Evaluation of the relationship between IL28B, IL10RB and IL28RA single-nucleotide polymorphisms and susceptibility to hepatitis C virus in Chinese Han population

Association between Psoriasis Disease and IFN-λ Gene Polymorphisms

Psoriasis is one of the most common chronic immune-mediated skin diseases, having a strong genetic predisposition. Psoriasis is a T-cell-mediated disease with a mixed Th1/Th17 cytokines environment. IL-23/IL-17 axis hyperactivation is the primary pathogenesis. Psoriasis lesions have been known to exhibit high IFN-λ1 and IFN-stimulated genes (ISGs) expression, which appears to be driven by Th17 cells. However, the role and mechanism of IFN-λs in psoriasis disease remains unknown. The study aimed to investigate the relationship between IL-28B and IL-29 gene polymorphisms with psoriasis disease and clinical severity. We performed single-nucleotide polymorphisms (SNPs) of IL-28B rs12979860 (IL-28 C/T), rs8099917 (IL-28 T/G), and IL-29 rs30461 (IL-29 T/C) in 140 patients with psoriasis disease and 159 healthy controls using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype and allele frequency distributions of the rs12979860 (IL-28 C/T) and rs30461 (IL-29 T/C) polymorphisms were similar in the patient and control groups and were not statistically significant. The TG genotype of rs8099917 was statistically significantly different in patients from both groups. The TG genotype increased the risk of disease1.9-fold. The G allele may be associated with the pathogenesis of psoriasis.

Novel susceptibility loci for A(H7N9) infection identified by next generation sequencing and functional analysis

The A(H7N9) virus strain that emerged in 2013 was associated with a high fatality rate and may become a long-term threat to public health. A(H7N9) disease incidence is disproportionate to viral exposure, suggesting that host genetic factors may significantly influence susceptibility to A(H7N9) infection. Human genome variation in conferring risk for A(H7N9) infection in Chinese populations was identified by a two-stage investigation involving 121 A(H7N9) patients and 187 healthy controls using next generation sequencing followed by functional analysis. As a result, a low frequency variant (rs189256251; P = 0.0303, OR = 3.45, 95% CI 1.05–11.35, chi-square test) and three HLA alleles (DQB1*06:01, DQA1*05:05 and C*12:02) were identified in A(H7N9) infected volunteers. In an A549 cell line carrying the rs189256251 variant CT genotype, A(H7N9) infection incidence was elevated 6.665-fold over control cells carrying the CC genotype. Serum levels of interferon alpha were significantly lower in patients with the CT genotype compared to the CC genotype (P = 0.01). The study findings of genetic predisposition to A(H7N9) in the Chinese population may be valuable in systematic investigations of A(H7N9) disease etiology.

Genetic Polymorphisms of the IFNLR1 Gene Correlate with HCV Infection and Biochemical Features of Chronic HCV Patients in Yunnan, China

Hepatitis C virus (HCV) infection could lead to serious liver diseases, but the pathogenic mechanisms were not completely clear. Cytokines play critical roles in infection, and the genetic polymorphisms in the cytokine genes are widely studied in infectious diseases. The variations in the IL28B gene were associated with HCV infection, viral clearance, and biochemical features of patients, but the studies of its receptor (IFNLR1/IL10RB) were rare. In this study, we collected 395 chronic HCV patients and 397 normal controls to investigate the genetic role of the IFNLR1 gene. Eight tagSNPs were genotyped, and the haplotypes were constructed. Genotypes CT (23.80% vs. 17.13%) and TT (75.19% vs. 81.36%) of rs7532146 showed higher and lower frequencies in HCV patients than that in controls (P = .022; P = .039). Haplotypes GGAATCTC (P = .028) and AAAGCCCT (P = .002) were risk factors for HCV infection, but haplotype GAAATCTT (P = .027) played protective role in HCV infection. Moreover, we identified that the ALT level was significantly lower in HCV patients with genotype TT of rs4489498 than those with other genotypes (CC vs. TT: P = .037; CT vs. TT: P = .013). HCV viral load was highest in HCV patients with genotype CC of rs4489498 than in patients with other two genotypes (CC vs. CT: P = .006; CC vs. TT: P = .039). In conclusion, the genotypes and haplotypes in the IFNLR1 gene were associated with HCV infection and biochemical features of Chinese HCV patients.

Interleukin 28A.rs12980602 and interleukin 28B.rs8103142 genotypes could be protective against HCV infection among Egyptians

Previous studies showed that interleukin (IL)-28B gene polymorphisms were associated with hepatitis C Virus (HCV) infection and treatment outcomes. We tested whether single-nucleotide polymorphisms (SNPs) in IL-28A and IL-28B are associated with HCV infection among Egyptians with HCV genotype 4 infections. We enrolled 144 chronic HCV patients, 72 spontaneously resolved HCV subjects, and 69 healthy controls. Four SNPs in IL-28A and IL-28B genes (IL-28A.rs12980602, IL-28B.rs12979860, IL-28B.rs8099917, and IL-28B.rs8103142) were genotyped. The most frequent IL-28B haplotype "TCT" was significantly more frequent in HCV-infected subjects than in HCV negative subjects (62.2% vs. 48.6%, respectively; p = 0.005). The frequency of IL-28A.rs12980602 "T" allele was significantly higher than the "C" allele in healthy controls compared to HCV-infected subjects (p < 0.001) with the "TT" genotype significantly higher in healthy controls compared to HCV-infected subjects (p < 0.001) with no association with viral load (p = 0.11) among chronically infected subjects. The results, also, confirmed the previous role of IL-28B SNPs in predicting HCV infection outcome. Importantly, IL-28B.rs8099917 "TT" genotype was significantly associated with low viral load in HCV-infected subjects, while the remaining three SNPs did not. The three IL-28B SNPs were in linkage disequilibrium (D' > 0.68; r2 > 0.43) for all comparisons in HCV patients, while there was no linkage disequilibrium of IL-28A polymorphisms and the three IL-28B SNPs. In conclusion, IL-28A.rs12980602 and IL-28B.rs8103142 TT genotype could be protective against HCV infection. Also, IL-28B.rs12979860, IL-28B.rs8099917, and IL-28B.rs8103142 SNPs predicted the outcome of HCV infection among genotype-4-infected Egyptians. Moreover, IL-28B.rs8099917 SNP affected the viral load in chronic HCV patients.

IL28B, IL29 and micro-RNA 548 in subacute sclerosing panencephalitis as a rare disease

Subacute sclerosing panencephalitis (SSPE) is a progressive neurodegenerative disease which affects children and young adults, caused by a persistent infection of defective measles virus. IFN-λs (IL-28A, IL-28B and IL-29) are a group of cytokines mediating antiviral responses. It has been shown that IL-29 levels are significantly higher in infected cells with defective measles virus. IL-29 expression is thought to be regulated at post-transcriptional level and miRNA-548 family targets the 3'UTR of the IFNL1 gene. Impaired immune system has an important role as well as viral factors in SSPE. The aim of our study investigates whether IL-28B, IL-29 levels and gene polymorphisms contribute to the damaged immune response leading to the development of SSPE. Also possible association of miR-548 family with IL-29 and SSPE is explored. Frequencies of rs12979860, rs8099917, rs30461, serum levels of IL-28B, IL-29 and expression levels of miR-548b, miR-548c, miR-548i are determined at 64 SSPE patients and 68 healthy controls. Serum IL-29 levels are statistically significant higher in SSPE patients. Allele frequencies of rs8099917 are statistically significant higher in SSPE patients and resulted G allele is found to increase 2.183-fold risk of SSPE. The expression levels of miR-548b-5p, miR-548c-5p and miR-548i are found to be statistically significant higher in SSPE patients. Dramatically increased level of IL-29 seen in patient group indicates that the elevated miR-548 expression is compensatory result of the over-activated immune system response. Further studies referred to IL28, IL29 and related miRNA's will be enlightened the pathogenesis of SSPE.

Polymorphisms in the Th17 cell-related RORC gene are associated with spontaneous clearance of HCV in Chinese women

BACKGROUND

Female gender and favorable IFNL3 genotypes are the primary independent predictors of spontaneous clearance of HCV infection. However, chronic hepatitis C infection occurs in numerous women carrying favorable IFNL3 genotypes, indicating that other host and/or virological factors contribute to the prognosis of infection.

METHODS

A cohort of 137 anti-HCV-positive female Han Chinese cases, including 64 chronic HCV carriers and 73 HCV spontaneous resolvers, was recruited in the study. 111 SNPs in 23 genes encoding HCV co-receptors, transcription factors, Toll-like receptors, co-stimulating molecules, and cytokines were selected for SNP analysis.

RESULTS

After comparison of genotypes and allelotype frequencies of 111 SNPs in 23 genes in the primary cohort, the SNPs rs9826 (P = 0.024 for CC/TT/CT; P = 0.015 for C allele/T allele) and rs1521177 (P = 0.017 for GG/TT/GT; P = 0.006 for G allele/T allele) in the RORC gene were significantly associated with spontaneous HCV clearance. In the sub-cohort carrying favorable IFNL3 genotypes (rs12979860CC, rs8099917 TT, rs12980275 AA), rs1521177 (genotype: P = 0.040; allelotype: P = 0.021) remained significantly associated with spontaneous HCV clearance. Importantly, the most common RORC haplotype rs9826-T/rs1521177-T was presented at significantly different frequencies in resolvers and carriers in both the primary cohort (P = 0.0027) and the IFNL3 favorable sub-cohort (P = 0.0117).

CONCLUSIONS

This study indicates that genetic polymorphisms in human Th17-related RORC gene are associated with different natural prognosis of HCV infection. The RORC haplotype, rs9826-T/rs1521177-T, was favorable for spontaneous clearance of HCV infection.

Immunogenetic studies of the hepatitis C virus infection in an era of pan-genotype antiviral therapies - Effective treatment is coming

What are the factors that influence human hepatitis C virus (HCV) infection, hepatitis status establishment, and disease progression? Firstly, one has to consider the genetic background of the host and HCV genotypes. The immunogenetic host profile will reflect how each infected individual deals with infection. Secondly, there are environmental factors that drive susceptibility or resistance to certain viral strains. These will dictate (I) the susceptibility to infection; (II) whether or not an infected person will promote viral clearance; (III) the immune response and the response profile to therapy; and (IV) whether and how long it would take to the development of HCV-associated diseases, as well as their severity. Looking at this scenario, this review addresses clinical aspects of HCV infection, following by an update of molecular and cellular features of the immune response against the virus. The evasion mechanisms used by HCV are presented, considering the potential role of exosomes in infection. Genetic factors influencing HCV infection and pathogenesis are the main topics of the article. Shortly, HLAs, MBLs, TLRs, ILs, and IFNLs genes have relevant roles in the susceptibility to HCV infection. In addition, ILs, IFNLs, as well as TLRs genes are important modulators of HCV-associated diseases. The viral aspects that influence HCV infection are presented, followed by a discussion about evolutionary aspects of host and HCV interaction. HCV and HIV infections are close related. Thus, we also present a discussion about HIV/HCV co-infection, focusing on cellular and molecular aspects of this interaction. Pharmacogenetics and treatment of HCV infection are the last topics of this review. The understanding of how the host genetics interacts with viral and environmental factors is crucial for the development of new strategies to prevent HCV infection, even in an era of potential development of pan-genotypic antivirals.

Interferon Lambda: Modulating Immunity in Infectious Diseases

Interferon lambdas (IFN-λs; IFNL1-4) modulate immunity in the context of infections and autoimmune diseases, through a network of induced genes. IFN-λs act by binding to the heterodimeric IFN-λ receptor (IFNLR), activating a STAT phosphorylation-dependent signaling cascade. Thereby hundreds of IFN-stimulated genes are induced, which modulate various immune functions via complex forward and feedback loops. When compared to the well-characterized IFN-α signaling cascade, three important differences have been discovered. First, the IFNLR is not ubiquitously expressed: in particular, immune cells show significant variation in the expression levels of and susceptibilities to IFN-λs. Second, the binding affinities of individual IFN-λs to the IFNLR varies greatly and are generally lower compared to the binding affinities of IFN-α to its receptor. Finally, genetic variation in the form of a series of single-nucleotide polymorphisms (SNPs) linked to genes involved in the IFN-λ signaling cascade has been described and associated with the clinical course and treatment outcomes of hepatitis B and C virus infection. The clinical impact of IFN-λ signaling and the SNP variations may, however, reach far beyond viral hepatitis. Recent publications show important roles for IFN-λs in a broad range of viral infections such as human T-cell leukemia type-1 virus, rotaviruses, and influenza virus. IFN-λ also potentially modulates the course of bacterial colonization and infections as shown for Staphylococcus aureus and Mycobacterium tuberculosis. Although the immunological processes involved in controlling viral and bacterial infections are distinct, IFN-λs may interfere at various levels: as an innate immune cytokine with direct antiviral effects; or as a modulator of IFN-α-induced signaling via the suppressor of cytokine signaling 1 and the ubiquitin-specific peptidase 18 inhibitory feedback loops. In addition, the modulation of adaptive immune functions via macrophage and dendritic cell polarization, and subsequent priming, activation, and proliferation of pathogen-specific T- and B-cells may also be important elements associated with infectious disease outcomes. This review summarizes the emerging details of the IFN-λ immunobiology in the context of the host immune response and viral and bacterial infections.

The vitamin D receptor gene ApaI polymorphism is associated with increased risk of renal cell carcinoma in Chinese population

Molecular epidemiologic studies previously reported that 1,25-dihydroxy vitamin D₃ (1,25(OH)₂ D₃) appears to influence cancer risk. It exerts its activity through the intracellular vitamin D receptor (VDR), which regulates the transcription of genes. This study aimed to investigate the genetic association of VDR polymorphisms with renal cell carcinoma (RCC) risk in the Chinese population. The genotypes of five VDR polymorphisms (TaqI, BsmI, Cdx-2, ApaI, and FokI) were studied using polymerase chain reaction in 302 RCC patients and 302 healthy controls. ApaI variant AA and AC genotypes were found to be associated with a significantly increased risk of RCC compared with the CC genotype (OR = 2.60, 95% CI = 1.39–4.85 for AA vs. CC, and OR = 1.52, 95% CI = 1.08–2.13 for AC vs. CC). The AA genotype was also associated with a higher Fuhrman grade (OR = 2.87, 95% CI = 1.15–7.16 for AA vs. CC). No significant difference was found between the other four VDR polymorphisms and RCC risk. Our study suggests that VDR ApaI genotypes may be involved in the increased risk and progression of RCC in the Chinese Han population.

Potential genetic markers for prediction of treatment response in Egyptian children infected with HCV genotype 4

BACKGROUND

Egypt has a high prevalence of hepatitis C virus (HCV) infection. Limitations of the current HCV treatment in children are low rate of sustained virological response, significant side effects and high expenses, making prediction of treatment response crucial.

AIM

This study aimed to investigate association of single nucleotide polymorphisms (SNPs) in interleukins (IL) 10, 28 and 29 genes in predicting the response to therapy in HCV infected children.

METHODS

Sixty-six Egyptian children infected with HCV genotype 4, receiving pegylated interferon alpha 2b and ribavirin, were included. Genotyping of six SNPs in interleukin 10, 28B and 29 gene as well as HCV genotype were analyzed by real-time polymerase chain reaction.

RESULTS

The CC genotype in IL28B; rs12979860 had 8.547 folds higher chance to develop sustained virological response than CT and TT genotypes (P=0.014). Genotype distribution of rs8099917 in IL28B gene (TG and GG genotypes) was found to be 3.348 more likely not to respond to treatment than the TT genotype (P=0.018). In multivariate analysis, interleukin 28 gene single nucleotide polymorphisms rs 12979860, interleukin 10 single nucleotide polymorphisms -592A > C and basal viral load were independent variables that significantly improved prediction of response to HCV therapy.

CONCLUSION

This association can be translated into clinical decision making for HCV treatment.

CD81 and CLDN1 polymorphisms and hepatitis C virus infection susceptibility: a case control study

CD81 and CLDN1 interact to form a CD81-CLDN1 co-receptor complex that is crucial in hepatitis C virus (HCV) entry. Variations in the two genes were shown to influence immunological functions; therefore, we hypothesized that polymorphisms in these genes may contribute to HCV susceptibility. A case-control study consisting of 461 patients and 461 controls was conducted to explore the associations between CD81 rs708564 and CLDN1 rs893051 and HCV susceptibility in a Chinese population. We found a decreased HCV risk associated with the CD81 rs708564 TT (odds ratio (OR) = 0.66, 95% CI = 0.44-0.98) genotype. The gene-gene interaction between CD81 and CLDN1 polymorphisms also decreased HCV risk in a joint multiplicative manner (OR for the presence of both CD81 rs708564 TT and CLDN1 rs893051 GG genotypes = 0.59, 95% CI = 0.36-0.97). Furthermore, the CD81 rs708564 TT genotype conferred a more pronounced decrease in HCV susceptibility in combination with lower levels of high-density lipoprotein cholesterol (HDL-C; OR = 0.71, 95% CI = 0.52-0.96), and higher levels of low-density lipoprotein cholesterol (OR = 0.24, 95% CI = 0.09-0.65). We also observed a decreased HCV susceptibility in individuals with higher HDL-C levels who carried the CLDN1 rs893051 G/C genotype. These findings suggest that homozygous CD81 rs708564 TT may be a genetic modifier for avoiding HCV infection whether as a sole single nucleotide polymorphism or combined with the CLDN1 rs893051 GG genotype, and this effect is associated with serum levels of lipoprotein.

The Role of Interferon-λ Locus Polymorphisms in Hepatitis C and Other Infectious Diseases

Since its discovery in 2003, the type III interferon-λ (IFN-λ) family has been found to contribute significantly to the host response to infection. Whilst IFN-λ shares many features with type I IFN induction and signalling pathways, the tissue-specific restricted expression of its receptor, IL28RA, makes IFN-λ a major mediator of host innate immunity in tissues and organs with a high epithelial cell content. Host susceptibility and responses to infection are known to be heterogeneous, and the identification of common genetic variants linked to disease outcome by genome-wide association studies (GWAS) has underscored the significance of host polymorphisms in responses to infection. Several such GWAS have highlighted the IFN-λ locus on chromosome 19q13 as an area of genetic variation significantly associated with hepatitis C virus (HCV) infection, and the rs12979860 genotype can be used in clinical practice as a biomarker for predicting a successful response to treatment with pegylated IFN and ribavarin. Here, we discuss IFN-λ genetic polymorphisms and their role in HCV and other infectious diseases as well as their potential impact on clinical diagnostics, patient stratification and therapy. Finally, the broader role of IFN-λ in the immunopathogenesis of non-infectious inflammatory diseases is considered.

Association of Hepatitis C Virus Infection and Interleukin-28B Gene Polymorphism in Chinese Children

Objective: To preliminarily explore the association of rs12979860 and rs8099917 SNPs with chronic HCV infection in Chinese Han children.

Methods: Chronic HCV infection patients (n=277; 1-17 years old, 4.5 years old in average) and healthy subjects (n=150, children; 2-17 years old, 5.2 years old in average) were recruited and tested by PCR combining direct sequencing. The differences between the rs12979860 and rs8099917 genotypes in patients and healthy subjects were compared.

Results: The genetic variations at rs12979860 and rs8099917 in chronic hepatitis C (CHC) children and healthy subjects did not differ significantly. The frequency of spontaneous clearance in CHC children was higher (47%), which is related to the genetic variations. The histological changes of patients were more significant compared to their clinical and biochemical indices, but they did not correlate with the genetic mutations at rs12979860 and rs8099917 significantly.

Conclusion: The rs12979860 and rs8099917 SNPs are independent factors predicting the spontaneous clearance of Chinese CHC children patients. The correlation between diseases outcomes are in need of further study.