Association of polymorphisms of programmed cell death-1 gene with chronic hepatitis B virus infection

Hepatitis B-related hepatocellular carcinoma: classification and prognostic model based on programmed cell death genes

Instruction

Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Programmed cell death (PCD) is a critical process in suppressing tumor growth, and alterations in PCD-related genes may contribute to the progression of HBV-HCC. This study aims to develop a prognostic model that incorporates genomic and clinical information based on PCD-related genes, providing novel insights into the molecular heterogeneity of HBV-HCC through bioinformatics analysis and experimental validation.

Methods

In this study, we analyzed 139 HBV-HCC samples from The Cancer Genome Atlas (TCGA) and validated them with 30 samples from the Gene Expression Omnibus (GEO) database. Various bioinformatics tools, including differential expression analysis, gene set variation analysis, and machine learning algorithms were used for comprehensive analysis of RNA sequencing data from HBV-HCC patients. Furthermore, among the PCD-related genes, we ultimately chose DLAT for further research on tissue chips and patient cohorts. Besides, immunohistochemistry, qRT-PCR and Western blot analysis were conducted.

Results

The cluster analysis identified three distinct subgroups of HBV-HCC patients. Among them, Cluster 2 demonstrated significant activation in DNA replication-related pathways and tumor-related processes. Analysis of copy number variations (CNVs) of PCD-related genes also revealed distinct patterns in the three subgroups, which may be associated with differences in pathway activation and survival outcomes. DLAT in tumor tissues of HBV-HCC patients is upregulated.

Discussion

Based on the PCD-related genes, we developed a prognostic model that incorporates genomic and clinical information and provided novel insights into the molecular heterogeneity of HBV-HCC. In our study, we emphasized the significance of PCD-related genes, particularly DLAT, which was examined in vitro to explore its potential clinical implications.

Evaluation of the possible association of PDCD-1 and LAG3 gene polymorphisms with hepatocellular carcinoma risk

PURPOSE

Programmed death-1 (PDCD-1) and lymphocyte activating 3 (LAG3), two important immunosuppressive molecules, play crucial roles in immune escape of tumor cells. This study evaluated the effects of PDCD-1 (rs10204525 and rs36084323), and LAG3 (rs870849 and rs1882545) gene polymorphisms on hepatocellular carcinoma (HCC) risk.

METHODS

341 patients with HCC and 350 cancer-free controls in the South Chinese population were included in a population-based case-control study. DNAs were extracted from peripheral blood samples. Genotypes were analyzed using multiplex PCR and sequencing. SNPs were analyzed using multiple inheritance models (co-dominant, dominant, recessive, and over-dominant).

RESULTS

The allele and genotype frequencies of neither of the four polymorphisms, adjusted for age and gender, differed between HCC patients and controls. The differences were also not significant after stratifying by gender and age. According to our results, HCC patients with rs10204525 TC genotype had significantly lower AFP levels than HCC patients with rs10204525 TT genotype (P = 0.004). Moreover, the frequency of PDCD-1 rs36084323 CT genotype reduced the risk of TNM grade (CT vs. C/C-T/T: OR = 0.57, 95%CI = 0.37-0.87, P = 0.049).

CONCLUSION

Our results demonstrated that the PDCD-1 (rs10204525 and rs36084323), and LAG3 (rs870849 and rs1882545) polymorphism did not influence the risk of HCC, PDCD-1 rs10204525 TC genotype was associated with the lower AFP levels and rs36084323 CT genotypes were related to HCC tumor grades in the South Chinese samples.

Are the Costimulatory Molecule Gene Polymorphisms (CTLA-4) Associated With Infection in Organ Transplantation? A Meta-Analysis

Organ transplantation has been linked to certain gene polymorphisms. The effect of gene polymorphisms-associated organ transplantation gene on infection, on the other hand, is yet unknown. The research studying the link between the CTLA-4 rs5742909, rs733618, rs4553808, rs231775, and polymorphisms of the organ transplantation gene and infection were found in PubMed, Web of Science, Scopus, and Embase, and the published articles from 2012 to 2020 were gathered. For the best estimation of the intended results, a random-effects model was used in this meta-analysis. In this study, 1,567 studies were initially included and 9 eligible studies were eligible for further analyses. A significant correlation between CTLA4+49 [A/G-231775 odds ratio (OR) = 077, 0.59-0.95] and CTLA4 [rs5742909TT OR: 0.09, 0.27-0.45] gene polymorphism with infection in organ transplantation was observed. Also, no significant association was found between other CTLA4 gene polymorphisms with infection in organ transplantation. Further studies involving gene-gene and gene-diet interactions should be conducted to investigate this association with infection.

Severe Immune-Related Adverse Events in Patients Treated with Nivolumab for Metastatic Renal Cell Carcinoma Are Associated with PDCD1 Polymorphism

Single nucleotide polymorphisms (SNPs) reportedly influence the effect of nivolumab in metastatic renal cell carcinoma (mRCC). This study aimed to evaluate the relationship between the clinical outcomes of patients with mRCC and SNPs in programmed cell death protein 1 (PD-1) protein-coding gene (PDCD1) and explore any potential correlation with patient prognosis and incidence of immune-related adverse events (irAEs). In total, 106 patients with mRCC, who were treated with nivolumab alone (n = 59) or nivolumab and ipilimumab (n = 47), were enrolled in the study. Three SNPs in the PDCD1 gene, namely PD-1.3, PD-1.5, and PD-1.6, were assessed. Patients harboring the PD-1.6 G allele experienced more severe (odds ratio, 3.390; 95% confidence interval 1.517–7.756; p = 0.003) and multiple (OR, 2.778; 95% CI, 1.020–6.993 p = 0.031) irAEs than those harboring the AA genotype. Thus, the existence of the PDCD1 PD-1.6 polymorphism (G allele) was associated with the occurrence of severe and multiple irAEs in patients with mRCC. Further evaluation of PDCD1 polymorphisms might help identify patients experiencing irAE by nivolumab treatment.

MicroRNAs at the Crossroad between Immunoediting and Oncogenic Drivers in Hepatocellular Carcinoma

Simple Summary

In recent years, treatments enhancing the antitumor immune response have revealed a new promising approach for advanced hepatocellular carcinoma (HCC). Beside favorable results in about one third of patients, much still remains to be done to face primary nonresponse, early, and late disease reactivation. Understanding the mechanisms underneath immune system modulation by immune checkpoint inhibitors in HCC might give additional opportunities for patient selection and combined approaches. MicroRNAs have emerged as relevant modulators of cancer cell hallmarks, including aberrant proliferation, invasion and migration capabilities, epithelial-to-mesenchymal transition, and glycolytic metabolism. At the same time, they contribute to the immune system development, response, and programs activation, with particular regard towards regulatory functions. Thus, miRNAs are relevant not only in cancer cells’ biology, but also in the immune response and interplay between cancer, microenvironment, and immune system.

Abstract

Treatments aimed to reverse the tumor-induced immune tolerance represent a promising approach for advanced hepatocellular carcinoma (HCC). Notwithstanding, primary nonresponse, early, and late disease reactivation still represent major clinical challenges. Here, we focused on microRNAs (miRNAs) acting both as modulators of cancer cell hallmarks and immune system response. We outlined the bidirectional function that some oncogenic miRNAs play in the differentiation and program activation of the immune system development and, at the same time, in the progression of HCC. Indeed, the multifaceted spectrum of miRNA targets allows the modulation of both immune-associated factors and oncogenic or tumor suppressor drivers at the same time. Understanding the molecular changes contributing to disease onset, progression, and resistance to treatments might help to identify possible novel biomarkers for selecting patient subgroups, and to design combined tailored treatments to potentiate antitumor approaches. Preliminary findings seem to argue in favor of a bidirectional function of some miRNAs, which enact an effective modulation of molecular pathways driving oncogenic and immune-skipping phenotypes associated with cancer aggressiveness. The identification of these miRNAs and the characterization of their ‘dual’ role might help to unravel novel biomarkers identifying those patients more likely to respond to immune checkpoint inhibitors and to identify possible therapeutic targets with both antitumor and immunomodulatory functions. In the present review, we will focus on the restricted panel of miRNAs playing a bidirectional role in HCC, influencing oncogenic and immune-related pathways at once. Even though this field is still poorly investigated in HCC, it might represent a source of candidate molecules acting as both biomarkers and therapeutic targets in the setting of immune-based treatments.

The Role of NcRNAs to Regulate Immune Checkpoints in Cancer

At present, the incidence of cancer is becoming more and more common, but its treatment has always been a problem. Although a small number of cancers can be treated, the recurrence rates are generally high and cannot be completely cured. At present, conventional cancer therapies mainly include chemotherapy and radiotherapy, which are the first-line therapies for most cancer patients, but there are palliatives. Approaches to cancer treatment are not as fast as cancer development. The current cancer treatments have not been effective in stopping the development of cancer, and cancer treatment needs to be imported into new strategies. Non-coding RNAs (ncRNAs) is a hot research topic at present. NcRNAs, which include microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), participate in all aspects of cancer biology. They are involved in the progression of tumors into a new form, including B-cell lymphoma, glioma, or the parenchymal tumors such as gastric cancer and colon cancer, among others. NcRNAs target various immune checkpoints to affect tumor proliferation, differentiation, and development. This might represent a new strategy for cancer treatment.

Circulating levels of sPD-1 and PD-1 genetic variants are associated with hepatitis B infection and related liver disease progression

BACKGROUND

Programmed cell death-1 (PD-1) variants and circulating levels of soluble PD-1 are associated with susceptibility to malignant and infectious disease. This study aimed to examine the association of PD-1.5 and PD-1.9 variants, and plasma sPD-1 levels with HBV infection and disease progression.

METHODS

The study cohort consists of HBV-infected adults (n=513) stratified by clinical course, including chronic hepatitis B (CHB, n=173), liver cirrhosis (LC, n=134), hepatocellular carcinoma (HCC, n=206), and matched healthy controls (HC, n=196). The PD-1.5 (rs2227981 C/T) and PD-1.9 (rs2227982 C/T) genetic variants were genotyped by Sanger sequencing, and plasma sPD-1 levels were quantified by enzyme immunoassay.

RESULTS

The plasma sPD-1 levels were significantly high among HBV patients. The highest plasma sPD-1 levels were observed in CHB patients, followed by the LC and HCC groups. In addition, the plasma sPD-1 levels correlated positively with liver inflammation (aspartate transaminase, AST: rho=0.57, P<0.0001 and alanine aminotransferase, ALT: rho=0.57, P<0.0001) and were positively correlated with liver fibrosis (AST to Platelet Ratio Index, APRI score: rho=0.53, P<0.0001). The PD-1.9 TT genotype was less frequent in CHB patients compared to LC, HCC and HCC+LC patients in both codominant and recessive models (P<0.01) and was found to be a risk factor for HCC predisposition [HCC vs. non-HCC: OR=2.0 (95% CI: 1.13-3.7), P_adj=0.017]. The PD-1.5 CT genotype was associated with a reduced risk of acquiring HCC [OR=0.6 (95%CI: 0.4-0.9), P_adj=0.031].

CONCLUSION

Our study concludes that sPD-1 levels are associated with liver inflammation and progression of liver fibrosis and the PD-1.5 and PD-1.9 variants are associated with HBV infection and progression of liver disease.

Immunotherapy against programmed death-1/programmed death ligand 1 in hepatocellular carcinoma: Importance of molecular variations, cellular heterogeneity, and cancer stem cells

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy related to diverse etiological factors. Different oncogenic mechanisms and genetic variations lead to multiple HCC molecular classifications. Recently, an immune-based strategy using immune checkpoint inhibitors (ICIs) was presented in HCC therapy, especially with ICIs against the programmed death-1 (PD-1) and its ligand PD-L1. However, despite the success of anti-PD-1/PD-L1 in other cancers, a substantial proportion of HCC patients fail to respond. In this review, we gather current information on biomarkers of anti-PD-1/PD-L1 treatment and the contribution of HCC heterogeneity and hepatic cancer stem cells (CSCs). Genetic variations of PD-1 and PD-L1 are associated with chronic liver disease and progression to cancer. PD-L1 expression in tumoral tissues is differentially expressed in CSCs, particularly in those with a close association with the tumor microenvironment. This information will be beneficial for the selection of patients and the management of the ICIs against PD-1/PD-L1.

Programmed cell death-1 single-nucleotide polymorphism rs10204525 is associated with human immunodeficiency virus type 1 RNA viral load in HIV-1-infected Moroccan subjects

Human Immunodeficiency Virus (HIV-1) infections are characterized by dysfunctional cellular and humoral antiviral immune responses. The progressive loss of effector functions in chronic viral infection has been associated with the up-regulation of programmed death-1 (PD-1), a negative regulator of activated T cells and Natural Killer cells. In HIV-1 infection, increased levels of PD-1 expression correlate with CD8 + T-cell exhaustion. In vitro, PD-1 blockade using PD-1 antibodies led to an increase in HIV-1 specific CD8 + T and memory B cell proliferation. We aimed to investigate the impact of PDCD1 rs10204525 polymorphism on HIV-1 susceptibility, AIDS development, and treatment response outcomes in HIV-1 infection in a Moroccan population. A total of 214 HIV-1 seropositive and 250 seronegative subjects were enrolled to investigate the association between the between the single-nucleotide polymorphism (SNP) rs10204525 of PDCD1 gene and HIV-1 pathogenesis using a predesigned TaqMan SNP genotyping assay. No significant association was found between rs10204525 and susceptibility to HIV-1 infection and AIDS development (p > 0.05). Genotype frequencies were significantly associated with the viral load before ART (p = 0.0105). HIV-1 viral load was significantly higher among subjects with the CC compared to TT genotype (p = 0.0043). In treated subjects, the median of viral load levels was significantly higher in CC and CT groups than TT subjects (p < 0.005). However, analysis of the correlation between CD4 + T-cell levels and PDCD1 polymorphism before and after ART showed no significant difference (p > 0.05). Our results demonstrated that rs10204525 polymorphism does not affect HIV-1 infection. However, this polymorphism may affect the response to treatment as measured by RNA viral load levels.

Genetic variants of programmed cell death 1 are associated with HBV infection and liver disease progression

The inhibitory effects of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) modulates T-cell depletion. T-cell depletion is one of the key mechanisms of hepatitis B virus (HBV) persistence, in particular liver disease progression and the development of hepatocellular carcinoma (HCC). This case–control study aimed to understand the significance of PD-1 polymorphisms (PD-1.5 and PD-1.9) association with HBV infection risk and HBV-induced liver disease progression. Genotyping of PD-1.5 and PD-1.9 variants was performed by direct Sanger sequencing in 682 HBV-infected patients including chronic hepatitis (CHB, n = 193), liver cirrhosis (LC, n = 183), hepatocellular carcinoma (HCC, n = 306) and 283 healthy controls (HC). To analyze the association of PD-1 variants with liver disease progression, a binary logistic regression, adjusted for age and gender, was performed using different genetic models. The PD-1.9 T allele and PD-1.9 TT genotype are significantly associated with increased risk of LC, HCC, and LC + HCC. The frequencies of PD-1.5 TT genotype and PD-1.5 T allele are significantly higher in HCC compared to LC patients. The haplotype CT (PD-1.5 C and PD-1.9 T) was significantly associated with increased risk of LC, HCC, and LC + HCC. In addition, the TC (PD-1.5 T and PD-1.9 C) haplotype was associated with the risk of HCC compared to non-HCC. The PD-1.5 CC, PD-1.9 TT, genotype, and the CC (PD-1.5 C and PD-1.9) haplotype are associated with unfavorable laboratory parameters in chronic hepatitis B patients. PD-1.5 and PD1.9 are useful prognostic predictors for HBV infection risk and liver disease progression.

Role of microRNA 4717, its effects on programmed cell death protein-1 in hepatitis B infection, and interaction between PDCD1 and miR-4717

It is suggested that programmed cell death protein-1 (PD-1) is involved in hepatitis B virus (HBV) infection, the leading cause of hepatocellular carcinoma globally. This study was multi-aimed, that is, to investigate the role of microRNA (miR) 4717 and its target, PD-1 and to determine how the rs10204525 polymorphism in the 3′ untranslated region (3′UTR) of PD-1 affects its interaction with miR-4717. The expression levels of miR-4717 with various single-nucleotide polymorphisms were measured by reverse transcription–quantitative polymerase chain reaction (RT-qPCR). A total of 54 tissue samples from HBV-infected individuals were collected, genotyped, and categorized into three groups; AA (n = 32), AG (n = 18), and GG (n = 4). The expression levels of gene PDCD1 and its corresponding PD-1 protein were significantly declined in the AA group as compared to AG and GG groups. There was a negative linear association between PDCD1 and miR-4717 in the tissue samples. HEPG2 cells transfected with an miR-4717 mimic or PD-1 small interfering (si)RNA exhibited significantly reduced expression levels of PDCD1 and PD-1, whereas cells transfected with an inhibitor of miR-4717 demonstrated greater expression levels of PDCD1 and PD-1 compared with the scramble control. In addition, cell viability and apoptosis were assessed in cells transfected with an miR-4717 mimic, PD-1 siRNA, or an miR-4717 inhibitor. Results revealed that treatment with the miR-4717 mimic or PD-1 siRNA enhanced viability of cells and reduced apoptosis. The results of this study suggest that rs10204525 polymorphism interferes with the interaction between PD-1 and miR-4717 and therefore induces apoptosis in liver cancer cells.

Association of rs10204525 genotype GG and rs2227982 CC combination in programmed cell death 1 with hepatitis B virus infection risk

Single nuclear polymorphism (SNP) of programmed cell death 1 (PD-1) was reported associated with hepatitis B virus (HBV) infection, but the SNP sites studied were limited. Whether the combination of 2 or more SNP sites could better represent the relationship between PD-1 SNP and HBV infection was not studied.Eight hundred ninety-eight HBV-infected patients (222 asymptomatic carriers [AsC], 276 chronic hepatitis B, 105 acute-on-chronic liver failure, and 295 liver cirrhosis) and 364 health controls of South China were enrolled in this study. Four PD-1 SNPs (rs10204525, rs2227982, rs41386349, and rs36084323) were selected and detected by TaqMan probe. The frequency of allele, genotype, and combination of different SNPs were compared between different groups.For allele frequency analysis, G allele of rs10204525 was protective factor (odds ratio (OR) = 0.823, 95% confidence interval (CI) = 0.679-0.997, P = .046) and T allele of rs2227982 was predisposing factor (OR = 1.231, 95% CI = 1.036-1.463, P = .018) in HBV infection. When analyzed in genotype frequency, the genotype GG of rs10204525 and CC of rs2227982 were protective factor of HBV infection. Combination of rs10204525 GG and rs2227982 CC was potent protective factor of HBV infection (OR = 0.552, 95% CI = 0.356-0.857, P = .007) and was also associated with lower HBV load (OR = 0.201, 95% CI = 0.056-0.728, P = .008) in AsC. The 4 SNP sites were not associated with progression of HBV-related liver disease.Rs10204525 and rs2227982 of PD-1 associate with HBV infection and combination of the 2 SNP sites can better predict host susceptibility in HBV infection.

Clinical Significance of Polymorphisms in Immune Response Genes in Hepatitis C-Related Hepatocellular Carcinoma

Background and Aims: Polymorphisms in the immune response genes can contribute to clearance of hepatitis C virus (HCV) infection but also mediate liver inflammation and cancer pathogenesis. This study aimed to investigate the association of polymorphisms in PD-1 (PDCD1), IFNL3 (IL28B), and TLR2 immune related genes in chronic HCV patients with different hepatic and lymphoproliferative HCV-related diseases. Methods: Selected PDCD1, IFNL3, and TLR2 genes were tested by molecular approaches in 450 HCV-positive patients with increasing severity of underlying liver diseases [including chronic infection (CHC), cirrhosis and hepatocellular carcinoma (HCC)], in 238 HCV-positive patients with lymphoproliferative diseases [such as cryoglobulinemia and non-Hodgkin lymphoma (NHL)] and in 94 blood donors (BD). Results: While the rs12979860 IFNL3 T allele was found a good marker associated with HCV-outcome together with the rs111200466 TLR2 del variant, the rs10204525 PD-1.6 A allele was found to have an insignificant role in patients with HCV-related hepatic disorders. Though in Asian patients the combination of IFNL3 and PD-1.6 markers better define the HCV-related outcomes, in our series of Caucasian patients the PD-1.6 A-allele variant was observed very rarely. Conclusion: Differences in the incidence of HCV-related HCC and clinical response between Asians and Europeans may be partially due to the distribution of PD-1.6 genotype that we found divergent between these two populations. On the other hand, we confirmed in this study that the polymorphic variants within IFNL3 and TLR2 immune response genes are significantly associated with HCV-related disease progression in our cohort of Italian patients.

Association of PD-1 gene with outcome of hepatitis C virus infection

Primary hepatitis C virus infection might be spontaneously cleared or become chronic. Polymorphisms in immune regulatory genes might influence the outcome. The aim of this study was to determine the frequency of genotypes and alleles of PD-1.3 and PD-1.5 gene loci in HCV infected patients and their association with the disease outcome. In this study 167 patients with chronic hepatic C and 42 individuals whose infection was spontaneously cleared, and a healthy control group comprising of 300 participants were included. The presence of chronic or spontaneously cleared infection amongst the participants was determined in advance by serologic and molecular methods. Genomic DNA was extracted using salting out method. PD-1 gene polymorphisms assay was performed using PCR-RFLP method. The frequency of alleles of PD-1.3 gene locus was significantly higher in the spontaneously cleared HCV infected group (P = 0.03) as well as the healthy control group (P = 0.04) in comparison to the chronic infected participants. In the case of PD-1.5 locus, there was no association between the frequency of inherited genotype or alleles and HCV infection outcome amongst the three groups. Haplotype analysis showed no statistically significant differences in the frequencies of different haplotypes between the three studied groups. Our finding collectively inferred that individuals with A allele at PD-1.3 locus might clear HCV infection more frequently than those with T allele. Instead, polymorphisms at PD-1.5 locus as well as haplotypes emerged from PD-1.3 G/A and PD-1.5 C/T might not be significant in the HCV infection outcome.

Programmed cell death-1 3'-untranslated region polymorphism is associated with spontaneous clearance of hepatitis B virus infection

Hepatitis B virus (HBV)-specific CD8+ T cells play an important role in the clearance of HBV infection. Programmed cell death-1 (PD-1), an immunosuppressive molecule that regulates T-cell activation and peripheral immune tolerance, is increasingly shown to influence the outcome of HBV infection. rs10204525, a single-nucleotide polymorphism in the 3'-untranslated region (3'-UTR) of PD-1, has been associated with susceptibility and disease progression of chronic HBV infection in far-eastern patients. The aim of our study was to assess the impact of rs10204525 variation on HBV infection in Moroccan patients. A total of 236 patients with chronic HBV infection and 134 individuals with spontaneous HBV resolution were genotyped using a Taqman assay. In addition, PD-1 mRNA expression in peripheral blood nuclear cells was determined by quantitative reverse-transcription polymerase chain reaction. We found that the AA genotype is protective (odds ratio, 0.43; 95% confidence interval, 0.19 to 0.97; P = 0.038) against HBV infection. Interestingly, PD-1 messenger RNA (mRNA) expression analysis has revealed that chronic HBV carriers with GG and GA displayed higher levels of PD-1 mRNA compared with corresponding genotypes in resolved subjects (P = 0.031 and 0.014, respectively). Our data suggest that Mediterranean HBV-infected patients carrying PD-1 GG and GA genotypes at rs10204525 have high PD-1 mRNA expression and may be more prone to installation of chronicity.

Functional variants of TIM-3/HAVCR2 3'UTR in lymphoblastoid cell lines

Aim

Variants of TIM-3/HAVCR2 3'UTR miRNA binding sites are significantly associated with cancer; however, roles in post-transcriptional regulation have not been elucidated.

Methods

The regulatory and coding region single nucleotide polymorphisms (SNPs) of TIM-3/HAVCR2 were identified using an online database. Single nucleotide polymorphism Function Prediction was used to predict potential functional relevance of miRNA binding sites.

Results

The analysis indicated rs9313439, rs4704846, rs3087616 and rs1036199 affect possible miRNA binding sites in TIM-3/HAVCR2 3'UTR. We used additional data on genotypes and limited minor allele frequency >5% in the HapMap populations. Only rs3087616 and rs4704846 were significantly associated with TIM-3/HAVCR2.

Conclusion

Both rs3087616 and rs4704846 could be putative variants mediating post-transcriptional regulation of the TIM-3/HAVCR2. Deeper understanding of how 3'UTR variants influence the activity by TIM-3/HAVCR2 for therapy against cancer.

Association of TNF-Alpha gene polymorphisms and susceptibility to hepatitis B virus infection in Egyptians

Tumor necrosis factor alpha (TNF-α) is one of the important cytokine in generating an immune response against hepatitis B virus (HBV). Genetic polymorphisms might influence gene transcription, leading to disturbance in cytokine production. We hypothesized that single nucleotide polymorphism (SNPs) in TNF-α gene could affect the pathogenesis of HBV. To test this hypothesis, we investigated the role of TNF-α polymorphism [-863C/A (rs1800630), -308G/A (rs1800629), -376G/A (rs1800750), -857C/T (rs1799724) and +489G/A (rs1800610)] in the susceptibility to chronic hepatitis B (CHB) infection. Polymorphisms of the TNF-α (-863C/A (rs1800630), -308G/A) were analyzed by Polymerase chain reaction sequence specific primer (PCR-SSP) while TNF-α (-376G/A, -857C/T and +489G/A) by PCR-restriction fragment length polymorphism (PCR-RFLP) in 104 patients with CHB and 104 healthy controls. The plasma level of TNF-α was measured using Enzyme-linked immunosorbent assay (ELISA). The study showed a significant increase in the frequency of -863CC, -376GA, -857CC, -857TT and +489GA genotypes and -863C, -376A, -857C, and +489A alleles in CHB patients compared to controls. In addition, CAGCG haplotype had a highest frequency in CHB patients. A strong Linkage Disequilibrium (LD) between TNF-α -863C/A (rs1800630) and -376G/A (D' = 0.7888, r² = 0.0200); -308G/A and -857C/T (D' = 0.9213, r² = 0.1770); -308G/A and +489G/A (D' = 0.9088, r² = 0.1576) was demonstrated. CHB patients had significantly lower levels of TNF-α compared to controls. In conclusion, our preliminary results suggest that -863C/A (rs1800630), -308G/A, -376G/A, and +489G/A of the TNF-α gene may play a role in HBV susceptibility in Egyptians. The significant reduction in TNF-α in CHB patient was independent of any particular genotype/haplotype in TNF-α.

Coinhibitory Pathways in the B7-CD28 Ligand-Receptor Family

Immune responses need to be controlled for optimal protective immunity and tolerance. Coinhibitory pathways in the B7-CD28 family provide critical inhibitory signals that regulate immune homeostasis and defense and protect tissue integrity. These coinhibitory signals limit the strength and duration of immune responses, thereby curbing immune-mediated tissue damage, regulating resolution of inflammation, and maintaining tolerance to prevent autoimmunity. Tumors and microbes that cause chronic infections can exploit these coinhibitory pathways to establish an immunosuppressive microenvironment, hindering their eradication. Advances in understanding T cell coinhibitory pathways have stimulated a new era of immunotherapy with effective drugs to treat cancer, autoimmune and infectious diseases, and transplant rejection. In this review we discuss the current knowledge of the mechanisms underlying the coinhibitory functions of pathways in the B7-CD28 family, the diverse functional consequences of these inhibitory signals on immune responses, and the overlapping and unique functions of these key immunoregulatory pathways.

Immune checkpoint proteins PD-1 and TIM-3 are both highly expressed in liver tissues and correlate with their gene polymorphisms in patients with HBV-related hepatocellular carcinoma

Immune checkpoint proteins programmed death-1 (PD-1) and T-cell immunoglobulin domain and mucin domain containing molecule-3 (TIM-3) expression and their gene polymorphisms have separately been shown to be associated with hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). This study simultaneously examined PD-1 and TIM-3 expression in liver tissues and PD1 and TIM3 polymorphisms and analyzed their correlations in 171 patients with HBV-related HCC and 34 patients with HBV-related cirrhosis.PD-1 and TIM-3 expression in liver tissues were examined by immunohistochemistry and the genotypes of PD1 rs10204525 and TIM3 rs10053538 polymorphisms were determined using genomic DNA extracted from peripheral blood as template.Both PD-1 and TIM-3 expressions in liver infiltrating lymphocytes of HCC tumor tissues were significantly higher than those in tumor adjacent tissues or cirrhotic tissues. The elevated PD-1 and TIM-3 expressions were significantly associated with higher tumor grades. The levels between PD-1 and TIM-3 expression in tumor tissues and tumor adjacent tissues had a significant positive intercorrelation. The expressions of PD-1 and TIM-3 in tumor tissues, tumor adjacent tissues, and cirrhotic tissues were significantly associated with PD1 and TIM3 polymorphisms, with genotype AA of PD1 rs10204525 and genotypes GT+TT of TIM3 rs10053538 being associated with significantly increased PD-1 and TIM-3 expression, respectively.These findings support the potential to improve the efficiency of immune checkpoint-targeted therapy and reduce resistance to the therapy by blocking both PD-1 and TIM-3 and suggest the potential to apply the genotype determination of PD1 rs10204525 and TIM3 rs10053538 as biomarkers of immune checkpoint-directed therapies.

Prognostic relevance of genetic variants involved in immune checkpoints in patients with colorectal cancer

PURPOSE

Genetic polymorphisms in genes involved in the immune response are already known to affect the anti-tumor immune response. This study systematically investigated the association of 14 functional SNPs in a panel of 7 genes (CCL2, CCR2, NT5E, IDO1, LAG3, PDL1, and PDCD1) involved in immune response checkpoints with the survival outcomes of Korean patients with colorectal cancer (CRC).

METHODS

The genomic DNA from 668 patients with curatively resected CRC was analyzed using a Sequenom MassARRAY, along with the association with recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Among the 14 SNPs, CCL2 rs4586 and PDCD1 rs10204525 were found to have an influence on the survival outcomes of the patients with resectable CRC. CCL2 rs4586 showed a significant correlation with OS in a recessive model in a univariate analysis, as well as a multivariate analysis. In addition, PDCD1 rs10204525 revealed a significant association with RFS and OS in a recessive model in a univariate analysis and exhibited a significant impact in a multivariate analysis.

CONCLUSION

In conclusion, this results suggest that the genetic predisposition of the host may affect the anti-tumor immune reaction in CRC. The results of this study may also be helpful when selecting targets for novel drug development to promote the anti-tumor immune response.

Association of programmed death-1 polymorphisms with the risk and prognosis of esophageal squamous cell carcinoma

Programmed death-1 (PD-1) is an immunoinhibitory receptor belonging to the CD28 family. This study was designed to investigate the association of PD-1 rs36084323:A>G, rs2227981:C>T, rs2227982:C>T and rs10204525:A>G single nucleotide polymorphisms (SNPs) with the risk and prognosis of esophageal squamous cell carcinoma (ESCC) in a high-incidence population from Northern China. These four SNPs were genotyped by polymerase chain reaction ligase detection reaction (PCR-LDR) method in 584 ESCC patients and 585 healthy controls. The rs2227981:C>T SNP C/T genotype increased the risk of ESCC for the smokers (OR = 1.483, 95% CI = 1.018-2.160) and rs2227982:C>T SNP C/T genotype enhanced susceptibility to ESCC for the females (OR = 1.708, 95% CI = 1.056-2.762). For rs10204525:A>G SNP, A/A genotype was related to increased risk of ESCC (OR = 1.735, 95% CI = 1.086-2.771) overall. Among the 584 ESCC patients, the survival information of 204 ESCC patients was collected. The rs36084323:A>G SNP A/G genotype was associated with lower risk of death in ESCC patients with upper gastrointestinal cancer (UGIC) family history (HR = 0.339, 95%CI = 0.115-0.996). The rs2227982:C>T SNP C/T genotype was associated with lower risk of death in smoker ESCC patients and ESCC patients with UGIC family history (HR = 0.409 and 0.292, 95%CI = 0.194-0.863 and 0.101-0.847). PD-1 rs2227981:C>T, rs2227982:C>T and rs10204525:A>G SNPs might be used as predictive markers of the susceptibility to ESCC for the Han nationality in a high-incidence population from Northern China. PD-1 rs36084323:A>G and rs2227982:C>T SNPs were associated with the prognosis of the Han ESCC patients in this high-incidence region.

Genetic polymorphisms of immune checkpoint proteins PD-1 and TIM-3 are associated with survival of patients with hepatitis B virus-related hepatocellular carcinoma

Programmed cell death protein 1 (PD-1) and T-cell immunoglobulin domain and mucin domain containing molecule 3 (TIM-3) are involved in hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). This study examined the associations of PD1 and TIM3 polymorphisms with the overall survival (OS) of a prospective cohort of 258 HBV-related HCC patients. Results showed that PD1 +8669 G allele-containing genotypes or TIM3 -1516 genotype GG were significantly associated with longer OS (P < 0.001 and P = 0.001, respectively). In multivariate analysis, PD1 +8669 G allele-containing genotypes and TIM3 -1516 genotype GG were independently associated with longer OS (hazard ratio (HR), 1.835; 95% confidence interval (CI), 1.342-2.509; P < 0.001 and HR, 2.070; 95%CI, 1.428-3.002; P < 0.001, respectively). PD1 +8669 G allele-containing genotypes were significantly associated with longer OS in patients receiving surgical (resection or radiofrequency) treatment, transcatheter arterial chemoembolization (TACE) or supportive and symptomatic treatment. TIM3 -1516 genotype GG was significantly associated with longer OS in TACE patients. In multivariate analysis, PD1 +8669 G allele-containing genotypes were independently associated with longer OS in each treatment population. TIM3 -1516 genotype GG was independently associated with longer OS in patients receiving surgical treatment or TACE. These findings suggest that PD1 +8669 A/G and TIM3 -1516 G/T polymorphisms may affect the prognosis of HBV-related HCC and may be new predictors of prognosis for HCC patients.

The Association Between Viral Infections and Co-stimulatory Gene Polymorphisms in Kidney Transplant Outcomes

Background

The surveillance of kidney transplant patients depends on function of different immunologic markers like co-stimulatory molecules. These molecules may also be associated with post kidney transplant viral related outcomes.

Objectives

The aim of this study was to investigate the possible associations between co-stimulatory molecule gene polymorphisms and viral infections in kidney transplant patients.

Patients and Methods

In total, 172 kidney transplant patients were included in this study. Single nucleotide polymorphisms in loci of co-stimulatory molecules including: PDCD.1, CD28, CTLA4 and ICOS, were analyzed in the studied patients by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. Active Cytomegalovirus (CMV) infection and history of hepatitis C virus (HCV) infection were analyzed in each kidney transplant patient using the CMV antigenemia kit and HCV antibody assay, according to the manufacturer’s instructions.

Results

CMV active infection was found in 31 of 172 (18.02%) kidney transplant patients. HCV infection was only found in two of the 172 (1.16%) studied patients. Significant associations were found between TT and TC genotypes of CTLA4 -1722T/C and T allele with acute rejection in CMV infected kidney transplant patients. A significant association was also found between the T allele of CD28 + 17 C/T genetic polymorphism and acute rejection in CMV infected kidney transplant patients. Significantly higher frequency of AA genotype and A allele of CTLA4 + 49AG polymorphism were found in CMV infected female patients. Also a significantly higher frequency of GG genotype and G allele of PDCD-1.3A/G polymorphisms were found in CMV infected female patients.

Conclusions

Based on these results, CTLA4 and CD28 genetic polymorphisms, which regulate T-cell activation, can influence active CMV infection in kidney transplant patients. These results should be confirmed by further investigations.

Association of genetic polymorphisms in CD8+ T cell inhibitory genes and susceptibility to and progression of chronic HBV infection

BACKGROUND

Previous studies have shown that multiple inhibitory genes play an important role in HBV-specific CD8+ T cell exhaustion and dysfunction in the setting of chronic HBV infection. Polymorphic variants of these genes are thought to be predisposing factors for HBV susceptibility, clearance, and disease progression. The aim of this retrospective study was to identify variants affecting chronic HBV infection in a Chinese Han population.

METHODS

We chose 28 tgSNPs from HapMap data on 5 key genes. They were genotyped on a total of 858 chronic HBV patients, 429 patients who underwent spontaneous recovery, and 239 healthy controls. We evaluated the correlation between the polymorphisms and HBV susceptibility, spontaneous clearance, and disease progression.

RESULTS

The association of rs3827537 of BIM genotype TA and allele A was significantly different (P=0.016, OR=2.049; P=0.031, OR=1.925) between HBV patients and healthy controls. The rs36084323 of PD-1, as well as rs3766377, rs485618, rs4656942 of CD244 showed significant associations with the risk for HBV-related cirrhosis and hepatocellular carcinoma (HCC) (P=0.009, OR=0.482; P=0.009, OR=4.573; P=0.015, OR=0.580; P=0.028, OR=2.855). MDR analysis revealed that the four SNPs (rs36084323, rs3766377, rs485618, rs4656942) modulated the predisposition to cirrhosis and HCC in patients with chronic HBV infection (P=0.006). Using a luciferase reporter assay, we demonstrated that various alleles of rs3766377 had differential effects, and rs3766377 and rs485618 might have interactive effects.

CONCLUSIONS

The present study reveals genetic associations among PD-1 and CD244 variants that may be involved in the development of cirrhosis and HCC in patients with chronic HBV infection. The BIM variant was associated with HBV susceptibility.

microRNA-4717 differentially interacts with its polymorphic target in the PD1 3' untranslated region: A mechanism for regulating PD-1 expression and function in HBV-associated liver diseases

Programmed cell death-1 (PD-1) is involved in hepatitis B virus (HBV) infection, the leading cause of hepatocellular carcinoma (HCC) worldwide. Single-nucleotide polymorphism, rs10204525, located in the PD1 3' untranslated regions (UTR), is associated with chronic HBV infection. MicroRNAs (miRNAs) regulate gene expression via specific binding to the target 3'UTR of mRNA. In this study, three miRNAs were predicted to putatively interact with PD1 rs10204525 polymorphic site of allele G. One of them, miRNA-4717, was demonstrated to allele-specifically affect luciferase activity in a dose-dependent manner in cells transfected with vectors containing different rs10204525 alleles. In lymphocytes from chronic HBV patients withrs10204525 genotype GG, miR-4717 mimics significantly decreased PD-1 expression and increased (TNF)-α and interferon (IFN)-γ production. miR-4717 inhibitor significantly increased PD-1 expression and decreased TNF-α and IFN-γ production although not significantly. In lymphocytes from chronic HBV patients with rs10204525 genotype AA, no similar effects were observed. miR-4717 levels in peripheral lymphocytes from patients with HBV-related chronic hepatitis, cirrhosis and HCC were significantly decreased. In conclusion, miR-4717 may allele-specifically regulate PD-1 expression through interaction with the 3' UTR of PD1 mRNA, leading to the alteration of immune regulation and affecting the susceptibility and disease course of chronic HBV infection.

Short Communication: Low Expression of Activation and Inhibitory Molecules on NK Cells and CD4(+) T Cells Is Associated with Viral Control

Chronic HIV-1 infection induces severe immune alterations, including hyperactivation, exhaustion, and apoptosis. In fact, viral control has been associated with low frequencies of these processes. Here, we evaluated the expression of activation and inhibitory molecules on natural killer (NK) and CD4(+) T cells and plasma levels of proinflammatory cytokines in individuals exhibiting viral control: a cohort of HIV-1-exposed-seronegative individuals (HESN) and a cohort of HIV controllers. There was lower expression of CD69, LAG-3, PD-1, and TIM-3 in both cohorts when compared to a low-risk population or HIV progressors. In addition, HIV controllers exhibited lower plasma levels of proinflamatory molecules TNF-α and IP-10. These findings suggest that individuals exhibiting viral control have lower basal expression of markers associated with cellular activation and particularly immune exhaustion.

Association between TNFAIP3 nonsynonymous single-nucleotide polymorphism rs2230926 and chronic hepatitis B virus infection in a Chinese Han population

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) gene have been linked to inflammatory, immunological and malignant diseases. Hepatitis B virus (HBV) infection is characterized by immunopathogenesis. This study investigated the association of rs2230926, a nonsynonymous SNP in TNFAIP3 gene, with chronic HBV infection.

METHODS

Four hundred and fifty-five patients with chronic HBV infection with clinical diseases of chronic hepatitis (n = 183), liver cirrhosis (n = 167) and hepatocellular carcinoma (n = 105), 92 HBV infection resolvers and 171 healthy controls were included. All subjects were of Chinese Han ethnicity. Genotyping of rs2230926 was carried out by polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

The gender and age between HBV patients, HBV infection resolvers and healthy controls had no statistical difference. The genotypes of rs2230926 in HBV patients, HBV infection resolvers and healthy controls are in Hardy-Weinberg equilibrium. The genotype and allele frequencies of TNFAIP3 rs2230926 polymorphism between HBV patients, HBV infection resolvers and healthy controls had no significant difference. The genotype and allele frequencies of TNFAIP3 rs2230926 polymorphism between HBV patients with chronic hepatitis, liver cirrhosis and hepatocellular carcinoma also showed no significant difference.

CONCLUSIONS

The TNFAIP3 rs2230926 polymorphism is not suggested to be associated with the susceptibility of chronic HBV infection or the progression of HBV-related diseases in this study. Replicative studies and studies in large control and HBV patient populations of different ethnicity by genotyping more polymorphisms in TNFAIP3 gene are needed.

PD-1 mRNA expression is associated with clinical and viral profile and PD1 3'-untranslated region polymorphism in patients with chronic HBV infection

Programmed cell death-1 (PD-1) is involved in hepatitis B virus (HBV) infection and single-nucleotide polymorphism (SNP) rs10204525 in the 3'-untranslated region (3' UTR) of PD1 gene was shown to be associated with the disease course of HBV infection. This study examined the associations of PD-1 mRNA expression with the clinical and viral profiles and the genotypes of rs10204525 in HBV infection. PD-1 mRNA levels in peripheral blood nuclear cells were determined by real-time quantitative reverse transcription polymerase chain reaction (PCR). PD1 rs10204525 was genotyped by bidirectional PCR amplification of specific alleles. The results showed that patients with chronic HBV infection had significantly elevated PD-1 mRNA levels than healthy controls. Patients with chronic hepatitis and hepatocellular carcinoma had significantly higher PD-1 mRNA levels than healthy controls. HBeAg (+) patients had significantly higher PD-1 mRNA levels than HBeAg (-) patients (P<0.001). PD-1 mRNA levels were sequentially increased with the elevation of HBV DNA levels. In HBV patients, but not in healthy controls, PD-1 mRNA levels were sequentially decreased from rs10204525 genotypes AA, AG to GG and the levels in genotype AA were significantly higher than in genotype GG (P=0.039). These findings suggest that increased PD-1 expression may affect the disease course of chronic HBV infection by facilitating HBV viral replication, and this may at least partially relate to PD1 3' UTR polymorphism.

Association of the costimulatory molecule gene polymorphisms and active cytomegalovirus infection in hematopoietic stem cell transplant patients

Determinative associations may exist between costimulatory molecule gene polymorphisms with a variety of post hematopoietic stem cell transplantation (HSCT) viral related clinical outcomes especially acute graft versus host disease (aGVHD). Therefore in this study the associations between costimulatory molecule gene polymorphisms including: cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death-1 (PD-1), inducible T cell costimulator (ICOS), and cluster differentiation 28 (CD28) with active cytomegalovirus (CMV) infection were evaluated in HSCT patients. The 72 allogeneic HSCT patients with and without aGVHD were enrolled in this cross sectional study between years: 2004-2011. The single nucleotide polymorphisms in loci of the costimulatory molecules including: CTLA4 gene (-318 C/T, 1722 T/C, 1661 A/G, +49 A/G), PD-1 gene (PD-1.3 A/G, PD-1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (+17 C/T) were analyzed in studied HSCT patients by PCR-RFLP methods. The active CMV infection was evaluated in fresh EDTA-treated blood samples of each allogeneic HSCT patients by CMV antigenemia kit according to manufacturer's instruction. Active CMV infection was found in 11 of 72 (15.27 %) of allogeneic HSCT patients. The T allele and TT genotype of the CD28 +17 C/T were significantly higher frequency in active CMV infected allogeneic HSCT patients experienced aGVHD. The G allele and GG genotype of the CTLA4 -1661 A/G were significantly higher frequent in active CMV infected allogeneic HSCT patients experienced low grade of aGVHD. Finally, finding of significant associations between CD28 +17 C/T and CTLA4 -1661 A/G genotypes with CMV active infection in allogeneic HSCT patients experienced aGVHD emphasize on the importance of the genetic pattern of costimulatory genes in outcomes of active CMV infection in HSCT patients needs completed studies.

Association of the costimulatory molecule gene polymorphisms and active cytomegalovirus infection in hematopoietic stem cell transplant patients

Determinative associations may exist between costimulatory molecule gene polymorphisms with a variety of post hematopoietic stem cell transplantation (HSCT) viral related clinical outcomes especially acute graft versus host disease (aGVHD). Therefore in this study the associations between costimulatory molecule gene polymorphisms including: cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death-1 (PD-1), inducible T cell costimulator (ICOS), and cluster differentiation 28 (CD28) with active cytomegalovirus (CMV) infection were evaluated in HSCT patients. The 72 allogeneic HSCT patients with and without aGVHD were enrolled in this cross sectional study between years: 2004-2011. The single nucleotide polymorphisms in loci of the costimulatory molecules including: CTLA4 gene (-318 C/T, 1722 T/C, 1661 A/G, +49 A/G), PD-1 gene (PD-1.3 A/G, PD-1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (+17 C/T) were analyzed in studied HSCT patients by PCR-RFLP methods. The active CMV infection was evaluated in fresh EDTA-treated blood samples of each allogeneic HSCT patients by CMV antigenemia kit according to manufacturer's instruction. Active CMV infection was found in 11 of 72 (15.27 %) of allogeneic HSCT patients. The T allele and TT genotype of the CD28 +17 C/T were significantly higher frequency in active CMV infected allogeneic HSCT patients experienced aGVHD. The G allele and GG genotype of the CTLA4 -1661 A/G were significantly higher frequent in active CMV infected allogeneic HSCT patients experienced low grade of aGVHD. Finally, finding of significant associations between CD28 +17 C/T and CTLA4 -1661 A/G genotypes with CMV active infection in allogeneic HSCT patients experienced aGVHD emphasize on the importance of the genetic pattern of costimulatory genes in outcomes of active CMV infection in HSCT patients needs completed studies.

Ankylosing spondylitis: from cells to genes

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown etiology, though it is considered an autoimmune disease. HLA-B27 is the risk factor most often associated with AS, and although the mechanism of involvement is unclear, the subtypes and other features of the relationship between HLA-B27 and AS have been studied for years. Additionally, the key role of IL-17 and Th17 cells in autoimmunity and inflammation suggests that the latter and the cytokines involved in their generation could play a role in the pathogenesis of this disease. Recent studies have described the sources of IL-17 and IL-23, as well as the characterization of Th17 cells in autoimmune diseases. Other cells, such as NK and regulatory T cells, have been implicated in autoimmunity and have been evaluated to ascertain their possible role in AS. Moreover, several polymorphisms, mutations and deletions in the regulatory proteins, protein-coding regions, and promoter regions of different genes involved in immune responses have been discovered and evaluated for possible genetic linkages to AS. In this review, we analyze the features of HLA-B27 and the suggested mechanisms of its involvement in AS while also focusing on the characterization of the immune response and the identification of genes associated with AS.

Genetic variations of PD1 and TIM3 are differentially and interactively associated with the development of cirrhosis and HCC in patients with chronic HBV infection

Cooperation or interaction of programmed cell death-1 (PD-1) and T cell immunoglobulin and mucin domain-containing molecule-3 (Tim-3) molecules is more relevant than either molecule alone to immune dysfunction in chronic viral infection and cancers. This study simultaneously investigated polymorphisms at PD1 +8669 and TIM3 -1516 loci in 845 hepatitis B virus (HBV) chronically infected patients [151 asymptomatic carriers, 202 chronic hepatitis, 221 cirrhosis and 271 hepatocellular carcinoma (HCC)], 141 HBV infection resolvers and 318 healthy controls. Multivariate analysis showed that, in addition to gender, age, ALT, albumin and HBV DNA, PD1 +8669 genotype AA was associated with cirrhosis compared with patients without cirrhosis (OR, 2.410; P=0.001). TIM3 -1516 genotypes GT+TT, together with gender, age, ALT, AST, direct bilirubin, albumin and HBeAg status, were associated with HCC compared with cirrhosis patients without HCC (OR, 2.142; P=0.011). The combined carriage of PD1 +8669 AA/TIM3 -1516 GT or TT was higher in cirrhosis and HCC pooled patients than in patients without cirrhosis (OR, 2.326; P=0.020) and in HCC patients than in cirrhosis patients (OR, 2.232; P=0.013). These data suggest that PD1 and TIM3 polymorphisms may differentially and interactively predispose cirrhosis and HCC in chronic HBV infection.

TIM3 gene polymorphisms in patients with chronic hepatitis B virus infection: impact on disease susceptibility and hepatocellular carcinoma traits

Hepatitis B virus (HBV) infection is associated with the development of acute and chronic liver diseases including hepatocellular carcinoma (HCC). T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3), which negatively regulates T-cell response and mediates phagocytosis of apoptotic cells, has been implicated in HBV infection and cancers. This study explored the polymorphisms of TIM3 gene in 535 patients with HBV-related liver diseases including 213 chronic hepatitis, 178 cirrhosis and 144 HCC, 72 HBV infection resolvers and 182 healthy controls and analyzed the effects of these polymorphisms on the disease susceptibility and HCC traits. TIM3-1541C/T, -1516G/T, -882C/T, -574G/T and +4259T/G polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Of the five polymorphisms genotyped, the allele T-containing genotypes (GT + TT), allele T and allele T-containing haplotype (CTCGT) of -1516G/T polymorphism were more frequent in HBV patients than in controls [P = 0.005, odds ratio (OR) = 2.300, 95% confidence interval (CI): 1.294-4.088; P = 0.004, OR = 2.266, 95% CI: 1.297-3.962; and P = 0.005, OR = 2.203, 95% CI: 1.260-3.854, respectively]. The allele T-containing genotypes and allele T of -1516G/T were associated with HCC tumor grade (P = 0.023 and P = 0.017, respectively) and lymph node metastasis (P = 0.024 and P = 0.017, respectively). These findings suggest that -1516G/T polymorphism in the promoter region of TIM3 gene may affect the disease susceptibility and HCC traits associated with HBV infection, potentially supporting the role of Tim-3 in T-cell dysfunction and exhaustion involved in persistent HBV infection and HCC development.

PDCD1 polymorphism amplifies the predisposing effect conferred by CTLA4 polymorphism in chronic hepatitis B virus infection

Programmed cell death 1 (PDCD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) both negatively regulate the T-cell response in chronic hepatitis B virus (HBV) infection. This study determined genotypes of PDCD1 -606 G/A and +8669 G/A and CTLA4 -318 C/T and +49 A/G polymorphisms in 172 chronic HBV patients and 145 healthy controls and analyzed the interaction between these polymorphisms of the 2 genes. The results indicated that carriage of the PDCD1 +8669 A allele was increased in HBV patients carrying the CTLA4 -318 CC genotype and carrying the CTLA4 +49 AA genotype compared with controls carrying the CTLA4 -318 CC genotype (80.2% vs 64.8%, p = 0.002, odds ratio [OR] = 2.202, 95% confidence interval [95% CI] = 1.326-3.656) and carrying the CTLA4 +49 AA genotype (18.6% vs 9.7%, p = 0.024, OR = 2.139, 95% CI = 1.093-4.187), respectively. More obviously, carriage of the PDCD1 +8669 AA genotype was significantly increased in HBV patients carrying the CTLA4 +49 AA genotype compared with controls carrying the same CTLA4 +49 genotype (14.0% vs 3.4%, p = 0.001, OR = 4.541, 95% CI = 1.686-12.230). These results suggest that the PDCD1 +8669 A allele and AA genotype may amplify the predisposing effect conferred by the CTLA4 polymorphism through PDCD1 and CTLA4 gene interaction in chronic HBV infection.

Immunopathogenesis and prognostic immune markers of chronic hepatitis B virus infection

Host immune responses induced by hepatitis B virus (HBV) infection not only substantially drive disease progression, but also significantly influence efficacy of antiviral treatments in HBV-infected individuals. Therefore, it is important to fully understand the course of immune pathogenesis and to find efficient immunological markers that can predict the disease progression of chronic HBV infection. This review introduces the current progress in clinical immunology and analyzes the mechanisms of antiviral effects and liver injury, which are induced by both innate and adaptive immune responses. The recently identified immunological markers indicated to be closely correlated with disease progression and antiviral efficacy during HBV infection are also summarized. Careful monitoring of these immune markers may help physicians to make decisions on when to begin or withdraw antiviral drugs, or to formulate the prognosis of acute-on-chronic liver failure (ACLF) patients in the clinic. Finally, this review highlights some novel therapeutic strategies to modulate host immunity that have been proposed to sustain antiviral control of chronic HBV infection, as well as the challenges that we are presently facing in the field.

HBcAg induces PD-1 upregulation on CD4+T cells through activation of JNK, ERK and PI3K/AKT pathways in chronic hepatitis-B-infected patients

Hyper-expression of programmed death-1 (PD-1) is a hallmark of exhausted T cells. In chronic hepatitis-B virus (HBV)-infected patients, PD-1 upregulation on T cells was often observed. The mechanism of it has not been fully understood. In this study, we examined the dynamic changes of PD-1 expression on T cells during the natural history of chronic HBV infection and explored the signaling pathway of PD-1 upregulation by the hepatitis-B core antigen (HBcAg). Sixty-seven chronic HBV-infected patients were categorized into an immune tolerance group, an immune clearance group and an inactive virus carrier group, and 20 healthy volunteers were chosen as normal control group. Peripheral blood mononuclear cells from patients and healthy volunteers, and T lymphocytes from healthy volunteers were separated. Results showed that the PD-1 expression level on CD4(+)T cells in every phase of chronic HBV infection was significantly higher than that in healthy volunteers, whereas such effects were not observed on CD8(+)T cells. In the immune clearance phase, a positive correlation was found between serum HBV DNA level and the PD-1 expression level on CD4(+)T cells. In all phases, no correlation was shown between serum alanine amino transferase (ALT) level and PD-1 expression level. Phosphorylation of JNK, ERK and AKT was induced by HBcAg, and inhibitors of JNK, ERK and PI3K/AKT significantly decreased the HBcAg-induced PD-1 upregulation on CD4(+)T cells. In conclusion, the PD-1 expression level on CD4(+)T cells was upregulated in every phase of chronic HBV infection, which was induced by HBcAg through JNK, ERK and PI3K/AKT signaling pathways.

Altered TNF-α and IFN-γ levels associated with PD1 but not TNFA polymorphisms in patients with chronic HBV infection

Production of tumor necrosis factor (TNF)-α and interferon (IFN)-γ, two important cytokines involved in the immune responses to hepatitis B virus (HBV) infection, may be influenced by gene polymorphisms of TNFA and PD1. This study determined the associations of serum TNF-α and IFN-γ levels with TNFA promoter -308 G/A and -238 G/A and PD1 -606 G/A and +8669 G/A polymorphisms in chronic HBV patients and healthy controls. The results showed that TNFA polymorphisms had no association with TNF-α and IFN-γ levels. However, patients with PD1 -606 AA genotype had lower TNF-α and IFN-γ levels. HBV infection in patients with PD1 +8669 GG genotype altered TNF-α to higher levels compared with controls. HBV patients with PD1 -606A/+8669A or -606G/+8669A haplotype tended to have significantly lower or higher TNF-α and IFN-γ levels, respectively. Combined with the lower frequency of PD1 +8669 GG genotype in HBV patients and the minor contribution of PD1 -606 G allele to the protective role of PD1 +8669 G allele, it is indicated that PD1 -606 G allele in a haplotype with PD1 +8669 G allele may have strong inhibitory effect on programmed cell death-1 (PD-1) function and thus reduce its negative impact on T-cell activation and function, leading to higher cytokines secretion and exhibiting a protective role, while the minor predisposing role of PD1 -606 AA genotype to chronic HBV infection may be incurred by decreasing the inhibitory effect on PD-1 function.

Polymorphisms in programmed death-1 gene are not associated with chronic HBV infection in Chinese patients

AIM

To investigate the association between the programmed death-1(PD-1) polymorphisms and genetic susceptibility of chronic hepatitis B virus (HBV) infection in Chinese patients.

METHODS

Two single nucleotide polymorphisms (SNPs), PD-1.1 G > A and PD-1.2 G > A, were genotyped in 539 patients with chronic HBV infection and 353 other family members (HbsAg-) from 256 nuclear families using polymerase chain reactiorestriction fragment length polymorphisms assay. The associations between PD-1 polymorphisms and genetic susceptibility of chronic HBV infection were analyzed usng the family-based association analysis method.

RESULTS

No association or linkage was detected among 539 patients. Univariate (single-marker) family-based association tests demonstrated that PD-1 genotypes, alleles and transmitted haplotypes are not associated with chronic HBV infection (all with P value more than 0.05). Transmission/disequilibrium test and sibship disequilibrium test analysis showed no excess of the alleles from heterozygous parents to affected offspring (P = 0.688880, P = 1.000000 respectively).

CONCLUSION

The data demonstrated that PD-1.1 and PD-1.2 polymorphisms are not associated with chronic HBV infection in Chinese patients.