REVIEW | doi:10.20944/preprints202105.0193.v1
Subject: Life Sciences, Immunology Keywords: Epitranscriptomics, acute myeloid leukemia, microRNA, CISH, Immunotherapeutics.
Online: 10 May 2021 (13:53:12 CEST)
Epigenetic alterations have contributed greatly to human carcinogenesis. Conventional epigenetic studies have been predominantly focused on DNA methylation, histone modifications and chromatin remodelling. However, recently, RNA modification (m6A-methylation) also termed ‘epitranscriptomics’ has emerged as a new layer of epigenetic regulation due to its diverse role in various biological processes. In this review, we have summarized the therapeutic potential of m6A-modifiers in controlling haematological disorders especially acute myeloid leukemia (AML). It is a type of blood cancer affecting specific subsets of blood-forming hematopoietic stem/progenitor cells (HSPCs) which proliferate rapidly and acquire self-renewable capacities with impaired terminal cell-differentiation and apoptosis leading to abnormal accumulation of white blood cells, and thus an alternative therapeutic approach is required urgently. Here, we have described how RNA m6A-modification machineries EEE (Editor/writer: Mettl3, Mettl14; Eraser/remover: FTO, ALKBH5 and Effector/reader: YTHDF-1/2) could be reformed into potential druggable candidate or as RNA modifying drug (RMD) to treat leukemia. Moreover, we have shed-light on the role of microRNA and suppressor of cytokine signalling (SOCS/CISH) in increasing anti-tumor immunity towards leukemia. We anticipate, our investigation will provide a fundamental knowledge in nurturing the potential of RNA modifiers in discovering novel therapeutics or immunotherapeutic procedures.
Thu, 31 December 2020
REVIEW | doi:10.20944/preprints202012.0810.v1
Subject: Life Sciences, Immunology Keywords: Krebs cycle; tricarboxylic acid cycle; cellular immunity; immunometabolism
Online: 31 December 2020 (13:16:37 CET)
Tricarboxylic acid cycle (TCA) is a series of chemical reactions in aerobic organisms used to generate energy via the oxidation of acetyl-CoA derived from carbohydrates, fatty acids, and proteins. In the eukaryotic system, the TCA cycle completely occurs in mitochondria, while the intermediates of the TCA cycle are retained in mitochondria due to their polarity and hydrophilicity. Under conditions of cell stress, mitochondria become disrupted and release their contents, which act as danger signals in the cytosol. Of note, the TCA cycle intermediates may also leak from dysfunctioning mitochondria and regulate cellular processes. Increasing evidence shows that the metabolites of the TCA cycle are substantially involved in the regulation of immune responses. In this review, we aimed to provide a comprehensive systematic overview of the molecular mechanisms of each TCA cycle intermediate that may play key roles in regulating cellular immunity in cell stress and discuss their implications for immune activation and suppression.
Thu, 24 December 2020
SHORT NOTE | doi:10.20944/preprints202012.0493.v2
Online: 24 December 2020 (13:51:51 CET)
Vaccines based on mRNA-containing lipid nanoparticles (LNPs) pioneered by Katalin Karikó and Drew Weissman at the University of Pennsylvania are a promising new vaccine platform used by two of the leading vaccine candidates against coronavirus disease in 2019 (COVID-19). However, there are many questions regarding their mechanism of action in humans that remain unanswered. Here we consider the immunological features of LNP components and off-target effects of the mRNA, both of which could increase the risk of side effects. We suggest ways to mitigate these potential risks by harnessing dendritic cell (DC) biology.
Mon, 21 September 2020
ARTICLE | doi:10.20944/preprints202009.0486.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; comorbidity; SARS-CoV-2; leukemia; NAFLD; psoriasis; cancer; type II diabetes
Online: 21 September 2020 (03:32:58 CEST)
Background: Comorbidities have been frequently reported in COVID-19 patients, which often lead to more severe outcomes. The underlying molecular mechanisms behind these clinical observations have not yet been explained. Herein, we investigated the disease-specific gene expression signatures that may induce susceptibility to SARS-CoV-2 infection. Methods: We studied 30 frequently occurring acute, chronic, or infectious diseases of recent times that have shown comorbidity in one or another respiratory disease(s) caused by pathogenic human infecting coronaviruses, especially SARS-CoV-2. We retrieved array-based gene expression data for each disease and control from relevant datasets. Subsequently, all the datasets were quantile normalized, and log-2 transformed data was used for analysis. Results The expression of ACE2 receptor and host proteases, namely FURIN and TMPRSS2 that are essential for cellular entry of SARS-CoV-2, was upregulated in all six studied subtypes of leukemia (hereafter, referred as leukemia). The expression of ACE2 was also increased in psoriasis, lung cancer, Non-alcoholic fatty liver disease (NAFLD), breast cancer, and pulmonary arterial hypertension patients. The expression of FURIN was higher in psoriasis, NAFLD, lung cancer, and in type II diabetic liver, whereas it was lowered in breast cancer. Similarly, the expression of TMPRSS2 was increased during lung cancer and type II diabetes; it was decreased during psoriasis, NAFLD, lung cancer, breast cancer, and cervical cancer.Furthermore, a heightened expression of genes that are involved in immune response was observed in leukemia patients, as shown by the higher expression of IFNA2, IFNA8, IFNA10, IFNA14, IFNA16, IFNA21, IFNB1, CXCL10, and IL6. The expression of JAK1, STAT1, IL6, and CXCL10 was higher in NAFLD. Besides, JAK1 and STAT1 were upregulated in type II diabetic muscles. In addition, most of the upregulated genes in COVID-19 patients showed a similar trend in leukemia, NAFLD, and psoriasis. Furthermore, SARS-CoV-2, SARS-CoV and MERS CoV, were found to commonly alter two genes, namely, CARBONIC ANHYDRASE 11 and CLUSTERIN.Conclusions: The genes that may confer susceptibility to SARS-CoV-2 infection are mostly upregulated in leukemia patients; hence, leukemia patients are relatively more susceptible to develop COVID-19, followed by other chronic disorders, such as, NAFLD, type II diabetes, psoriasis, and hypertension. This study identifies key genes that are altered in the studied diseases types, which may aid in the infection of SARS-CoV-2 and underlie COVID-19 associated comorbidities.
Sun, 13 September 2020
REVIEW | doi:10.20944/preprints202009.0301.v1
Subject: Life Sciences, Immunology Keywords: Atherosclerosis; Phospholipases; Macrophages; T cells; Lipins
Online: 13 September 2020 (23:45:55 CEST)
Phospholipases are a family of lipid altering enzymes that can either reduce or increase bioactive lipid levels. Bioactive lipids elicit signaling responses, activate transcription factors, promote g-coupled protein activity, and modulate membrane fluidity that mediate cellular function. Phospholipases and the bioactive lipids they produce are important regulators on immune cell activity, dictating both pro-inflammatory and pro-resolving activity. During atherosclerosis, pro-inflammatory and pro-resolving activities govern atherosclerosis progression and regression respectively. This review will look at the interface of phospholipase activity, immune cell function, and atherosclerosis.
Thu, 27 August 2020
Subject: Life Sciences, Immunology Keywords: Anti-inflammation; Endotoxin shock; Atraric acid; Lichen; Heterodermia hypoleuca
Online: 27 August 2020 (12:10:17 CEST)
As symbionts of fungi and algae, lichens produce a variety of secondary products which pharmacological activities. This study aimed to investigate the anti-inflammatory activities of Heterodermia hypoleuca and its main compound, atraric acid. The results confirmed that atraric acid could regulating induced pro-inflammatory cytokine, nitric oxide, induced nitric oxide synthase and cyclooxygenase-2 expression by lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Means while, atraric acid down-regulated expression of phosphorylated IκB, ERK and nuclear factor kappa B (NFκB) signaling pathway to exhibit anti-inflammatory effects in LPS-stimulated RAW264.7 cells. Based on these results, the anti-inflammatory effect of atraric acid during LPS-induced endotoxin shock in a mouse model was confirmed. In the atraric acid treated-group, cytokine production was decreased in the peritoneum and serum, and each organ damaged by LPS-stimulation was recovered. These results show that atraric acid has an anti-inflammatory effect and its molecular mechanism may be involved in the inactivation of the ERK/NFκB signaling pathway, demonstrating its value as a potential therapeutic for inflammatory diseases.
ARTICLE | doi:10.20944/preprints202008.0612.v1
Online: 27 August 2020 (10:40:50 CEST)
Despite the availability of therapeutic treatments, multiple myeloma is an incurable haematological disorder. In this study, we aimed to clarify the role of CXorf48 as a therapeutic target in multiple myeloma. Based on a previously identified HLA-A*24:02-restiricted epitope from this novel cancer/testis antigen, we characterized the activities of cytotoxic T lymphocytes (CTLs) specific to this antigen against myeloma cells and evaluated the effects of demethylating agents in increasing antigen expression and enhancing the cytotoxic activity of CTLs. CXorf48 expression was examined by RT-PCR using nine myeloma cell lines. Cell lines with low CXorf48 expression were treated by demethylating agents (DMAs), 5-azacytidine (5-aza), and 5-aza-2'-deoxycytidine (DAC) to evaluate gene expression using quantitative RT-PCR. Furthermore, CXorf48-specific CTLs were induced from peripheral blood mononuclear cells of HLA-A*24:02-positive healthy donors to evaluate antigen recognition using ELISpot and 51Cr cytotoxicity assays. CXorf48 was widely expressed in myeloma cells and gene expression was significantly increased by DMAs. Furthermore, CXorf48-specific CTLs recognized DMA-treated myeloma cells. These findings suggest that CXorf48 is a useful target for immunotherapy, such as vaccination, in combination with demethylating agents for the treatment of patients with myeloma.
Fri, 21 August 2020
TECHNICAL NOTE | doi:10.20944/preprints202008.0467.v1
Subject: Life Sciences, Immunology Keywords: HLA diversity; HLA frequency; predicted T-cell epitopes; immunogenic breath
Online: 21 August 2020 (03:39:15 CEST)
Existing approaches to identifying predictive T-cell epitopes have traditionally utilized either 2-digit HLA super-families or more commonly autologous HLA alleles to facilitate the predictions, but frequently they may not consider their representation within a population. Here we propose a modification to this concept whereby subsets of individuals are selected for their specific HLA allele profiles and the representation they provide within a given population. Using this targeted approach to HLA selection and the linkages to specific individuals may enable the design of restricted experimental strategies.
Sun, 2 August 2020
REVIEW | doi:10.20944/preprints202008.0020.v1
Subject: Life Sciences, Immunology Keywords: SARS-CoV-2; COVID-19; Immunopathogenesis; Cytokine storm; IL-6; macrophages; neutrophils
Online: 2 August 2020 (11:53:17 CEST)
The coronavirus disease 2019 (COVID-19) is now a global pandemic caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Unlike other known coronaviruses, such as the Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV-2 reveals new clinical, immunological, and pathologic features. The lymphocyte depletion, macrophage and neutrophil hyperactivation, cytokine dysregulation, thrombophilia, delayed antiviral response, and immune exhaustion are key immunological findings linked to the clinical progression of this disease. Understanding and identifying the underlying immunological basis of COVID-19 is crucial to designing effective therapies. Here, we provide an overview of immunopathogenesis driven by SARS-CoV-2 after its interactions with the immune system.
Sat, 25 July 2020
ARTICLE | doi:10.20944/preprints202007.0618.v1
Subject: Life Sciences, Immunology Keywords: Innate immune memory; inflammatory response; β-glucan; flow cytometry; primary chicken monocytes; macrophages
Online: 25 July 2020 (18:00:05 CEST)
Beta-glucan-stimulated mammalian macrophages show an increased responsiveness to secondary stimulation in a nonspecific manner. This phenomenon is known as trained innate immunity. Our study aimed to explore training of primary chicken monocytes. We hypothesized that primary chicken monocytes, similar to their mammalian counterparts, can be trained with β-glucan resulting in increased responses of these cells to a secondary stimulus. Primary blood monocytes of white leghorn chickens were primary stimulated with β-glucan microparticulates (M-βG), LPS, recombinant chicken interleukin-4 (IL-4) or combinations of these components for 48 h. On day 6, the primary stimulated cells were secondary stimulated with LPS. Nitric oxide (NO) production levels were measured as an indicator of pro-inflammatory activity. In addition, the cells were analysed by flow cytometry to characterize the population of trained cells and to investigate the expression of surface markers associated with activation. After the secondary LPS stimulation, surface expression of CSF1R and the activation markers CD40 and MHC-II was higher on macrophages that were trained with a combination of M-βG and IL-4 compared to unstimulated cells. This increased expression was paralleled by enhanced NO production. In conclusion, this study showed that trained innate immunity can be induced in primary chicken monocytes with β-glucan, which is in line with previous experiments in mammalian species. Innate immune training may have potential to improve health and vaccination strategies within the poultry sector.
Tue, 14 July 2020
REVIEW | doi:10.20944/preprints202007.0305.v1
Subject: Life Sciences, Immunology Keywords: spondyloarthritis; HLA-B27; pathogenesis; inflammation; arthritogenic peptides; unfolded protein response; ERAP1; gut dysbiosis
Online: 14 July 2020 (11:39:13 CEST)
Spondyloarthritis comprises of a group of inflammatory diseases of the joints and spine with various clinical manifestations. The group includes ankylosing spondylitis, reactive arthritis, psoriatic arthritis, arthritis associated with inflammatory bowel disease, and undifferentiated spondyloarthritis. The exact etiology and pathogenesis of spondyloarthritis are still unknown, but five hypotheses explaining the pathogenesis exist. These hypotheses suggest that spondyloarthritis is caused by arthritogenic peptides, an unfolded protein response, HLA-B27 homodimer formation, malfunctioning endoplasmic reticulum aminopeptidases, and, last but not least, gut inflammation and dysbiosis. Here we discuss the five hypotheses and the evidence supporting each. In all of these hypotheses, HLA-B27 plays a central role. It is likely that a combination of these hypotheses, with HLA-B27 taking center stage, will eventually explain the development of spondyloarthritis in predisposed individuals.
Sun, 12 July 2020
ARTICLE | doi:10.20944/preprints202007.0252.v1
Subject: Life Sciences, Immunology Keywords: SARS-Co-V2; Paediatric hyperinflammation; MIS-C; PIMS-TS
Online: 12 July 2020 (12:09:35 CEST)
We describe the innate and adaptive immune system trajectory in Multi-system inflammatory syndrome of childhood (MIS-C), at acute(within 72 hours of hospitalization), resolution (at clinical improvement) and convalescent phase. In our cohort, in the acute phase, 68% of the children were SARS-CoV-2 seropositive, with hypercytokinenemia (high interleukin(IL)-1beta,IL-6,IL-8,IL-10,IL-17, interferon gamma), procoagulant state, myocardial dysfunction, activated neutrophils and monocytes; differential T and B cell subset lymphopenia; activated chemokine receptor type-7 positive and gamma-delta T cell subsets; antigen presenting cells had reduced HLA-DR expression; and B-cell class-switch responses occurred with illness resolution. MIS-C is an immunopathogenic illness associated with SARS-CoV-2 infections in children.
Fri, 10 July 2020
REVIEW | doi:10.20944/preprints202007.0206.v1
Subject: Life Sciences, Immunology Keywords: Collagen triple helix repeat containing 1; CTHRC1; rheumatoid arthritis; biomarker; bone erosion; cartilage destruction; fibroblast-like synoviocytes; Wnt signaling
Online: 10 July 2020 (07:51:23 CEST)
Rheumatoid arthritis (RA) is a chronic autoimmune disease, causing inflammation of joints, cartilage destruction and bone erosion. Biomarkers and new drug targets are actively sought and progressed to improve available options for patient treatment. The Collagen Triple Helix Repeat Containing 1 protein (CTHRC1) may have an important role as a biomarker for rheumatoid arthritis, as CTHRC1 protein concentration is significantly elevated in the peripheral blood of rheumatoid arthritis patients, compared to osteoarthritis (OA) patients and healthy individuals. CTHRC1 is a secreted glycoprotein that promotes cell migration and has been implicated in arterial tissue-repair processes. Furthermore, high CTHRC1 expression is observed in many types of cancer and this is associated with cancer metastasis to the bone and poor prognosis. However, the function of CTHRC1 in RA is still largely undefined. The aim of this review is to summarize recent findings on the role of CTHRC1 as a potential biomarker and pathogenic driver of RA progression that may be linked to the pathogenic behavior of fibroblast-like synoviocytes, cartilage destruction, and bone erosion.
Tue, 7 July 2020
ARTICLE | doi:10.20944/preprints202007.0130.v1
Subject: Life Sciences, Immunology Keywords: Neutrophil extracellular traps (NETs); intestinal barrier integrity; DNase I; DSS/TNBS-induced colitis
Online: 7 July 2020 (16:34:41 CEST)
Aberrant neutrophil extracellular trap (NET) formation and the loss of barrier integrity in inflamed intestinal tissues have long been associated with inflammatory bowel disease (IBD). However, whether NETs alter intestinal epithelium permeability during colitis remains elusive. Here, we demonstrated that NETs promote the breakdown in intestinal barrier function for the pathogenesis of intestinal inflammation in mouse models of colitis. NETs were abundant in the colon of mice with colitis experimentally induced by dextran sulfate sodium (DSS) or 2,4,6-trinitrobenzene sulfonic acid (TNBS). Analysis of the intestinal barrier integrity revealed that NETs impaired gut permeability, enabling the initiation of luminal bacterial translocation and inflammation. Furthermore, NETs induced the apoptosis of epithelial cells and disrupted the integrity of tight junctions and adherens junctions. Intravenous administration of DNase I, an enzyme that dissolves the web-like DNA filaments of NETs, during colitis restored the mucosal barrier integrity which reduced the dissemination of luminal bacteria, and attenuated intestinal inflammation in both DSS and TNBS models. We conclude that NETs serve a detrimental factor in the gut epithelial barrier function leading to the pathogenesis of mucosal inflammation during acute colitis.
Sun, 5 July 2020
REVIEW | doi:10.20944/preprints202007.0090.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; Immunotherapy; Immunomodulator; Antibody; Plasma; Immunoglobulins
Online: 5 July 2020 (17:01:31 CEST)
Since the outbreak of SARS CoV-2 infection (Covid-19), healthcare professionals worldwide have been trying to find disease management and control alternatives to encourage immunotherapies. Immunotherapy is an efficient therapeutic option used against comparable viral contaminations such as MERS-CoV and SARS-CoV. The aim of the current study is to assess the existing knowledge associated with SARS-CoV-2 immunotherapy. Information available in published articles and their quality highlights the importance of following strict scientific rules for clinical outcomes. Thus, these studies have shown enough data to confirm that immunomodulation is the main topic investigated in research about Covid-19 therapy. Therefore, it is possible saying that immunotherapy is certainly the appropriate option against this virus.
Thu, 2 July 2020
HYPOTHESIS | doi:10.20944/preprints202007.0009.v1
Online: 2 July 2020 (13:36:14 CEST)
Coronavirus and COVID-19 infections continue to wreak havoc across the world. Interestingly, the COVID-19 infections and deaths display a clear seven-day cycles. Mathematical analysis using linear mixed-effects models show that this periodicity is not due to reporting errors. We hypothesize that these COVID-19 cycles are related to natural immune cycles which also oscillate every seven days. These immune cycles are regulated by stress and mediated through the endocrine and the central nervous systems. Our routine activities and lifestyle of more stressful weekdays flanked by less stressful, relaxing weekends define the seven-day immune cycles. The synchronized low immunity levels in the population is responsible for repeated seven-day waves of pathogenic infections such as COVID-19. The new understanding of the role of immune oscillations will help in developing strategies to enhance our immunity through modified lifestyle and better, innovative prophylactic and therapeutic approaches against infectious diseases.
Sun, 21 June 2020
ARTICLE | doi:10.20944/preprints202006.0249.v1
Subject: Life Sciences, Immunology Keywords: SARS-CoV-2; TMPRSS2; antibody epitopes; glycosylation sequons; heparin
Online: 21 June 2020 (10:12:34 CEST)
The 2019 novel SARS-like coronavirus (SARS-CoV-2) entry depends on the host membrane serine protease TMPRSS2, which can be blocked by some clinically-proven drugs. Here we analyzed spatial relevance between glycosylation sequons and antibody epitopes and found that, different from SARS-CoV S, most high-surface-accessible epitopes of SARS-CoV-2 S are blocked by the glycosylation, and the optimal epitope with the highest surface accessibility is covered by the S1 cap. TMPRSS2 inhibitor treatments may prevent unmasking of this epitope and therefore prolong virus clearance and may induce antibody-dependent enhancement. Interestingly, a heparin-binding sequence immediately upstream of the S1/S2 cleavage site has been found in SARS-CoV-2 S but not in SARS-CoV S. Binding of SARS-CoV-2 with heparins may lead to exposure of S686, which then facilitates the S1/S2 cleavage, induces exposure of the optimal epitope, and therefore increases the antibody titres. A combination of heparin and vaccine (or convalescent serum) treatments thus is recommended.
REVIEW | doi:10.20944/preprints202006.0248.v1
Subject: Life Sciences, Immunology Keywords: probiotic; upper respiratory tract infection (URTI); infection; prevention; common cold
Online: 21 June 2020 (10:07:31 CEST)
Background: Probiotics can provide health benefits to an individual by regulation of the immune system. Many clinical trials have found that probiotics can prevent upper respiratory tracts infections. Aim: To perform a systematic review and meta-analysis of available trials to investigate the effectiveness of probiotics in the prevention of upper respiratory tract infections in individuals of all ages. Conclusion: Probiotics were found to be better in reducing the number of participants who experienced acute URTI, the average duration per episode of acute URTI, use of antibiotics in URTI related cases and absence due to URTI. Side effects were found to be minor, making probiotics a good candidate for clinical use. This shows that probiotics are effective in preventing acute URTIs. However, due to limited studies and small sample size, the results are subjected to bias and should be interpreted with care.
Wed, 17 June 2020
REVIEW | doi:10.20944/preprints202006.0211.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; diagnosis; ELISA; RDT; point-of-care test; antibody; proteins
Online: 17 June 2020 (08:36:25 CEST)
The ongoing pandemic of COVID-19 has not only commenced a global health emergency but agitated various aspects of humanity. During this period of crisis researchers over the world have ramped their efforts to constrain the disease in all possible ways whether it is vaccination, therapy, or diagnosis. Since the spread of the disease has not yet elapsed sharing the ongoing research findings could be the key to disease control and management. An early and efficient diagnosis could leverage the outcome until a successful vaccine is developed. Molecular tests both in-house and commercial kits are preferably being used worldwide in the COVID-19 diagnosis. However, the limitation of high prices and lengthy procedures impede their use for mass testing. Keeping the constant rise of infection in mind search for an alternative test that should be cost-effective, simple, and suitable for large scale testing and surveillance is a need of an hour. One such alternative could be the immunological tests. Therefore, in the last few months deluge of immunological rapid tests has been developed and validated across the globe. The objective of the present review is to share the diagnostic performance of various immunological assays reported so far in SARS-CoV-2 case detection. The article consolidated the studies (published and preprints) related to the serological tests such as chemiluminescence, enzyme-linked and lateral flow-based point-of-care tests in COVID-19 diagnosis and updated the current scenario. This review will hopefully be an add-on in COVID-19 research and will contribute to congregate the evidence for decision-making.
Sun, 7 June 2020
ARTICLE | doi:10.20944/preprints202006.0087.v1
Subject: Life Sciences, Immunology Keywords: SARS-CoV-2; CMap; Cytokine Storm; NF-kB; Glucocorticoids; MEK; Estrogens
Online: 7 June 2020 (12:04:46 CEST)
The ongoing COVID-19 pandemic is one of the biggest health and societal challenges of the recent decades. Among the causes of mortality triggered by SARS-CoV-2 infection, the presence of an inflammatory "cytokine storm" (CS) at later stages of the disease has been found to play a determinant role. Here, we used available transcriptomic data from the bronchoalveolar lavage fluid (BALF) of COVID-19 patients suffering from a CS to obtain gene-signatures associated to this pathological process. Using these signatures, we interrogated the Connectivity MAP (CMap) dataset that contains the effects of over 5,000 small molecules on the transcriptome of human cancer cell lines, and looked for molecules which effects on transcription mimic or oppose those associated to the CS. Consistent with their medical use, this analysis found a significant enrichment of glucocorticoids or inhibitors of the Janus Kinases (JAK) as drugs that could revert the CS. On the other hand, molecules that potentiate the immune response such as PKC activators are predicted to worsen the CS. Besides these expected findings, our analysis also reveals a potential effect of the antibiotic doxycycline or MAPK/RAF/MEK inhibitors in reverting the CS, or of topoisomerase inhibitors and the anti-alcohol abuse drug disulfiram in potentiating its effects. Finally, our analyses support that the gender-related differences in the severity of COVID-19 are related to the anti-inflammatory properties of female hormones. While acknowledging that this is an analysis based on limited available data, we decided to share it as a resource that might help others in the selection of drugs that could be tested in the context of experimental models of CS triggered by viral infections.
Thu, 4 June 2020
COMMUNICATION | doi:10.20944/preprints202006.0030.v1
Online: 4 June 2020 (08:04:33 CEST)
There is a global rise in the emergence of infectious diseases and the enigmatic coronavirus disease 2019 (COVID-19) being the most recent one. It is ravaging the world with little understanding of its etiology and factors affecting its transmission dynamics. Meanwhile, seasonal variations in weather are major factors impacting infectious disease transmission patterns. Developing countries are likely to be most affected by weather changes, largely because of challenges such as inadequate drainage and sewage management systems, healthcare facilities, education, and funding to efficiently mitigate infectious diseases. In Nigeria, weather conditions alternate between rainy and dry seasons. Conditions such as rainfall, flood, and humidity have been reported to influence infectious disease transmission. Thus, understanding the impact of weather changes in transmission dynamics and immune response to COVID 19 will help in preventive measures and policy making to curtail its spread most especially in Nigeria as the rainy season fully sets in.
Sat, 9 May 2020
REVIEW | doi:10.20944/preprints202005.0157.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; SARS-Cov-2; cytokine storm; inflammation; immunosenescence
Online: 9 May 2020 (08:35:51 CEST)
The dysregulated release of cytokines has been identified as one of the key factors behind poorer outcomes in COVID-19. This ‘cytokine storm ‘produces an excessive inflammatory and immune response, especially in the lungs, leading to acute respiratory distress (ARDS), pulmonary edema and multi-organ failure. Alleviating this inflammatory state is crucial to improve prognosis. Pro-inflammatory factors play a central role in COVID-19 severity, especially in patients with comorbidities In these situations, an overactive, untreated immune response can be deadly, suggesting that mortality in COVID-19 cases is likely due to this virally driven hyperinflammation. Administering immunomodulators has not yielded conclusive improvements in other pathologies characterized by dysregulated inflammation such as sepsis, SARS-CoV-1 and MERS. The success of these drugs at reducing COVID-19-driven inflammation is still anecdotal and comes with serious risks. It is also imperative to screen the elderly for risk factors that predispose them to severe COVID-19. Immunosenescence and comorbidities should be taken into consideration. In this review, we summarize the latest data available about the role of the cytokine storm in COVID-19 disease severity as well as potential therapeutic approaches to ameliorate it. We also examine the role of inflammation in other diseases often comorbid with COVID-19, such as aging, sepsis, and pulmonary disorders. Finally, we identify gaps in our knowledge and suggest priorities for future research aimed at stratifying patients according to risk as well as personalizing therapies in the context of COVID19-driven hyperinflammation.
Sun, 3 May 2020
REVIEW | doi:10.20944/preprints202005.0041.v1
Subject: Life Sciences, Immunology Keywords: Vimentin; Cell surface vimentin; SARS-CoV; Vimentin-pathogen interactions; Anti-vimentin autoantibodies; Inflammation
Online: 3 May 2020 (09:00:43 CEST)
Vimentin is an intermediate filament protein that plays key roles in integration of cytoskeletal functions, and therefore in basic cellular processes such as cell division and migration. Consequently, vimentin has complex implications in pathophysiology. Vimentin is required for a proper immune response, but it can also act as an autoantigen in autoimmune diseases or as a damage signal. Although vimentin is a predominantly cytoplasmic protein, it can also appear at extracellular locations, either in a secreted form or at the surface of numerous cell types, often in relation to cell activation, inflammation, injury or senescence. Cell surface targeting of vimentin appears to associate with the occurrence of certain posttranslational modifications, such as phosphorylation and/or oxidative damage. At the cell surface, vimentin can act as a receptor for bacterial and viral pathogens. Indeed, vimentin has been shown to play important roles in virus attachment and entry of severe acute respiratory syndrome-related coronavirus (SARS-CoV), dengue and encephalitis viruses, among others. Moreover, the presence of vimentin in specific virus-targeted cells and its induction by proinflammatory cytokines and tissue damage contribute to its implication in viral infection. Here, we recapitulate some of the pathophysiological implications of vimentin, including the involvement of cell surface vimentin in interaction with pathogens, with a special focus on its role as a cellular receptor or co-receptor for viruses. In addition, we provide a perspective on approaches to target vimentin, including antibodies or chemical agents that could modulate these interactions to potentially interfere with viral pathogenesis, which could be useful when multi-target antiviral strategies are needed .
Subject: Life Sciences, Immunology Keywords: COVID-19; Chronic diseases; Aging; Immune response; Public health; Healthy Aging
Online: 3 May 2020 (08:15:24 CEST)
As the novel COVID-19 disease spreads around the world, the most affected population are those who suffer from the most common chronic diseases, such as obesity, hypertension, and type 2 diabetes, which are quite associated with the so-called age-related diseases. On the other hand, since the Spanish influenza outbreak, humanity has not experienced an infectious disease that synergizes so quickly with chronic diseases, making it mortal for those individuals with comorbidities. In this context, COVID-19 is challenging for health systems all around the world due to the high prevalence of chronic diseases. Nowadays, we are facing the beginning of a new era in which health infectious and chronic diseases meet. Therefore, epidemiologic and biomedical researchers must work together to solve further contingencies, and politicians should direct science-centered decisions on public health. In the present paper, we make an urgent call to learn from the COVID-19 lessons in order to mitigate the chronic diseases prevalence and to address the influence of the infectious diseases on the aging process; since we are about to begin the Decade of Healthy Aging.
Thu, 30 April 2020
COMMUNICATION | doi:10.20944/preprints202004.0206.v2
Online: 30 April 2020 (05:10:43 CEST)
The World Health Organisation declared Covid-19 as a pandemic on 11th March 2020. The main approach to tackle Covid-19 worldwide is to screen and provide supportive care to patients. For screening purpose RT-qPCR based test are used as an initial detections assay. The test is expensive, time consuming and not suitable for mass scale screening/ confirmation requirement. A recent advancement is development of Immunoassay procedures (liquid Phase tests or bed side 10-20minute strip test). In order to help and accelerate bringing life to normal after lock down, Pakistan is in dire need to develop and adopt the immunoassay procedures for mass scale screening and confirmation of COVID-19 infection. It is cheap and easy to perform without a lab requirement.
Wed, 22 April 2020
SHORT NOTE | doi:10.20944/preprints202004.0363.v2
Online: 22 April 2020 (06:23:01 CEST)
Covid-19 is often related to hyperinflammation that drives lung or multi-organ injury. The immunopathological mechanisms that cause excessive inflammation following SARS-Cov-2 infection are under investigation while different approaches to limit hyperinflammation in affected patients are being proposed. Here, a computational protein-protein interaction network approach was used on recently available data to identify possible Covid-19 inflammatory mechanisms and bioactive genes. First, network analysis of putative SARS-Cov-2 cellular receptors and their directly associated proteins, led to the mining of a robust neutrophil response signature and multiple relevant inflammatory genes. Second, analysis of RNA-seq datasets of lung epithelial cells infected with SARS-Cov-2 revealed that infected cells specifically expressed neutrophil-attracting chemokines, further supporting the likely role of neutrophils in Covid-19 inflammation. Third, analysis of RNA-seq datasets of bronchoalveolar lavage fluid from Covid-19 patients, identified neutrophil-specific genes and chemokines. Different immunoregulatory and neutrophil-relevant molecules mined here such as, TNFR, IL8, CXCR1, CXCR2, ADAM10, GPR84, MME-neprilysin, ANPEP and LAP3 are druggable and might be therapeutic targets in efforts to limit SARS-Cov-2 inflammation in severe clinical cases. The role of neutrophils in Covid-19 needs to be studied further.
Mon, 20 April 2020
SHORT NOTE | doi:10.20944/preprints202004.0363.v1
Online: 20 April 2020 (12:38:59 CEST)
Covid-19 is often related to hyperinflammation that drives lung or multi-organ damage and mortality. The immunopathological mechanisms that cause excessive inflammation following SARS-Cov-2 infection are under investigation while different approaches to limit hyperinflammation in affected patients are being proposed. Here, a computational network approach was used on recently available data to identify possible Covid-19 inflammatory mechanisms. First, network analysis of putative SARS-Cov-2 cellular receptors and their directly associated interacting proteins, led to the mining of a robust neutrophil-response signature and multiple relevant inflammatory response genes. Second, analysis of RNA-seq datasets of lung epithelial cells infected with SARS-Cov-2 found that infected cells specifically expressed neutrophil-attracting chemokines, further supporting the likely role of neutrophils in Covid-19 inflammation. The role of neutrophils in Covid-19 needs to be studied further. Different immunoregulatory molecules and pathways presented here (TNF Receptor, IL8, CXCR1, CXCR2, ADAM10, GPR84, MME-neprilysin, ANPEP, LAP3) are druggable and might be therapeutic targets in efforts to limit SARS-Cov-2 inflammation in severe clinical cases.
Sun, 19 April 2020
BRIEF REPORT | doi:10.20944/preprints202004.0353.v1
Online: 19 April 2020 (16:54:43 CEST)
We have proposed a model considering two equally sized population (group A and group B) with low and high levels of disease tolerance. We have argued that in the more tolerant group (group B) the progression of the disease with respect to time will be slow with lower number of infections at any given time. We attribute this effect to the innate immunity which advantageously, can also be one of the major contributing factors for flattening the curve. We have compared the growth of Covid-19 disease in various countries to understand this effect.
Mon, 13 April 2020
BRIEF REPORT | doi:10.20944/preprints202004.0206.v1
Online: 13 April 2020 (03:40:08 CEST)
The World Health Organisation declared Covid-19 as a pandemic on 11th March 2020. The main approach to tackle Covid-19 worldwide is to screen and provide supportive care to patients. For screening purpose RT-qPCR based test are used as an initial detections assay. The test is expensive, time consuming and not suitable for mass scale screening/ confirmation requirement. A recent advancement is development of Immunoassay procedures (liquid Phase tests or bed side 10-20minute strip test). In order to help and accelerate bringing life to normal after lock down, Pakistan is in dire need to develop and adopt the immunoassay procedures for mass scale screening and confirmation of COVID-19 infection. It is cheap and easy to perform without a lab requirement.
Thu, 9 April 2020
CONCEPT PAPER | doi:10.20944/preprints202004.0158.v1
Subject: Life Sciences, Immunology Keywords: Covid-19; SARS-CoV-2; Inflamm-aging; mtDNA; Telomere; Inflammation
Online: 9 April 2020 (14:43:41 CEST)
More than 1,000,000 confirmed cases of COVID-19 have been registered worldwide since the beginning of the pandemic in Wuhan on December 2019. The high mortality rate of COVID-19 is associated with age, gender and the presence of comorbidities. Biochemical data have shown that COVID-19 patients develop a local and systemic hyper-inflammatory response associated with poor outcome. Therefore, the understanding of the biological mechanisms underlying SARS-CoV-2-induced inflammation is a compelling need. Following this reasoning, here we will focus on the importance of the progressive age-related development of a pro-inflammatory state (aka inflamm-aging) in the understanding of the unbalanced inflammatory response against SARS-CoV-2 in aged people. In particular, we underpin the role of mitochondrial DNA and genomic DNA telomeric sequences in local and systemic mechanisms of inflammation. Indeed, the leakage of mtDNA out of its natural compartment (i.e. the mitochondrion), into the cytoplasm and in the extracellular environment is a powerful trigger of innate immunity and inflammation, as part of an evolutionary-conserved signaling mechanism of cellular damage (e.g. viral infection). High levels of circulating mtDNA are increased in aged people and set up as inflammatory markers of poor prognosis in intensive care unit patients. In turn, telomeric DNA, which can be released into the cytoplasm and in the extracellular environment upon cell damage, has been proven to exert potent anti-inflammatory activity. Since that aged people (particularly those affected by co-morbidity) are equipped with shortened telomeres, we posit that, in aged people affected by COVID-19 the release of mtDNA, coupled with insufficient telomeric DNA favors the onset of a detrimental inflammatory response. In this regard, we highlight that the mechanism of action of some currently used drugs, as well as potential new ones may be better understood under the light of the above-depicted theoretical framework thus explaining how studies on inflamm-aging may help to understand and combat COVID-19 pandemic.
REVIEW | doi:10.20944/preprints202004.0122.v2
Subject: Life Sciences, Immunology Keywords: melatonin; coronavirus; pandemic; SARS-CoV-2; bat; lung; apoptosis; programmed cell death; mortality; morbidity; COVID-19; drug
Online: 9 April 2020 (09:24:47 CEST)
The current COVID-19 pandemic is one of the most devastating events in recent history. The virus causes relatively minor damage to young, healthy populations, imposing life-threatening danger to the elderly and people with diseases of chronic inflammation. Therefore, if we could reduce the risk for vulnerable populations, it would make the COVID-19 pandemic more similar to other typical outbreaks. Children don’t suffer from COVID-19 as much as their grandparents and have a much higher melatonin level. Bats are nocturnal animals possessing high levels of melatonin, which may contribute to their high anti-viral resistance. Viruses induce an explosion of inflammatory cytokines and reactive oxygen species, and melatonin is the best natural antioxidant that is lost with age. The programmed cell death coronaviruses cause, which can result in significant lung damage, is also inhibited by melatonin. Coronavirus causes inflammation in the lungs which requires inflammasome activity. Melatonin blocks these inflammasomes. General immunity is impaired by anxiety and sleep deprivation. Melatonin improves sleep habits, reduces anxiety and stimulates immunity. Fibrosis may be the most dangerous complication after COVID-19. Melatonin is known to prevent fibrosis. Mechanical ventilation may be necessary but yet imposes risks due to oxidative stress, which can be reduced by melatonin. Thus, by using the safe over-the-counter drug melatonin, we may be immediately able to prevent the development of severe disease symptoms in coronavirus patients, reduce the severity of their symptoms, and/or reduce the immuno-pathology of coronavirus infection on patients’ health after the active phase of the infection is over.
Wed, 8 April 2020
REVIEW | doi:10.20944/preprints202004.0122.v1
Subject: Life Sciences, Immunology Keywords: melatonin; coronavirus; pandemic; SARS-CoV-2; bat; lung; p62; apoptosis; programmed cell death; mortality; morbidity; prevention; vaccine; adjuvant; drug; symptoms
Online: 8 April 2020 (08:13:26 CEST)
The current COVID-19 pandemic is one of the most devastating events in recent history. The virus causes relatively minor damage to young, healthy populations, imposing life-threatening danger to the elderly and people with diseases of chronic inflammation. So, if we could reduce the risk for vulnerable populations, it would make the COVID-19 pandemic more similar to other typical outbreaks. Children do not suffer from COVID-19 as much as their grandparents and have a much higher melatonin level. Bats also do not suffer from the virus they transmit, and bats too have a much higher level of melatonin. Viruses generate an explosion of reactive oxygen species, and melatonin is the best natural antioxidant that is lost with age. Melatonin inhibits the programmed cell death which coronaviruses induce, causing significant lung damage. Coronavirus causes inflammation in the lungs which requires inflammasome activity. Melatonin blocks the inflammasome. The immune response is impaired by anxiety and sleep deprivation. Melatonin improves sleep habits, reduces anxiety and stimulates immunity. Fibrosis may be the most dangerous complication after COVID-19. Melatonin is known to prevent fibrosis. Mechanical ventilation may be necessary but yet imposes risks due to oxidative stress, which can be reduced by melatonin. Thus, by using the safe over-the-counter drug melatonin, we may be immediately able to prevent the development of severe disease symptoms in coronavirus patients, reduce the severity of their symptoms, and/or reduce the negative effects of coronavirus infection on patients’ health after the active phase of the infection is over.
Tue, 7 April 2020
HYPOTHESIS | doi:10.20944/preprints202004.0101.v1
Online: 7 April 2020 (12:07:22 CEST)
On March 11, 2020, the World Health Organization declared the coronavirus outbreak a pandemic. Since December 2019, the world has experienced an outbreak of coronavirus disease 2019 (COVID-19). Epidemiology, risk factors, and clinical characteristics of patients with COVID-19 have been reported but the factors affecting the immune system against COVID-19 have not been well described. In this article, we provide a novel hypothesis to describe how an increase in cellular adenosine triphosphate (c-ATP) can potentially improve the efficiency of innate and adaptive immune systems to either prevent and fight off COVID-19.
Mon, 6 April 2020
REVIEW | doi:10.20944/preprints202004.0060.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; coronavirus; cytokine storm; immunity; ADE; cross-reactive antibody; rapamycin; mTOR inhibotors
Online: 6 April 2020 (14:03:00 CEST)
COVID-19 has become a severe global public health concern. The critical illness has a mortality rate of 61.5%, and thus, reducing the severity and mortality is top priority. Currently, inflammatory storms are considered as the cause of critical illness and death due to COVID-19. However, After systematical review of the literature, we proposed that cross-reactive antibodies-associated antibody-dependent enhancement (ADE) may actually be the cause of cytokine storms. If the activation of memory B cells can be selectively inhibited in high-risk patients at an early stage of COVID-19 to reduce the production of cross-reactive antibodies of the virus, we speculate that the ADE can be avoided and severe symptoms can be prevented. The mammalian target of rapamycin (mTOR) inhibitors satisfy such conditions. We recommend that pharmaceutical companies conduct clinical trials urgently.
Mon, 16 March 2020
REVIEW | doi:10.20944/preprints202003.0254.v1
Subject: Life Sciences, Immunology Keywords: zebrafish; inflammation; tumour initiation; macrophage; neutrophil; cancer; pre-neoplastic; live imaging; tumourigenesis; tumour model
Online: 16 March 2020 (01:31:28 CET)
The zebrafish is now an important model organism for cancer biology studies and provides some unique and complementary opportunities in comparison to the mammalian equivalent. The translucency of zebrafish has allowed in vivo live imaging studies of tumour initiation and progression at the cellular level thus providing novel insights into our understanding of cancer. Here we summarise and discuss available transgenic zebrafish tumour models and what we have gleaned from them with respect to cancer inflammation. In particular, we focus on the host inflammatory response toward transformed cells during the pre-neoplastic stage of tumour development. We discuss features of tumour associated macrophages and neutrophils in mammalian models and present evidence which supports the idea that these inflammatory cells promote early stage tumour development and progression. Direct live imaging of tumour initiation in zebrafish models has shown that the intrinsic inflammation induced by pre-neoplastic cells is tumour promoting. Signals mediating leukocyte recruitment to pre-neoplastic cells in zebrafish correspond to signals mediating leukocyte recruitment in mammalian tumours. The activation state of macrophages and neutrophils recruited to pre-neoplastic cells appears to be heterogenous, as seen in mammalian models, which provides an opportunity to study the plasticity of innate immune cells during tumour initiation. Although several potential mechanisms are described that might mediate the trophic function of innate immune cells during tumour initiation in zebrafish, there are several unknowns that are yet to be resolved. Rapid advancement of genetic tools and imaging technologies for zebrafish will facilitate research into the mechanisms that modulate leukocyte function during tumour initiation and identify targets for cancer prevention.
Thu, 12 March 2020
Subject: Life Sciences, Immunology Keywords: immune system; viral infection; influenza; COVID-19; micronutrients; vitamins; omega-3 fatty acids; minerals; vitamin C; vitamin D
Online: 12 March 2020 (04:30:45 CET)
Public health practices including handwashing and vaccinations help reduce the spread and impact of infections. Nevertheless, the global burden of infection is high, and additional measures are necessary. Acute respiratory tract infections, for example, are responsible for approximately 2.65 million deaths per year. The role nutrition plays in supporting the immune system is well-established. A wealth of mechanistic and clinical data show that vitamins, including vitamins A, B6, B12, C, D, E, and folate; trace elements, including zinc, iron, selenium, magnesium, and copper; and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid play important and complementary roles in supporting the immune system. Inadequate intake and status of these nutrients are widespread, leading to a decrease in resistance to infections and as a consequence an increase in disease burden. Against this background the following conclusions are made: 1) Supplementation with the above micronutrients and omega-3 fatty acids is a safe, effective, and low-cost strategy to help support optimal immune function; 2) Supplementation above the RDA, but within recommended upper safety limits, for specific nutrients such as vitamins C and D is warranted; and 3) Public health officials are encouraged to include nutritional strategies in their recommendations to improve public health.
Tue, 25 February 2020
ARTICLE | doi:10.20944/preprints202002.0359.v1
Online: 25 February 2020 (05:18:22 CET)
During December 2019, a novel coronavirus named as 2019-nCoV, has emerged in Wuhan, China. The human to human transmission of this virus has also been established. Untill now the virus has infected more than seven thousand people and has spread to fifteen countries. The World Health Organization (WHO) has declared 2019-nCoV as global health emergency due to its outburst well beyond China. There is need to develop some vaccines or therapeutics to control or prevent 2019-nCoV infections. The bottleneck with current conventional approaches is that these require longer time for vaccine development. However, computer assisted approaches help us to produce effective vaccine in short time compared with conventional methods. In this study, bioinformatics analysis was used to predict B cell and T cell epitopes of surface glycoprotein of 2019-nCoV that could be suitable to trigger significant immune response. The sequence of surface glycoprotein was collected from the database and analyzed to identify the immunogenic epitope. Both B cell and T cell epitopes were analyzed so the predicted epitopes can stimulate both cellular and humoral immune responses. We predicted 13 B cell and 05 T cell epitopes that later on were joined with GPGPG linker to make a single peptide. This computational approach to design a multi epitope peptide vaccine against emerging 2019-nCoV allows us to find novel immunogenic epitopes against the antigen targets of surface 2019-nCoV surface glycoprotein. This multi epitope peptide vaccine may prove effective to combat 2019-nCoV infections.
Fri, 14 February 2020
Subject: Life Sciences, Immunology Keywords: NK cell biology; NK cell subsets; NK activating receptors; cell adhesion molecules; granule polarization; cytotoxicity assay; cis interactions; trogocytosis; NK cell degranulation; NK-Based Immunotherapies
Online: 14 February 2020 (03:13:05 CET)
NK population is characterized by distinct NK cell subsets which respond differently to the various activating stimuli. For this reason, the determination of the optimal cytotoxic activation of the different NK subsets can be a crucial aspect to be exploited to counter cancer cells in oncologic patients. To evaluate how the triggering of different combination of activating receptors can affect the cytotoxic responses of different NK cell subsets, we developed a microbead-based degranulation assay. By using this new assay, we were able to detect CD107a+ degranulating NK cells even within the less cytotoxic subsets (i.e. resting CD56bright and unlicensed CD56dim NK cells), thus demonstrating its high sensitivity. Interestingly, signals delivered by the co-engagement of NKp46 with 2B4, but not with CD2 or DNAM-1, strongly cooperate to enhance degranulation on both licensed and unlicensed CD56dim NK cells. Of note, 2B4 is known to bind CD48 hematopoietic antigen, therefore this observation may provide the rationale why CD56dim subset expansion correlates with successful hematopoietic stem cell transplantation mediated by alloreactive NK cells against host T, DC and leukemic cells, while sparing host non-hematopoietic tissues and graft versus host disease. The assay further confirms that activation of LFA-1 on NK cells leads to their granule polarization, even if, in some cases, this also takes to an inhibition of NK degranulation, suggesting that LFA-1 engagement by ICAMs on target cells may differently affect NK cell response. Finally, we observed that NK cells undergo a time-dependent spontaneous (cytokine-independent) activation after blood withdrawal, an aspect that may strongly bias the evaluation of the resting NK cell response. Altogether our data may pave the way to develop new NK activation and expansion strategies that target the highly cytotoxic CD56dim NK cells and can be feasible and useful for cancer and viral infection treatment.
Sat, 8 February 2020
Subject: Life Sciences, Immunology Keywords: 2019-nCoV; coronavirus; peptide vaccine; CD4+ epitope; CD8+ epitope
Online: 8 February 2020 (05:56:31 CET)
In this report, we demonstrate that it is possible to design epitope-based peptide vaccine candidates to counteract the novel China coronavirus (2019-nCoV) by using an approach similar to the one used in cancer neoantigen vaccination therapy. We identified multiepitope peptide vaccine candidates against 2019-nCov that can potentially trigger both CD4+ and CD8+ T cell immune response with increased efficiency due to the presence of CD4+ and CD8+ T cell epitopes and a cathepsin-sensitive linker. Furthermore, we suggest that the peptide design strategy should incorporate population-specific HLA alleles in order to optimize binding specificity of the peptides. We refer to this as populationalized vaccinomics.
Thu, 30 January 2020
ARTICLE | doi:10.20944/preprints202001.0369.v1
Subject: Life Sciences, Immunology Keywords: pistachio; cashew; peanut; hazelnut; almond; chestnut; allergen; pressure processing; thermal processing
Online: 30 January 2020 (12:55:27 CET)
Tree nuts confer many health benefits because of their high content of vitamins and antioxidants and they are increasingly consumed in the last the years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensure safety and to enhance organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond and chestnut was investigated. Processing based on heat and /or pressure and Ultra high pressure (HHP, 300-600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). Differences among tree nut varieties were found regarding to protein content, SDS and immunoblotting profile. High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity
Sat, 18 January 2020
REVIEW | doi:10.20944/preprints202001.0203.v1
Subject: Life Sciences, Immunology Keywords: immunoglobulin (Ig); nonsense-mediated mRNA decay (NMD); nonsense-associated altered splicing (NAS); B lymphocytes; plasma cells
Online: 18 January 2020 (10:21:18 CET)
The presence of premature termination codons (PTCs) in transcripts is dangerous for the cell as they encode potentially deleterious truncated proteins that can act with dominant-negative or gain-of-function effects. To avoid synthesis of these shortened polypeptides, several RNA surveillance systems can be activated to decrease the level of PTC-containing mRNAs. Nonsense-mediated mRNA decay (NMD) ensures an accelerated degradation of mRNAs harboring PTCs by using several key NMD factors such as up-frameshift (UPF) proteins. Another pathway called nonsense-associated altered splicing (NAS) upregulates transcripts that have skipped disturbing PTCs by alternative splicing. Therefore, these RNA quality control processes eliminate abnormal PTC-containing mRNAs from the cells by using positive and negative responses. In this review, we will describe the general mechanisms of NMD and NAS and their respective involvement in the decay of aberrant immunoglobulin and TCR transcripts in lymphoid cells.
Thu, 16 January 2020
ARTICLE | doi:10.20944/preprints202001.0174.v1
Subject: Life Sciences, Immunology Keywords: computational modeling; agent based modeling; systems biology; multiple sclerosis; immunity; degenerative disease.
Online: 16 January 2020 (12:00:22 CET)
As of today, 20 disease modifying drugs (DMD) have been approved for the treatment of relapsing multiple sclerosis (MS) and, based on their efficacy, they can be grouped into moderate-efficacy DMDs and high-efficacy DMDs. The choice of the drug mostly relies on the judgement and experience of neurologists and the evaluation of therapeutic response can only be obtained by monitoring clinical and magnetic resonance imaging (MRI) status during follow up. In an era where therapies are focused on personalization, the aim of this study is to develop a modeling infrastructure to predict the evolution of relapsing MS and the response to treatments. We built a computational modeling infrastructure named UISS (Universal Immune System Simulator) able to simulate the main features and dynamics of the immune system activities. We extended UISS to simulate all the underlying MS pathogenesis and its interaction with the host immune system. This simulator is a multi-scale, multi-organ, agent based simulator with an attached module capable of simulating the dynamics of specific biological pathways at the molecular level. We simulated six MS patients with different relapsing-remitting courses. These patients were characterized on the basis of their age, sex, presence of oligoclonal bands, therapy and MRI lesion load at onset. The simulator framework is made freely available and can be used following the links provided in the availability section. Even though the model can be further personalized employing immunological parameters and genetic information, based on the available data we generated a few simulation scenarios for each patient, including those who matched the real clinical and MRI history. Moreover, for two patients, the simulator anticipated the timing of subsequent relapses, which really occurred, suggesting that UISS may have the potential to assist MS specialists in predicting the course of the disease and the response to treatment.
Wed, 15 January 2020
Online: 15 January 2020 (12:06:20 CET)
Up to forty percent of dairy cows develop metritis or endometritis when pathogenic bacteria infect the uterus after parturition. However, resilient cows remain healthy even when exposed to the same pathogens. Here, we provide a perspective on the mechanisms that dairy cows use to prevent postpartum uterine disease. We suggest that resilient cows prevent the development of uterine disease using the three complimentary defensive strategies of avoiding, tolerating and resisting infection with pathogenic bacteria. Avoidance maintains health by limiting the exposure to pathogens. Avoidance mechanisms include intrinsic behaviors to reduce the risk of infection by avoiding pathogens or infected animals, perhaps signaled by the fetid odor of uterine disease. Tolerance improves health by limiting the tissue damage caused by the pathogens. Tolerance mechanisms include neutralizing bacterial toxins, protecting cells against damage, enhancing tissue repair, and reprogramming metabolism. Resistance improves health by limiting the pathogen burden. Resistance mechanisms include inflammation driven by innate immunity and adaptive immunity, with the aim of killing and eliminating pathogenic bacteria. Farmers can also help cows prevent the development of postpartum uterine disease by avoiding trauma to the genital tract, reducing stress, and feeding animals appropriately during the transition period. Understanding the mechanisms of avoidance, tolerance and resistance to pathogens will inform strategies to generate resilient animals and prevent uterine disease.
Mon, 13 January 2020
ARTICLE | doi:10.20944/preprints201912.0238.v2
Subject: Life Sciences, Immunology Keywords: CCR6-CCL20 Axis; Colitis; Winnie; Multi-system pathophysiology; Molecular signalling; Immune mechanisms
Online: 13 January 2020 (11:07:04 CET)
The immunomodulatory behaviour of the CCR6/CCL20 axis in multi -system pathophysiology and molecular signalling was investigated at two clinically significant time points, using a Ccr6 - deficient mouse model of spontaneous colitis. Four groups of mice, (C57BL/6J, Ccr6-/- of C57BL/6J, Winnie x Ccr6 -/- and Winnie) were utilized and (I) colonic clinical parameters (2) histology of colon, spleen, kidney and liver (3) T and B lymphocyte distribution in the spleen and MLN by flowcytometry (5) colonic CCL20, phosphorylated PI3K and phosphorylated Akt expression by immunohistochemistry and (6) colonic cytokine expression by RT-PCR were evaluated. CCR6 deficiency was shown to attenuate inflammation in the spleen, liver and gut while renal histology remained unaffected. Marked focal lobular inflammation with reactive nuclear features were observed in hepatocytes and a significant neutrophil infiltration in red pulp with extra medullary hemopoiesis in the spleen existed in Winnie. These changes were considerably reduced in Winnie x Ccr6-/- with elevated goblet cell numbers and mucus production in the colonic epithelium. Results indicate that Ccr6- deficiency in the colitis model contributes towards resolution of disease. Our findings demonstrate an intricate networking role for CCR6 in immune activation, which is downregulated by Ccr6 deficiency, and could provide newer clinical therapies in colitis.
Sun, 22 December 2019
ARTICLE | doi:10.20944/preprints201912.0293.v1
Subject: Life Sciences, Immunology Keywords: radiotherapy; glioblastoma; membrane Hsp70; dose and time kinetics; NK cell activity
Online: 22 December 2019 (10:32:50 CET)
The major stress-inducible Hsp70 (HSPA1A) is overexpressed in highly aggressive tumor cells including glioblastoma multiforme and presented on their plasma membrane. Ionizing irradiation increases cytosolic and membrane-bound Hsp70 (mHsp70) on tumor cells. Depending on its intracellular or membrane localization, Hsp70 either promotes tumor growth or serves as a target for the innate immune system. To define the optimal window for a therapy with Hsp70-tageting NK cells the kinetics of the mHsp70 density on the plasma membrane of human glioma cells (U87) has been studied after radiotherapy by multiparameter flow cytometry. Cell cycle dependent alterations in the mHsp70 expression were excluded by seeding different cell numbers on day 0. Low dose irradiation (2 Gy) results in a slow upregulation of the mHsp70 density in U87 cells which peaks on day 4 and starts to decline from day 7 onwards. In contrast, higher radiation doses (4 Gy, 6 Gy) resulted in a faster upregulation of mHsp70 expression on days 2 and 1, respectively, followed by a decline from day 5 onwards. Functionally, elevated mHsp70 densities correlate with an improved lysis by Hsp70-targeting NK cells. In summary, the kinetics of changes in the mHsp70 density upon irradiation on tumor cells is time and dose-dependent.
Wed, 18 December 2019
ARTICLE | doi:10.20944/preprints201912.0238.v1
Subject: Life Sciences, Immunology Keywords: CCR6-CCL20 Axis; colitis; multi-system pathophysiology; molecular signalling; immune mechanisms; Winnie
Online: 18 December 2019 (04:54:36 CET)
The immunomodulatory behaviour of the CCR6/CCL20 axis on multi -system pathophysiology and molecular signalling was investigated at two clinically significant time points, using a Ccr6 - deficient mouse model of spontaneous colitis. Four groups of mice, (C57BL/6J, Ccr6-/- of C57BL/6J, Winnie x Ccr6 -/- and Winnie) were utilized and (I) colonic clinical parameters (2) histology of colon, spleen, kidney and liver (3) T and B lymphocyte distribution in the spleen and MLN by flowcytometry (5) colonic CCL20, PI3K and phosphorylated Akt expression by immunohistochemistry and (6) colonic cytokine expression by RT-PCR were evaluated. CCR6 influenced upregulation of inflammation in the spleen, liver and gut while renal histology remained unaffected. Marked focal lobular inflammation with reactive nuclear features were observed in hepatocytes and a significant neutrophil infiltration in red pulp with extra medullary hemopoiesis in the spleen existed in Winnie. These changes were considerably reduced in Winnie x Ccr6-/- with elevated goblet cell numbers and mucus production in the colonic epithelium. Results indicate that Ccr6- deficiency in the colitis model contributes towards resolution of disease. Our findings demonstrate an intricate networking role for CCR6 in immune activation, which is downregulated by Ccr6 deficiency, and could provide newer clinical therapies in colitis.
Sun, 15 December 2019
ARTICLE | doi:10.20944/preprints201912.0186.v1
Subject: Life Sciences, Immunology Keywords: transcription factors; cytokines; autoimmunity; dendritic cells
Online: 15 December 2019 (13:16:35 CET)
Tolerogenic dendritic cells are crucial to control development of autoreactive T cell responses and prevention of autoimmunity. We have reported that NOD.CD11cStat5b-CA transgenic mice expressing a constitutively active form of Stat5b under the control of CD11c promoter are protected from diabetes and that Stat5b-CA-expressing DCs are tolerogenic and halt ongoing diabetes in NOD mice. However, the molecular mechanisms by which Stat5b-CA modulates DC tolerogenic function is not fully understood. Here, we used bone marrow-derived DCs from NOD.CD11cStat5b-CA transgenic mice (Stat5b-CA.BMDC) and found that Stat5b-CA.BMDC displayed high levels of MHC class II, CD80, CD86, PD-L1 and PD-L2 and produced elevated amounts of TGFβ but low amounts of TNF and IL-23. Stat5b-CA.BMDCs upregulated Irf4 and downregulated Irf8 genes and protein expression and promoted CD11c+CD11b+ DC2 subset differentiation. Interestingly, we found that the histone methyltransferase Ezh2 interacted with Stat5b-CA complex that bound GAS sequences in the Irf8 enhancer whereas Ezh2 did not interact with GAS sequences in the case of the Irf4 promoter. Injection of Stat5b-CA.BMDCs to prediabetic NOD mice halted progression of islet inflammation and protected against diabetes. Importantly, inhibition of Ezh2 in tolerogenic Stat5b-CA.BMDCs reduced their ability to prevent diabetes development in NOD recipient mice. Taken together, our data suggest that the active form of Stat5b induces tolerogenic DC function by modulating IRF4 and IRF8 expression through recruitment of Ezh2 and highlight the fundamental role of Ezh2 in Stat5b-mediated induction of tolerogenic DCs function.
Tue, 29 October 2019
ARTICLE | doi:10.20944/preprints201910.0330.v1
Online: 29 October 2019 (10:23:19 CET)
Accumulating evidence suggests that mast cells should play critical roles in disruption and maintenance of intestinal homeostasis, although it remains unknown how they affect local microenvironment. Interleukin-9 (IL-9) was found to play critical roles in intestinal mast cell accumulation induced in various pathological conditions, such as parasite infection and oral allergen-induced anaphylaxis. Newly recruited intestinal mast cells trigger inflammatory responses and damage epithelial integrity through release of a wide variety of mediators including mast cell proteases. We established a novel culture model (mucosal mast cell-like cultured mast cells, MMC-like MCs), in which murine IL-3-dependent bone marrow-derived cultured mast cells (BMMCs) were further cultured in the presence of stem cell factor and IL-9. In MMC-like MCs, drastic up-regulation of Mcpt1 and Mcpt2 was found. Although histamine storage and tryptase activity were significantly downregulated in the presence of SCF and IL-9, it was entirely reversed when mast cells were co-cultured with a murine fibroblastic cell line, Swiss 3T3. MMC-like MCs underwent degranulation upon IgE-mediated antigen stimulation, which was found to less sensitive to lower concentrations of IgE in comparison with BMMCs. This model might be useful for investigation of the spatiotemporal changes of newly recruited intestinal mast cells.
Thu, 3 October 2019
REVIEW | doi:10.20944/preprints201907.0134.v2
Subject: Life Sciences, Immunology Keywords: lymphocytic choriomeningitis virus (LCMV); viral infection; autoimmunity; molecular mimicry; bystander activation; immune tolerance
Online: 3 October 2019 (13:51:08 CEST)
Viral infections are a natural part of our existence. They can affect us in many ways that are the result of the interaction between the viral pathogen and our immune system. Most times the resulting immune response is beneficial for the host. The pathogen gets cleared thus protecting our vital organs with no other consequences. Conversely, the reaction of our immune system against the pathogen can cause organ damage (immunopathology) or lead to autoimmune disease. To date, there are several mechanisms for virus-induced autoimmune disease, including molecular mimicry and bystander activation, in support of the “fertile field” hypothesis, terms defined in our review. On the flip side, viral infections have been associated with protection from autoimmunity through mechanisms that include Treg invigoration and immune deviation, in support of the “hygiene hypothesis”, also defined here. Infection with lymphocytic choriomeningitis virus (LCMV) is one of the prototypes showing that the interaction of our immune system with viruses can either accelerate or prevent autoimmunity. Studies using mouse models of LCMV have helped conceive and establish several concepts that we today know and explain how viruses can lead to autoimmune activation or induce tolerance. Some of the most important mechanisms established during the course LCMV are described in this short review.
Fri, 27 September 2019
REVIEW | doi:10.20944/preprints201909.0306.v1
Subject: Life Sciences, Immunology Keywords: influenza virus; humoral response; hemagglutinin (HA) of influenza virus; broad neutralizing antibody(bnAb); heterosubtypic immunity of influenza; original antigenic sin "OAS"; "universal" influenza vaccine; protein microarray assay; mPLEX-Flu assay; multiple dimensional assays (MDA))
Online: 27 September 2019 (08:34:56 CEST)
The human antibody response to influenza virus infection or vaccination is as complicated as it is essential for protection against flu. The constant antigenic changes of the virus to escape human herd immunity hinder the yearly selection of vaccine strains since it is hard to predict which virus strains will circulate for the coming flu season. A "universal" influenza vaccine that could induce broad cross-influenza subtype protection would help to alleviate this burden. However, the human antibody response is intricate and often obscure, with factors like antigenic seniority or original antigenic sin "OAS", and back-boosting ensuring that each person mounts a unique immune response to infection or vaccination with any new influenza virus strain. Notably, the effects of existing antibodies on cross-protective immunity after repeated vaccinations are unclear. More research is needed to characterize the mechanisms at play, but traditional assays such as hemagglutinin inhibition (HAI) and microneutralization (MN) are excessively limited in scope and too resource-intensive to effectively meet this challenge. In the past ten years, new multiple dimensional assays (MDAs) have been developed to help overcome these problems by simultaneously measuring antibodies against a large panel of influenza hemagglutinin (HA) proteins with a minimal amount of sample in a high throughput way. MDAs will likely be a powerful tool for accelerating the study of the humoral immune response to influenza vaccination and the development of a universal influenza vaccine.
Sat, 14 September 2019
REVIEW | doi:10.20944/preprints201909.0144.v1
Subject: Life Sciences, Immunology Keywords: immunoglobulin; IVIG; LcrV; PcrV; translocation; type III secretory toxin; type III secretion system; V-antigen
Online: 14 September 2019 (19:18:28 CEST)
The mechanisms underlying the effects of γ-globulin therapy for bacterial infections are thought to involve bacterial cell lysis via complement activation, phagocytosis via bacterial opsonization, toxin neutralization, and antibody-dependent cell-mediated cytotoxicity. Nevertheless, recent advances in the study of pathogenicity in gram-negative bacteria have raised the possibility of an association between γ-globulin and bacterial toxin secretion. Over time, new toxin secretion systems like the type III secretion system have been discovered in many pathogenic gram-negative bacteria. With this system, the bacterial toxins are directly injected into the cytoplasm of the target cell through a special secretory apparatus without any exposure to the extracellular environment and, therefore, with no opportunity for antibodies to neutralize the toxin. However, because antibodies against the V-antigen, which is located on the needle-shaped tip of the bacterial secretion apparatus, can inhibit toxin translocation, this raises the hope that the toxin might be susceptible to antibody targeting. Because multi-drug resistant bacteria are now prevalent, inhibiting this secretion mechanism is attractive as an alternative or adjunctive therapy against lethal bacterial infections. Thus, it would not be unreasonable to define the blocking effect of anti-V-antigen antibodies as the fifth mechanism for immunoglobulin action against bacterial infections.
Fri, 23 August 2019
REVIEW | doi:10.20944/preprints201908.0242.v1
Subject: Life Sciences, Immunology Keywords: rheumatology, immunology, precision medicine, biologic drugs
Online: 23 August 2019 (09:54:02 CEST)
Tumour necrosis factor-α is a key mediator of inflammation in rheumatoid arthritis its discovery led to the development of highly successful anti-TNF therapy. Subsequently, other biologic drugs targeting immune pathways, namely interleukin-6 blockade, B cell depletion, and T cell co-stimulation blockade, have been developed. Not all patients respond to a biologic drug leading to a knowledge gap between biologic therapies available and the confident prediction of response. So far, genetic studies have failed to uncover clinically informative biomarkers to predict response. Given that the targets of biologics are immune pathways, immunological study has become all the more pertinent. Furthermore, advances in single cell technology have enabled the characterisation of many leucocyte subsets. Studying the blood immunophenotype may therefore define biomarker profiles relevant to each individual patient’s disease and treatment outcome. This review summarises our current understanding of how immune biomarkers might be able to predict treatment response to biologic drugs.
Sat, 17 August 2019
REVIEW | doi:10.20944/preprints201908.0186.v1
Subject: Life Sciences, Immunology Keywords: heat shock protein (HSP); extracellular vesicle (EV); exosome; oncosome; immune evasion; resistance-associated secretory phenotype (RASP); EMT; hypoxia; biomarker; liquid biopsy
Online: 17 August 2019 (16:15:01 CEST)
Extracellular vesicles (EV) released by tumor cells are a major aspect of the resistance-associated secretory phenotype (RASP), by which immune evasion can be established. Heat shock proteins (HSPs) are an evolutionarily conserved family of molecular chaperones, which stabilize proteins, minimize protein misfolding and aggregation within the cell, besides facilitating protein translocation, refolding and degradation. (i) Releases of extracellular HSPs (ex-HSP) and EV-associated HSPs (EV-HSP) are essential in RASP, by which molecular cotransfer of HSPs with oncogenic factors into recipient cells can promote cancer progression and resistance against stress such as hypoxia, radiation, chemicals, and immune system. (ii) RASP of tumor cells can eject anticancer drugs, molecularly targeted therapeutics, and immune checkpoint inhibitors with EVs. (iii) Cytotoxic lipids can be also released from tumor cells as RASP. Nevertheless, ex-HSP and EV-HSP can play immunostimulatory and immunosuppressive roles by binding to receptors such as LRP1/CD91/A2MR, scavenger receptors, and toll-like receptors expressed on recipient cells. Liquid biopsy of HSPs in body fluids may be useful in diagnosis, prognosis, and treatment in cancer. Regarding HSP90-targeted therapeutics, we summarize the pros, cons, and problem solutions in this review. Although production of HSPs are canonically induced by heat shock factor 1 (HSF1) and hypoxia-inducible factor 1 (HIF-1), recent studies discovered that production of HSPs is also regulated by matrix metalloproteinase 3 (MMP3) and heterochromatin protein 1 (HP1) and production of cochaperone CDC37 is reciprocally regulated by myeloid zinc finger 1 (MZF1) and SCAN-D1.
Mon, 12 August 2019
REVIEW | doi:10.20944/preprints201908.0140.v1
Online: 12 August 2019 (11:48:20 CEST)
Up to forty percent of dairy cows can develop metritis or endometritis when bacteria infect the uterus after parturition. However, it is unclear why other cows exposed to similar pathogens do not develop uterine disease. We suggest that resilient dairy cows prevent the development of uterine disease using the three complimentary defensive strategies of avoiding, tolerating and resisting infection with pathogenic bacteria. Avoidance maintains health by limiting the exposure to pathogens. Avoidance includes intrinsic behaviors to prevent exposure to pathogens or infected animals, perhaps signaled by the fetid odor of uterine disease. Tolerance improves health by limiting the tissue damage caused by the pathogen burden. Tolerance depends on controlling the tissue damage that pathogens cause in the endometrium by neutralizing bacterial toxins, enhancing tissue repair, and inducing adaptive metabolic responses. Resistance improves health by limiting the pathogen burden. Resistance relies on the immune system generating an inflammatory response in the endometrium to eliminate pathogenic bacteria. People who manage dairy cows can also help prevent uterine disease by using extended lactations, avoiding trauma to the genital tract, maintaining hygiene, and supplying appropriate nutrition during the transition period and after parturition to counter the metabolic stress of lactation. Developing new ways to prevent uterine disease depends on increasing our understanding of the mechanisms of avoidance, tolerance and resistance to pathogens in the postpartum uterus.
Mon, 5 August 2019
ARTICLE | doi:10.20944/preprints201908.0062.v1
Subject: Life Sciences, Immunology Keywords: dendritic cell; cancer vaccine; vaccination; acquired immunity; granulocyte colony-stimulating factor; tetramer analysis
Online: 5 August 2019 (12:35:50 CEST)
Significant recent advances in cancer immunotherapeutics include the vaccination of cancer patients with tumor antigen-associated peptide-pulsed dendritic cells (DCs). DC vaccines with homogeneous, mature, and functional activities are required to achieve effective acquired immunity; however, the yield of autologous monocyte-derived DCs varies in each patient. Priming with a low dose of recombinant human granulocyte colony-stimulating factor (rhG-CSF) 16–18 h prior to apheresis resulted in 50% more harvested monocytes, with a significant increase in the ratio of CD11c+CD80+ DCs/apheresed monocytes. The detection of antigen-specific cytotoxic T lymphocytes after Wilms’ tumor 1-pulsed DC vaccination was higher in patients treated with rhG-CSF than those who were not, based on immune monitoring using tetramer analysis. Our study is the first to report that DC vaccines for cancer immunotherapy primed with low-dose rhG-CSF are expected to achieve higher acquired immunogenicity.
Tue, 9 July 2019
REVIEW | doi:10.20944/preprints201907.0134.v1
Subject: Life Sciences, Immunology Keywords: lymphocytic choriomeningitis virus (LCMV); viral infection; autoimmunity; molecular mimicry; bystander activation; immune tolerance
Online: 9 July 2019 (14:29:24 CEST)
Viral infections make a natural part of our existence. They can affect us in hundreds of different ways that are the result of the interaction between the viral pathogen and our immune system. Most times the resulting immune response is beneficial for the host. The pathogen gets cleared protecting our vital organs with no other consequences. Sometimes, things go wrong and the reaction of our immune system against the pathogen causes organ damage (immunopathology) or leads to autoimmune disease. To date, there are several mechanisms for virus-induced autoimmune disease, including molecular mimicry and bystander activation, in support of the “fertile field” hypothesis. On the flip side, viral infections have been associated with protection from autoimmunity through mechanisms that include Treg invigoration and immune deviation, in support of the “hygiene hypothesis”. Infection with lymphocytic choriomeningitis virus (LCMV) is one of the prototype viral systems showing that the interaction of our immune system with the viruses can either accelerate or prevent autoimmunity. Studies using LCMV have helped conceive and establish several concepts that we today know and explain how viruses can lead to autoimmune activation or induce tolerance. Some of the most important mechanisms established in LCMV are described in this short review.
Tue, 4 June 2019
ARTICLE | doi:10.20944/preprints201906.0028.v1
Subject: Life Sciences, Immunology Keywords: autoimmunity; toll-like receptors; TLR; nucleotide-binding oligomerization domain; NOD1; major histocompatibility complex; MHC; human leukocyte antigens; HLA; proteasome; innate immunity; adaptive immunity; T cells; B cells; antibodies; microbiome; tolerance; self; non-self; antigen processing
Online: 4 June 2019 (10:21:32 CEST)
Current theories of autoimmunity are diverse, sometimes contradictory, and suffer from incompleteness. Although substantial evidence exists that adaptive and innate immunity, sex, genetic predisposition, and the microbiome all play essential roles in autoimmune disease etiologies and pathogenesis, and that antigen processing is altered during disease induction, no existing theory integrates all of these factors through a single, coherent mechanism. In an attempt to focus the field on the need to elucidate such an integrative mechanism, I propose one possibility here that, if nothing else, helps to identify the nature of the problems that need to be addressed. My theory is that autoimmune diseases are induced by normal immunological responses to unique pairs of complementary antigens, at least one of which is a molecular mimic of a host target. Each antigen in the complementary pair induces a complementary immune response (T or B cell); although each immune response is idiotypic in origin, the antigenic complementarity results in what appears to be an idiotype-anti-idiotype relationship between the responses. Additionally, because of the antigenic complementarity, each immune response mimics one of antigens, abrogating the distinction between self and non-self. If at least one of the antigens mimics a host antigen, then the resulting immunological civil war spreads to a host tissue. Complementary antigens also alter antigen processing so that antigens that would normally be proteolytically digested are presented by the major histocompatibility complex (MHC) to T and B cell receptors inducing a cross-reactive immune response. The resulting civil war is supported by the innate immune system due to the complementarity of the initiating antigens.. Complementary antigens stimulate synergistic toll-like receptors (TLR) and/or nucleotide-binding oligomerization receptors (NOD) resulting in up-regulation of cytokine production and further stimulation of the adaptive immune response. Because the immune responses (e.g., antibodies) mimic the initiating antigens, this synergistic activation of innate immunity becomes chronic. Additionally, TLR and NOD function are highly sensitive to sex hormones, some becoming up-regulated and some down-regulated in the presence of either testosterone or estrogens. This sensitivity explains how sex modifies susceptibility to autoimmune diseases. Genetic mutations in TLR, NOD and MHC further alter antigen presentation and the degree to which antigens stimulate an immune response explaining how genetics also modifies susceptibility. Finally, sex hormones also alter the host microbiome, which in turn modulates autoimmune disease risk by shaping the immunological nature of self and by mediating susceptibility to microbial infection. Moreover, it appears that the microbiome camouflages itself from the immune system by mimicking the host antigenic repertoire; the mimicry between the antigens of the microbiome and the host results in selective attacks on microbiome constituents concomitant with any autoimmune attack on host tissues. This antigenic complementarity theory thereby integrates all major elements known to affect, or be affected by, autoimmune diseases and provides a set of testable implications.
Fri, 31 May 2019
REVIEW | doi:10.20944/preprints201905.0386.v1
Subject: Life Sciences, Immunology Keywords: CRISPR, clonal selection, totipotent, multipotent, T cell receptors, B cell receptors, precommitted, lymphocyte, T cell vaccine, T cell vaccination
Online: 31 May 2019 (11:12:33 CEST)
Transfer factor is the name given to material derived from activated lymphocytes that is probably composed of a complex of a peptide and a short segment of RNA and which has the reported ability to transfer specific T cell immunity to uncommitted lymphocytes. Many independent groups around the world reported isolating transfer factors between 1955 and 1990 and demonstrating their ability to transfer passive immunity from one animal or individual to another, often within 24 hours of inoculation. Such activity is potentially revolutionary both in making T cell vaccines readily manufacturable and also because the existence of transfer factors would undermine the basic assumptions of the clonal selection theory, which currently dominates immunological theory. Unfortunately, lack of the microanalytical and synthetic techniques required to properly identify transfer factors, combined with safety factors associated with it derivation from blood sources susceptible to HIV and prion infections, put an end to transfer factor research after 1990. This paper reviews the evidence supporting transfer factor activity and suggests that this potentially revolutionary concept be resurrected and subjected to renewed scrutiny in light of CRISPR-Cas mechanisms and because of its potential to make possible T cell vaccination and provide a novel basis for understanding immunological function.
Mon, 27 May 2019
REVIEW | doi:10.20944/preprints201905.0310.v1
Subject: Life Sciences, Immunology Keywords: DNA vaccine; HIV-1; enhancer element; circovirus; dose sparing; immunogenicity
Online: 27 May 2019 (10:25:38 CEST)
DNA vaccines are stable, safe, cost effective to produce and relatively quick and easy to manufacture. However, to date DNA vaccines have shown relatively poor immunogenicity in humans despite promising preclinical results. Consequently, a number of different approaches have been investigated to improve the immunogenicity of DNA vaccines. These include the use of improved delivery methods, adjuvants, stronger promoters and enhancer elements to increase antigen expression, and codon optimization of the gene of interest. This review describes the creation and use of a DNA vaccine vector containing a porcine circovirus (PCV-1) enhancer element that significantly increases recombinant antigen expression and immunogenicity and allows for dose sparing. A 172bp region containing the PCV-1 capsid protein promoter (Pcap) and a smaller element (PC; 70 bp) within this were found to be equally effective. DNA vaccines containing the Pcap region expressing various HIV-1 antigens were found to be highly immunogenic in mice, rabbits and macaques, at 4 to 10-fold lower doses than normally used and to be highly effective in heterologous prime-boost regimens. By lowering the amount of DNA used for immunization, safety concerns over injecting large amounts of DNA into humans can be overcome.
Fri, 24 May 2019
ARTICLE | doi:10.20944/preprints201905.0290.v1
Subject: Life Sciences, Immunology Keywords: β-D-glucan; glucan binding protein; host defense; innate immunity
Online: 24 May 2019 (08:56:43 CEST)
The recognition of (1→3)-β-D-glucans (BGs) by β-1,3-D-glucan recognition protein (BGRP) found in invertebrates plays a significant role in the activation of toll pathway and pro-phenol oxidase system in insect host defense against fungal invasion. To examine the structural diversity of BGs in BGRP interaction, the binding specificity of BGRPs cloned from four different insectswas characterized using ELISA. Recombinant BGRPs expressed as Fc-fusion proteins of human IgG1 bound to solid phase BGs. Because of the binding specificities, the BGRPs were categorized into two different ultrastructure- binding characters. The BGRPs from Silkworm and Indian meal moth bound to BGs containing triple-helical structure. Other BGRPs from red flour beetle and yellow mealworm beetle showed no binding to triple-helical BGs, but to alkaline-treated BGs, which have partially opened helical conformation. These evidences suggest that the innate immune system distinguishes different BG conformations and it is equipped for the diversity of BG structures.
Fri, 12 April 2019
ARTICLE | doi:10.20944/preprints201904.0148.v1
Subject: Life Sciences, Immunology Keywords: chronic hepatitis C; chronic hepatitis B; innate immune response; adaptive immune response; cytokine; chemokine
Online: 12 April 2019 (10:59:21 CEST)
Background: Cytokines and chemokines are critical regulators of innate and adaptive immunities during viral infection. We examined innate and adaptive immune responses to hepatitis C virus (HCV) and hepatitis B virus (HBV) at baseline and against controls. Methods: Twenty-seven cytokines were evaluated before treatment in 27 patients with chronic hepatitis C(CHC) [genotype1 (n=20), genotype2 (n=7), HCVRNA 5.72IU/ml] and 12 chronic hepatitis B(CHB) [e-antigen (Ag) (+) (n=5), e-Ag (-) (n=7), HBVDNA 6.191.31Logcopies/ml] and against controls(n=5). Results: Th1 and Th2 cytokines were significantly higher (p<0.05) in CHB than in CHC. The levels of IL-IL10 in CHC and CHB, and IL15 in CHC(genotype2) and CHB were significantly lower (p<0.05) than in controls. The levels of CXCL8 in CHC and CHB, IL12 in CHC and CHB [e-Ag (-)] and CXCL10 in CHC and CHB were significantly higher (p<0.05) than in controls. IFN-γwas higher in CHB than in controls. Conclusion: Cytokines levels differed between CHB and CHC before treatment. Innate immune responses were impaired in CHB with HBeAg(-) and CHC, but not in CHB with HBeAg(+) with high viral loads. Adaptive immune responses were impaired in CHB and CHC and appear to reflect the distinct state of virus-host immune interactions between CHB and CHC.
Wed, 10 April 2019
ARTICLE | doi:10.20944/preprints201904.0118.v1
Subject: Life Sciences, Immunology 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.
Mon, 1 April 2019
REVIEW | doi:10.20944/preprints201904.0007.v1
Subject: Life Sciences, Immunology Keywords: dendritic cells; Th2 immunity; genetic factors; environmental factors; Th2 disorders; therapeutic approaches
Online: 1 April 2019 (10:14:44 CEST)
Dendritic cells (DCs) are the professional antigen-presenting cells that recognize and present antigens to naïve T cells to induce antigen-specific adaptive immunity. Among the T-cell subsets, T helper type 2 (Th2) cells produce the humoral immune responses required for protection against helminthic disease by activating B cells. DCs induce a Th2 immune response at a certain immune environment. Basophil, eosinophil, mast cells, and type 2 innate lymphoid cells also induce Th2 immunity. However, in the case of DCs, controversy remains regarding which subsets of DCs induce Th2 immunity, which genes in DCs are directly or indirectly involved in inducing Th2 immunity, and the detailed mechanisms underlying induction, regulation, or maintenance of the DC-mediated Th2 immunity against allergic environments and parasite infection. A recent study has shown that a genetic defect in DCs causes an enhanced Th2 immunity leading to a severe atopic dermatitis. We summarize the Th2 immune-inducing DC subsets, the genetic and environmental factors which involved in DC-mediated Th2 immunity, and current therapeutic approaches for Th2-mediated immune disorders. This review is to provide an improved understanding of DC-mediated Th2 immunity and Th1/Th2 immune balancing, leading to control over their adverse consequences.
Wed, 13 February 2019
ARTICLE | doi:10.20944/preprints201902.0117.v1
Online: 13 February 2019 (15:16:44 CET)
Tumor necrosis factor-α (TNFα), one of the major pro-inflammatory cytokines, plays a key role in an effective immune response. However, the chronic presence of TNFα can lead to several inflammatory disorders like rheumatoid arthritis, psoriasis, Crohn’s disease etc. Inhibition of TNFα by pharmacological inhibitors or antibodies has proven to be effective in palliative treatment to some extent. The aim of this study was to develop an anti-TNFα antibody which may be used as a therapeutic option to inhibit TNFα-mediated cytotoxicity. We characterized several hybridoma clones secreting monoclonal antibodies (mAbs) to human-TNFα. Four mAbs rescued L929 fibroblast cells from TNFα-triggered cell death and one of these, namely C8 was found to have the highest affinity. To gain insights into the mechanism by which mAb C8 inhibits human TNFα-mediated toxicity, the epitope corresponding to the mAb was delineated. The antigenic determinant was found to comprise of the stretch of amino acids 99-120, of which, 102-104 (QRE) form the core epitope. The observation was supported by bioinformatics analyses of an antigen-antibody complex model. In addition, the binding affinity of mAb C8 to TNFα was found to be comparable with that of Infliximab which is a commercially available anti TNFα mAb.
Tue, 8 January 2019
ARTICLE | doi:10.20944/preprints201901.0065.v1
Subject: Life Sciences, Immunology Keywords: acute HIV infection; vaccines; CD8$^+$ T cells; immune response; multiple epitopes; competition; mathematical model
Online: 8 January 2019 (11:22:41 CET)
Multiple lines of evidence indicate that CD8$^+$ T cells are important in the control of HIV-1 (HIV) replication. However, CD8$^+$ T cells induced by natural infection cannot eliminate the virus or reduce viral loads to acceptably low levels in most infected individuals. Understanding the basic quantitative features of CD8$^+$ T-cell responses induced during the course of HIV infection may therefore inform us about the limits that HIV vaccines, which aim to induce protective CD8$^+$ T-cell responses, must exceed. Using previously published experimental data from a cohort of HIV-infected individuals with sampling times from acute to chronic infection we defined the quantitative properties of CD8$^+$ T-cell responses to the whole HIV proteome. In contrast with a commonly held view, we found that the relative number of HIV-specific CD8$^+$ T-cell responses (response breadth) changed little over the course of infection (first 400 days post-infection), with moderate but statistically significant changes occurring only during the first 35 symptomatic days. This challenges the idea that a change in the T-cell response breadth over time is responsible for the slow speed of viral escape from CD8$^+$ T cells in the chronic infection. The breadth of HIV-specific CD8$^+$ T-cell responses was not correlated with the average viral load for our small cohort of patients. Metrics of relative immunodominance of HIV-specific CD8$^+$ T-cell responses such as Shannon entropy or the Evenness index were also not significantly correlated with the average viral load. Our mathematical-model-driven analysis suggested extremely slow expansion kinetics for the majority of HIV-specific CD8$^+$ T-cell responses and the presence of intra- and interclonal competition between multiple CD8$^+$ T-cell responses; such competition may limit the magnitude of CD8$^+$ T-cell responses, specific to different epitopes, and the overall number of T-cell responses induced by vaccination. Further understanding of mechanisms underlying interactions between the virus and virus-specific CD8$^+$ T-cell response will be instrumental in determining which T-cell-based vaccines will induce T-cell responses providing durable protection against HIV infection.
Thu, 3 January 2019
ARTICLE | doi:10.20944/preprints201901.0003.v1
Subject: Life Sciences, Immunology Keywords: mast cell; dexamethasone; trimeric G protein; Mrgpr; skin; inflammation
Online: 3 January 2019 (08:55:29 CET)
Steroidal anti-inflammatory drugs are widely used for treatment of chronic cutaneous inflammation, such as atopic dermatitis, although it remains unknown how they modulate cutaneous mast cell functions. Murine connective tissue-type mast cells, which were sensitive to mast cell secretagogues, such as compound 48/80 and substance P, were generated by co-culture of bone marrow-derived mast cells with Swiss 3T3 fibroblasts in the presence of stem cell factor. This process was accompanied by up-regulation of a subunit of a trimeric G protein, Gi1, and several Mas-related G protein-coupled receptor (Mrgpr) subtypes. Secretagogue-induced degranulation and up-regulation of these genes were suppressed when they were cultured in the presence of a synthetic glucocorticoid, dexamethasone. The profiles of granule constituents were drastically altered by dexamethasone. Several Mrgpr subtypes were found to be expressed in the cutaneous tissues and their expression levels were decreased in response to topical application of dexamethasone. The numbers of degranulated cutaneous mast cells in response to compound 48/80 were decreased in mice treated with dexamethasone. These results suggest that mast cell-mediated IgE-independent cutaneous inflammation could be suppressed by steroidal anti-inflammatory drugs through down-regulation of Gai1 and several Mrgpr subtypes in mast cells.
Fri, 28 December 2018
ARTICLE | doi:10.20944/preprints201812.0336.v1
Subject: Life Sciences, Immunology Keywords: complement factor H (CFH); molecular docking; molecular dynamics (MD) simulation; computational alanine scanning (CAS); experimental alanine scanning (EAS)
Online: 28 December 2018 (06:55:53 CET)
The details of antigen-antibody interactions and the identification of epitopes are critical for the development of monoclonal antibody drugs. Ab42 is a native human-derived anti-CFH monoclonal antibody. In this study, the interaction between antigen pCFH and antibody (Ab42) was theoretically demonstrated by molecular docking and MD simulation, combined with free energy calculation and computational alanine scanning (CAS), and key amino acids and epitopes were identified. Experimental alanine scanning (EAS) was then carried out to verify the results of the calculation, and our results indicated that Ab42 antibody forms hydrogen bonds and interacts hydrophobically with pCFH through the Tyr315, Ser100, Gly33, and Tyr53 residues on its CDR, while the main pCFH epitopes are located at the six sites of Pro441, Ile442, Asp443, Asn444, Ile447, and Thr448. In conclusion, this study has explored the mechanism of antigen-antibody interaction from both theoretical and experimental aspects, and our results have important theoretical significance for the design and development of relevant antibody drugs.
Sun, 2 December 2018
ARTICLE | doi:10.20944/preprints201812.0003.v1
Subject: Life Sciences, Immunology Keywords: NK cell clones; IL-2; K562-mbIL21; membrane-bound IL-21
Online: 2 December 2018 (10:33:00 CET)
A pattern of NK cell heterogeneity in each individual determines proliferative and functional responses of NK cells to activating stimuli. Obtaining the progeny of a single cell by cloning original population is one of the ways to study the NK cell heterogeneity. In this work, we used single cell sorting into a plate and stimulation by IL-2 and gene-modified K562 feeder cells expressing membrane-bound IL-21 (K562-mbIL21) that led to generation of phenotypically confirmed and functionally active NK cell clones. We applied two models of clone cultivation, which differently affected their phenotype, lifespan and functional activity. The first model, which included weekly restimulation of clones with K562-mbIL21 and IL-2, resulted in the generation of relatively short-lived (5-7 weeks) clones of highly activated NK cells. HLA-DR expression in the expanded NK cells correlated strongly with IFN-γ production. The second model, in which NK cells were restimulated mainly with IL-2 alone, produced long-lived clones (8-14 weeks) that expanded up to 107 cells with lower ability to produce IFN-γ. Our method is applicable for studying variability in phenotype, proliferative and functional activity of the certain NK cell progeny in response to the stimulation, which may help in selecting NK cells best suited for clinical use.
Tue, 20 November 2018
ARTICLE | doi:10.20944/preprints201811.0483.v1
Subject: Life Sciences, Immunology Keywords: IFN-γ; histamine; splenocyte; histamine H1 receptor, histidine decarboxylase
Online: 20 November 2018 (05:35:39 CET)
Accumulating evidence suggests that histamine synthesis induced in several types of tumor tissues should modulate tumor immunity. We found that a transient histamine synthesis was induced in CD11b+Gr-1+splenocytes derived from BALB/c mice transplanted with a syngeneic colon carcinoma, CT-26, when they were co-cultured with CT-26 cells. Significant levels of IFN-γ were produced under this co-culture condition. We explored the modulatory roles of histamine on IFN-γ production and found that several histamine receptor antagonists, such as pyrilamine, diphenhydramine, JNJ7777120, and thioperamide, could significantly suppress IFN-γ production. However, suppression of IFN-γ production by these antagonists was also found when splenocytes were derived from the Hdc-/- BALB/c mice. Suppressive effects of these antagonists were found on IFN-γ production induced by concanavalin A or the combination of an anti-CD3 antibody and an anti-CD28 antibody in a histamine-independent manner. Murine splenocytes were found to express H1 and H2 receptors, but not H3 and H4 receptors. IFN-γ production in the Hh1r-/- splenocytes induced by the combination of an anti-CD3 antibody and an anti-CD28 antibody was significantly suppressed by these antagonists. These findings suggest that pyrilamine, diphenhydramine, JNJ7777120, and thioperamide could suppress IFN-γ production in activated splenocytes in histamine-independent manner.
Thu, 15 November 2018
REVIEW | doi:10.20944/preprints201811.0350.v1
Subject: Life Sciences, Immunology Keywords: mannose-binding lectin; poultry; production system; pathogens; innate immune response
Online: 15 November 2018 (08:37:05 CET)
Bacterial pathogens have been attributed to poultry housing structure, financial strength, and incessant use of antibiotics, variable seasons and management systems practiced. Variant forms of bacterial pathogens can be detected by recognizing the molecular pattern of the pathogens through an innate immune mechanism such as mannose-binding lectin. Mannose-binding lectin (MBL) possesses an innate pattern recognition molecule that easily sequestered to region of infections and inflammations. This works by attaching itself to antigen surface thus hinders proliferation and disease activity in the host organism. Baker’s method, nephelometric assays technique, Enzyme-Linked Immunosurbent Assay technique, Polymerase Chain Reaction, Deoxyribonucleic Acid typing and other biotechnology related methods are techniques used in detecting and quantifying MBL. Mannose-binding lectin levels in serum can be influenced by age, management systems, feed formulation strategies and seasons. Therefore, knowledge of MBL should be encouraged in all aspect of poultry production, in order to discourage incessant use of drugs at a slight exposure to prevailing bacterial which can help in maximizing cost.
Wed, 7 November 2018
REVIEW | doi:10.20944/preprints201811.0165.v1
Subject: Life Sciences, Immunology Keywords: gluten immunogenic peptides; celiac disease; gluten quantitation; gluten food analysis
Online: 7 November 2018 (14:28:08 CET)
Gluten is a complex mixture of storage proteins in cereals like wheat, barley and rye. Prolamins are the main components of gluten. Their high content in proline and glutamine makes them water-insoluble and difficult to digest in the gastrointestinal tract. Partial digestion generates peptide sequences which trigger immune responses in celiac and gluten-sensitive patients. Gluten detection in food is challenging because of the diversity, in various food matrices, of protein proportions and their immunogenicity. Attempts to develop standard reference materials have been unsuccessful. We present here a summary of recent studies reporting the detection of dominant Gluten Immunogenic Peptides (GIP) sharing epitopes presented in the α-gliadin 33-mer, the most important celiac disease-immunogenic sequence within gluten. GIP were not only detectable and quantifiable in very different kind of difficult to analyze food, but also in stool and urine of celiac patients on a supposedly gluten-free diet (GFD), providing the first simple and objective means to assess adherence to the GFD. Methods to specifically and sensitively detect the most active GIP in food and biological fluids are rational candidates may use similar analytical standard references for determination of the immunopathological risk of gluten exposure in gluten-related diseases.
Tue, 30 October 2018
REVIEW | doi:10.20944/preprints201810.0707.v1
Online: 30 October 2018 (06:45:05 CET)
The immune system plays a major role in the surveillance and control of malignant cells, with the presence of tumor infiltrating lymphocytes (TILs) correlating with better patient prognosis in multiple tumor types. The development of ‘checkpoint blockade’ and adoptive cellular therapy has revolutionized the landscape of cancer treatment and highlights the potential of utilizing the patient’s own immune system to eradicate cancer. One mechanism of tumor-mediated immunosuppression that has gained attention as a potential therapeutic target is the purinergic signaling axis, whereby the production of the purine nucleoside adenosine in the tumor microenvironment can potently suppress T and NK cell function. The production of extracellular adenosine is mediated by the cell surface ectoenzymes CD73, CD39 and CD38 and therapeutic agents have been developed to target these as well as the downstream adenosine receptors (A1R, A2AR, A2BR, A3R) to enhance anti-tumor immune responses. This review will discuss the role of adenosine and adenosine receptor signaling in tumor and immune cells with a focus on their cell-specific function and their potential as targets in cancer immunotherapy.
Tue, 16 October 2018
ARTICLE | doi:10.20944/preprints201810.0346.v1
Subject: Life Sciences, Immunology Keywords: immunity; leukocyte; lymphocyte; flow cytometry; glucose; exercise
Online: 16 October 2018 (08:59:44 CEST)
Using a randomized, crossover approach, cyclists (N = 20, overnight fasted) engaged in three 75-km time trials while ingesting water (WAT) or carbohydrate (0.2 g/kg every 15 minutes) from bananas (BAN) or a 6% sugar beverage (SUG). Blood samples were collected pre-exercise and 0 h-, 1.5 h-, and 21 h-post-exercise, and analyzed for NK cytotoxicity activity (NKCA) using pure NK cell populations. The two carbohydrate trials (BAN, SUG) compared to WAT were associated with higher post-exercise glucose, and lower cortisol, total blood leukocyte, neutrophil, and NK cell counts (interaction effects, P < 0.001). The immediate post-exercise increase in NK cell counts was higher in WAT (78%) compared to BAN (32%) and SUG (15%) trials (P ≤ 0.017). The 1.5 h post-exercise decrease in NK cell counts did not differ after WAT (−46%), BAN (−46%), and SUG (−51%) trials. The pattern of change in post-exercise NKCA differed between trials (P < 0.001). The 1.5 h post-exercise decreases in NKCA were 23%, 29%, and 33% in the WAT, BAN, and SUG trials, respectively, but trial contrasts did not differ significantly. Carbohydrate ingestion from BAN or SUG attenuated immediate-post-exercise increases in leukocyte, neutrophil, and NK cell counts, but did not counter the 1.5-h decreases in NK cell counts and NKCA.
Fri, 12 October 2018
CONCEPT PAPER | doi:10.20944/preprints201810.0277.v1
Subject: Life Sciences, Immunology Keywords: antibody; network; sequence; structure; clonality; B cell; systems biology; quantitative biology
Online: 12 October 2018 (17:01:13 CEST)
Based on the key molecule of humoral adaptive immunity, the antibody, evolution of the system comprises molecular genetic, cell biologic and immunologic mechanisms, and as a network the system is likely governed and can be characterized by physical rules as well. While deep sequencing can provide vast amounts of data related primarily to clonal relationships, functional interpretation of such data is hampered by the inherent limitations of converting sequence to structure to function. In this paper a novel model of structural interaction space, termed radial adjustment of system resolution, or RADARS, is proposed. The model is based on the radial growth of resolution of structural recognition, corresponding to increasing affinity of immune reactivity, and the virtual infinity of directions of growth, corresponding to the ability to respond to almost any molecular structure. Levels of interaction strength appear as shells of the sphere representing the system. B-cell development and immune responses can be readily interpreted in the model and quantitative properties of the antibody network can be inferred from the physical properties of a quasi-spherical system growing multi-radially. The system is described by double-Pareto distribution, sampling the lognormally distributed equilibrium constants at a rate of phi square. Finally, general strategies for merging antibody sequence space into structural space are outlined.
Tue, 2 October 2018
REVIEW | doi:10.20944/preprints201810.0033.v1
Subject: Life Sciences, Immunology Keywords: apoptosis; viral persistence, hepatitis C virus; immunity; chronic infection
Online: 2 October 2018 (16:34:19 CEST)
Hepatitis C virus (HCV) represents a challenging global health threat in ~200 million infected individuals. Clinical data suggests that only ~10-15% of acutely HCV-infected individuals will achieve spontaneous viral clearance despite exuberant virus-specific immune responses, which is largely attributed to difficulties in recognizing the pathognomonic symptoms during the initial stages of exposure to the virus. Given the paucity of a suitable small animal model, it is also equally challenging to study the early phases of viral establishment. Further, the host factors contributing to HCV chronicity in a vast majority of acutely HCV-infected individuals largely remain unexplored. The last few years have witnessed a surge in studies showing that HCV adopts a myriad mechanisms to disconcert virus-specific immune responses in the host to establish persistence that includes, but not limited to viral escape mutations, viral growth at privileged sites, and antagonism. Here, we discussed a few hitherto poorly explained mechanisms employed by HCV that are believed to lead to chronicity in infected individuals. A better understanding of these mechanisms would aid the design of improved therapeutic targets against viral establishment in susceptible individuals.
REVIEW | doi:10.20944/preprints201810.0031.v1
Online: 2 October 2018 (15:36:06 CEST)
Multiple sclerosis is an autoimmune disorder where both T cells and B cells are implicated in pathology. However, it remains unclear how these two distinct populations cooperate to drive disease. There is ample evidence from studies in both MS patients and mouse models that Th17, B cells, and follicular T helper (TFH) cells contribute to disease. This review article describes the literature that identifies mechanisms by which Th17, TFH, and B cells cooperatively drive disease activity in MS and EAE. The curation of this literature has identified that CNS-infiltrating TFH cells act with TH17 cell to contribute to an inflammatory B cell response in neuroinflammation. This demonstrates that TFH cells and their products are promising targets for therapies in MS.
Mon, 17 September 2018
REVIEW | doi:10.20944/preprints201809.0291.v1
Subject: Life Sciences, Immunology Keywords: CCR6, CCL20, Inhibitors, TH17, Treg, Inflammatory diseases, Cancer
Online: 17 September 2018 (09:31:43 CEST)
Prototypical functions of the chemokine receptor CCR6 include immune regulation by manoeuvring cell chemotaxis and selective delimiting of the pro-inflammatory TH17 and regulatory Treg subsets during chronic or acute systemic inflammation. Inhibition of CCR6 is proposed to attenuate disease symptoms and promote recuperation of multiple inflammatory and autoimmune disorders. Prescription medicines with pharmacodynamics involving the inhibition of the chemokine axis CCR6-CCL20 is very limited. Developing such therapeutics is still at an early experimental stage which has mostly utilized pre-clinical models and neutralizing mono or polyclonal antibodies against either partner, CCR6 or CCL20. Other methods have been constitutive use of small molecules as peptide inhibitors or small interfering ribonucleic acid (siRNA) to interfere with transcription at the nuclear level. We in our review aim at introducing the wide array of potential CCR6-CCL20 inhibitors that have been tried to date in the research field with accent on attendant immune-modulator capacity and which are immensely promising compounds as forerunners of future curatives. 16 different tractable inhibitors of the CCR6-CCL20 duo have been identified to possess high medicinal potential to the drug developers worldwide to treat autoimmune and inflammatory diseases. A multitude of antibody preparations are already available in the current pharmaceutical market as patented treatment for diseases in which the CCR6-CCL20 axis is operative, yet must be used only as supplements with existing routinely prescribed medication as they collectively produce adverse side effects. Novel inhibitors are needed to evaluate this invaluable therapeutic target which holds much promise in the research and development of complaisant remedies for inflammatory diseases.
Fri, 14 September 2018
BRIEF REPORT | doi:10.20944/preprints201809.0264.v1
Subject: Life Sciences, Immunology Keywords: azaphenothiazine; anti-inflammatory activity; CXCL10; KERTr cells; keratinocytes; IFNβ; TLR3;
Online: 14 September 2018 (12:42:52 CEST)
An azaphenothiazine derivative, 6-chloroethylureidoethyldiquino[3,2-b;2’,3’-e][1,4]thiazine (DQT) has recently been shown to exhibit immunosuppressive activities in mouse models. It also inhibited the expression of CXCL10 at the protein level, at non-toxic concentrations, in the culture of KERTr cells treated with double-stranded RNA, poly(I:C). In this report, we demonstrated that DQT inhibits the transcription of the CXCL10 gene. Although CXCL10 is an IFNγ-inducible protein, we found that the CXCL10 protein was induced without the detectable release of IFNγ or IκB degradation. Hence, we concluded that IFNγ or NFκB were not involved in the regulation of the CXCL10 gene in KERTr cells transfected with poly(I:C) as well as in the inhibitory activity of DQT. On the other hand, we found that IFNβ was induced under the same conditions and its expression was inhibited by DQT. Kinetic analysis showed that an increase in IFNβ concentrations occurred 4-8 h after poly(I:C) treatment, while the concentration of CXCL10 was undetectable at that time and started to increase later, when IFNβ reached high levels. Therefore, DQT may be regarded as a new promising inhibitor of IFNβ expression and IFNβ-dependent downstream genes and proteins, e.g., CXCL10 chemokine, which is implicated in pathogenesis of autoimmune diseases.
Wed, 29 August 2018
REVIEW | doi:10.20944/preprints201808.0503.v1
Subject: Life Sciences, Immunology Keywords: HMB; Branched-chain amino acid; Strength training; Sports nutrition; Inflammation.
Online: 29 August 2018 (14:12:18 CEST)
β-hydroxy β-methylbutyrate (HMB) is a bioactive metabolite formed from breakdown of the branched-chain amino acid leucine. Given the popularity of HMB supplements among different athletes, specifically, those who engage in regular resistance training, this review was performed to summarize current literature on some aspects of HMB supplementation that have received less attention. Because of the small number of published studies, it has not been possible to conclude the exact effects of HMB on cardiovascular parameters, oxidative stress and inflammatory markers. Thus, the interpretation of outcomes should be taken cautiously. However, the data presented here suggest that acute HMB supplementation may attenuate pro-inflammatory response following an intense resistance exercise in athletes. Also, the available findings collectively indicate that chronic HMB consumption in conjunction with resistance training has no more adaptive advantages associated with decreasing cardiovascular risk factors and oxidative stress markers. Taken together, there is clearly a need for further well-designed, longer duration studies to support these findings and determine whether HMB supplementation affects the adaptations induced by resistance training associated with body’s inflammatory condition, antioxidative defense system, and cardiovascular risk factors in humans.
Tue, 21 August 2018
REVIEW | doi:10.20944/preprints201808.0381.v1
Subject: Life Sciences, Immunology Keywords: CCR6, CCL20, Inflammatory Bowel Disease, Inflammation, Suppression, TH17 cells, Regulatory Treg cells
Online: 21 August 2018 (15:04:43 CEST)
Inflammatory bowel disease (IBD) is a CC chemokine receptor 6 (CCR6) - associated immune mediated disorder which has attracted an extensive superfluity of experimental analyses. IBD has come to the fore of varied scrutinizing owing to its complexity by nature for comprising of two synergistic sub phenotypes; Crohn’s disease (CD) and Ulcerative colitis (UC). Both these disease entities cause potent immune dysregulation followed by intense tissue damage within the gut mucosal system, initiating symptoms which are severely debilitating. Multiple causative factors are said to be responsible for IBD but direct immune dysfunction is kindled by overplay of innate and adaptive immune responses produced against a pathogenic microbial attack through the weakened or leaky gut epithelial barrier. Once immune homeostasis is not achieved by tolerating agents, the self-assertive adaptive immunity mobilize its various T and B cell cohorts initializing their allied immune mechanisms by vigorously deploying them towards the site of infection. CCR6 and its unique solitary ligand CC-chemokine ligand 20 (CCL20) are small protein molecules which are abundantly expressed by T and B lymphocytes and act as chemotactic immune-modulatory envoys that help in the deployment of the effector lymphocyte arm of the immune system, producing two directly opposing outcomes in IBD. This dichotomous immunity consists of either immune tolerance or inflammation which then develops into a chronic state, remaining catatonic to inherent immunity or targeted clinical therapy. In this review, we have chronologically identified a plethora of experimental studies radiating into 14 different compartments highlighted in the visual depiction which have employed both mouse models and clinical subjects spanning a period of nearly two decades. In doing so, we expect the research community would further benefit by tracing through the history, thereby understanding the CCR6 –CCL20 axis in IBD and identifying the gaps in literature which can be fortuitously filled in the future.
Mon, 20 August 2018
ARTICLE | doi:10.20944/preprints201808.0357.v1
Subject: Life Sciences, Immunology Keywords: Astragalin galactoside, hydrophilic modification, Th1 cell, Dendritic cell, adjuvant
Online: 20 August 2018 (12:58:07 CEST)
A flavonoid Astragalin (kaempferol-3-O-β-D-glucopyranoside, Ast) has several biological activities including anti-oxidant, anti-HIV, and anti-allergic effects. Nonetheless, its insolubility in hydrophilic solvents imposes restrictions on its therapeutic applications. In this study, we investigated the effects of water-soluble astragalin-galactoside (kaempferol-3-O- β-D-isomaltotrioside, Ast-Gal) on dendritic cell (DC) maturation and T helper (Th) cell-mediated immune responses. Ast-Gal significantly increased maturation and activation of DCs through up-regulation of surface markers, such as CD80, CD86, and MHC II in a dose-dependent manner, while Ast had little effects. Also, Ast-Gal-treated DCs markedly secreted immune-stimulating cytokines such as IL-1β, IL-6, and IL-12. Importantly, Ast-Gal strongly increased expression of IL-12, a polarizing cytokine of Th1 cells. In a co-culture system of DCs and CD4+ T cells, Ast-Gal-treated DCs preferentially differentiates naïve CD4+ T cells into Th1 cells. The addition of neutralizing IL-12 mAb to cultures of Ast-Gal-treated DCs and CD4+ T cells significantly increased IFN- γ production, thereby indicating that Ast-Gal-stimulated DCs enhance the Th1 response through IL-12 production by DCs. Injection with Ast-Gal-treated DCs in mice increased IFN-γ-secreting Th1 cell population. Collectively, these findings indicate that hydrophilically modified astragalin can enhance Th1-mediated immune responses via DCs, and point to a possible application of water-soluble astragalin-galactoside as an immune adjuvant.
Wed, 8 August 2018
ARTICLE | doi:10.20944/preprints201808.0156.v1
Subject: Life Sciences, Immunology Keywords: Sporothrix schenckii; bone-marrow-derived dendritic cells; vaccine; sporotrichosis
Online: 8 August 2018 (04:32:10 CEST)
Sporotrichosis is a subcutaneous mycosis affecting humans and other animals that can be transmitted a zoonosis with cats as the main vector. The conventional anti-fungal therapy is especially inefficient in immunocompromised patients, who tend to develop the most severe forms of the disease, thus prompting the search for alternative therapies. Given their antigen-presenting properties, dendritic cells (DCs) have been used in both prophylactic and therapeutic vaccination strategies. Hence, this study aims to assess the use of DCs as a prophylactic tool in sporotrichosis by evaluating the immune profile induced by Sporothrix schenckii cell wall proteins (SsCWP)-stimulated bone-marrow-derived DCs (BMDCs). Mouse BMDCs were stimulated with SsCWP for 24 hours and analyzed for the surface expression of co-stimulatory molecules and TLR-4, as well as the secretion of proinflammatory cytokines and IL-10. Following that, activated BMDCs were cocultured with splenocytes for 72 hours and had the same cytokines measured in the supernatant. SsCWP-stimulated BMDCs showed higher expression of CD80, CD86, and CD40, but not TLR-4, and higher secretion of IL-6, IL-17A, and TNF. On the other hand, higher levels of IFN-γ, IL-10, and IL-2 were found in the supernatants of the coculture as compared with the BMDCs alone; TNF secretion was almost completely abrogated, whereas IL-6 was only partially inhibited and IL-17A was unaffected. Our results thus suggest SsCWP-stimulated BMDCs are able to induce a Th1-prone cytokine profile, known to be protective against other fungal diseases. This result could lead to evaluate the development of prophylactic and/or therapeutic DC-based tools against sporotrichosis.
Mon, 23 July 2018
REVIEW | doi:10.20944/preprints201807.0434.v1
Online: 23 July 2018 (21:33:29 CEST)
The tissue micro environment or milieu consists of a highly dynamic population of cellular and non-cellular components which constitute a complex regulatory network aimed at maintaining the organ homeostasis. In the modern medicine the discovery of miRNAs is undoubtedly a promising field of research and they are essential in orchestrating immune system logic and their release in the gut micro milieu can directly affect bacterial gene expression. Here, we brieﬂy review the role of microRNAs, focuses on their role on immune system components in physiological and pathophysiological gut micro milieu.
Tue, 17 July 2018
REVIEW | doi:10.20944/preprints201807.0304.v1
Subject: Life Sciences, Immunology Keywords: IBD; CCR6; CCL20; Immune mechanisms; T helper lymphocytes
Online: 17 July 2018 (10:37:41 CEST)
Inflammatory bowel disease (IBD) has evoked a significant interest in human immunobiology given its tactical immune evasion methodologies resulting in acute immune destabilization. IBD comprising of Crohn’s disease and Ulcerative colitis manifest as chronic inflammation in the gut mucosa, leading to complexities involving immune dysregulation in the T helper lymphocyte arm effecting disease pathogenicity. The mucosa of the alimentary canal is constantly exposed to a myriad of food antigens and luminal microorganisms for which a consistent host-protective mechanism is operative in healthy people. Lowered mucosal immune expression which allows penetration of the epithelial barrier by infective pathogenic microbes, elicits both innate and adaptive immune responses in the gut culminating in aberrant intestinal inflammation. Interestingly, IBD leukocyte repertoire is significantly entwined with chemokine assisted chemotactic navigation into the sites of inflammation which is also thought to generate favourable immune suppressive responses. The functions of the cognate chemokine receptor, CCR6, which binds with its unique ligand CCL20, are expected to tilt the balance between upregulation of homeostatic tolerance and inflammatory pathophysiology. This review aims at critically examining the CCR6 driven immune pathways; TH1/TH2, TH1/TH17, TH17/ Treg, IL-23/IL-17, Akt/ERK-1 /2, ILC3 for systematic investigation of its underlying mechanisms in the future and to underpin its importance in resolving IBD aetiopathology. Thus, CCR6 occupies an exclusive position in gut immunology which renders it an invaluable therapeutic tool for the production of novel medicaments to treat IBD.
Wed, 11 July 2018
ARTICLE | doi:10.20944/preprints201807.0201.v1
Subject: Life Sciences, Immunology Keywords: proteoliposome, Neisseria meningitidis, LPS, proinflammatory cytokines, adjuvant
Online: 11 July 2018 (12:49:21 CEST)
Neisseria meningitidis outer membrane vesicles or proteoliposomes (PLs) has been used as vaccines and adjuvant. Despite the presence of potentially toxic amounts of lipopolysaccharide (LPS), they have been shown to be safe, well tolerated, and immunogenic. This suggests that LPS-PL may have reduced LPS toxicity. We show here that the ability of PL to induce pro-inflammatory cytokine production in human U937 histiocytic cell line is significantly lesser than that of an equivalent concentration of purified LPS, thus confirming that certain components or physical properties of PL reduce the pro-inflammatory activity of their endogenous LPS. To investigate the mechanisms responsible for this protective effect, PLs were fractionated and assayed the ability of the resulting fractions to induce inflammatory cytokine expression. Several individual PLs fractions were more potent inducers of pro-inflammatory cytokine production than the unfractionated PLs. The majority of the pro-inflammatory activities appeared to be mediated by the presence of LPS in the fractions, as shown by the ability of an anti-CD14 antibody to block it. However, in two PL fractions, the production of IL-8 and to a lesser extent IL-6 was not inhibited by anti-CD14 treatment, indicating that pro-inflammatory components other than LPS could also be present in PL. Eight proteins present in the fractions were identified by n-terminal sequencing. Our results suggest that two of them PorB and particularly the RmpM protein may also contribute to the pro-inflammatory activity of N. meningitidis PL. Our results could support the development of PLs as vaccine adjuvant.
Mon, 9 July 2018
ARTICLE | doi:10.20944/preprints201807.0136.v1
Subject: Life Sciences, Immunology Keywords: Hyperbaric oxygen; Neuroinflammation; burn; Galectin-3; Toll-like receptor-4
Online: 9 July 2018 (12:03:39 CEST)
Hyperbaric oxygen (HBO) treatment has been proven to attenuate neuroinflammation in rats. This study aimed to determine the potential mechanism underlying the anti-inflammatory effects of HBO treatment on burn-induced neuroinflammation in rats. Thirty-six adult male Sprague–Dawley (SD) rats were randomly assigned to the following six groups (n = 6 per group): (1) sham burn with sham HBO treatment, (2) sham burn with HBO treatment, (3) burn with 1-week sham HBO treatment, (4) burn with 2-week sham HBO treatment, (5) burn with 1-week HBO treatment, and (6) burn with 2-week HBO treatment. SD rats that received third-degree burn injury were used as a full-thickness burn injury model. Subsequently, we analyzed the expression of proteins involved in the galectin-3 (Gal-3)-dependent Toll-like receptor-4 (TLR-4) pathway through enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC) analysis, and Western blotting, and a behavior test was also conducted. The behavior test revealed that HBO treatment significantly suppressed mechanical hypersensitivity in the burn with HBO treatment group compared with the burn with sham HBO treatment group (p < 0.05). ELISA results showed that tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) levels in the dorsal horn of the spinal cord and the skin were significantly decreased in the burn with HBO treatment group compared with the burn with sham HBO treatment group (p < 0.05). Western blotting results demonstrated that HBO treatment significantly reduced the expression of Gal-3 and TLR-4 in the dorsal horn of the spinal cord in the burn with HBO treatment group compared with the burn with sham HBO treatment group (p < 0.05). IHC analysis results showed that the expression of Gal-3, TLR-4, CD68, and CD45 in the dorsal horn of the spinal cord was significantly lower in the burn with HBO treatment group than in the burn with sham HBO treatment group (p < 0.05), and the expression of CD68 and macrophage migration inhibitory factor (MIF) in the right hind paw skin was significantly lower. The expression of vimentin and fibroblast growth factor (FGF) in the right hind paw skin was significantly higher after HBO treatment (p < 0.05). This study proved that early HBO treatment relieves neuropathic pain, inhibits the Gal-3-dependent TLR-4 pathway, and suppresses microglia/macrophage activation in a rat model.
Fri, 6 July 2018
ARTICLE | doi:10.20944/preprints201805.0466.v2
Subject: Life Sciences, Immunology Keywords: influenza; serum; IgG; humoral antibody; original antigenic sin; hemagglutinin
Online: 6 July 2018 (07:53:32 CEST)
The first exposure to influenza is thought to impact subsequent immune responses later in life. The consequences of this can be seen during influenza epidemics and pandemics with differences in morbidity and mortality for different birth cohorts. There is a need for better understanding of how vaccine responses are affected by early exposures to influenza viruses. In this analysis of hemagglutination inhibition (HI) antibody responses in two cohorts of military personnel we noticed differences related to age, sex, prior vaccination, deployment and birth year. These data suggest that HI antibody production, in response to influenza vaccination, is affected by these factors. The magnitude of this antibody response is associated with, among other factors, the influenza strain that circulated following birth.
Thu, 5 July 2018
COMMUNICATION | doi:10.20944/preprints201807.0104.v1
Subject: Life Sciences, Immunology Keywords: Rumex crispus, Cordyceps sinensis, splenocytes, LPS
Online: 5 July 2018 (16:33:14 CEST)
We investigated the efficacy of a Rumex crispus and Cordyceps sinensis mixture made using the Beopje (Korea traditional processing method to remove anti-nutrients and enhance phytochemicals) method to regulate immune cell responses toward nitric oxide (NO) production, pro-inflammatory cytokines, and inflammation related genes in mice splenocytes. The six experimental groups were as follows: control (control), Rc-Cs (Rumex crispus (Rc) and Cordyceps sinensis (Cs) mixture, 6:4), TMC (Taemyeongcheong, commercial healthy drink containing Rc-Cs), LPS (lipopolysaccharide), LPS+Rc-Cs, and LPS+TMC. The Rc-Cs mixture reduced nitric oxide (NO) production in LPS-induced splenocytes. Moreover, Rc-Cs enhanced production of the pro-inflammatory cytokines TNF-α, IFN-γ, IL-1β, and IL-6 compared to the control (no treatment). However, Rc-Cs inhibited production of pro-inflammatory cytokines in LPS-induced splenocytes. In addition, LPS+Rc-Cs also significantly suppressed mRNA expression of IL-1β and IL-6 compared to LPS treatment. Interestingly, Rc-Cs did not increase mRNA levels of iNOS and COX-2, which are inflammation related genes compared to the control, while LPS+Rc-Cs reduced mRNA levels of iNOS and COX-2 compared LPS alone (p < 0.05). TMC showed a similar pattern compared to Rc-Cs. Therefore, Rc-Cs treatment in splenocytes enhanced NO production and pro-inflammatory cytokines compared to the control, whereas Rc-Cs treatment in LPS-induced splenocytes reduced NO production, pro-inflammatory cytokines, and inflammation related genes. Thus, Rc-Cs regulated immune cells responses by increasing pro-inflammatory cytokines in splenocytes and reducing toxin (LPS)-induced inflammation. These results indicate that a Rumex crispus and Cordyceps sinensis mixture (Rc-Cs) and TMC containing Rc-Cs promote immune cells responses and anti-inflammatory activities.
Fri, 22 June 2018
ARTICLE | doi:10.20944/preprints201806.0340.v1
Subject: Life Sciences, Immunology Keywords: T-regulatory cells, immune regulation, Foxp3, PPARγ, autoimmune diabetes, NOD mouse, Thiazolidinediones, ciglitazone.
Online: 22 June 2018 (09:33:32 CEST)
Immunomodulation as means of immunotherapy has been studied in major research and clinical laboratories for many years. T-Regulatory (Treg) cell therapy is one of the modulator used in immunotherapy approaches. Similarly, nuclear receptor peroxisome proliferator activated receptor gamma (PPARγ) has extensively been shown to play a role as an immuno-modulator during inflammation. Given their mutual roles in downregulating the immune response, current study examined the influence of PPARγ ligands i.e thiazolidinedione (TZD) class of drugs on Foxp3 expression and possible crosstalk between PPARγ and nTreg cells of NOD and NOR mice. Results showed that TZD drug, ciglitazone and natural ligand of PPARγ 15d-prostaglandin downregulated Foxp3 expression in activated nTreg cells from both NOD and NOR mice. Interestingly, addition of the PPARγ inhibitor, GW9662 further downregulated Foxp3 expression in these cells from both mice. We also found that PPARγ ligands negatively regulate Foxp3 expression in activated nTreg cells via PPARγ-independant mechanism(s). These results demonstrate that both natural and synthetic PPARγ ligands capable of suppressing Foxp3 expression in activated nTreg cells of NOD and NOR mice. This may suggest that the effect of PPARγ ligands in modulating Foxp3 expression in activated nTreg cells is different from their reported effects on effector T cells. Given the capability to suppress foxp3 gene, it is possible to be tested as immunomodulators in cancer-related studies.
Thu, 7 June 2018
ARTICLE | doi:10.20944/preprints201806.0120.v1
Subject: Life Sciences, Immunology Keywords: colitis disease; Eucheuma cottonii; inflammatory cytokines; red seaweed
Online: 7 June 2018 (12:22:21 CEST)
This study aims to determine the protective effects of red seaweed Eucheuma cottonii (EC) ethanol extract on acute colitis disease in mice. Male BALB/c mice used for acute colitis disease model by induced 2.5% (w/v) of dextran sulfate sodium (DSS) for 7 days for all groups, except control group. The DSS-induced mice then treated by three different doses of EC extracts (0.35, 0.70, 1.75 g/kg body weight), curcumin (as a positive control, 0.10 g/kg), and a group was orally only by water. In 8th day, the mice sacrificed and collected the blood, then measured the body weight, colon weight, and colon length. Disease activity index (DAI), pro-inflammatory such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, as well as IL-10 as anti-inflammatory were measured. The results showed that after treatment for 7 days, EC extract protected the weight loss and decreased the colon weight per length ratio. In addition, EC extract also decreased the pro-inflammatory cytokines expression in serum and increased the IL-10. Moreover, EC extract protected the colonic tissue damage. According to this results, the EC ethanol extract might be can used for the treatment of colitis disease.
REVIEW | doi:10.20944/preprints201806.0107.v1
Subject: Life Sciences, Immunology Keywords: CCR6; CCL20; TH17; Treg, inflammation; multiple organs; health and disease
Online: 7 June 2018 (08:49:51 CEST)
Chemokine C-C receptor 6 (CCR6) and its exclusive ligand CCL20 is an extremely important chemokine receptor-ligand pair which controls cell migration and immune induction during inflammatory disease. Not many scientific studies have been undertaken to study its immune mechanisms in detail, but its unique contribution to steady state cell chemotaxis in upholding immune tolerance and regulating immune homeostasis during inflammation is evident in multiple organ systems, including lung, liver, kidney, skin, brain, eye, joints, gonads and the gut in the human body. The role of CCR6 is constitutively expressed as a series of much debilitating severe inflammatory and autoimmune diseases, HIV and cancer metastasis. CD4+ T cells, the central organizers of adaptive immunity, are stringently mobilized by the CCR6/CCL20 axis also induced by cytokines and a host of other factors in a carefully executed immune modulation scenario, to bring about a delicate balance between pro-inflammatory TH17 cells and regulatory Treg cells. Although the exact immune regulatory role is not elucidated yet, CCR6/CCL20 axis is implicated as a front runner which determines the polarization of TH17 and Treg cells and consequently the resolution or progression of many debilitating disorders. This review therefore aims at emphasizing the pleiotropic significance of the chemokines CCR6 and CCL20 in immunologic function in multiple organ systems thereby hoping to accentuate its value in future therapeutic modalities.
Tue, 5 June 2018
ARTICLE | doi:10.20944/preprints201806.0064.v1
Subject: Life Sciences, Immunology Keywords: adipose-derived mesenchymal stem cells; intraperitoneal therapy; biodistribution; efficacy; colitis
Online: 5 June 2018 (11:33:18 CEST)
Mesenchymal stem cells (MSCs) have emerged as a promising treatment for inflammatory diseases. It is described that the immunomodulatory effect of MSCs takes place both by direct cell-to-cell contact and by means of soluble factors that leads to an increased accumulation of regulatory immune cells at the sites of inflammation. Similar efficacy of MSCs has been described regardless the route of administration used, the inflammation conditions and the MHC context. These observations arise the question as to whether the migration of the MSCs to the inflamed tissues is a pre-requisite to achieve their beneficial effect. To address this, we examined the biodistribution and the efficacy of intraperitoneal luciferase-expressing human expanded adipose derived stem cells (Luci-eASCs) in a mouse model of colitis. Luci-eASC-infused mice were stratified according to their response to the Luci-eASC treatment. According to the stratification criteria, there was a tendency to increase the bioluminescence signal in the intestine at the expense of a decrease in the bioluminescence signal in the liver in the `responder´ mice. These data thus suggest that the accumulation of the eASCs to the inflamed tissues is beneficial to achieve an optimal modulation of inflammation.
Thu, 31 May 2018
ARTICLE | doi:10.20944/preprints201805.0466.v1
Subject: Life Sciences, Immunology Keywords: influenza; serum; IgG; humoral antibody; original antigenic sin; hemagglutinin
Online: 31 May 2018 (10:51:16 CEST)
The first exposure to influenza is thought to impact subsequent immune responses later in life. The consequences of this can be seen during influenza epidemics and pandemics with differences in morbidity and mortality for different birth cohorts. With the development of new universal vaccines there is need for better understanding of how vaccine responses are affected by early exposures to influenza viruses. In this analysis of hemagglutination inhibition (HI) antibody responses in two cohorts of military personnel we noticed differences related to birth year. These data suggest that HI antibody production, in response to influenza vaccination, is affected by influenza activity in the years following birth. The magnitude of this antibody response is associated with, among other factors, the influenza strain that circulated following birth.
Thu, 24 May 2018
ARTICLE | doi:10.20944/preprints201805.0351.v1
Subject: Life Sciences, Immunology Keywords: PPARgamma first trimester placenta; decidual macrophages; miscarriage
Online: 24 May 2018 (13:24:08 CEST)
PPARgamma belongs to the group of nuclear receptors which is expressed in the trophoblast and together with other factors is responsible for the maintenance of pregnancy. Apart from that PPARgamma is also a main factor for macrophage polarization. The aim of this study was to investigate the combined expression pattern and frequency of PPARgamma under physiological circumstances and in spontaneous and recurrent miscarriages in the trophoblast and in maternal macrophages of the decidua. Human placental tissues of the first trimester (15 physiologic pregnancies, 15 spontaneous abortion & 16 recurrent miscarriage placentas) were analyzed for expression of the nuclear receptor PPARgamma. Expression changes were evaluated by immunohistochemistry and RT-PCR in trophoblast and in maternal macrophages of the decidua. Maternal macrophages were identified by double immunofluorescence using CD68 as marker for macrophages. The intermediate villous trophoblast revealed a significantly lower PPARgamma expression in spontaneous and recurrent abortion. Maternal macrophages express PPARgamma. Their number is significantly enhanced in the decidua of spontaneous miscarriages whereas in recurrent miscarriages maternal macrophages seem to express PPARgamma only in very few cases. PPARgamma is associated with an M2 polarization state that is common for decidual macrophages. The lack of PPARgamma in recurrent miscarriage decidual macrophages seems to be associated with a specific inflammatory response against the fetus.
Wed, 23 May 2018
ARTICLE | doi:10.20944/preprints201805.0322.v1
Subject: Life Sciences, Immunology Keywords: crotoxin; macrophages; neutrophils; inflammation; ATP; reactive oxygen and nitrogen species; cytokines; co-culture model
Online: 23 May 2018 (09:12:45 CEST)
Crotoxin (CTX), the predominant toxin in Crotalus durissus terrificus snake venom (CdtV), has anti-inflammatory and immunomodulatory effects. Despite its inhibitory action on neutrophil migration and phagocytosis, CTX does not directly affect the production of reactive oxygen species (ROS) by the neutrophils. In contrast, it enhances the generation of reactive oxygen and nitrogen intermediates by macrophages. Given the importance of macrophage-neutrophil interactions in innate antimicrobial defense, the aim of this study was to investigate the effect of CTX on neutrophil ROS production and killing activity, either through CTX-treated macrophage co-culture or conditioned medium of CTX-treated macrophages. The results showed an important modulatory action of CTX on the neutrophil function as well as neutrophil-macrophage interactions, as demonstrated by the increased production of hydrogen peroxide, hypochlorous acid, nitric oxide and TNF-α, along with the increased fungicidal activity of neutrophils.
Tue, 15 May 2018
ARTICLE | doi:10.20944/preprints201805.0207.v1
Subject: Life Sciences, Immunology Keywords: antibody; Isotype IgA; Pertuzumab; allosteric; biologics; constant region; variable region
Online: 15 May 2018 (07:51:15 CEST)
Therapeutics antibodies have increasingly shifted the paradigm of disease treatments, from small molecules to biologics, especially in cancer therapy. Despite the increasing number of antibody candidates, much remains unknown about the antibody and how its various regions interact. In fact, the constant region can govern effects that might be useful in reducing the unwanted consequences resulted from systemic circulation. For this reason, apart from the commonly used IgG isotypes, IgA antibodies are promising therapeutics drugs, given its localized mucosal effects. While the antibody Fc effector cell activity has been well explored, recent research has shown evidences that the constant region of the antibody can also influence antigen binding, challenging the conventional idea of region-specific antibody functions. To further investigate this, we analyzed the IgA antibody constant and its allosteric effects onto the antigen binding regions, using recombinant Pertuzumab IgA1 and IgA2 variants. We found mutations in the C-region to reduce Her2 binding, and our computational structural analysis showed that such allosteric communications were highly dependent on the antibody hinge, providing the evidence to consider antibodies as a whole protein rather than a sum of functional regions.
Tue, 10 April 2018
CONCEPT PAPER | doi:10.20944/preprints201804.0115.v1
Subject: Life Sciences, Immunology Keywords: omega-3 and omega-6 polyunsaturated fatty acids; colorectal cancer; cancer immune therapy
Online: 10 April 2018 (08:05:27 CEST)
Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been found to be modulators of immune function. Additionally, they may affect the growth of colorectal cancer (CRC). With the advent of novel treatment approaches in oncology targeting immune checkpoint inhibition and aiming to boost the immune response against tumors the exact role of n-3 and n-6 PUFA in inflammation as well as in CRC needs to be re-evaluated in order to understand potential interactions with these new treatment paradigms. Interestingly, for the cyclooxygenase (COX) inhibitor aspirin a possible synergistic effect together with a PD1-Ligand antibody has been shown. However, could n-3 PUFA be disadvantageous in the context of immune tumor therapy due to an immune suppressive effect that has been described for these fatty acids in the past, or could they also enhance the effect of immune checkpoint inhibition? In this paper, we discuss the current data regarding the immune modulatory as well as the anti-CRC effect of n-3 PUFA. Arguing towards an immune-activating effect of n-3 PUFA, we demonstrate the results of a pilot study. Here, we show that incubation of human peripheral blood mononuclear cells (PBMCs) with the n-3 PUFA docosahexaenoic acid (DHA) significantly decreases CRC-cell supernatant-triggered secretion of IL-10 and increases secretion of TNF-a, while the omega-6 polyunsaturated fatty acid (n-6 PUFA) arachidonic acid (AA) reduced TNF-a secretion. These changes in cytokine secretion upon incubation with DHA demonstrate a possible enhancing effect of n-3 PUFA on an anti-tumor immune response.
Tue, 27 March 2018
ARTICLE | doi:10.20944/preprints201803.0224.v1
Subject: Life Sciences, Immunology Keywords: Myeloid-derived suppressor cells (MDSCs); dendritic cells (DCs); M1 macrophages; M2 macrophages; xenograft tumor; allograft tumor; lipopolysaccharide (LPS)
Online: 27 March 2018 (12:03:56 CEST)
Macrophages and dendritic cells (DCs) acquire functionally distinct properties in response to various environmental stimuli; the interaction of these cells with myeloid-derived suppressor cells (MDSCs) in tumor microenvironments regulates cancer progression. Immunodeficient mice lacking T cells are less likely to reject human cancer cells because of major histocompatibility complex (MHC) mismatches. The xenograft tumor microenvironment, comprising human cancer and mouse host cells, exhibits more complex bidirectional signaling and function than a syngeneic tumor microenvironment. Here human and mouse colorectal cancer cells were transplanted into nude mice to elucidate differences in macrophage, DC, and MDSC functions in human xenograft and mouse allograft tumor models. Plasma interferon-γ and interleukin-18 concentrations in the former model after intraperitoneal lipopolysaccharide (LPS) administration were significantly higher than those in the latter model and non-transplanted control group. Splenic MHC class I, II, and CD80 expression increased in CD11b+ and MDSC populations after LPS administration in only the xenograft tumor model. The number of CD80- and MRC1-expressing cells decreased upon LPS administration in only the xenograft tumor. These results suggxest that macrophages and DCs function normally in xenograft tumor models, whereas their functions in response to LPS administration vary in allograft tumor models.
Mon, 19 March 2018
ARTICLE | doi:10.20944/preprints201803.0146.v1
Subject: Life Sciences, Immunology Keywords: Inflammatory Bowel Diseases; ulcerative colitis; American ginseng; Panaxynol; macrophages
Online: 19 March 2018 (08:32:22 CET)
Ulcerative colitis has a significant impact on the quality of life for the patients, and can substantially increase the risk of colon cancer in patients suffering long-term. Conventional treatments provide only modest relief paired with a high risk of side effects, while complementary and alternative medicines can offer safe and effective options. Over the past decade, we have shown that American ginseng has anti-oxidant and anti-inflammatory properties that can suppress mouse colitis and prevent colitis associated colon cancer. With the goal of isolating a single active compound, we further fractionated the hexane fraction, and found the most abundant molecule in this fraction was the polyacetylene, Panaxynol. After isolating and characterizing Panaxynol, we tested the efficacy of Panaxynol in the treatment and prevention of colitis in mice and studied the mechanism of action. We demonstrate here that Panaxynol effectively treats colitis in a Dextran Sulfate Sodium mouse model by targeting macrophages for DNA damage and apoptosis. Positive outcomes from this study could take American ginseng one-step further towards becoming a conventional drug for the treatment of colitis, and possibility exploring other autoimmune diseases associated with macrophage dysfunction.
Sat, 20 January 2018
REVIEW | doi:10.20944/preprints201801.0189.v1
Subject: Life Sciences, Immunology Keywords: microbes; autoimmunity; glycolipids,alpha-GalactosylCeramide; sulfatide; CD1d; NKT.
Online: 20 January 2018 (13:59:26 CET)
Natural killer T cells (NKT) are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II and NKT-like expressing different antigen receptors (TCR) were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defence against infections but, on the other hand, their effector functions can be involved in the pathogenesis of several inflammatory disorders due to their exposure to different microbial or self antigens, respectively. A deep understanding of the biology and functions of type I, II and NKT-like cells as well as their interplay with cell types acting in innate (Neuthrophils, Innate Lymphoid cells, Machrophages and Dendritic cells) and adaptive immunity (CD4+,CD8+ and Double Negative T cells) should be important to design potential immunotherapies for infectious and autoimmune diseases.
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