Association of interferon-alpha gene polymorphisms with chronic hepatitis B virus infection

IFNA1 and IFNA13 Genes Confer Genetic Predisposition to Ankylosing Spondylitis-Associated Uveitis in a Chinese Population

OBJECTIVES

Uveitis is considered the most frequent extra-articular manifestation of Ankylosing Spondylitis (AS). Genetic factors play an important role in the pathogenesis of AS with uveitis. In this study, we investigated susceptibility genes of AS concomitant with uveitis.

METHODS

First, 9p21-24 was selected as the region of susceptibility genes. Second, several candidate genes were selected from this region by bioinformatics analysis. Thirdly, a two-stage case control study was used to verify these candidate genes. The first stage included 50 AS with uveitis, 50 AS without uveitis, and 145 healthy controls. The qPCR+direct sequencing and cloning sequencing were used to identify SNPs in this stage. The second stage included 245 AS with uveitis, 360 AS without uveitis, and 530 healthy controls.

RESULTS

IFNA1, IFNB1, IFNA8, and IFNA13 were selected as candidate genes. In the first stage, it was found that the frequency of IFNA1 rs28383797 (G allele) and IFNA13 rs653778 (T allele) in AS with uveitis was higher than that in AS without uveitis and healthy controls. In the second stage, more samples were used to verify the two SNPs. After comprehensive data analysis in the two stages, the frequency of rs28383797 G allele and rs653778 T allele in AS with uveitis was significantly higher than that in AS without uveitis (P = 1.9 × 10^-7, OR = 2.161, 95%CI = 1.609-2.902 and P = 1.5 × 10^-9, OR = 2.028, 95%CI = 1.610-2.554) and healthy controls.

CONCLUSIONS

Rs653778 (T allele) of IFNA13 and rs28383797 (G allele) of IFNA1 were associated with AS concomitant uveitis, and may act as the susceptibility genes of AS with uveitis in the Chinese population.

Role of Functional IFNL4, IFNLR1, IFNA, IFNAR2 Polymorphisms in Hepatitis B virus-related liver disease in Han Chinese population

Recent studies show that variants in some interferon genes together with interferon receptor genes are associated with the outcome of infectious diseases. We examined the association between the risk of hepatitis B virus (HBV)-related liver disease and the functional polymorphisms within IFNL4, IFNLR1, IFNA1, IFNA2, IFNA5 and IFNAR2 genes (14 loci in all) in a Han Chinese population. A total of 3128 people participated and were divided into 5 groups: healthy controls, natural clearance, chronic hepatitis B(CHB), liver cirrhosis and hepatocellular carcinoma (HCC). Significant associations were observed for 4 variants in IFNAR2, IFNLR1 with HBV infection, and IFNLR1-rs4649203 was associated with HBV recovery. Moreover, we demonstrated the clear relevance of 5 polymorphisms in IFNA1, IFNA2, IFNL4 with HCC. Three SNPs in IFNL4 gene may be important susceptible factors for the progression of HBV-related liver disease by trend chi-square test. The IFNL4 haplotype conformed by rs12971396_G, rs8113007_T and rs7248668A was more frequent in HCC than CHB and LC group. Three polymorphisms in the 5' region of the IFNL4 gene are associated with the progression of HBV-related liver disease. IFNA1- rs1831583 and IFNA2- rs649053 are associated with the development of HCC. IFNLR1- rs4649203, rs7525481 are predictors for HBV infection, and rs4649203 is a predictor of spontaneous clearance. IFNAR2 -rs1051393, rs12233338 may be predictive markers of HBV infection in the Chinese population.

Association Between the Telomerase rs2736098_TT Genotype and a Lower Risk of Chronic Hepatitis B and Cirrhosis in Chinese Males

OBJECTIVES

Chronic hepatitis B (CHB) is caused by infection of hepatitis B virus (HBV) and liver cirrhosis (LC) is its most common complication. The accumulated evidence indicates a genetic context of HBV infection phenotypes. Here we determine a potential association of CHB/LC with the genetic variant of telomerase reverse transcriptase (TERT), a key player in aging including immune-senescence.

METHODS

The study included 227 Chinese CHB patients and 315 sex/age-matched healthy controls. TERT rs2736098 and rs2736100 genotyping was performed using pre-designed TaqMan SNP genotyping assay kits. Leukocyte telomere length (LTL) was determined using quantitative PCR.

RESULTS

The rs2736098_CT/CC genotypes were significantly associated with risk of CHB compared to the TT one (OR 2.265, 95% CI 1.202-4.269, P=0.015). A similar association was also found in CHB patients with cirrhosis (CT/CC vs TT: OR 2.398, 95% CI 1.168-4.922, P=0.02). Further analyses showed that the rs2736098_TT genotype difference occurred between male controls and patients (P=0.008) and male CT/CC-carriers exhibited highly increased risk of CHB compared to male controls (CT+CC vs TT, OR 3.182, 95% CI 1.350-7.500, P=0.01). There was no difference in the rs2736100 variants between controls and CHB patients. LTL was not different between cases and controls.

CONCLUSIONS

The TERT rs2736098_TT genotype is associated with a lower CHB and LC risk in Chinese males, which may have implications in CHB pathogenesis and prevention.

Association between the IFNA1 (-2Cx2192;T) Polymorphism and Increased IFNAR1 Gene Expression Levels in Chronic Hepatitis B Infection

BACKGROUND

Single nucleotide polymorphisms and variant expression of some interferon (IFN) genes in individuals with chronic hepatitis B virus (HBV) infection might be related to higher viral load and disease complications. Thereby, whole blood samples of 208 patients (94 chronic HBV-infected patients and 114 HBV immune subjects) were analyzed to investigate the association between IFNG (-5Ax2192;G), IFNA1 (-2Cx2192;T) and IFNAR1 (-97Tx2192;C) genes with their expression levels and HBV viral load.

METHODS

Genotyping was performed by high-resolution melting analysis with quantitative PCR (qPCR). Viral load quantification and gene expression were also carried out using qPCR.

RESULTS

Chronic HBV-infected subjects with IFNA1 CT genotype and T allele were more likely to develop protection against HBV when compared to immune subjects with wild-type genotype (IFNA1 CT/CC: OR = 0.45, p = 0.01, and T/C allele: OR = 0.55; p < 0.01). In patients with IFNAR1 wild-type TT genotype, the expression levels of this receptor may explain the lower viral load (r(2) = 0.40; p = 0.04) and protection against chronic infection.

CONCLUSIONS

These findings suggest that the polymorphic variant of IFNA1 (-2) gene is associated with chronic HBV infection, and high expression levels of the IFNAR1 gene and low levels of IFNA1 might contribute to the pathogenesis of chronic infection in these subjects.

Viral (hepatitis C virus, hepatitis B virus, HIV) persistence and immune homeostasis

Immune homeostasis is a host characteristic that maintains biological balance within a host. Humans have evolved many host defence mechanisms that ensure the survival of individuals upon encountering a pathogenic infection, with recovery or persistence from a viral infection being determined by both viral factors and host immunity. Chronic viral infections, such as hepatitis B virus, hepatitis C virus and HIV, often result in chronic fluctuating viraemia in the face of host cellular and humoral immune responses, which are dysregulated by multi-faceted mechanisms that are incompletely understood. This review attempts to illuminate the mechanisms involved in this process, focusing on immune homeostasis in the setting of persistent viral infection from the aspects of host defence mechanism, including interferon-stimulated genes, apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3), autophagy and interactions of various immune cells, cytokines and regulatory molecules.

The hepatitis B virus-associated tumor microenvironment in hepatocellular carcinoma

In contrast to a majority of cancer types, the initiation of hepatocellular carcinoma (HCC) is intimately associated with a chronically diseased liver tissue, with one of the most prevalent etiological factors being hepatitis B virus (HBV). Transformation of the liver in HBV-associated HCC often follows from or accompanies long-term symptoms of chronic hepatitis, inflammation and cirrhosis, and viral load is a strong predictor for both incidence and progression of HCC. Besides aiding in transformation, HBV plays a crucial role in modulating the accumulation and activation of both cellular components of the microenvironment, such as immune cells and fibroblasts, and non-cellular components of the microenvironment, such as cytokines and growth factors, markedly influencing disease progression and prognosis. This review will explore some of these components and mechanisms to demonstrate both underlying themes and the inherent complexity of these interacting systems in the initiation, progression, and metastasis of HBV-positive HCC.

Association of interferon-gamma induced protein 10 promoter polymorphisms with the disease progression of hepatitis B virus infection in Chinese Han population

Background and Aims

Interferon-gamma induced protein 10 (IP-10) was suggested to be involved in liver injury in viral hepatitis. This study aimed to investigate the impact of the single nucleotide polymorphisms (SNP) G-201A (rs1439490) in IP-10 gene on disease progression of hepatitis B virus (HBV) infection.

Methods

The -201 SNP in IP-10 promoter was genotyped from 577 patients with different illness categories and 275 health controls; In vitro IP-10 promoter activity was compared between haplotype GG and AA homozygotes using luciferase reporter system in HepG2 cells. In vivo expression of IP-10 was compared between patients with -201 AA genotype and GG genotype.

Results

The detected frequency of G-201A SNP was 17.8%, 25.3%, 26.6%, and 13.8% for patients with acute hepatitis B (AHB), patients with mild chronic hepatitis B (CHB-M), patients with severe chronic hepatitis B (CHB-S), and health controls, respectively. In vitro IP-10 promoter-driven luciferase activity in pGL3-Enhancer-201A transfected HepG2 cells was 1.43-fold higher than that in pGL3-Enhancer-201G transfected HepG2 cells (P<0.01). In vivo IP-10 transcriptional expression of peripheral blood mononuclear cells was 1.38-fold higher in patients with -201 AA genotype than in patients with -201 GG genotype (P<0.01).

Conclusion

G-201A in promoter region of IP-10 gene was associated with liver disease progression in patients with HBV infection through up-regulating IP-10 expression.