REVIEW Download: 32| View: 132| Comments: 1 | 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 Download: 63| View: 167| Comments: 0 | 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 Download: 25| View: 102| Comments: 0 | 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 Download: 53| View: 160| Comments: 0 | 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 Download: 70| View: 183| Comments: 0 | 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 Download: 117| View: 280| Comments: 0 | 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 Download: 51| View: 159| Comments: 0 | 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 Download: 36| View: 115| Comments: 0 | 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 Download: 73| View: 54| Comments: 0 | 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 Download: 60| View: 226| Comments: 0 | 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 Download: 55| View: 195| Comments: 0 | 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 Download: 52| View: 172| Comments: 0 | 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 Download: 64| View: 133| Comments: 0 | 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 Download: 78| View: 164| Comments: 0 | 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 Download: 119| View: 210| Comments: 1 | 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 Download: 112| View: 512| Comments: 0 | 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 Download: 55| View: 131| Comments: 0 | 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 Download: 98| View: 82| Comments: 0 | 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 Download: 96| View: 241| Comments: 0 | 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 Download: 76| View: 135| Comments: 0 | 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 Download: 48| View: 70| Comments: 0 | 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 Download: 110| View: 61| Comments: 0 | 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 Download: 129| View: 79| Comments: 0 | 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 Download: 276| View: 245| Comments: 0 | 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 Download: 81| View: 70| Comments: 0 | 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 Download: 99| View: 162| Comments: 0 | 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 Download: 115| View: 168| Comments: 0 | 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 Download: 155| View: 161| Comments: 0 | 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 Download: 186| View: 88| Comments: 0 | 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 Download: 95| View: 131| Comments: 0 | 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 Download: 273| View: 269| Comments: 0 | 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 Download: 143| View: 159| Comments: 0 | 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 Download: 129| View: 169| Comments: 0 | 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 Download: 148| View: 146| Comments: 0 | 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 Download: 159| View: 140| Comments: 0 | 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 Download: 194| View: 170| Comments: 0 | 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 Download: 170| View: 172| Comments: 0 | 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 Download: 184| View: 176| Comments: 0 | 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 Download: 189| View: 170| Comments: 0 | 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 Download: 225| View: 232| Comments: 0 | 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 Download: 148| View: 207| Comments: 0 | 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 Download: 343| View: 371| Comments: 0 | 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 Download: 175| View: 195| Comments: 0 | 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 Download: 185| View: 211| Comments: 0 | 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 Download: 208| View: 255| Comments: 0 | 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 Download: 195| View: 262| Comments: 0 | 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 Download: 208| View: 322| Comments: 0 | 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 Download: 306| View: 289| Comments: 0 | 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 Download: 371| View: 371| Comments: 0 | 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 Download: 270| View: 221| Comments: 0 | 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 Download: 385| View: 402| Comments: 0 | 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 Download: 260| View: 275| Comments: 0 | 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.
Tue, 2 January 2018
ARTICLE Download: 340| View: 358| Comments: 0 | doi:10.20944/preprints201801.0012.v1
Subject: Life Sciences, Immunology Keywords: rheumatoid arthritis; citrulline-peptides; autoantibody; affinity; cross-reaction; targeting
Online: 2 January 2018 (11:50:04 CET)
Background: In rheumatoid arthritis (RA), anti-citrullinated protein/peptide antibodies (ACPAs) are responsible for disease onset and progression, however, our knowledge is limited on ligand binding affinities of autoantibodies with different citrulline-peptide specificity. Methods: Citrulline-peptide specific ACPA IgGs were affinity purified and tested by ELISA. Binding affinities of ACPA IgGs and serum antibodies were compared by surface plasmon resonance (SPR) analysis. Bifunctional nanoparticles harboring a multi-epitope citrulline-peptide and a complement activating peptide were used to induce selective depletion of ACPA producing B cells. Results: KD values of affinity purified ACPA IgGs varies between 10-6-10-8 M and inversely correlate with disease activity. Based on their cross-reaction with citrulline-peptides we designed a novel multi-epitope peptide, containing Cit-Gly and Ala-Cit motifs in two-two copies, separated with a short, neutral spacer. This peptide detects antibodies in RA sera with 66 % sensitivity and 98 % specificity in ELISA and is recognized by 90% of RA sera, while none of the healthy samples in SPR. When coupled to nanoparticles, the multi-epitope peptide specifically targets and depletes ACPA producing B cells ex vivo. Conclusions: The unique multi-epitope peptide designed on the basis of ACPA cross-reactivity might be suitable to develop better diagnostics and novel therapies for RA.
Mon, 30 October 2017
ARTICLE Download: 430| View: 568| Comments: 0 | doi:10.20944/preprints201710.0180.v1
Subject: Life Sciences, Immunology Keywords: primary Sjögren's syndrome; alpha-1-antitrypsin; inhibitor; 4-hydroxy-2-nonenal; autoantibody isotypes; serum
Online: 30 October 2017 (04:30:59 CET)
The aim of this study was to examine oxidative stress and low level of alpha-1-antitrypsin (A1AT) in primary Sjögren's syndrome (pSS), and evaluate the associated autoreactivity against unmodified and their 4-hydroxy-2-nonenal (HNE)-modified peptides with pSS. Two differentially expressed proteins, alpha-1-acid glycoprotein 1 (A1AG1) and A1AT, exhibited 2-fold differences, and their HNE modifications were identified by depleted-albumin and immunoglobulin G (IgG) serum protein, in-solution digestion, in-gel digestion, and nano-LC-MS/MS from pSS patients and age-matched healthy controls (HCs). Furthermore, levels of proteins, confirmation of HNE modifications, HNE-protein adducts and autoreactivity against unmodified and their HNE-modified peptides were further validated. Levels of the HNE-protein adduct and A1AG1 were significantly higher in pSS patients than HCs, but levels of A1AT were significantly lower in pSS patients compared to HCs. Only the HNE modification of A1AT was confirmed. Further, concentrations of anti-A1AT50-63 IgG and anti-A1AT50-63 HNE IgA were significantly lower in pSS patients than HCs. Our study suggests that elevated HNE-protein adduct, oxidative stress, level [odds ratio (OR) 4.877, p = 0.003], lowered A1AT level (OR 3.910, p = 0.010) and a decreased level of anti-A1AT50-63 IgG (OR 3.360, p = 0.010) showed an increased risk in pSS patients compared to HCs, respectively.
Fri, 22 September 2017
ARTICLE Download: 459| View: 426| Comments: 0 | doi:10.20944/preprints201709.0106.v1
Subject: Life Sciences, Immunology Keywords: IRF5; transcriptional factors; immuno-stimulation; nervous necrosis virus; malabar grouper (epinephelus malabaricus)
Online: 22 September 2017 (08:58:20 CEST)
Interferon regulatory factor 5 (IRF5) is known to be involved in the innate immune response and pro-inflammatory cytokines. However, the roles of IRF5 in immune responses in Malabar grouper (Epinephelus malabaricus) have not been extensively explored. In this study, IRF5 gene was identified and characterized from M. grouper. The full-length IRF5 cDNA consisted of a 5’ terminal untranslated region (5’-UTR) of 289 bp and a 3’-UTR of 542 bp, an open reading frame (ORF) of 1500 bp encoding a polypeptide of 499 amino acids with a predicted molecular mass of 56.28 kDa and isoelectric point (pI) of 5.2. The putative MgIRF5 protein consists of four important conserved domains: a helix DNA-binding domain (DBD) at the N-terminus, a middle region, an IRF association domain (IAD) and a virus activated domain (VAD) at the C-terminus. Sequence alignment and phylogenetic analysis showed that highest sequence similarity of IRF5 was observed between the IRF5 genes from Oplegnathus fasciatus and Miichthys miiuy. The mRNA transcripts of IRF5 were detected in a wide range of tissues types from healthy M. grouper with highest expression in muscle, liver and skin. After treatment with poly (I: C), it was significantly up-regulated in spleen and liver tissues. When infected with NNV, the expression level of MgIRF5 was up-regulated in spleen and head kidney and their transcriptional responses to IRF5 increased in the grouper kidney cells. This approach suggests that MgIRF5 is important in the underlying mechanism of the innate immune responses against antiviral response.
Mon, 14 August 2017
REVIEW Download: 575| View: 522| Comments: 0 | doi:10.20944/preprints201705.0209.v2
Subject: Life Sciences, Immunology Keywords: influenza virus; apoptosis; antiviral agent; innate immunity; host response
Online: 14 August 2017 (04:41:22 CEST)
Human influenza A viruses (IAVs) cause global pandemics and epidemics, which remain serious threats to public health because of the shortage of effective means of control. To combat the surge of viral outbreaks, new treatments are urgently needed. Developing new virus control modalities requires better understanding of virus-host interactions. Here we describe how IAV infection triggers cellular apoptosis, and how this process can be exploited towards development of new therapeutics, which might be more effective than the currently available anti-influenza drugs.
Sat, 12 August 2017
REVIEW Download: 413| View: 427| Comments: 0 | doi:10.20944/preprints201708.0048.v1
Online: 12 August 2017 (21:30:37 CEST)
T cell Non-Hodgkin lymphoma is a heterogeneous disease ranging from malignancies arising from thymic T cells halted in development, through to mature, circulating peripheral T cells. The latter cases are diagnostically problematic with many entering the category of peripheral T cell lymphoma, not otherwise specified (PTCL, NOS). Anaplastic Large Cell Lymphoma is one of the exceptions to this whereby aberrant expression of Anaplastic Lymphoma Kinase and distinctive presence of cell surface CD30 places this entity in its own class. Besides expression of a well-studied oncogenic translocation, ALCL, ALK+ may also have a unique pathogenesis with a thymic origin like T lymphoblastic lymphoma but a peripheral presentation akin to PTCL. This review discusses evidence towards the potential origin of ALCL, ALK+ and mechanisms that may give rise to its unique phenotype.
Tue, 27 June 2017
REVIEW Download: 600| View: 628| Comments: 0 | doi:10.20944/preprints201706.0121.v1
Subject: Life Sciences, Immunology Keywords: autophagy； immune system； cancer；cell death；metabolic homeostasis
Online: 27 June 2017 (06:30:17 CEST)
Autophagy is a highly conserved catabolic mechanism that mediates the degradation of damaged cellular components by inducing their fusion with lysosomes. This process provides cells with an alternative source of energy for the synthesis of new proteins and the maintenance of metabolic homeostasis in stressful environments. Numerous studies have demonstrated beneficial roles for the induction as well as the suppression of autophagy in cancer cells. Autophagy may induce either survival or death depending on the cell/tissue type. Radiation therapy is widely used therapeutic option to treat cancer, and it induces autophagy in human cancer cell line. Also, melatonin seems to affect cancer cell death via regulation of programmed cell death. In this review, we summarize the current understanding of autophagy and its regulation in cancer.
Tue, 30 May 2017
REVIEW Download: 592| View: 754| Comments: 0 | doi:10.20944/preprints201705.0209.v1
Subject: Life Sciences, Immunology Keywords: influenza virus; apoptosis; antiviral agent; innate immunity; host response
Online: 30 May 2017 (07:13:09 CEST)
Human influenza A viruses (IAVs) cause global pandemics and epidemics, which remain serious threats to public health because of the shortage of effective means of control. To combat the surge of viral outbreaks, new treatments are urgently needed. Developing new virus control modalities requires better understanding of virus-host interactions. Here we describe how IAV infection triggers cellular apoptosis, and how this process can be exploited towards development of new therapeutics, which might be more effective than the currently available anti-influenza drugs.
Wed, 24 May 2017
REVIEW Download: 744| View: 589| Comments: 0 | doi:10.20944/preprints201705.0176.v1
Online: 24 May 2017 (08:48:15 CEST)
Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors or differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B, a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.
Mon, 8 May 2017
REVIEW Download: 836| View: 540| Comments: 0 | doi:10.20944/preprints201705.0062.v1
Subject: Life Sciences, Immunology Keywords: microbiome; probiotics, dietary supplements; nutrition; HIV infection, inflammation
Online: 8 May 2017 (12:10:17 CEST)
Microbiota plays a key role in various body’s functions, physiological, metabolic and immunological processes, through different mechanisms such as the regulation of the development and/or functions of different types of immune cells in the intestines. Several evidences indicate that alteration in the gut microbiota can influence infectious and non-infectious diseases. Bacteria that resides on the mucosal surface or within the mucus layer participate in interactions with the host immune system, and a healthy gut microbiota is essential for the development of mucosal immunity. The immunomodulatory activity of probiotics has been proposed in several bowel disorders or in aging-related dysfunctions. In HIV infected patients, the intestinal immune system is affected and inflammation persists during ART therapy too. Several studies are in progress to investigate the ability of probiotics to modulate epithelial barrier functions, microbiota composition and microbial translocation in HIV infection. This mini-review aims to suggest how the use of probiotics is beneficial not only in maintaining a healthy status but also to improve conditions in HIV subjects.
Mon, 24 October 2016
ARTICLE Download: 979| View: 1233| Comments: 0 | doi:10.20944/preprints201610.0101.v1
Subject: Life Sciences, Immunology Keywords: reactive oxygen species (ROS); asthma; montelukast; long-acting β2 agonist (LABA); corticosteroid; monocyte
Online: 24 October 2016 (05:50:30 CEST)
Asthma is a chronic inflammatory airway disease induced by many environmental factors. The inhalation of allergens and pollutants promote the reactive oxygen species (ROS) production leading to airway inflammation, hyper-responsiveness and remodeling in allergic asthma. The effects of asthma medications on ROS production are unclear. The present study investigated the anti-ROS effects of current asthma medications including inhaled corticosteroid (ICS; budesonide and fluticasone), leukotriene receptor antagonist (LTRA; montelukast), long acting β2 agonists (LABAs; salmeterol and formoterol) and a new extra-LABA (indacaterol). The human monocyte cell line THP-1 cells were pre-treated with different concentrations of the asthma medications at different time-points after hydrogen peroxide (H2O2) stimulation. H2O2 production was measured with DCFH-DA by flow cytometry. Montelukast, fluticasone and salmeterol suppressed H2O2-induced ROS production. Indacaterol enhanced H2O2-induced ROS production. Budesonide and formoterol alone had no anti-ROS effects, but the combination of these two drugs significantly suppressed H2O2-induced ROS production. Different asthma medications have different anti-ROS effects on monocytes. The combination therapy with LABA and ICS seemed not be the only choice for asthma control. Montelukast may be also a good supplemental treatment for the poorly-controlled asthma because of its powerful anti-ROS effects. Our findings provide a novel therapeutic view in asthma.