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Identification of Variants of Hepatitis C Virus (HCV) Entry Factors in Patients Highly Exposed to HCV but Remaining Uninfected: An ANRS Case-Control Study.

ABSTRACT: Hepatitis C virus (HCV) causes persistent infection in 75% of cases and is a major public health problem worldwide. More than 92% of intravenous drug users (IDU) infected by human immunodeficiency virus type 1 (HIV-1) are seropositive for HCV, and it is conceivable that some HIV-1-infected IDU who remain uninfected by HCV may be genetically resistant.Here we conducted a case-control study to identify mutations in HCV entry coreceptors in HIV-infected IDU who remained uninfected by HCV. We recruited 138 patients, comprising 22 HIV+ HCV- case IDU and 116 HIV+ HCV+ control IDU. We focused on coreceptors in which point mutations are known to abolish HCV infectivity in vitro. Our previous study of the Claudin-1 gene revealed no specific variants in the same case population. Here we performed direct genomic sequencing of the Claudin-6, Claudin-9, Occludin and Scavenger receptor-B1 (SCARB1) gene coding regions. Most HIV+ HCV- IDU had no mutations in HCV coreceptors. However, two HIV+ HCV- patients harbored a total of four specific mutations/variants of HCV entry factors that were not found in the HIV+ HCV+ controls. One case patient harbored heterozygous variants of both Claudin-6 and Occludin, and the other case patient harbored two heterozygous variants of SCARB1. This suggests that HCV resistance might involve complex genetic events and factors other than coreceptors, a situation similar to that reported for HIV-1 resistance.

SUBMITTER: Fouquet B

PROVIDER: S-EPMC4646460 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Identification of Variants of Hepatitis C Virus (HCV) Entry Factors in Patients Highly Exposed to HCV but Remaining Uninfected: An ANRS Case-Control Study.

Fouquet Baptiste B Ghosn Jade J Quertainmont Yann Y Salmon Dominique D Rioux Christophe C Duvivier Claudine C Delfraissy Jean-François JF Misrahi Micheline M

PloS one 20151116 11

Hepatitis C virus (HCV) causes persistent infection in 75% of cases and is a major public health problem worldwide. More than 92% of intravenous drug users (IDU) infected by human immunodeficiency virus type 1 (HIV-1) are seropositive for HCV, and it is conceivable that some HIV-1-infected IDU who remain uninfected by HCV may be genetically resistant.Here we conducted a case-control study to identify mutations in HCV entry coreceptors in HIV-infected IDU who remained uninfected by HCV. We recrui ...[more]

PMID: 26571379

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Project description:Background & aimsPolymorphisms in the interleukin-28B (IL28B) gene are associated with outcomes from infection with hepatitis C virus (HCV). However, the role of these polymorphisms in protecting injection drug users who are at high risk for HCV infection but do not have detectable antibodies against HCV or HCV RNA (exposed uninfected) has not been demonstrated. We investigated whether these individuals have the IL28B genotype rs12979860-CC, which protects some individuals against HCV infection.MethodsSeventy-four exposed uninfected individuals, 89 spontaneous resolvers, and 234 chronically infected individuals were genotyped to determine single nucleotide polymorphisms at IL28B.rs12979860.ResultsExposed, uninfected individuals had a significantly lower frequency of the protective genotype (rs12979860-CC) than anti-HCV-positive spontaneous resolvers (41.9% vs 69.7%, respectively; P=.0005; odds ratio [OR], 0.31; 95% confidence interval [CI]: 0.16-0.60) but a similar frequency to patients who were chronically infected (41.9% vs 43.6%, respectively; P=ns). However, exposed, uninfected individuals had a significantly higher frequency of homozygosity for killer cell immunoglobulin-like receptor 2DL3:group 1 HLA-C (KIR2DL3:HLA-C1) than those with chronic infection (31.1% vs 13.3%, respectively; P=.0008; OR, 2.95; 95% CI: 1.59-5.49). For patients who spontaneously resolved infection, IL28B and KIR:HLA protected, independently, against chronic HCV infection, based on logistic regression and synergy analyses (synergy factor, 1.3; 95% CI: 0.37-4.75; P synergy=.6).ConclusionsIL28B and KIR2DL3:HLA-C1 are independently associated with spontaneous resolution of viremia following HCV exposure. Resistance to HCV infection in exposed uninfected cases is associated with homozygosity for KIR2DL3:HLA-C1 but not the single nucleotide polymorphism IL28B.rs12979860. Uninfected individuals are therefore a distinct population from patients who spontaneously resolve HCV infection. Distinct, nonsynergistic innate immune mechanisms can determine outcomes of HCV exposure.

Project description:A distinctive feature of HCV is that its life cycle depends on lipoprotein metabolism. Viral morphogenesis and secretion follow the very low-density lipoprotein (VLDL) biogenesis pathway and, consequently, infectious HCV in the serum is associated with triglyceride-rich lipoproteins (TRL). Lipoprotein lipase (LPL) hydrolyzes TRL within chylomicrons and VLDL but, independently of its catalytic activity, it has a bridging activity, mediating the hepatic uptake of chylomicrons and VLDL remnants. We previously showed that exogenously added LPL increases HCV binding to hepatoma cells by acting as a bridge between virus-associated lipoproteins and cell surface heparan sulfate, while simultaneously decreasing infection levels. We show here that LPL efficiently inhibits cell infection with two HCV strains produced in hepatoma cells or in primary human hepatocytes transplanted into uPA-SCID mice with fully functional human ApoB-lipoprotein profiles. Viruses produced in vitro or in vivo were separated on iodixanol gradients into low and higher density populations, and the infection of Huh 7.5 cells by both virus populations was inhibited by LPL. The effect of LPL depended on its enzymatic activity. However, the lipase inhibitor tetrahydrolipstatin restored only a minor part of HCV infectivity, suggesting an important role of the LPL bridging function in the inhibition of infection. We followed HCV cell entry by immunoelectron microscopy with anti-envelope and anti-core antibodies. These analyses demonstrated the internalization of virus particles into hepatoma cells and their presence in intracellular vesicles and associated with lipid droplets. In the presence of LPL, HCV was retained at the cell surface. We conclude that LPL efficiently inhibits HCV infection by acting on TRL associated with HCV particles through mechanisms involving its lipolytic function, but mostly its bridging function. These mechanisms lead to immobilization of the virus at the cell surface. HCV-associated lipoproteins may therefore be a promising target for the development of new therapeutic approaches.

Project description:BackgroundTo explore associations between PON1 rs854560, rs662, 705,379, HCV clearance, and interactions between tested PON1 single nucleotide variants (SNVs) and interferon-λ4 gene (IFNL4) rs368234815 variant in hemodialyzed individuals.MethodsThe study included 83 HD individuals who spontaneously resolved HCV infection (all had known IFNL4 rs368234815 variant) and 104 individuals with persistently positive blood tests for HCV RNA (102 were IFNL4 rs368234815 variant successfully genotyped). We genotyped PON1 by high-resolution melt analysis (rs662) or predesigned TaqMan SNV Genotyping Assay (rs854560, rs705379). We used a logistic regression model to assess the association between genetic data and HCV outcome while adjusting for clinical confounding variables. Epistatic interactions between tested PON1 SNVs and IFNL4 rs368234815 were analyzed by the multifactor dimensionality reduction method.ResultsIn the recessive inheritance model, PON1 rs662 GG (OR 9.94, 95% CI 1.20-82.7, P = 0.022) and rs854560 TT (OR 4.31, 95% CI 1.62-11.5, P = 0.003) genotypes were associated with a higher probability for HCV clearance. The haplotype composed of rs662A_rs854560A_rs705379 was not associated with spontaneous HCV clearance. The IFNL4 rs368234815 TT/TT variant was equally distributed among individuals bearing different PON1 SNVs. The epistatic gene-gene analysis did not reveal the interaction between tested PON1 SNVs and IFNL4 rs368234815 (P = 0.094). Regression model, including the PON1 rs662 GG genotype, the PON1 rs854560 genotype, the IFNL4 rs368234815 TT/TT genotype, age at RRT onset, RRT duration, and chronic glomerulonephritis as possible explanatory variables for spontaneous HCV clearance, showed that significant predictors of spontaneous HCV clearance were the IFNL4 rs368234815 TT/TT genotype (OR 2.607, 95% CI 1.298-5.235, P = 0.007), PON1 rs854560 TT (OR 6.208, 1.962-19.644, P = 0.002), PON1 rs662 GG (OR 10.762, 1.222-94.796, P = 0.032), and RRT duration (OR 0.930, 95% CI 0.879-0.984, P = 0.011).ConclusionIn HD individuals, PON1 rs662 GG and rs854560 TT are associated with a higher frequency of spontaneous HCV clearance.

Dataset Information

Identification of Variants of Hepatitis C Virus (HCV) Entry Factors in Patients Highly Exposed to HCV but Remaining Uninfected: An ANRS Case-Control Study.

Publications

Identification of Variants of Hepatitis C Virus (HCV) Entry Factors in Patients Highly Exposed to HCV but Remaining Uninfected: An ANRS Case-Control Study.

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