The recommended treatment for patients with chronic hepatitis C, pegylated interferon-alpha (PEG-IFN-alpha) plus ribavirin (RBV), does not provide sustained virologic response (SVR) in all patients. We report a genome-wide association study (GWAS) to null virological response (NVR) in the treatment of patients with hepatitis C virus (HCV) genotype 1 within a Japanese population. We found two SNPs near the gene IL28B on chromosome 19 to be strongly associated with NVR (rs12980275, P = 1.93 x 10(-13), and rs8099917, 3.11 x 10(-15)). We replicated these associations in an independent cohort (combined P values, 2.84 x 10(-27) (OR = 17.7; 95% CI = 10.0-31.3) and 2.68 x 10(-32) (OR = 27.1; 95% CI = 14.6-50.3), respectively). Compared to NVR, these SNPs were also associated with SVR (rs12980275, P = 3.99 x 10(-24), and rs8099917, P = 1.11 x 10(-27)). In further fine mapping of the region, seven SNPs (rs8105790, rs11881222, rs8103142, rs28416813, rs4803219, rs8099917 and rs7248668) located in the IL28B region showed the most significant associations (P = 5.52 x 10(-28)-2.68 x 10(-32); OR = 22.3-27.1). Real-time quantitative PCR assays in peripheral blood mononuclear cells showed lower IL28B expression levels in individuals carrying the minor alleles (P = 0.015).
Although liver fibrosis reflects disease severity in chronic hepatitis patients, there has been no simple and accurate system to evaluate the therapeutic effect based on fibrosis. We developed a glycan-based immunoassay, FastLec-Hepa, to fill this unmet need. FastLec-Hepa automatically detects unique fibrosis-related glyco-alteration in serum hyperglycosylated Mac-2 binding protein within 20 min. The serum FastLec-Hepa counts increased with advancing fibrosis and illustrated significant differences in medians between all fibrosis stages. FastLec-Hepa is sufficiently sensitive and quantitative to evaluate the effects of PEG-interferon-α/ribavirin therapy in a short post-therapeutic interval. The obtained fibrosis progression is equivalent to -0.30 stages/year in patients with sustained virological response, and 0.01 stages/year in relapse/nonresponders. Furthermore, long-term follow-up of the severely affected patients found hepatocellular carcinoma developed in patients after therapy whose FastLec-Hepa counts remained above a designated cutoff value. FastLec-Hepa is the only assay currently available for clinically beneficial therapy evaluation through quantitation of disease severity.
Various genotypes of the hepatitis B virus (HBV) induce liver disease of distinct severity, but the underlying virological differences are not well defined. Huh7 cells were transfected with plasmids carrying 1.24-fold the HBV genome of different genotypes/subgenotypes (2 strains each for Aa/A1, Ae/A2, Ba/B2 and D; 3 each for Bj/B1 and C). HBV DNA levels in cell lysates, determined by Southern hybridization, were the highest for C followed by Bj/Ba and D/Ae (P < .01), and the lowest for Aa (P < .01), whereas in culture media, they were the highest for Bj, distantly followed by Ba/C/D and further by Ae/Aa (P < .01). The intracellular expression of core protein was more than 3-fold lower for Ae/Aa than the others. Hepatitis B e antigen (HBeAg) was excreted in a trend similar to that of HBV DNA with smaller differences. Secretion of hepatitis B surface antigen (HBsAg) was most abundant for Ae followed by Aa, Ba, Bj/C and remotely by D, which was consistent with mRNA levels. Cellular stress determined by the reporter assay for Grp78 promoter was higher for C and Ba than the other genotypes/subgenotypes (P < .01). Severe combined immunodeficiency mice transgenic for urokinase-type plasminogen activator (uPA/SCID), with the liver replaced for human hepatocytes, were inoculated with virions passed in mouse and recovered from culture supernatants. HBV DNA levels in their sera were higher for C than Ae by 2 logs during 4-7 weeks after inoculation. In conclusion, virological differences among HBV genotypes were demonstrated both in vitro and in vivo.
HCV infection is associated with gut dysbiosis, even in patients with mild liver disease. Additionally, overgrowth of viridans streptococci can account for hyperammonemia in CH and LC. Further studies would help to propose a novel treatment strategy because the gut microbiome can be therapeutically altered, potentially reducing the complications of chronic liver disease.
Mutations in the S region of the hepatitis B virus (HBV) envelope gene are associated with immune escape, occult infection, and resistance to therapy. We previously identified naturally occurring mutations in the S gene that alter HBV virion secretion. Here we used transcomplementation assay to confirm that the I110M, G119E, and R169P mutations in the S domain of viral envelope proteins impair virion secretion and that an M133T mutation rescues virion secretion of the I110M and G119E mutants. The G119E mutation impaired detection of secreted hepatitis B surface antigen (HBsAg), suggesting immune escape. The R169P mutant protein is defective in HBsAg secretion as well and has a dominant negative effect when it is coexpressed with wild-type envelope proteins. Although the S domain is present in all three envelope proteins, the I110M, G119E, and R169P mutations impair virion secretion through the small envelope protein. Conversely, coexpression of just the small envelope protein of the M133T mutant could rescue virion secretion. The M133T mutation could also overcome the secretion defect caused by the G145R immune-escape mutation or mutation at N146, the site of N-linked glycosylation. In fact, the M133T mutation creates a novel N-linked glycosylation site ( 131 NST 133 ). Destroying this site by N131Q/T mutation or preventing glycosylation by tunicamycin treatment of transfected cells abrogated the effect of the M133T mutation. Our findings demonstrate that N-linked glycosylation of HBV envelope proteins is critical for virion secretion and that the secretion defect caused by mutations in the S protein can be rescued by an extra glycosylation site.The hepatitis B virus (HBV) is an enveloped DNA virus with a tropism for the liver. The 3.2-kb HBV genome harbors genes encoding core protein and its secreted version (called HBeAg), DNA polymerase, the transcriptional transactivator HBx, and envelope proteins. The envelope gene, which is completely overlapped by the polymerase gene, has three in-frame AUG codons that can serve as alternative translation initiation sites. This leads to the expression of three coterminal envelope proteins: large (L), middle (M), and small (S). The sequence unique to the L protein is called the pre-S1 domain, while a downstream sequence shared with the M protein is called the pre-S2 domain. The S domain is present in all three envelope proteins. The S and M proteins are translated from a 2.1-kb subgenomic RNA with a heterogeneous 5Ј end, while the L protein is expressed from a longer (2.4-kb) subgenomic RNA. The S protein is the most abundantly expressed envelope protein. The L and S proteins exist in nonglycosylated and monoglycosylated forms (L protein, p39 and gp42, respectively; S protein, p24 and gp27, respectively) due to a facultative Nlinked glycosylation site (N-X-S/T) at N146 of the S domain. The M protein contains an extra, constitutive N-linked glycosylation site at position 4 in the pre-S2 domain and consequently exists in monoglycosylated (gp33) and diglycosylated (gp36) form...
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