In most adult patients, hepatitis B is a self-limiting disease leading to life-long protective immunity, which is the consequence of a robust adaptive immune response occurring weeks after HBV infection. Intriguingly, HBV-specific T cells can be detected shortly after infection but the mechanisms underlying this early immune priming and its consequences for subsequent control of viral replication are poorly understood. Using primary human and murine hepatocytes and mouse models of transgenic and adenoviral HBV expression, we show that HBV-expressing hepatocytes produce endoplasmic reticulum (ER)-associated endogenous antigenic lipids including lysophospholipids that are generated by HBV-induced secretory phospholipases and lead to activation of natural killer T (NKT) cells. The absence of NKT cells, CD1d or a defect in ER-associated transfer of lipids onto CD1d results in diminished HBV-specific T and B cell responses and delayed viral control. NKT cells may therefore contribute to control of HBV infection through sensing of HBV-induced modified self-lipids.

ObjectiveThe clinical significance of polymorphisms in the interleukin-28B gene encoding interferon (IFN)-λ3, which has antiviral effects, is known in chronic HCV but not in HBV infection. Thus, we measured IFN-λ3 levels in patients with HBV and investigated its clinical significance and association with nucleos(t)ide (NUC) analogue administration.DesignSerum IFN-λ3 level was measured in 254 patients with HBV with varying clinical conditions using our own high sensitivity method. The resulting values were compared with various clinical variables. In addition, cell lines originating from various organs were cultured with NUCs, and the production of IFN-λ3 was evaluated.ResultsHigher serum IFN-λ3 levels were detected in the patients treated with nucleotide analogues (adefovir or tenofovir) compared with those treated with nucleoside analogues (lamivudine or entecavir). There were no other differences in the clinical background between the two groups. A rise in the serum IFN-λ3 levels was observed during additional administration of the nucleotide analogues. In vitro experiments showed that the nucleotide analogues directly and dose-dependently induced IFN-λ3 production only in colon cancer cells. Furthermore, the supernatant from cultured adefovir-treated colon cancer cells significantly induced IFN-stimulated genes (ISGs) and inhibited hepatitis B surface antigen (HBsAg) production in hepatoma cells, as compared with the supernatant from entecavir-treated cells.ConclusionsWe discovered that the nucleotide analogues show an additional pharmacological effect by inducing IFN-λ3 production, which further induces ISGs and results in a reduction of HBsAg production. These findings provide novel insights for HBV treatment and suggest IFN-λ3 induction as a possible target.

Background: Cytokines and host factors triggering innate immunity against hepatitis B virus (HBV) are not well understood.Results: IL-1 and TNFα induced cytidine deaminase AID, an anti-HBV host factor, and reduced HBV infection into hepatocytes.Conclusion: IL-1/TNFα reduced host susceptibility to HBV infection through AID up-regulation.Significance: Proinflammatory cytokines modulate HBV infection through a novel innate immune pathway involving AID.

We have recently demonstrated that immunization with hepatitis C virus-like particles (HCV-LPs) generated in insect cells can elicit both humoral and cellular immune responses in BALB͞c mice. Here, we evaluate the immunogenicity of HCV-LPs in HLA2.1 transgenic (AAD) mice in comparison to DNA immunization. HCV-LP immunization elicited a significantly stronger humoral immune response than DNA immunization. HCV-LP-immunized mice also developed stronger HCV-specific cellular immune responses than DNA-immunized mice as determined by using quantitative enzyme-linked immunospot (ELISpot) assay and intracellular cytokine staining. In BALB͞c mice, immunization with HCV-LPs resulted in a >5 log10 reduction in vaccinia titer when challenged with a recombinant vaccinia expressing the HCV structural proteins (vvHCV.S), as compared to 1 log 10 decrease in DNA immunization. In HLA2.1 transgenic mice, a 1-2 log10 reduction resulted from HCV-LP immunization, whereas no reduction was seen from DNA immunization. Adoptive transfer of lymphocytes from HCV-LP-immunized mice to naive mice provided protection against vvHCV.S challenge, and this transferred immunity can be abrogated by either CD4 or CD8 depletion. Our results suggest that HCV-LPs can induce humoral and cellular immune responses that are protective in a surrogate HCV challenge model and that a strong cellular immunity provided by both CD4 and CD8 effector lymphocytes may be important for protection from HCV infection.

YKL-40 may be a useful non-invasive serum marker to estimate the degree of liver fibrosis and to evaluate the efficacy of IFN therapies in patients with HCV-associated liver disease.

SUMMARY:Human hepatocellular carcinomas (HCCs) show resistance to apoptosis mediated by several death receptors.Because cellular FLICE/caspase-8 -inhibitory protein (cFLIP) is a recently identified intracellular inhibitor of caspase-8 activation that potently inhibits death signaling mediated by all known death receptors, including Fas, TNF-receptor (TNF-R), and TNF-related apoptosis-inducing ligand receptors (TRAIL-Rs), we investigated the expression and function of cFLIP in human HCCs. We found that cFLIP is constitutively expressed in all human HCC cell lines and is expressed more in human HCC tissues than in nontumor liver tissues. Metabolic inhibitors, actinomycin D (ActD) or cycloheximide (CHX), dramatically rendered HCC cells sensitive to Fas-mediated apoptosis. Neither caspase-8 nor caspase-3 was activated by agonistic anti-Fas antibody alone, but both caspases were activated by Fas stimulation in the presence of ActD or CHX, indicating the importance of caspase-8 inhibitors that are sensitive to metabolic inhibitors. Actually, cFLIP expression was decreased in ActD or CHX treatment. cFLIP down-regulation induced by cFLIP antisense oligodeoxynucleotides sensitized HLE cells to Fas, TNF-R, and TRAIL-R-mediated apoptosis. Furthermore, cFLIP over-expression activated nuclear factor (NF)-B and cFLIP down-regulation attenuated NF-B activation induced by TNF-␣ or TRAIL. Pretreatment with pan-caspase-inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD-fmk), restored NF-B activity attenuated by cFLIP down-regulation. cFLIP expression was increased by TNF-␣, TRAIL, or vascular endothelial growth factor but decreased by wortmannin, indicating that cFLIP expression is regulated by both the NF-B and phosphatidylinostiol-3 kinase (PI-3)/Akt pathways. These results suggest that cFLIP plays an important role in cell survival not simply by inhibiting death-receptor-mediated apoptosis but also by regulating NF-B activation in human

The polymorphisms in the interleukin (IL)-28B (interferon-lambda [IFN]-k3) gene are strongly associated with the efficacy of hepatitis C virus (HCV) clearance. Dendritic cells (DCs) sense HCV and produce IFNs, thereby playing some cooperative roles with HCVinfected hepatocytes in the induction of interferon-stimulated genes (ISGs). Blood dendritic cell antigen 3 (BDCA3) 1 DCs were discovered as a producer of IFN-k upon Toll-like receptor 3 (TLR3) stimulation. We thus aimed to clarify the roles of BDCA3 1 DCs in anti-HCV innate immunity. Seventy healthy subjects and 20 patients with liver tumors were enrolled. BDCA3 1 DCs, in comparison with plasmacytoid DCs and myeloid DCs, were stimulated with TLR agonists, cell-cultured HCV (HCVcc), or Huh7.5.1 cells transfected with HCV/ JFH-1. BDCA3 1 DCs were treated with anti-CD81 antibody, inhibitors of endosome acidification, TIR-domain-containing adapter-inducing interferon-b (TRIF)-specific inhibitor, or ultraviolet-irradiated HCVcc. The amounts of IL-29/IFN-k1, IL-28A/IFN-k2, and IL-28B were quantified by subtype-specific enzyme-linked immunosorbent assay (ELISA). The frequency of BDCA3 1 DCs in peripheral blood mononuclear cell (PBMC) was extremely low but higher in the liver. BDCA3 1 DCs recovered from PBMC or the liver released large amounts of IFN-ks, when stimulated with HCVcc or HCV-transfected Huh7.5.1. BDCA3 1 DCs were able to induce ISGs in the coexisting JFH-1-positive Huh7.5.1 cells. The treatments of BDCA3 1 DCs with anti-CD81 antibody, cloroquine, or bafilomycin A1 reduced HCVcc-induced IL-28B release, whereas BDCA3 1 DCs comparably produced IL-28B upon replication-defective HCVcc. The TRIF-specific inhibitor reduced IL-28B release from HCVcc-stimulated BDCA3 1 DCs. In response to HCVcc or JFH-1-Huh7.5.1, BDCA3 1 DCs in healthy subjects with IL-28B major (rs8099917, TT) released more IL-28B than those with IL-28B minor genotype (TG). Conclusion: Human BDCA3 1 DCs, having a tendency to accumulate in the liver, recognize HCV in a CD81-, endosome-, and TRIF-dependent manner and produce substantial amounts of IL-28B/IFN-k3, the ability of which is superior in subjects with IL-28B major genotype. (HEPATOLOGY 2013;57:1705-1715 H epatitis C virus (HCV) infection is one of the most serious health problems in the world. More than 170 million people are chronically infected with HCV and are at high risk of developing liver cirrhosis and hepatocellular carcinoma. Genomewide association studies have successfully identified the genetic polymorphisms (single nucleotide polymorphisms, SNPs) upstream of the promoter region of the

The proportion of patients who progress to chronicity following acute hepatitis B (AHB) varies widely worldwide. Moreover, the association between viral persistence after AHB and hepatitis B virus (HBV) genotypes in adults remains unclear. A nationwide multicenter study was conducted throughout Japan to evaluate the influence of clinical and virological factors on chronic outcomes in patients with AHB. For comparing factors between AHB patients with viral persistence and those with self-limited infection, 212 AHB patients without human immunodeficiency virus (HIV) coinfection were observed in 38 liver centers until serum hepatitis B surface antigen (HBsAg) disappeared or a minimum of 6 months in cases where HBsAg persisted. The time to disappearance of HBsAg was significantly longer for genotype A patients than that of patients infected with non-A genotypes. When chronicity was defined as the persistence of HBsAg positivity for more than 6 or 12 months, the rate of progression to chronicity was higher in patients with genotype A, although many cases caused by genotype A were prolonged cases of AHB, rather than chronic infection. Multivariate logistic regression analysis revealed only genotype A was independently associated with viral persistence following AHB. A higher peak level of HBV DNA and a lower peak of alanine aminotransferase (ALT) levels were characteristics of AHB caused by genotype A. Treatment with nucleotide analogs (NAs) did not prevent progression to chronic infection following AHB overall. Subanalysis suggested early NA initiation may enhance the viral clearance. Conclusion: Genotype A was an independent risk factor for progression to chronic infection following AHB. Our data will be useful in elucidating the association between viral persistence after AHB, host genetic factors, and treatment with NAs in future studies. (HEPATOLOGY 2014;59:89-97) Abbreviations: AHB, acute hepatitis B; ALT, alanine aminotransferase; anti-HBc, antibody to hepatitis B core antigen; anti-HBs, antibody to HBsAg; HBeAg, hepatitis B e-antigen; CLIA, chemiluminescent enzyme immunoassay; EIA, enzyme immunoassay; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; HIV, human immunodeficiency virus; IgM, immunoglobulin M; anti-HBe, antibody to HBeAg; NAs, nucleotide analogs; RPHA, reverse passive hemagglutination.From the