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Background & Aims Infectious hepatitis C virus (HCV) particles bind to host lipoproteins such as low-density lipoproteins ( LDLs). Low-density lipoprotein receptors (LDLR) have been termed candidate receptors for HCV- LDL complexes. Functional host genetic single nucleotide polymorphisms ( SNPs) in the apolipoprotein E ( APOE) gene encoding apolipoprotein E (apoE) - a major structural LDL component and natural ligand of LDLR - likely influence the course of HCV infection. We investigated the prevalence of APOE SNPs in two large and independent cohorts of patients with chronic HCV infection compared to respective controls. Methods We genotyped 996 chronically HCV-infected patients; 179 patients with spontaneous HCV clearance; 283 individuals with non- HCV-associated liver disease; and 2 234 healthy controls. Results APOE genotype proportions in patients with persistent HCV infection significantly differed from healthy controls ( P = 0.007) primarily because of a substantial under-representation of APOE4 alleles in chronically HCV-infected patients (10.2%) compared to 13.0% in healthy controls ( P = 0.001). The distribution of APOE4 allele positive genotypes (ε2ε4, ε3ε4, ε4ε4) also significantly differed between chronically HCV-infected patients and healthy controls (1.4%, 17%, 1% vs. 2.4%, 20.5%, 1.7%; P = 0.001), suggesting a protective effect of the APOE4 allele in HCV infection. This was confirmed by a significant over-representation of the APOE4 allele in patients with spontaneous HCV clearance (17.6%; P = 0.00008). The APOE4 allele distribution in patients with non- HCV-associated liver disease (14.0%) was very similar to healthy controls and also differed from chronically HCV-infected patients ( P = 0.012), suggesting HCV specificity. Conclusions Our findings suggest that the APOE4 allele may confer a protective effect in the course of HCV infection. [ABSTRACT FROM AUTHOR]

Abstract: Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G>A, c.1413G>A, and c.*52G>A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3′UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p = 0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p = 0.006) and negatively associated with c.1413G>A heterozygosity (33.0% vs. 46.1%, p = 0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection. [Copyright &y& Elsevier]

Interleukin-12 (IL-12) governs the Th1-type immune response, affecting the spontaneous and treatment-induced recovery from HCV-infection. We investigated whether the IL12B polymorphisms within the promoter region (4bp insertion/deletion) and the 3′-UTR (1188-A/C), which have been reported to influence IL-12 synthesis, are associated with the outcome of HCV infection.We analyzed 186 individuals with spontaneous HCV clearance, 501 chronically HCV infected patients, and 217 healthy controls. IL12B 3′-UTR and promoter genotyping was performed by Taqman-based assays with allele-specific oligonucleotide probes and PCR-based allele-specific DNA-amplification, respectively.The proportion of IL12B promoter and 3′-UTR genotypes did not differ significantly between the different cohorts. However, HCV genotype 1-infected patients with high baseline viremia carrying the IL12B 3′-UTR 1188-C-allele showed significantly higher sustained virologic response (SVR) rates (25.3% vs. 46% vs. 54.5% for A/A, A/C and C/C) due to reduced relapse rates (24.2% vs. 12% vs. zero % for A/A, A/C and C/C).IL12B 3′-UTR 1188-C-allele carriers appear to be capable of responding more efficiently to antiviral combination therapy as a consequence of a reduced relapse rate. No association of IL12B polymorphisms and self-limited HCV infection could be demonstrated. [Copyright &y& Elsevier]

Background: The endoplasmic reticulum (ER) is the cellular site for protein folding. ER stress occurs when protein folding capacity is exceeded. This stress induces a cyto-protective signaling cascades termed the unfolded protein response (UPR) aimed at restoring homeostasis. While acute ER stress is lethal, chronic sub-lethal ER stress causes cells to adapt by attenuation of UPR activation. Hepatitis C virus (HCV), a major human pathogen, was shown to cause ER stress, however it is unclear whether HCV induces chronic ER stress, and if so whether adaptation mechanisms are initiated. We wanted to characterize the kinetics of HCV-induced ER stress during infection and assess adaptation mechanisms and their significance. Methods and Findings: The HuH7.5.1 cellular system and HCV-transgenic (HCV-Tg) mice were used to characterize HCVinduced ER stress/UPR pathway activation and adaptation. HCV induced a wave of acute ER stress peaking 2-5 days postinfection, which rapidly subsided thereafter. UPR pathways were activated including IRE1 and EIF2α phosphorylation, ATF6 cleavage and XBP-1 splicing. Downstream target genes including GADD34, ERdj4, p58ipk, ATF3 and ATF4 were upregulated. CHOP, a UPR regulated protein was activated and translocated to the nucleus. Remarkably, UPR activity did not return to baseline but remained elevated for up to 14 days post infection suggesting that chronic ER stress is induced. At this time, cells adapted to ER stress and were less responsive to further drug-induced ER stress. Similar results were obtained in HCVTg mice. Suppression of HCV by Interferon-α 2a treatment, restored UPR responsiveness to ER stress tolerant cells. Conclusions: Our study shows, for the first time, that HCV induces adaptation to chronic ER stress which was reversed upon viral suppression. These finding represent a novel viral mechanism to manipulate cellular response pathways. [ABSTRACT FROM AUTHOR]

Recently CC chemokine receptor 5 (CCR5) related immune mechanisms and a functional mutation of the CCR5 gene have been implicated in hepatitis C virus (HCV) infection in a cohort of predominantly hemophiliac patients. The present study investigated the frequency and clinical consequences of the CCR5 Δ32 mutation in two genetically homogeneous populations of HCV infected patients with a different risk profile for infection. Genomic DNA samples from 333 German patients with chronic HCV infection were screened by PCR for the presence of the CCR5 Δ32 polymorphism. In-hospital patients admitted for other diseases than viral hepatitis but with a comparable risk for HCV exposure were used as control population (n=125). Allele frequencies of CCR5 Δ32 polymorphism did not differ significantly between the two groups (7.6% and 9.5%, respectively) and control subjects (10.4%), and did not deviate from Hardy-Weinberg equilibrium in any group. Furthermore, there were no major differences between patients with respect to HCV genotypes, viral loads, liver enzymes, or fibrosis scores in relation to the presence or absence of the heterozygous CCR5 Δ32 mutation. Differences in inflammatory scores in liver biopsy samples and response to antiviral therapy in CCR5 Δ32 heterozygotes in one cohort could neither be reproduced in the other group of patients nor when both cohorts were pooled. These results argue against a strong effect of the CCR5 Δ32 deletion regarding these phenotypes. In conclusion, we found no increased frequency of the CCR5 Δ32 polymorphism in two independent cohorts of patients with HCV infection but without hemophilia as the main risk factor for infection. As the major difference to investigations demonstrating an association between CCR5 Δ32 and HCV infection is the selection of cases and controls, our study emphasizes the importance of epidemiological criteria for association studies of HCV infection. [ABSTRACT FROM AUTHOR]