding domain which has an important role in facilitating viral entry and infection of the host cells. SARS-CoV-2 has demonstrated the ability to evolve by accumulating mutations in the spike protein to escape the humoral response of the host. The aim of this study is to compare the titers of neutralizing an-tibodies against the variants of SARS-CoV-2 by analyzing the sera of recovered and vaccinated healthcare workers (HCWs). 293 HCWs were enrolled and divided into three cohorts as follows: 91 recovered from SARS-CoV-2 infection (nVP); 102 vac-cinated who became positive after the primary cycle (VP); 100 vaccinated with complete primary cycle who concluded the follow-up pe-riod without becoming positive (VN). Higher neutraliza-tion titers were observed in the vaccinated subjects’ arms com-pared to the nVP arm. Differences in neutralization titers between arms for single variant were statistically significant (p<0.001) except for titers against the Alpha variant (p<0.05) between nVP and VP. Within the nVP group, the number of subjects with the absence of neutralizing antibodies was high. The presence of high-er titers in patients with a complete primary cycle compared to patients recovered from the infec-tion suggests a better efficacy of artificial immunization compared to natural im-munization, further encouraging the promotion of vaccination even in subjects with previous infection.
ARTICLE | doi:10.20944/preprints202309.1907.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Bisphenol A diglycidyl ether; derivatives; broad-spectrum polyclonal antibodies; AuNPs; immunochromatographic; canned food
Online: 28 September 2023 (17:24:06 CEST)
Bisphenol A diglycidyl ether (BADGE) is widely existed in the inner coating of canned foods. It migrates into food and generate various derivatives in the process of storage, such as Bisphenol A (2, 3-dihydroxypropyl) glycidyl ether (BADGE·H2O), Bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl) and Bisphenol A (3-chloro-2-hydroxypropyl) (2, 3-dihydroxypropyl) glycidyl ether (BADGE·HCl·H2O), which have negative effects on human health. A gold nanoparticle-based immu-nochromatographic assay for simultaneous detection of BADGE and its derivatives was developed by using a broad-spectrum polyclonal antibody, and the detection can be finished in 15 min. The visuali-zation of results was processed by Adobe Photoshop CC software to achieve quantitative analysis and the detection limit (IC15) is 0.97ng/mL. The recoveries of BADGE and its derivatives at various spiking levels in canned food samples ranged from 79.86% to 93.81%. The detection results of the proposed immu-nochromatographic assay were also validated by HPLC analysis, and got good consistency (R2=0.9580).
ARTICLE | doi:10.20944/preprints202308.1899.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: SARS-CoV-2; BNT162b2 vaccine; cancer patients; anti-neoplastic treatment; chemotherapy; antibodies; immunogenicity.
Online: 29 August 2023 (03:49:55 CEST)
The BNT162b2 vaccine is globally used for preventing morbidity and mortality related to COVID-19. Cancer patients have had priority for receiving the vaccine due to their diminished immunity. This study reports the response of administering the 3rd and 4th vaccine doses to can-cer patients receiving active anti-neoplastic treatment. 142 patients have received two doses of the mRNA-based BNT162b2 COVID-19 vaccine, while 76 and 25 patients have received three and four doses, respectively. The efficacy of the humoral response following two vaccine doses was diminished in cancer patients, especially in the group of patients receiving chemotherapy. In a multivariate analysis, patients after three and four BNT162b2 vaccine doses were more likely to have antibody titers in the upper tertile compared to patients after two doses of the vaccine (odds ratio (OR) 7.62 (95% CI 1.38-42.12), p=0.02 and 17.15 (95% CI 5.01-58.7), p<0.01, respective-ly). Unlike the response after two doses, the 3rd and 4th BNT162b2 vaccine booster doses, had an increased efficacy of 95-100% in cancer patients while on active treatment. This result could be explained by different mechanisms including the development of memory B cells.
REVIEW | doi:10.20944/preprints202307.0962.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: COVID pass; SARS-CoV-2 antigen test; SARS-CoV-2 antibodies; societal restrictions
Online: 14 July 2023 (05:20:20 CEST)
To control the COVID-19 pandemic, many countries implemented vaccination and imposed societal restrictions both at the national level and for international travel. As a check of the corona status, a COVID pass has been issued. A COVID pass could be obtained when fully vaccinated against COVID-19, having recovered from a documented COVID-19 episode, or a recent (24-48 hours) negative SARS-CoV-2 antigen test. A global analysis of SARS-CoV-2 immune status (determined by past infection and/or vaccination), vaccination rates, as well as societal restrictions in controlling the COVID-19 pandemic is presented.
BRIEF REPORT | doi:10.20944/preprints202304.0364.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: ChAdOx1 nCoV-19; immunogenicity; SARS-CoV-2; COVID-19; neutralizing antibodies; durability; booster
Online: 14 April 2023 (10:20:45 CEST)
Vaccines are crucial for controlling the COVID-19 pandemic, and booster doses are becoming increasingly important. This study aimed to assess the efficacy of the ChAdOx1 nCoV-19 vaccine from AstraZeneca as a third dose in healthcare workers at different time intervals (one, three, and six months). Two methods to measure immune response—ELISA (EUROIMMUN Medizinische Labordiagnostika AG, Luebeck, Germany) and ELISpot (Mabtech AB, Macka Strand, Sweden)—were used. A total of 170 participants were included in the study. The results showed that while IgG levels decreased at six months compared to levels at one and three months, they were still significantly higher than the baseline. Furthermore, neutralizing levels at three and six months after the third dose were not significantly different. These findings suggest that the immune response induced by the vaccine is robust and effective for several months. These results have significant implications for public health policymakers, as they provide strong support for booster vaccinations. The ChAdOx1 nCoV-19 vaccine appears to be a reliable option for preventing the spread of COVID-19, and this study provides valuable information for healthcare workers and policymakers in managing the pandemic.
HYPOTHESIS | doi:10.20944/preprints202303.0441.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: IgG4 antibodies; mRNA vaccines; immuno-tolerance; auto-immunity; SARS-CoV-2; COVID-19.
Online: 27 March 2023 (03:56:26 CEST)
Due to the health crisis caused by SARS-CoV-2, the creation of a new vaccine platform based on mRNA was implemented. Globally, around 13.32 billion COVID-19 vaccine doses of diverse platforms have been given, and up to this date, 69.7% of the total population received at least one injection of a COVID-19 vaccine. Although these vaccines prevent hospitalization and severe forms of the disease, increasing evidence has shown they do not produce sterilizing immunity, allowing people to suffer frequent re-infections. Recent research has also raised concerns that mRNA vaccines could induce immune tolerance, which, added to that caused by the virus itself, could complicate the clinical course of a COVID-19 infection. Furthermore, recent investigations have found high IgG4 levels in people who were administered two or more injections of mRNA vaccines. It has been suggested that an increase in IgG4 levels could have a protecting role by preventing immune over-activation, similar to that occurring during successful allergen-specific immunotherapy by inhibiting IgE-induced effects. Altogether, evidence suggests that the reported increase in the IgG4 levels detected after repeated vaccination with the mRNA vaccines is not a protective mechanism; rather, it may be a part of the immune tolerance mechanism to the spike protein that could promote unopposed SARS-CoV2 infection and replication by suppressing natural antiviral responses. IgG4-induced suppression of the immune system due to repeated vaccination can also cause autoimmune diseases, promotes cancer growth, and autoimmune myocarditis in susceptible individuals.
ARTICLE | doi:10.20944/preprints202105.0530.v2
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: SARS-CoV-2; COVID-19; antibodies; cohort; population-based; body mass index; ECLIA
Online: 23 September 2021 (11:10:54 CEST)
In March 2020, several mass gathering events were related to the Falles festival in Borriana (Spain), resulting in a 536 laboratory-confirmed COVID-19 cases outbreak among participants. Our objective was to estimate anti-SARS-CoV-2 antibodies persistence six months after and factors associated with antibody response. A prospective population-based cohort study was carried out by the Public Health Center of Castellon and the Emergency and Clinical Analysis and Microbiology Services of Hospital de la Plana in Vila-real. In October 2020, sero-epidemiologic study to estimate the persistence of anti-SARS-CoV-2 antibodies by a electrochemiluminescence immunoassay (ECLIA) was implemented. We enrolled 484 (90.2%) of the 536 members of the initial outbreak cohort and detected persistent antibodies in 479 (99%) without re-infection episodes. Five participants had a negative antibody test. Factors associated with a negative result were a lower body mass index (BMI), and less contact with other COVID-19 cases. Among the 469 participants with two ECLIA tests, 96 (20.5%) had an increase of antibodies and 373 (79.5%) a decline. Increased antibodies were associated with older age, higher BMI, more severe illness, and low current smokers. After a COVID-19 infection, a high proportion of cases maintained detectable anti-SARS-CoV-2 antibodies.
ARTICLE | doi:10.20944/preprints202106.0611.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Within-host modeling; Dengue fever; immune response; antibodies; viral load; Antibody-Dependent Enhancement
Online: 25 June 2021 (09:21:23 CEST)
Dengue fever is a viral mosquito-borne infection, a major international public health concern. With 2.5 billion people at risk of acquiring the infection around the world, disease severity is influenced by the immunological status of the individual, seronegative or seropositive, prior to natural infection. Caused by four antigenically related but distinct serotypes, DENV-1 to DENV-4, infection by one serotype confers life-long immunity to that serotype and a period of temporary cross-immunity (TCI) to other serotypes. The clinical response on exposure to a second serotype is complex with the so-called Antibody-Dependent enhancement (ADE) process, a disease augmentation phenomenon when pre-existing antibodies to previous dengue infection do not neutralize but rather enhance the new infection, used to explain the etiology of severe disease. In this paper, we present a minimalistic mathematical model framework developed to describe qualitatively the dengue immunological response mediated by antibodies. Three models are analyzed and compared: i) primary dengue infection, ii) secondary dengue infection with the same (homologous) dengue virus and iii) secondary dengue infection with a different (heterologous) dengue virus. We explore the features of viral replication, antibody production, and infection clearance over time. The model is developed based on body cells and free virus interactions resulting in infected cells activating antibody production. Our mathematical results are qualitatively similar to the ones described in the empiric immunology literature, providing insights on the immunopathogenesis of severe disease. Results presented here are of use for future research directions to evaluate the impact of dengue vaccines.
ARTICLE | doi:10.20944/preprints202010.0346.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Trypanosoma cruzi; Presenilin; aspartic protease; SPOT-synthesis; anti-peptide antibodies; immunolocalization; transmembrane domains
Online: 16 October 2020 (12:01:25 CEST)
The increasing detection of infections of Trypanosoma cruzi, the etiological agent of Chagas disease, in non-endemic regions beyond Latin America has risen to be a major public health issue. With an impact in the millions of people, current treatments rely on antiquated drugs that produce severe side effects and are considered nearly ineffective for the chronic phase. The minimal progress in the development of new drugs highlights the need for advances in basic research on crucial biochemical pathways in T. cruzi to identify new targets. Here, we report on the T. cruzi presenilin-like transmembrane aspartyl enzyme, a protease of the aspartic class in a unique phylogenetic subgroup with T. vivax separate from protozoans. Computational analyses suggests it contains 9 transmembrane domains and an active site with the characteristic PALP motif of the A22 family. Multiple linear B-cell epitopes were identified by SPOT synthesis analysis with Chagasic patient sera. Two were chosen to generate rabbit antisera, whose signal was primarily localized to the flagellar pocket, intracellular vesicles and endoplasmic reticulum in parasites by whole cell immunofluorescence. The results suggest that the parasitic presenilin-like enzyme could have a role in the secretory pathway and serve as a biomarker for infections.
ARTICLE | doi:10.20944/preprints201808.0481.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Irukandji syndrome; box jellyfish; CSL antivenom; nematocyst extracts; antigenicity; human sera; human antibodies
Online: 29 August 2018 (05:23:55 CEST)
Carukia barnesi (Cb), Malo kingi (Mk) and Chironex fleckeri (Cf) are dangerous Australian box jellyfish species that provoke distinct and not well understood envenomation syndromes. Specifically, Cb and Mk are small, rare and able to induce a systemic syndrome of generalised muscle pain and catecholamine excess termed “Irukandji syndrome”; Cf has been widely regarded as one of the most venomous organisms in the animal kingdom causing severe sting site pain combined with potentially lethal cardiotoxicity. Building on past studies of major chirodropid and carybdeid species venoms, this study compared the utility of various cubozoan specific antibody reagents to better define the relationships between venom proteins from both exemplar Irukandji species (Cb and Mk) and the archetype C. fleckeri box jellyfish. With the aid of commercial ovine derived Cf-specific antivenom, mouse antibodies reactive to Cb and Mk and rabbit antibodies specific to two Cf toxins (CfTX-1 and 2), as well as human sera, the cross-reactivity of jellyfish species-specific polyclonal antibodies against these three cubozoan venoms was investigated. Immunoblot assays revealed distinc levels of immune recognition across the three species, indicating that Mk specific reagents may bind both Irukandji and Cf venoms. Irukandji venom appears to be antigenic with the exception of a few proteins in the range of 43/46 kDa maybe homologous to CfTX-1 and 2. The implications of such antibody binding for future antivenom development require further investigation.
REVIEW | doi:10.20944/preprints202209.0233.v1
Subject: Medicine And Pharmacology, Urology And Nephrology Keywords: COVID-19 prophylaxis; COVID-19 treatment; Kidney transplantation; Vaccination; Monoclonal antibodies; Small antivirus molecules
Online: 16 September 2022 (02:00:02 CEST)
Abstract Kidney transplant recipients, because of a weak immune response due to the assumption of immunosuppressant are exposed to the risk of COVID-19 infection. This fact realize the problem on how to treat the severe infection without carrying the risk of acute rejection due to the reduction of the immunosuppressive drugs. The best are the prophylactic measures to be taken before transplantation as vaccination. If the patient is already transplanted, three measures may be undertaken: Vaccination, use of monoclonal antibodies, use of therapeutic antiviral small molecules. Concerning vaccination is still debated which one is the best and how many doses should be given. The surge of new virus variant is the major problem and invites to find new active vaccines. In addition, not all the transplanted patients develop antibodies. The other measure is the use of monoclonal antibodies. They may be used as prophylaxis or in the early stage of the disease. Finally, the antiviral small molecules may be used again as prophylaxis or treatment. Their major drawback are the interference with the immunosuppressive drugs and the fact that some of them cannot be administered to patients with low eGFR.
REVIEW | doi:10.20944/preprints202207.0250.v1
Subject: Biology And Life Sciences, Virology Keywords: Emergence of Omicron and its mechanism; mutation and sub-lineages; Monoclonal antibodies; Antiviral drugs
Online: 18 July 2022 (07:48:00 CEST)
With the ongoing COVID pandemic, the emergence of a novel omicron variant in November 2021 has chaos the world. Despite mass vaccination, this omicron has spread rapidly raising concerns around the globe. The Omicron variant has a vast array of mutations as compared to another variant of concern with overall 50 mutations where 30 mutations are present in its spike protein. This mutation has led to immune escape and more transmissibility compared to other variants, including Delta. A cluster of mutations (H655Y, N679K, and P681H) present at the omicron spike protein could aid in transmission. Currently, no virus-specific data are available to predict the efficacy of anti-viral and mAbs drugs. However, two monoclonal antibody drugs: Sotrovimab and Evusheld are authorized for emergency use in COVID patients. This virus is not fading away soon. The easiest solution and less expensive measure to fight against this pandemic are following COVID appropriate protocols.There is need to strengthen the level of research for development of potential vaccines and anti-viral drugs. It is also important to monitor and expand genomic surveillance to keep track of the emergence of new variants thus avoiding the spread of new diseases worldwide. This article highlights the emergence of omicron and vast number of mutation in its protein. In addition, recent advancement in drugs approved by FDA to treat COVID patients has been listed and focused in this paper.
ARTICLE | doi:10.20944/preprints202108.0130.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Zika virus; non-structural protein 1; site-directed mutagenesis; polyclonal antibodies; antigen-capture ELISA
Online: 5 August 2021 (09:11:41 CEST)
Infection with Zika virus (ZIKV), a member of the Flavivirus genus of the Flaviviridae family, typically results in mild self-limited illness, but severe neurological disease occurs in a limited subset of patients. In contrast, serious outcomes commonly occur in pregnancy that affect the developing fetus, including microcephaly and other major birth defects. The genetic similarity of ZIKV to other widespread flaviviruses, such as dengue virus (DENV), presents a challenge to the development of specific ZIKV diagnostic assays. Nonstructural protein 1 (NS1) is established for use in immunodiagnostic assays for flaviviruses. To address the cross-reactivity of ZIKV NS1 with proteins from other flaviviruses we used site-directed mutagenesis to modified putative epitopes. Goat polyclonal antibodies to variant ZIKV NS1 were affinity-purified to remove antibodies binding to the closely related NS1 protein of DENV. An antigen-capture ELISA configured with the affinity-purified polyclonal antibody showed a linear dynamic range between approximately 500 to 30 ng/mL, with a limit of detection of between 1.95 and 7.8 ng/mL. NS1 proteins from DENV, yellow fever virus, St. Louis encephalitis virus and West Nile virus showed significantly reduced reactivity in the ZIKV antigen-capture ELISA. Refinement of approaches similar to those employed here could lead to development of ZIKV-specific immunoassays suitable for use in areas where infections with related flaviviruses are common.
ARTICLE | doi:10.20944/preprints202101.0024.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: SARS-CoV-2 antibodies; COVID-19; infertility; lockdown; IVF; SARS-CoV-2 serological testing
Online: 4 January 2021 (12:07:44 CET)
The COVID-19 pandemic had profound negative effects on millions of couples affected by infertility and in need to resort to assisted reproductive technologies. There is no consensus over the optimal way and moment of screening triage-negative asymptomatic patients and staff. We present SARS-CoV-2 antibodies’ (IgM, IgG) seroprevalence in 516 triage-negative patients and 30 fertility care providers. The sampling for SARS-CoV-2 serological assays took place from the lockdown release throughout the second half of 2020 (17.05 - 01.12.2020). It revealed an increased seroprevalence of antibodies that closely followed the local epidemiology of COVID-19, with the highest rate of seropositivity coincident with the peak of the second wave. From 546 triage-negative individuals whose blood samples were assessed for SARS-CoV-2 antibodies, 6% yielded positive results. The overall seroconversion rate was 2.8% for IgG and 5.1% for IgM. In the group with positive IgM, we observed a negative predictive value for IgM of 98.36% (95% CI: 88.79 – 99.78%), which is clinically meaningful. Serological testing of triage-negative patients up to seven days prior to the actual fertility procedure might avoid the more expensive and not more sensitive molecular testing currently being used for patient screening in most fertility units.
ARTICLE | doi:10.20944/preprints202008.0114.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Immune response; SARS-CoV-2 antibodies response; Covid-19 management; Maglumi; Architect; method comparison.
Online: 5 August 2020 (08:09:11 CEST)
The role of the immune response to SARS-CoV-2 infection is not yet well known, in particular about the persistence of circulating antibodies. The aim of the study is to compare the results of two automated systems for the determination of IgG antibodies against SARS CoV-2 and to assess the time course of the IgG response after the onset of symptoms for a period longer than that evaluated to date. IgG were measured in 98 specimens of 55 subjects with COVID-19 (time from the onset of symptoms from 3 to 109 days) using the automated tests "Abbott SARS-COV-2 IgG" and the "MAGLUMI 2019-nCoV IgG". The two methods had a concordance of 91.8%, but the quantitative correlation showed very dispersed results. All the specimens resulted positive after 17 days from the onset of the synptoms. However, the median concentrations of IgG, after a rapid increase up to about 20 days, quickly decrease to about 15% of the maximum for Maglumi. The same samples measured by Architect showed a quite constant trend up to 80 day, and then an only moderate decline. The titer of IgG against SARS-CoV-2 in patients exposed to COVID-19 may significantly and rapidly decrease, with a different time-course depending on the method used for the determination.
REVIEW | doi:10.20944/preprints201807.0004.v1
Subject: Biology And Life Sciences, Virology Keywords: influenza; neutralising antibodies; vestigial esterase; antibody dependent cell-mediated cytotoxicity; pH-induced conformational changes
Online: 2 July 2018 (08:33:45 CEST)
Initial attempts to develop monoclonal antibodies as therapeutics to resolve influenza infections focused mainly on searching for antibodies with the potential to neutralise the virus in vitro with classical haemagglutination inhibition and micro-neutralisation assays. This led to the identification of many antibodies that bind to the head domain of haemagglutinin (HA) which generally have potent neutralisation capabilities that block viral entry or viral membrane fusion. However, this class of antibodies has a narrow breadth of protection in that they are usually strain specific. This led to the emphasis on stalk targeting antibodies which are able to bind a broad range of viral targets that span across different influenza subtypes. Recently, a third class of antibodies targeting the vestigial esterase (VE) domain have been characterised. In this review, we describe the key features of neutralising VE targeting antibodies and compare them with head and stalk class antibodies.
REVIEW | doi:10.20944/preprints202310.2067.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: anti-DNA antibodies; systemic lupus erythematosus (SLE); penetration; endocytosis; neutrophil extracellular traps (NETs); NETosis; pathogenesis
Online: 31 October 2023 (12:34:43 CET)
Anti-DNA antibodies are hallmark autoantibodies produced in systemic lupus erythematosus (SLE), but their pathogenetic roll is not fully understood. Accumulating evidence suggests that some anti-DNA antibodies enter different types of live cells and affect the pathophysiology of SLE by stimulating or impairing these cells. Circulating neutrophils in SLE are activated by type I interferon or other stimuli and primed to release neutrophil extracellular traps (NETs) on additional stimulation. Anti-DNA antibodies are also involved in this process and may induce NET release. Thereafter, they bind and protect extracellular DNA in the NETs from digestion by nucleases, resulting in increased NET immunogenicity. This review discusses the pathogenetic role of anti-DNA antibodies in SLE, mainly focusing on recent progress in the two research fields concerning antibody penetration into live cells and NETosis.
ARTICLE | doi:10.20944/preprints202309.0748.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: SARS-CoV-2; coronavirus; monoclonal antibodies; resistance; nanopore; Sweden; whole-genome sequencing; receptor binding domain
Online: 12 September 2023 (11:14:08 CEST)
Monoclonal antibodies (mAbs) are an important treatment option for COVID-19 caused by SARS-CoV-2, especially in immunosuppressed patients. However, this treatment option can become ineffective due to mutations in the SARS-CoV-2 genome, mainly in the receptor binding domain (RBD) of the spike (S) protein. In the present study 7950 SARS-CoV-2 positive samples from the Uppsala and Örebro regions of central Sweden collected between March 2022 and May 2023 were whole-genome sequenced using next-generation sequencing, mainly with the Nanopore sequencing method. Pango lineages were determined and all single nucleotide polymorphism (SNP) mutations that occurred in these samples were identified. The dominant sublineages changed over time and mutations conferring resistance to currently available mAbs became common. Notable ones are R346T and K444T mutations in the RBD that confer significant resistance against tixagevimab and cilgavimab mAbs. Further, mutations conferring a high-fold resistance to bebtelovimab, such as the K444T and V445P mutations, were also observed in the samples. This study highlights that resistance mutations have over time rendered currently available mAbs ineffective against SARS-CoV-2 in most patients. Therefore, there is a need for continued surveillance of resistance mutations and the development of new mAbs that target more conserved regions of the RBD.
BRIEF REPORT | doi:10.20944/preprints202306.1419.v1
Subject: Biology And Life Sciences, Virology Keywords: Hepatitis B surface antigen (HBsAg); Hepatitis B core antibodies (anti-HBc); HBV; HIV; Botswana; Africa
Online: 20 June 2023 (09:42:20 CEST)
: (1) Background: Hepatitis B core antibodies (anti-HBc) are a marker of hepatitis B virus (HBV) exposure; hence a normal HBV serology profile is characterized by HBV surface antigen (HBsAg) and anti-HBc positivity. However atypical HBV serologies occur and we aimed to determine the prevalence of an atypical profile (HBsAg+/anti-HBc-) in a cohort of people with HIV-1 (PWH) in Botswana. (2) Methods: Plasma samples from an HIV-1 cohort in Botswana (2013-2018) were used. Samples were screened for HBsAg and anti-HBc. Next generation sequencing was done using the GridION platform. Wilcoxon rank-sum test and Chi-squared tests were used for comparison of continuous and categorical variables respectively. (3) Results: HBsAg+/anti-HBc- prevalence was 13.7% (95% CI 10.1 – 18.4) (36/263). HBsAg+/anti-HBc- participants were significantly younger (p<0.001), female (p=0.02), ART naïve (p=0.04) and had detectable HIV viral load (p=0.02). There were no mutational differences in sequences isolated from participants with HBsAg+/anti-HBc- versus those with HBsAg+/anti-HBc+ serology. (4) Conclusions: We report a high HBsAg+/anti-HBc– atypical serology profile prevalence among PWH in Botswana. We caution against HBV testing algorithms that consider only anti-HBc+ samples for HBsAg testing as they are likely to underestimate HBV prevalence. Studies to elucidate the mechanisms and implications of this profile are warranted.
CASE REPORT | doi:10.20944/preprints202301.0469.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: anti-calcitonin gene-related peptide monoclonal antibodies; cluster headache; migraine; real-world; galcanezumab; fremanezumab; comorbidity
Online: 26 January 2023 (04:24:39 CET)
A new treatment option for cluster headache (CH) prevention is needed. Monoclonal antibodies (mABs) against calcitonin gene-related peptide (CGRP) ligands are used as a preventative treatment for migraine. Considering the CGRP’s role in the CH attack’s ignition and upkeep, fremanezumab and galcanezumab have been evaluated for CH preventative treatment. However, only high-dose (300 mg) galcanezumab was proven for episodic CH prevention. We herein report 3 cases of migraine and comorbid CH with previous failures of preventive treatments. The 2 cases were treated with fremanezumab and the one with non-high-dose galcanezumab. All 3 cases showed good results not only on migraine but also on CH attacks. Our report suggested the efficacy of CGRP-mABs for CH prevention. Our cases differed from the cases in the phase 3 trials of CGRP-mABs for CH prevention in the following 2 points. First, the patients had both migraine and comorbid CH. Second, the combined use of CGRP-mABs with preventative drugs for CH, such as verapamil and/or prednisolone, was performed. Future accumulation of real-world data may prove the efficacy of CGRP-mABs for CH prevention.
REVIEW | doi:10.20944/preprints202012.0167.v2
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Matrix metalloproteinase; MMPs; protease; TIMPs; exosite; small molecule inhibitors; monoclonal antibodies; proteomics; N-terminomics; TAILS
Online: 24 March 2021 (16:23:28 CET)
Matrix metalloproteinases (MMPs) have been demonstrated to have both detrimental and protective functions in inflammatory diseases. Several MMP inhibitors, with the exception of Periostat®, have failed in Phase III clinical trials. As an alternative strategy, recent efforts have been focussed on the development of more selective inhibitors or targeting other domains than their active sites (e.g., exosites, ectosites) through specific small molecule inhibitors or monoclonal antibodies. Here, we present some examples that aim to better understand the mechanisms of conformational changes/allosteric control of MMPs functions. In addition to MMP inhibitors, we discuss unbiased global approaches such as proteomics and N-terminomics to identify new MMP substrates and achieve a better understanding of the roles of these proteases in diseases.
REVIEW | doi:10.20944/preprints202011.0558.v1
Subject: Biology And Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; Adjuvants; Vaccine Production; Vaccine Delivery; Clinical Trials; Neutralizing Antibodies; Th1
Online: 22 November 2020 (11:57:51 CET)
With the COVID-19 pandemic now ongoing for close to a year, people all over the world are still waiting for a vaccine to become available. The initial focus of accelerated global research and development efforts to bring a vaccine to market as soon as possible was on novel platform technologies that promised speed but had limited history in the clinic. In contrast, recombinant protein vaccines, with numerous examples in the clinic for many years, missed out on the early wave of investments from government and industry. Emerging data are now surfacing suggesting that recombinant protein vaccines indeed might offer an advantage or complement to the nucleic acid or viral vector vaccines that will likely reach the clinic faster. Here, we summarize the current public information on the nature and on the development status of recombinant subunit antigens and adjuvants targeting SARS-CoV-2 infections.
REVIEW | doi:10.20944/preprints201803.0227.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Antivenom; snakebite; small molecule toxin inhibitors; oligonucleotides; antibodies; phage display; next generation antivenom; recombinant antivenom
Online: 27 March 2018 (13:41:46 CEST)
With the inclusion of snakebite envenoming on the World Health Organisation’s list of Neglected Tropical Diseases, an incentive has been established to promote research and development effort in novel snakebite antivenom therapies. Different technological approaches are being pursued by different research groups, including the use of small molecule inhibitors against enzymatic toxins, as well as peptide and oligonucleotide-based aptamers and antibody-based biotherapeutics against both enzymatic and non-enzymatic toxins. In this article, the most recent advances in these fields are presented, and the advantages, disadvantages, and feasibility of using different toxin-neutralizing molecules are reviewed. Particular focus within small molecules is directed towards the inhibitors, varespladib, batimastat, and marimastat, while in the field of antibody-based therapies, novel recombinant polyclonal plantivenom technology is discussed.
ARTICLE | doi:10.20944/preprints202310.0305.v1
Subject: Medicine And Pharmacology, Other Keywords: HIV-1 infection; SARS-CoV-2 infection; Neutralizing antibodies; mRNA Vaccines; T-cell immunity; Immunity waning
Online: 6 October 2023 (05:08:35 CEST)
Background. Waning of neutralizing and cell-mediated immune response after the primary vac-cine cycle (PVC) and the first booster dose (BD) is of concern, especially for PLWH with a CD4 count ≤200 cells/ mm3.Methods.Neutralizing antibodies (nAbs) titers by microneutralization assay against WD614G /Omicron BA.1 and IFNγ production by ELISA assay were measured in samples of PLWH at 4 time points [2 and 4 months post-PVC (T1 and T2), 2 weeks and 5 months after the BD (T3 and T4)]. Participants were stratified by CD4 count after PVC (LCD4, <200/mm3; ICD4, 201-500/mm3 and HCD4, >500/mm3). Mixed models were used to compare mean responses over T1-T4 across CD4 groups. Results. 314 PLWH on ART (LCD4=56; ICD4=120; HCD4=138) were enrolled. At T2, levels of nAbs were significantly lower in LCD4 vs ICD4/HCD4 (p=0.04). BD was crucial for increasing nAbs titres above 1:40 at T3 and up to T4 for WD614G. A positive T cell response after PVC was observed in all groups, regardless of CD4 (p=0.31). Conclusions. Waning of nAbs after PVC was more important in LCD4 group. BD managed to re-establish higher levels of nAbs against WD614G which were retained for 5 months. The level of T-cellular response was significantly higher in HCD4 and ICD4 compared to the LCD4 group although it remained above detectable levels over the entire study period regardless of CD4 count. Keywords: HIV-1 infection; SARS-CoV-2 infection;
BRIEF REPORT | doi:10.20944/preprints202212.0219.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: SARS-CoV-2 breakthrough infections; vaccines; anti-spike antibody levels; humoral response; IgG specific salivary antibodies
Online: 13 December 2022 (02:28:02 CET)
SARS-CoV-2 breakthrough infections, associated with waning immunity, increase systemic antibody levels. In this study, we analyzed the impact of the infection timing on the magnitude of the systemic humoral response and whether breakthrough infections also boost antibody levels in the salivary compartment. We observed that the combination of infection plus vaccination, regardless of infection timing, produced a sharp increase of systemic antibodies, being higher in subjects infected after third doses. Moreover, despite high systemic antibody levels, breakthrough infections after dose 3 occurred and boosted antibody levels in the salivary compartment. These results lead to rethink the current vaccination strategies against COVID-19 and the use of salivary anti-SARS-CoV-2 antibodies for disease surveillance and vaccination follow-up.
REVIEW | doi:10.20944/preprints202207.0256.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: cancer; immunotherapy; adverse events; immune checkpoints inhibitors; chimeric antigen receptor therapy; bispecific antibodies; toxicity; renal; oncology
Online: 18 July 2022 (09:21:56 CEST)
Modern oncological therapy utilizes various types of immunotherapy. Immune checkpoint inhib-itors (ICIs), chimeric antigen receptor T cells (CAR-T) therapy, cancer vaccines and bispecific an-tibodies are improving patients’ outcomes. However, stimulation of the immune system, benefi-cial in terms of fighting against cancer, generates the risk of harm to other cells in a patient's body. Kidney damage belongs to the relatively rare adverse events (AEs). Best described, but still, su-perficially, are renal AEs in patients treated with ICIs. International guidelines issued by Euro-pean Society for Medical Oncology (ESMO) and American Society of Clinical Oncology (ASCO) cover the management of immune-related adverse events (irAEs) during ICI therapy. There are scarce data concerning renal adverse drug reactions of other immunotherapeutic methods. This implicates the need for the collection of safety data during ongoing clinical trials and in the re-al-life world to characterize the hazard related to the use of new immunotherapies and manage-ment of irAEs.
REVIEW | doi:10.20944/preprints202012.0419.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: immune checkpoint; lymphoid neoplasms; programmed death 1; cytotoxic T-lymphocyte antigen 4; monoclonal antibodies; combination therapies
Online: 17 December 2020 (08:10:05 CET)
Immunotherapy has been considered for years as a viable and attractive treatment option for patients with cancer. Among immunotherapy arsenal, the targeting of intratumoral immune cells by immune-checkpoint inhibitory agents has recently revolutionized the treatment of several subtypes of tumours. These approaches aimed at restoring an effective anti-tumour immunity, rapidly reached the market thanks to the simultaneous identification of inhibitory signals that dampen an effective antitumor response in a large variety of neoplastic cells, and the clinical development of monoclonal antibodies targeting checkpoint receptors. Leading therapies in solid tumours are mainly focused on the cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4) and programmed-death 1 (PD-1) pathways. These approaches have found a promising testing ground in both Hodgkin lymphoma and non-Hodgkin lymphoma, mainly because in these diseases the malignant cells interact with the immune system and commonly provide signals that regulate immune function. Although several trials have already demonstrated evidence of therapeutic activity with some checkpoint inhibitors in lymphoma, many of the immunologic lessons learned from solid tumours may not directly translate to lymphoid malignancies. In this sense, the mechanisms of effective antitumor responses are different between the different lymphoma subtypes, while the reasons for this substantial difference remain partially unknown. This review will discuss the current advances of immune-checkpoint blockade therapies in B-cell lymphoma and will build a projection of how the field may evolve in the near future. In particular, we will analyze the current strategies being evaluated both preclinically and clinically with the aim to foster the use of immune-checkpoint inhibitors in non-Hodgkin lymphoma, including combination approaches with chemotherapeutics, biological agents and/or different immunologic therapies.
REVIEW | doi:10.20944/preprints202309.1934.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: uterine leiomyoma; fibroid; pregnancy; therapy; targets; inhibitors; vaccines; humanized antibodies; MED12; HMGA2; fumarate hydratase; IL17B; MMP11; MMP16
Online: 28 September 2023 (04:38:19 CEST)
The uterine leiomyoma is the most common benign tumor in women of childbearing age. It may lead to problem of conception or complications during gestational period. The methods of treatment can be surgical (myomectomy and hysterectomy, embolization of arteries) and therapeutic treatment (Ulipristal acetate, Leuprolide acetate, Cetrorelix, Goserelin, Mifeprestone). Both approaches are efficient, but are incompatible with pregnancy planning. Therefore, there is a call for medical practice in developing therapeutical means of preventing leiomyoma onset in patients planning on pregnant. Based on the analysis of GWAS data on the search for mononucleotide polymorphisms associated with the risk of leiomyoma, meta-transcriptomic and meta-methylomic studies, target proteins have been proposed. Prospective therapeuticals of leiomyoma may be based on chemical compounds, humanized recombinant antibodies, vaccines based on markers of the uterine leiomyoma cells that are absent in the adult organism, DNA and RNA preparations. Three different nosological forms of the disease associated with driver mutations in the MED12, HMGA2 and FH genes should be considered when developing or prescribing drugs. E.g. synthetic inhibitors and vaccines based on matrix metalloproteinases MMP11 and MMP16 are expected to be effective only for the prevention of the occurrence of MED12-dependent nodules.
ARTICLE | doi:10.20944/preprints202204.0165.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: Coronavirus SARS-CoV-2; seroprevalence; antibodies; nucleocapsid antigen; antigen receptor binding domain; seropositivity; St. Petersburg; volunteers; vaccination
Online: 18 April 2022 (10:42:54 CEST)
Since the detection of the first COVID-19 patient, 2 years have passed, during which more than 287,862,000 people fell ill globally, of which about 1.9% died. Implementation of SARS-CoV-2 control programs required efforts from almost all countries. An important direction in the fight against COVID-19 was the formation of herd immunity, the main tool for managing the pandemic. Study goal: to assess the seroprevalence of antibodies (Abs) to SARS-CoV-2 nucleocapsid (Nc) and receptor binding domain (RBD) in the St. Petersburg population during the COVID-19 pandemic. Materials and methods. A longitudinal cohort randomized monitoring study of Ab seroprevalence (SARS-CoV-2 Nc, RBD) was organized and conducted according to a unified methodology developed by Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute. For this purpose, a cohort of 1000 volunteers was formed who participated in all five stages of seromonitoring. The cohort was divided into 7 age groups: 1-17; 18-29; 30-39; 40-49; 50-59; 60-69; 70; and older (70+) years. Seropositivity levels (Nc, RBD) were assessed by quantitative and qualitative enzyme immunoassays. During the 2nd year of monitoring, some volunteers were vaccinated with the GamCOVIDVac (84%) or EpiVacCorona (11.6%) vaccines approved in Russia. Statistical processing was carried out using the Excel 2010 software package. Confidence intervals for shares and percentages (95% CI) were calculated using the method of A. Wald and J. Wolfowitz with adjustment (A. Agresti, B.A. Coull). The statistical significance of differences was calculated by z-test, using the appropriate online calculator (p<0.05), unless indicated. Results. There was a trend towards: an increase in Nc seropositivity in stages 1-3 of seromonitoring, with a decrease in stages 4-5 among children and adults. The share of RBD seropositive steadily increased during all 5 stages of seromonitoring. The most frequently found were low anti-RBD Abs levels (22.6-220 BAU/ml). High Ab levels were recorded statistically significantly less frequently. Asymptomatic forms were observed in 84-88% of SARS-CoV-2 seropositive volunteers. By the 5th stage of monitoring, this indicator significantly decreased to 69.8% (95% CI: 66.1-73.4). The monitoring revealed a statistically significant increase in anti-RBD Abs, alongside a statistically significant decrease in the proportion of Nc seropositive. This dynamic was especially characteristic of persons vaccinated with GamCOVIDVac. Conclusion. Prior to the use of specific vaccines, a seroprevalence of anti-Nc Abs was noted. After the introduction of the GamCOVIDVac vaccine in adults, a decrease in the level of anti-Nc Abs was noted due to an increase in the proportion of RBD seropositive persons.
ARTICLE | doi:10.20944/preprints202201.0226.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Hepatitis C virus (HCV); liver; samples; structure; electrochemiluminescence (ECL); ELISA method (Enzyme-Linked Immunosorbent Assay); antigen-antibodies
Online: 17 January 2022 (12:37:22 CET)
Objective: The study aimed to manage and to analyse the results of the laboratory tests, available nowadays, used from routine clinical practice, for screening of hepatitis C. Methods: comparison of ELISA method results (Enzyme-Linked Immunosorbent Assay) and chemiluminescence methods results. Beside previously mentioned, the study show the structural comparison of normal liver and pathologic liver with hepatic cirrhosis, using permanent samples colored after the technique protocol. Statistical analysis of this study results, was performed using the laboratory informatic system. Results: The results of the study are substantial and intricate. For this purpose, the results of preliminary EСL screening method of patients at risk for HCV who took part in the study, are presented in tables and figures. Results of this study are various and are correlate from different perspectives. Also good to mention that the correlations of results were used in order to identify a possible relationships between indicators of ELISA method and ECL index. More than, correlations antibodies detected in ECL and ELISA are point out. Conclusion: EСL and ELISA method results, are relevant for screening and for diagnostic confirmation in HCV risk patients. Unfotunately in the present study, were impossible to conclude about false-negative results. Good to know our opinion that RT-PCR technique, it is considered proper for the diagnosis of HCV.
REVIEW | doi:10.20944/preprints202101.0471.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: aptamer; aptasensor; diagnosis; imaging; sequencing; therapeutics; probes; fluorescence; pathogenic bacteria; cancer cells; monoclonal antibodies; SELEX; nucleic acids
Online: 25 January 2021 (10:18:16 CET)
Issues presented by the application of monoclonal antibodies in diagnostic assays and as curative agents can make the use of such molecules cost-prohibitive and sometimes even unsafe. This has warranted the development of short single-stranded oligonucleotides known as Aptamers. The structural malleability of these short DNA or RNA nucleotide segments allows them to exist in distinct conformations. SELEX (Systematic Evolution of Ligands by Exponential Enrichment) is a multi-step process for synthesis of aptamers. Each step of this procedure is governed by a diverse set of factors that influence production efficiency, binding affinity, and specificity of the oligonucleotides. Headway in aptamer research has been made in recent years by the introduction of newer iterations of the SELEX process. A greater number of studies are now being carried out to incorporate aptamers into existing disease detection tools and therapies. An overview has been given first on the key aptamer properties and the process of their production (with its newer iterations), contrasting each of them with that of monoclonal antibodies. Possible manifold applications afforded due to unique aptamer characteristics are also discussed. A keen review is further provided on the design, development and use of fluorescent aptamers in bioimaging, sequencing or profiling, and treatment of pathogenic bacteria and tumor cells.
ARTICLE | doi:10.20944/preprints201712.0106.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: graphene; electrochemical biosensors; cancer; diagnosis; electrical detection; Alzheimer’s disease; dementia; neurodegenerative disorders; cardiovascular; blood biomarkers; antibodies; proteins
Online: 2 January 2018 (05:21:45 CET)
We report on the development of chemical vapour deposition (CVD) based graphene field effect transistor (GFET) immunosensors for the sensitive detection of Human Chorionic Gonadotropin (hCG), a glycoprotein risk biomarker of certain cancers. The GFET sensors were fabricated on Si/SiO2 substrate using photolithography with evaporated chromium and sputtered gold contacts. GFET channels were functionalized with a linker molecule to immobile anti-hCG antibody on the surface of graphene. Binding reaction of the antibody with varying concentration levels of hCG antigen demonstrated the limit of detection of the GFET sensors to be below 1 pg/mL using four-probe electrical measurements. We also show annealing can significantly improve the carrier transport properties of GFETs and shift the Dirac point (Fermi level) with reduced p-doping in back-gated measurements. The developed GFET biosensors are generic and could find applications in a broad range of medical diagnostics in addition to cancer, such as neurodegenerative (Alzheimer’s, Parkinson’s and Lewy body) and cardiovascular disorders.
ARTICLE | doi:10.20944/preprints202311.0296.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: SARS-CoV-2; Variants; Spike Glycoprotein; Receptor Binding Motif, Receptor Binding Domain; Neutralizing Antibodies; Ig subclasses; IgG; IgA
Online: 7 November 2023 (11:27:48 CET)
Global economic and social burden was caused by the SARS-CoV-2 spread worldwide. Despite the end of the pandemic, there is a concern about virulent evolving variants of the virus which can bypass the humoral immune response induced by vaccination or infection. Crucial to the viral entrance, amino acid residues in the RBM region, which interacts with cellular receptor ACE2, can elicit neutralizing antibody response. Herein we determine the immunogenicity of one-dose or heterologous dose vaccinated serum against wild-type and mutated RBM region. Despite low antibody response to wild-type SARS-CoV-2 RBM, omicron variants possess four mutations in RBM (S477N, T478K, E484A, F486V) that induce even less antibody titers. The most predominant responses were against IgA and IgG. While neutralizing antibodies (nAbs) predominantly target the RBD, our investigation revealed a diminished seroreactivity within the RBD's crucial region, the receptor-binding motif (RBM), potentially impacting the production of protective nAbs. S1WT and S2WT RBM peptides binding to nAbs were evaluated through microscale thermophoresis, and higher affinity (35 nM) was obtained for sequence S2WT (GSTPCNGVEGFNCYF), containing the FNCY patch. Our data indicates that SARS-CoV-2 RBM is not an immunodominant region in vaccinated individuals. Understanding the intricate dynamics of the humoral response and its interplay with viral evolution and host genetics is essential for the formulation of effective vaccination strategies, not only against SARS-CoV-2 but also for future emerging coronaviruses.
ARTICLE | doi:10.20944/preprints202310.0759.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: pore-forming toxin; monoclonal antibodies; epitope; site-directed mutagenesis, enzyme immunoassay, phage display; modeling of three-dimensional structure
Online: 12 October 2023 (04:37:50 CEST)
Hemolysin II (HlyII) – one of the pathogenic factors of Bacillus cereus, a pore-forming β-barrel toxin – possesses a C-terminal extension of 94 amino acid residues, designated as the C-terminal domain of HlyII (HlyIICTD), which plays an important role in the functioning of the toxin. Our previous work described a monoclonal antibody (HlyIIC-20), capable of strain-specific inhibi-tion of hemolysis caused by HlyII, and demonstrated the dependence of the efficiency of hemol-ysis on the presence of proline at position 324 in HlyII outside the conformational antigenic de-terminant. In this work, we studied 16 mutant forms of HlyIICTD. Each of the mutations, ob-tained by multiple site-directed mutagenesis leading to the replacement of amino acid residues lying on the surface of the 3D structure of HlyIICTD, led to a decrease in the interaction of HlyIIC-20 with the mutant form of the protein. Changes in epitope structure confirm the high conformational mobility of HlyIICTD required for the functioning of HlyII. Comparison of the effect of the introduced mutations on the effectiveness of interaction between HlyIICTD and HlyIIC-20 and a control antibody recognizing a non-overlapping epitope enabled identifying the amino acid residues N339, K340 included in the conformational antigenic determinant rec-ognized by HlyIIC-20.
ARTICLE | doi:10.20944/preprints202308.0151.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: COVID-19; SARS-CoV-2 Seroprevalence; Vaccination Status; SARS-CoV-2; anti-SARS-CoV-2 antibodies; Albanian population
Online: 2 August 2023 (10:10:13 CEST)
Understanding the dynamics of humoral immune responses throughout the COVID-19 pandemic is crucial for optimizing vaccine strategies. This study aimed to investigate the impact of infection and vaccine-induced immunity on the Albanian population from August 2021 to August 2022. Two independent samples from the Albanian general population were analyzed using an ELISA method to assess IgG class anti-Spike (S1) and anti-Nucleocapsid (N) SARS-CoV-2 antibodies. The results revealed a robust immune response among vaccinated individuals with prior COVID-19 infection who received only one vaccine dose. In the 2022 cohort, most individuals who received one vaccine dose achieved comparable seropositivity and antibody levels to those who received two doses. However, individuals aged 61 and over required two or three vaccine doses to reach the same level of immune response as the younger population. Notably, the time elapsed since infection or vaccination did not significantly impact the immune response. These findings highlight the importance of hybrid immunity and suggest that one vaccine dose may be sufficient for most individuals with prior COVID-19 infection. However, additional doses are necessary for optimal protection in older individuals. This study provides unique insights into humoral immune response dynamics that can be used to refine ongoing COVID-19 population vaccination strategies for middle-income countries with low vaccination coverage.
REVIEW | doi:10.20944/preprints202207.0242.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: mouse models; Plasmodium; Adaptive immunity; Innate immunity; T cells; B cells; Macrphages; Neutrophils; Antibodies; Cytokines; parasite control; immunopathogensis
Online: 18 July 2022 (03:12:30 CEST)
Malaria comprises a spectrum of disease syndromes and the immune system is a major participant in malarial disease. This is particularly true in relation to the immune responses elicited against blood stages of Plasmodium-parasites that are responsible for the pathogenesis of infection. Mouse models of malaria are commonly used to dissect the immune mechanisms underlying disease. While no one mouse model of Plasmodium infection completely recapitulates all the features of malaria in humans, collectively the existing models are invaluable for defining the events that lead to the immunopathogenesis of malaria. Here we review the different mouse models of Plasmodium infection that are available, and highlight some of the main contributions these models have made with regards to identifying immune mechanisms of parasite control and the immunopathogenesis of malaria.
ARTICLE | doi:10.20944/preprints201808.0030.v1
Subject: Biology And Life Sciences, Virology Keywords: Dengue virus; Zika virus; T-cell epitopes; cross-reactive T cells; immunodominance; neutralizing antibodies; antibody-dependent-enhancement (ADE)
Online: 2 August 2018 (05:04:43 CEST)
The high level of dengue virus (DENV) seroprevalence in areas where Zika virus (ZIKV) is circulating and the cross-reactivity between these two viruses have raised concerns on the risk of increased ZIKV disease severity for patients with a history of previous DENV infection. To determine the role of DENV pre-immunity in ZIKV infection, we analysed the T and B cell responses against ZIKV in donors with or without previous DENV infection. Using PBMCs from donors living in an endemic area in Colombia, we have identified, by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assay, most of the immunodominant ZIKV T-cell epitopes in the non-structural proteins NS1, NS3 and NS5. Analyses of the T and B-cell responses in the same donors revealed a stronger T-cell response against peptides conserved between DENV and ZIKV, with a higher level of ZIKV-neutralizing antibodies in DENV-immune donors, in comparison with DENV-naïve donors. Strikingly, the potential for antibody mediated enhancement of ZIKV infection was reduced in donors with sequential DENV and ZIKV infection in comparison with donors with DENV infection only. Altogether, these data suggest that individuals with DENV immunity present improved immune responses against ZIKV.
BRIEF REPORT | doi:10.20944/preprints202212.0518.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: immunoassay; epitope coverage; quantitative antibody binding; protein microarray; SARS-CoV-2 antibodies; humoral response; SARS-CoV-2 re-infection
Online: 27 December 2022 (10:43:18 CET)
The COVID-19 pandemic continues to affect individuals across the globe, with some individuals experiencing more severe disease than others. The relatively high frequency of re-infections and breakthrough infections observed with SARS-CoV-2 highlights the importance of extending our understanding of immunity to COVID-19. Here we aim to shed light on the importance of antibody titers and epitope utilization in protection from re-infection. Health care workers are highly exposed to COVID-19 and are therefore also more likely to become re-infected. We utilized quantitative, multi-antigen, multi-epitope SARS-CoV-2 protein microarrays to measure IgG and IgA titers against various domains of the nucleocapsid and spike proteins. Potential re-infections in a large, diverse health care worker cohort (N=300) during the second wave of the pandemic were identified by assessing the IgG anti-N titers before and after the second wave. We assessed epitope coverage and antibody titers between the 'single infection’ and ‘re-infection’ groups. Clear differences were observed in the breadth of the anti-N response before the second wave, with the epitope coverage for both IgG (p=0.019) and IgA (p=0.015) being significantly increased in those who did not become re-infected compared to those who did. Additionally, the IgG anti-N (p=0.004) and anti-S titers (p=0.018) were significantly higher in those not re-infected. These results highlight the importance of the breadth of elicited antibody epitope coverage following natural infection in protection from re-infection and disease in the COVID-19 pandemic.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: SARS-CoV-2; S-protein; RBD; COVID-19; neutralizing antibodies; serology; T-cells; vaccines; animal models; Operation Warp Speed
Online: 27 October 2020 (11:25:32 CET)
Multiple preventive vaccines are being developed to counter the COVID-19 pandemic. The leading candidates have now been evaluated in non-human primates (NHPs) and human Phase 1 and/or Phase 2 clinical trials. Several vaccines have already advanced into Phase 3 efficacy trials, while others will do so before the end of 2020. Here, we summarize what is known of the antibody and T-cell immunogenicity of these vaccines in NHPs and humans. To the extent possible, we compare how the vaccines have performed, taking into account the use of different assays to assess immunogenicity and inconsistencies in how the resulting data are presented. We also summarize the outcome of SARS-CoV-2 challenge experiments in immunized macaques, while noting variations in the protocols used, including but not limited to the virus challenge doses.
ARTICLE | doi:10.20944/preprints201911.0131.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: epitope; monoclonal antibodies; open reading frame 3 protein; apoptosis; p53; porcine circovirus type 2; thimerosal; interfere; antibody binding; lymphocyte
Online: 12 November 2019 (16:20:27 CET)
Porcine circovirus type 2 (PCV2) is a small non-enveloped DNA virus that causes swine immunosuppression by inducing apoptosis in lymphocytes. The ORF3 protein plays a major role in PCV2-induced apoptosis in porcine kidney cells, but there is little information regarding this protein in PCV2-infected lymphocytes. In this study, hybridoma screening and epitope mapping were determined by using an indirect ELISA. The mAb 7D3 against ORF3 peptide (residues 35–65) of PCV2 were generated in this study. In vivo situation, the mAb 7D3 recognized ORF3 protein existed in PCV2-infected apoptotic porcine PBMCs. It is noteworthy that thimerosal interfered with the binding of mAb 7D3 to epitope and it was diminished by adding cysteine. Additionally, thimerosal interacting with cysteine-containing peptide was demonstrated by the PTI assay. Furthermore, thimerosal specifically interacted with the antigen-binding sites of mAb 7D3. This study suggested that thimerosal blockade the occlusion of the antigen-binding sites of mAb 7D3 to bind ORF3 peptide (residues 35–65) via thimerosal interacting with cysteine residues which should be located within the antigen-binding sites of mAb 7D3. Overall, the mAb 7D3 has been characterized and it will be a valuables tool in future studies of ORF3 function and the wider mechanism of cell apoptosis caused by PCV2 infection. Similarly, these techniques will be useful for applications in detecting thimerosal too.