Impaired toll-like receptor 3-mediated immune responses from macrophages of patients chronically infected with hepatitis C virus

Analysis of Glaucoma Associated Genes in Response to Inflammation, an Examination of a Public Data Set Derived from Peripheral Blood from Patients with Hepatitis C

Introduction

Glaucoma is the second leading cause of blindness worldwide and despite its prevalence, there are still many unanswered questions related to its pathogenesis. There is evidence that oxidative stress and inflammation play a major role in disease progression. Glaucoma patients from several studies showed altered gene expression in leukocytes, revealing the possibility of using peripheral biomarkers to diagnose or stage glaucoma. The fact that glaucoma is associated with gene expression changes in tissues distant from the retina underscores the possible involvement of systemic oxidative stress and inflammation as potential contributing or compounding factors in glaucoma.

Methods

We assembled a list of oxidative stress and inflammatory markers related to glaucoma based on a review of the literature. In addition, we utilized publicly available data sets of gene expression values collected from peripheral blood mononuclear cells and macrophages from two patient groups: those chronically infected by the hepatitis C virus and those who have cleared it. Activation of the innate immune response can render cells or tissues more responsive to a second delayed proinflammatory stimulus. Additional gene expression data from these cells after subsequent polyinosinic:polycytidylic acid treatment, used to elicit an acute inflammatory response, allowed for the investigation of the acute inflammatory response in these groups. We used fold-change comparison values between the two patient groups to identify genes of interest.

Results

A comparison analysis identified 17 glaucoma biomarkers that were differentially expressed in response to HCV-mediated inflammation. Of these 17, six had significant p-values in the baseline vs treated values. Expression data of these genes were compared between patients who had cleared the Hepatitis C virus versus those who had not and identified three genes of interest for further study.

Discussion

These results support our hypothesis that inflammation secondary to Hepatitis C virus infection affects the expression of glaucoma biomarker genes related to the antioxidant response and inflammation. In addition, they provide several potential targets for further research into understanding the relationship between innate responses to viral infection and inflammatory aspects of glaucoma and for potential use as a predictive biomarker or pharmacological intervention in glaucoma.

Association of toll-like receptors single nucleotide polymorphisms with HBV and HCV infection: research status

Background

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections have become increasingly severe worldwide and are a threat to public health. There have been a number of studies conducted recently on the relationship of single nucleotide polymorphisms (SNPs) to innate immune receptor genes such as toll-like receptors (TLRs). Some literature suggests that SNPs of TLRs are associated with HBV and HCV infection. We summarized the role of TLRs gene polymorphisms associated with HBV and HCV infections and explored their possible mechanisms of action.

Methodology

PubMed and Web of Science were used to perform the literature review. Related articles and references were identified and used to analyze the role of TLRs gene polymorphism in HBV and HCV infection.

Results

TLRs gene polymorphisms may have beneficial or detrimental effects in HBV and HCV infection, and some SNPs can affect disease progression or prognosis. They affect the disease state by altering gene expression or protein synthesis; however, the mechanism of action is not clearly understood.

Conclusions

Single nucleotide polymorphisms of TLRs play a role in HBV and HCV infection, but the mechanism of action still needs to be explored in future studies.

Ubiquitin-related molecular classification and risk stratification of hepatocellular carcinoma

The roles of ubiquitin-related genes in hepatocellular carcinoma (HCC) have not been thoroughly investigated. This study aimed to systematically examine ubiquitin-related genes and identify subtypes and stratify prognosis of HCC by using ubiquitin-related signatures. Survival, biological processes, tumor microenvironment (TME), and genomic alterations of the HCC subtypes were investigated. Patients with HCC were classified into two subtypes (clusters 1 and 2) with distinct survival outcomes, pathways, and genomic alterations. Cluster 2 had better prognosis than did cluster 1. Hepatitis B, hepatitis C, Janus tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, and natural killer cell-mediated cytotoxicity were enriched in cluster 1. Moreover, cluster 2 had a higher immune score and immune cell infiltrations, whereas cluster 1 had a lower immune score and immune infiltrations. Additionally, mutations, amplifications, and deletions among the phosphatidylinositol 3-kinase (PI3K)-AKT, p53, and receptor tyrosine kinase (RTK)-RAS pathways more frequently occurred in cluster 1, while those among the Hippo, MYC, and Notch signaling pathways were found in cluster 2. Finally, a prognostic signature, consisting of eight ubiquitin-related genes, was established and validated. In brief, our study established a new classification and developed a prognostic signature for HCC.

Germline Genetic Variants of Viral Entry and Innate Immunity May Influence Susceptibility to SARS-CoV-2 Infection: Toward a Polygenic Risk Score for Risk Stratification

The ongoing COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2 has affected all aspects of human society with a special focus on healthcare. Although older patients with preexisting chronic illnesses are more prone to develop severe complications, younger, healthy individuals might also exhibit serious manifestations. Previous studies directed to detect genetic susceptibility factors for earlier epidemics have provided evidence of certain protective variations. Following SARS-CoV-2 exposure, viral entry into cells followed by recognition and response by the innate immunity are key determinants of COVID-19 development. In the present review our aim was to conduct a thorough review of the literature on the role of single nucleotide polymorphisms (SNPs) as key agents affecting the viral entry of SARS-CoV-2 and innate immunity. Several SNPs within the scope of our approach were found to alter susceptibility to various bacterial and viral infections. Additionally, a multitude of studies confirmed genetic associations between the analyzed genes and autoimmune diseases, underlining the versatile immune consequences of these variants. Based on confirmed associations it is highly plausible that the SNPs affecting viral entry and innate immunity might confer altered susceptibility to SARS-CoV-2 infection and its complex clinical consequences. Anticipating several COVID-19 genomic susceptibility loci based on the ongoing genome wide association studies, our review also proposes that a well-established polygenic risk score would be able to clinically leverage the acquired knowledge.

Participation of Endosomes in Toll-Like Receptor 3 Transportation Pathway in Murine Astrocytes

TLR3 provides immediate type I IFN response following entry of stimulatory PAMPs into the CNS, as it is in HSV infection. The receptor plays a vital role in astrocytes, contributing to rapid infection sensing and suppression of viral replication, precluding the spread of virus beyond neurons. The route of TLR3 mobilization culminating in the receptor activation remains unexplained. In this research, we investigated the involvement of various types of endosomes in the regulation of the TLR3 mobility in C8-D1A murine astrocyte cell line. TLR3 was transported rapidly to early EEA1-positive endosomes as well as LAMP1-lysosomes following stimulation with the poly(I:C). Later, TLR3 largely associated with late Rab7-positive endosomes. Twenty-four hours after stimulation, TLR3 co-localized with LAMP1 abundantly in lysosomes of astrocytes. TLR3 interacted with poly(I:C) intracellularly from 1 min to 8 h following cell stimulation. We detected TLR3 on the surface of astrocytes indicating constitutive expression, which increased after poly(I:C) stimulation. Our findings contribute to the understanding of cellular modulation of TLR3 trafficking. Detailed analysis of the TLR3 transportation pathway is an important component in disclosing the fate of the receptor in HSV-infected CNS and may help in the search for rationale therapeutics to control the replication of neuropathic viruses.

Association of TLR3 single nucleotide polymorphisms with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors

INTRODUCTION:

The human T-lymphotropic virus type 1 (HTLV-1) has a single-stranded RNA genome and expresses specific proteins that have oncogenic potential. Approximately 15 to 20 million people worldwide have been infected by this virus. Changes in protein or gene expression are the effects of single nucleotide polymorphisms (SNPs) within the Toll-like receptor 3 (TLR3) gene. The function and efficacy of signal transduction also lead to modified immune responses. The present study aimed to investigate the association of SNPs within TLR3 (rs3775291 and rs3775296) with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors.

METHODS:

This study was performed on 100 HTLV-1-infected asymptomatic blood donors and 118 healthy blood donors. Genomic DNA from all participants was purified and then amplified using specific PCR primers. SNPs within TLR3 were evaluated using the restriction fragmentation length polymorphism technique, and the results were analyzed using SPSS software (version 22).

RESULTS:

The frequencies of the TLR3 (rs3775296) CC, CA, AA genotypes were 70%, 24%, and 6% in the patient group, and 50.8%, 44.9%, and 4.2% in the control group, respectively. There was a significant difference in the frequency distribution of TLR3 (rs3775296) genotypes and alleles, but not in the frequency distribution of TLR3 (rs3775291) genotypes between the patient and control groups.

CONCLUSIONS:

The TLR3 SNP rs3775296 was significantly associated with HTLV-1 infection and may be a protective factor against this viral infection.

Classical swine fever virus Shimen infection increases p53 signaling to promote cell cycle arrest in porcine alveolar macrophages

Classical swine fever virus (CSFV) replicates in macrophages and causes persistent infection. Despite its role in disastrous economic losses in swine industries, the molecular mechanisms underlying its pathogenesis are poorly understood. The virus evades the neutralizing immune response, subverting the immune system to ensure its own survival and persistence. Our genome-wide analysis of porcine alveolar macrophage transcriptional responses to CSFV Shimen infection using the Solexa/Illumina digital gene expression system revealed that p53 pathway components and cell cycle molecules were differentially regulated during infection compared to controls. Further, we investigated the molecular changes in macrophages infected with CSFV Shimen, focusing on the genes involved in the p53 pathway. CSFV Shimen infection led to phosphorylation and accumulation of p53 in a time-dependent manner. Furthermore, CSFV Shimen infection upregulated cyclin-dependent kinase inhibitor 1A (p21) mRNA and protein. In addition, CSFV Shimen infection induced cell cycle arrest at the G1 phase, as well as downregulation of cyclin E1 and cyclin-dependent kinase 2 (CDK2). The expression of genes in the p53 pathway did not change significantly after p53 knockdown by pifithrin-α during CSFV Shimen infection. Our data suggest that CSFV Shimen infection increases expression of host p53 and p21, and inhibits expression of cyclin E1 and CDK2, leading to cell cycle arrest at the G1 phase. CSFV may utilize this strategy to subvert the innate immune response and proliferate in host cells.

Association of Toll-Like Receptor 3 Single-Nucleotide Polymorphisms and Hepatitis C Virus Infection

Toll-like receptor 3 (TLR3) plays a key role in innate immunity by recognizing pathogenic, double-stranded RNAs. Thus, activation of TLR3 is a major factor in antiviral defense and tumor eradication. Although downregulation of TLR3 gene expression has been mainly reported in patients infected with hepatitis C virus (HCV), the influence of TLR3 genotype on the risk of HCV infection, HCV-related cirrhosis, and/or hepatocellular carcinoma (HCC) remains to be determined. Single-nucleotide polymorphisms (SNPs) within the TLR3 gene and their associations with HCV-related disease risk were investigated in a Saudi Arabian population in this study. Eight TLR3 SNPs were analyzed in 563 patients with HCV, which consisted of 437 patients with chronic HCV infections, 88 with HCV-induced liver cirrhosis, and 38 with HCC. A total of 599 healthy control subjects were recruited to the study. Among the eight TLR3 SNPs studied, the rs78726532 SNP was strongly associated with HCV infection when compared to that in healthy control subjects. The rs5743314 was also strongly associated with HCV-related liver disease progression (cirrhosis and HCC). In summary, these results indicate that distinct genetic variants of TLR3 SNPs are associated with HCV infection and HCV-mediated liver disease progression in the Saudi Arabian population.

HCV core protein binds to gC1qR to induce A20 expression and inhibit cytokine production through MAPKs and NF-κB signaling pathways

Hepatitis C virus (HCV) infection is characterized by a strong propensity toward chronicity. During chronic HCV infection, HCV core protein is implicated in deregulating cytokine expression that associates with chronic inflammation. A20 is known as a powerful suppressor in cytokine signaling, in this study, we explored the A20 expression in macrophages induced by HCV core protein and the involved signaling pathways. Results demonstrated that HCV core protein induced A20 expression in macrophages. Silencing A20 significantly enhanced the secretion of IL-6, IL-1β and TGF-β1, but not IL-8 and TNF. Additionally, HCV core protein interacted with gC1qR, but not TLR2, TLR3 and TLR4 in pull-down assay. Silencing gC1qR abrogated core-induced A20 expression. Furthermore, HCV core protein activated MAPK, NF-κB and PI3K/AKT pathways in macrophages. Inhibition of P38, JNK and NF-κB but not ERK and AKT activities greatly reduced the A20 expression. In conclusion, the study suggests that HCV core protein ligates gC1qR to induce A20 expression in macrophages via P38, JNK and NF-κB signaling pathways, which leads to a low-grade chronic inflammation during HCV infection. It represents a novel mechanism by which HCV usurps the host for persistence.

Toll-Like Receptor 3 is Associated With the Risk of HCV Infection and HBV-Related Diseases

There are inconsistent data on the association of risk of hepatitis virus infection and hepatitis virus-related diseases with the toll-like receptor 3 (TLR3) gene.Several common polymorphism sites were targeted to assess the risk of HBV infection, HCV infection, and HBV-related diseases.Meta-analysis combining data for 3547 cases and 2797 controls from 8 studies was performed in this study. Pooled ORs were calculated to measure the risk of hepatitis virus infection and hepatitis virus-related diseases. Fixed-effects pooled ORs were calculated using the Mantel-Haenszel method.The TLR3 gene was associated with a significantly increased risk of HBV-related diseases among 1355 patients and 1130 controls ([pooled OR, [95%CI]: 1.30, [1.15-1.48] for dominant; 1.77, [1.35-2.31] for recessive; 1.28 [1.16-1.41] for allele frequency). Subgroup analyses by a polymorphism site indicated an increased risk of HCV infection in relation to the TT/CT genotypes of rs3775291 (1.50 [1.11-2.01]), and a decreased risk ascribed to the T allele (0.20 [0.16-0.25]). We also noted an association between rs3775291 and significantly increased risk of HBV-related diseases (2.23 [1.55-3.21]). No significant inter-study heterogeneity or publication bias was detected in the analyses.These data suggest a likely effect on the risk to infect HCV and develop HBV-related diseases for the TLR3 gene. Large-scale studies with racially diverse populations are required to validate these findings.

Neutralizing antibodies against West Nile virus identified directly from human B cells by single-cell analysis and next generation sequencing

West Nile virus (WNV) infection is an emerging mosquito-borne disease that can lead to severe neurological illness and currently has no available treatment or vaccine. Using microengraving, an integrated single-cell analysis method, we analyzed a cohort of subjects infected with WNV - recently infected and post-convalescent subjects - and efficiently identified four novel WNV neutralizing antibodies. We also assessed the humoral response to WNV on a single-cell and repertoire level by integrating next generation sequencing (NGS) into our analysis. The results from single-cell analysis indicate persistence of WNV-specific memory B cells and antibody-secreting cells in post-convalescent subjects. These cells exhibited class-switched antibody isotypes. Furthermore, the results suggest that the antibody response itself does not predict the clinical severity of the disease (asymptomatic or symptomatic). Using the nucleotide coding sequences for WNV-specific antibodies derived from single cells, we revealed the ontogeny of expanded WNV-specific clones in the repertoires of recently infected subjects through NGS and bioinformatic analysis. This analysis also indicated that the humoral response to WNV did not depend on an anamnestic response, due to an unlikely previous exposure to the virus. The innovative and integrative approach presented here to analyze the evolution of neutralizing antibodies from natural infection on a single-cell and repertoire level can also be applied to vaccine studies, and could potentially aid the development of therapeutic antibodies and our basic understanding of other infectious diseases.

Toll-like receptor 3 expression and function in childhood idiopathic nephrotic syndrome

The efficacy of steroids and immunosuppressive treatments in idiopathic nephrotic syndrome (INS) hints at the implication of immune cells in the pathophysiology of the disease. Toll-like receptor (TLR) dysfunctions are involved in many kidney diseases of immune origin, but remain little described in INS. We investigated the expression and function of TLRs in peripheral blood mononuclear cells (PBMC) of INS children, including 28 in relapse, 23 in remission and 40 controls. No child had any sign of infection, but a higher Epstein-Barr virus viral load was measured in the PBMC of relapsing patients. TLR-3 expression was increased in B cells only during INS remission. There was a negative correlation between proteinuria and TLR-3 expression in total and the main subsets of PBMC from INS patients. The expression of TLR-8 was also increased in both CD4(+) T cells and B cells in INS remission. There was a negative correlation between proteinuria and TLR-8 expression in total PBMC, CD4(+) T cells and B cells of INS patients. Nevertheless, TLR-3 and TLR-8 expression was normalized in all PBMC subsets in an additional group of 15 INS patients in remission with B cell repletion after rituximab therapy. Paradoxically, interferon (IFN) regulatory factor 3 transactivation was increased in PBMC of all INS patients. In-vitro secretion of IFN-α and interleukin 6 were increased spontaneously in PBMC of INS remission patients, whereas PBMC from all INS patients displayed an impaired IFN-α secretion after TLR-3 stimulation. Thus, TLR-3 pathway dysfunctions may be closely involved in INS pathogenesis.

Up-regulation of A20/ABIN1 contributes to inefficient M1 macrophage polarization during Hepatitis C virus infection

BACKGROUND

Anti-hepatitis C virus (HCV) responses are often accompanied by an increase in alanine aminotransferase levels in HCV-infected patients, indicating that inflammatory responses are compromised by the virus. Additionally, inflammation is associated with M1-polarizated macrophages, which secrete cytokines such as tumor necrosis factor-α, interleukin-1, and interleukin-12, and present antigens through phagocytosis. HCV-encoded proteins are presented as specific viral antigens in particular infectious steps that influence the immune response. For instance, HCV antigens impact macrophage PD-1 and Tim-3 expression, and contribute to impaired viral clearance. Furthermore, circulatory HCV antigens from infected patients inhibit dendritic cell differentiation, which raises the possibility that HCV antigens may also interfere with macrophage polarization.

METHODS

In this study, the impact of HCV antigen stimulation on M1-polarized macrophages was investigated. The influence of HCV antigens was evaluated by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Specific changes were investigated clinically by flow cytometry and immunofluorescence. Effects of NF-κB during the process were analyzed by western blot.

RESULTS

HCV infection dampened M1 macrophage polarization ex vivo and in vitro. After antigen stimulation, NF-κB signaling was suppressed by the up-regulation of A20 and A20-binding inhibitor of NF-κB binding protein, which likely leads to a variation of functional molecules such as tumor necrosis factor-α, CD163, matrix metalloproteinases, transferrin receptor-1, and CD100, reflecting an anti-inflammatory reaction against M1-polarization.

CONCLUSION

HCV antigens stimulation up-regulates A20/A20-binding inhibitor of NF-κB binding protein expression, which consequently contributes to inefficient M1 macrophage polarization.

Polymorphisms of the Toll-Like Receptor-3 Gene in Autoimmune Adrenal Failure and Type 1 Diabetes in Polish Patients

Infectious agents are plausible environmental triggers for autoimmunity in genetically susceptible individuals. Polymorphic variants of genes implicated in innate immunity may affect immune responses and hence promote auto-aggressive reactions. Genes such as Toll-like receptor-3 (TLR3), which participate in recognizing conserved foreign molecules and mounting the first line of defence against viral infections, are promising functional candidates in autoimmune conditions. We investigated the association of the TLR3 variants, rs13126816 and rs3775291, with the autoimmune endocrine disorders, Addison's disease (AD) and type 1 diabetes (T1D) in the Polish population. The study comprised 168 AD patients, 524 individuals with T1D and 592 healthy controls. Genotyping was performed by real-time PCR. Distribution of the TLR3 genotypes and alleles did not reveal significant differences between patients and controls (p > 0.05). No effect on age at disease onset was found in affected cohorts. This analysis does not support an association between TLR3 variants and the risk for autoimmune destruction of the adrenal cortex and beta cells. However, innate immunity merits further studies in autoimmune endocrine conditions.

TLR3 polymorphisms are associated with virologic response to hepatitis C virus (HCV) treatment in HIV/HCV coinfected patients

BACKGROUND

Toll-like receptor-3 (TLR3) is a cellular receptor that may recognize double-stranded RNA (dsRNA) from viruses, resulting in production of proinflammatory cytokines and interferons, which are important for the adaptive immune response.

OBJECTIVES

To analyze the association between Toll-like receptor-3 (TLR3) polymorphisms (rs3775291 and rs13126816) and virologic response to pegylated interferon-alpha plus ribavirin (pegIFNα/RBV) therapy in HIV/HCV coinfected patients.

STUDY DESIGN

We performed a retrospective study in 321 naïve patients treated with pegIFNα/RBV. Genotyping was performed by using the GoldenGate(®) assay with VeraCode(®). The outcome variables were early virologic response (EVR) and sustained virologic response (SVR).

RESULTS

In a multivariate analysis, rs3775291 A allele decreased the likelihood of achieving EVR (aOR = 0.20; p = 0.018) and SVR (aOR = 0.38; p = 0.024). Regarding rs13126816, the percentage of EVR decreased with each minor A allele (p = 0.034) in HCV-GT2/3 patients, although no significant association was obtained in the multivariate analysis (p = 0.076). Regarding TLR3 haplotypes (comprised of rs3775291 and rs13126816), GT2/3 patients with AA haplotype had decreased odds of achieving EVR (p = 0.030), whereas GG haplotype increased the likelihood (p = 0.018). Regarding SVR, GG haplotype carriers had increased odds of achieving SVR (p = 0.019, p = 0.043 and p = 0.070 for all, GT2/3 and GT1/4 patients, respectively). Besides, GT1/4 patients with GA haplotype had lower odds of achieving SVR (p = 0.039).

CONCLUSIONS

Our study shows the first evidence that two TLR3 polymorphisms (rs3775291 and rs13126816) seem to be related to the HCV therapy response in HCV/HIV coinfected patients.

CyTOF supports efficient detection of immune cell subsets from small samples

Analysis of immune cell states is paramount to our understanding of the pathogenesis of a broad range of human diseases. Immunologists rely on fluorescence cytometry for cellular analysis, and while detection of 8 markers is now well established, the overlap of fluorescent signals limits efficiency. Mass cytometry or CyTOF (Cytometry by Time-Of-Flight) is a new technology for multiparameter single cell analysis that overcomes many limitations of fluorescence-based flow cytometry and can routinely detect as many as 40 markers per sample. This technology provides tremendous detail for cellular analysis of multiple cell populations simultaneously and is a powerful technique for translational investigations. Here we present reproducible detection of immune cell subsets starting with as few as 10,000 cells. Our study provides methods to employ CyTOF for small samples, which is especially relevant for investigation of limited patient biopsies in translational and clinical research.

Systems immunology reveals markers of susceptibility to West Nile virus infection

West Nile virus (WNV) infection is usually asymptomatic but can cause severe neurological disease and death, particularly in older patients, and how individual variations in immunity contribute to disease severity is not yet defined. Animal studies identified a role for several immunity-related genes that determine the severity of infection. We have integrated systems-level transcriptional and functional data sets from stratified cohorts of subjects with a history of WNV infection to define whether these markers can distinguish susceptibility in a human population. Transcriptional profiles combined with immunophenotyping of primary cells identified a predictive signature of susceptibility that was detectable years after acute infection (67% accuracy), with the most prominent alteration being decreased IL1B induction following ex vivo infection of macrophages with WNV. Deconvolution analysis also determined a significant role for CXCL10 expression in myeloid dendritic cells. This systems analysis identified markers of pathogenic mechanisms and offers insights into potential therapeutic strategies.

Immune markers associated with host susceptibility to infection with West Nile virus

Infections with West Nile virus (WNV) are typically asymptomatic, but some patients experience severe neurological disease and even death. Over 1500 fatalities have resulted from the more than 37,000 WNV cases in the USA between 1999 and 2012. While it is clear that age is a significant risk factor, markers of immune status associated with susceptibility to severe infections are incompletely defined. We have taken advantage of stable characteristics of individual status to profile immune markers from a stratified cohort of healthy subjects with a history of asymptomatic or severe infection with WNV. We characterized individual variations in antibody and serum cytokine levels and genome-wide transcriptional profiles of peripheral blood cells (PBMCs). While antibody levels were not significantly different between cohorts, we found that subjects with a history of severe infection had significantly lower levels of serum IL-4, and that these changes in IL-4 levels were associated with altered gene expression patterns in PBMCs. In addition, we identified a signature of 105 genes that displayed altered expression levels when comparing subjects with a history of asymptomatic or severe infection. These results suggest that systems-level analysis of immune system status can be used to identify factors relevant for susceptibility to severe infections, and specifically point to an important contribution for IL-4 in resistance to WNV infection.

The immunological, environmental, and phylogenetic perpetrators of metastatic leishmaniasis

Cutaneous leishmaniases have persisted for centuries as chronically disfiguring parasitic infections affecting millions of people across the subtropics. Symptoms range from the more prevalent single, self-healing cutaneous lesion to a persistent, metastatic disease, where ulcerations and granulomatous nodules can affect multiple secondary sites of the skin and delicate facial mucosa, even sometimes diffusing throughout the cutaneous system as a papular rash. The basis for such diverse pathologies is multifactorial, ranging from parasite phylogeny to host immunocompetence and various environmental factors. Although complex, these pathologies often prey on weaknesses in the innate immune system and its pattern recognition receptors. This review explores the observed and potential associations among the multifactorial perpetrators of infectious metastasis and components of the innate immune system.

Role of innate immunity in the development of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide. It is caused by a variety of risk factors, most common ones being infection with hepatitis viruses, alcohol, and obesity. HCC often develops in the background of underlying cirrhosis, and even though a number of interventional treatment methods are currently in use, recurrence is fairly common among patients who have had a resection. Therefore, whole liver transplantation remains the most practical treatment option for HCC. Due to the growing incidence of HCC, intense research efforts are being made to understand cellular and molecular mechanisms of the disease so that novel therapeutic strategies can be developed to combat liver cancer. In recent years, it has become clear that innate immunity plays a critical role in the development of a number of liver diseases, including HCC. In particular, the activation of Toll-like receptor signaling results in the generation of immune responses that often results in the production of pro-inflammatory cytokines and chemokines, and could cause acute inflammation in the liver. In this review, the current knowledge on the role of innate immune responses in the development and progression of HCC is examined, and emerging therapeutic strategies based on molecular mechanisms of HCC are discussed.

The genetics of innate immunity sensors and human disease

Since their discovery, innate immunity microbial sensors have been increasingly studied and shown to play a critical role in innate responses to microbes in several experimental in vitro, ex vivo, and animal models. However, their role in the human response to infection in natural conditions has just started to be deciphered, by means of clinical studies of primary immunodeficiencies and epidemiological genetic studies. Here, we summarize the major findings concerning the genetic diversity of the various families of microbial sensors in humans, and of other molecules involved in the signaling pathways they trigger. Specifically, we review the genetic associations, revealed by both clinical and epidemiological genetics studies, of microbial sensors from five different families: Toll-like receptors, C-type lectin receptors, NOD-like receptors, RIG-I-like receptors, and cytosolic DNA sensors. In particular, we consider the relationships between variation at the genes encoding these molecules and susceptibility to and the severity of infectious diseases and other clinical conditions associated with immune dysfunction, including autoimmunity, inflammation, allergy, and cancer. Despite the fact that the genetic links between innate immunity sensors and human disorders remain still limited, human genetics studies are increasingly improving our understanding of the genuine functions of microbial sensors and downstream signaling molecules in the natural setting.