Background and Aims
The hepatitis B core‐related antigen (HBcrAg), a composite antigen of precore/core gene including classical hepatitis B core protein (HBc) and HBeAg and, additionally, the ...precore‐related antigen PreC, retaining the N‐terminal signal peptide, has emerged as a surrogate marker to monitor the intrahepatic HBV covalently closed circular DNA (cccDNA) and to define meaningful treatment endpoints.
Approach and Results
Here, we found that the woodchuck hepatitis virus (WHV) precore/core gene products (i.e., WHV core‐related antigen WHcrAg) include the WHV core protein and WHV e antigen (WHeAg) as well as the WHV PreC protein (WPreC) in infected woodchucks. Unlike in HBV infection, WHeAg and WPreC proteins were N‐glycosylated, and no significant amounts of WHV empty virions were detected in WHV‐infected woodchuck serum. WHeAg was the predominant form of WHcrAg, and a positive correlation was found between the serum WHeAg and intrahepatic cccDNA. Both WHeAg and WPreC antigens displayed heterogeneous proteolytic processing at their C‐termini, resulting in multiple species. Analysis of the kinetics of each component of the precore/core‐related antigen, along with serum viral DNA and surface antigens, in HBV‐infected chimpanzees and WHV‐infected woodchucks revealed multiple distinct phases of viral decline during natural resolution and in response to antiviral treatments. A positive correlation was found between HBc and intrahepatic cccDNA but not between HBeAg or HBcrAg and cccDNA in HBV‐infected chimpanzees, suggesting that HBc can be a better marker for intrahepatic cccDNA.
Conclusions
In conclusion, careful monitoring of each component of HBcrAg along with other classical markers will help understand intrahepatic viral activities to elucidate natural resolution mechanisms as well as guide antiviral development.
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•In patients with chronic HBV infection, T cell responses are inhibited, leading to an inability to control the virus.•One of the most common inhibitors present on exhausted T cells ...is PD-1, which likely contributes to T cell dysfunction.•A single dose of either 0.1 or 0.3 mg/kg of nivolumab, with or without GS-4774, was well tolerated and effective.
To evaluate the hypothesis that increasing T cell frequency and activity may provide durable control of hepatitis B virus (HBV), we administered nivolumab, a programmed death receptor 1 (PD-1) inhibitor, with or without GS-4774, an HBV therapeutic vaccine, in virally suppressed patients with HBV e antigen (HBeAg)-negative chronic HBV.
In a phase Ib study, patients received either a single dose of nivolumab at 0.1 mg/kg (n = 2) or 0.3 mg/kg (n = 12), or 40 yeast units of GS-4774 at baseline and week 4 and 0.3 mg/kg of nivolumab at week 4 (n = 10). The primary efficacy endpoint was mean change in HBV surface antigen (HBsAg) 12 weeks after nivolumab. Safety and immunologic changes were assessed through week 24.
There were no grade 3 or 4 adverse events or serious adverse events. All assessed patients retained T cell PD-1 receptor occupancy 6–12 weeks post-infusion, with a mean total across 0.1 and 0.3 mg/kg cohorts of 76% (95% CI 75–77), and no significant differences were observed between cohorts (p = 0.839). Patients receiving 0.3 mg/kg nivolumab without and with GS-4774 had mean declines of −0.30 (95% CI −0.46 to −0.14) and −0.16 (95% CI −0.33 to 0.01) log10 IU/ml, respectively. Patients showed significant HBsAg declines from baseline (p = 0.035) with 3 patients experiencing declines of >0.5 log10 by the end of study. One patient, whose HBsAg went from baseline 1,173 IU/ml to undetectable at week 20, experienced an alanine aminotransferase flare (grade 3) at week 4 that resolved by week 8 and was accompanied by a significant increase in peripheral HBsAg-specific T cells at week 24.
In virally suppressed HBeAg-negative patients, checkpoint blockade was well-tolerated and led to HBsAg decline in most patients and sustained HBsAg loss in 1 patient.
Chronic hepatitis B virus infection (CHB) is characterized by a dysfunctional immune response. In patients with CHB, inhibitory receptors, such as programmed death receptor 1 (PD-1) are overexpressed on T cells, leading to an ineffective immune response in the liver. Herein, we show that the PD-1 inhibitor, nivolumab, is safe and effective for the treatment of virally suppressed patients with CHB.
Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au/) number: ACTRN12615001133527.
Non invasive immunologic markers of virus-induced liver disease are unmet needs. We tested the clinical significance of quantitative total and IgM-anti-HBc in well characterized ...chronic-HBsAg-carriers. Sera (212) were obtained from 111 HBsAg-carriers followed-up for 52 months (28-216) during different phases of chronic-HBV-genotype-D-infection: 10 HBeAg-positive, 25 inactive-carriers (HBV-DNA≤2000IU/ml, ALT<30U/L), 66 HBeAg-negative-CHB-patients and 10 with HDV-super-infection. In 35 patients treated with Peg-IFN±nucleos(t)ide-analogues (NUCs) sera were obtained at baseline, end-of-therapy and week-24-off-therapy and in 22 treated with NUCs (for 60 months, 42-134m) at baseline and end-of-follow-up. HBsAg and IgM-anti-HBc were measured by Architect-assays (Abbott, USA); total-anti-HBc by double-antigen-sandwich-immune-assay (Wantai, China); HBV-DNA by COBAS-TaqMan (Roche, Germany). Total-anti-HBc were detectable in all sera with lower levels in HBsAg-carriers without CHB (immune-tolerant, inactive and HDV-superinfected, median 3.26, range 2.26-4.49 Log10 IU/ml) versus untreated-CHB (median 4.68, range 2.76-5.54 Log10 IU/ml), p<0.0001. IgM-anti-HBc positive using the chronic-hepatitis-cut-off" (0.130-S/CO) were positive in 102 of 212 sera (48.1%). Overall total-anti-HBc and IgM-anti-HBc correlated significantly (p<0.001, r=0.417). Total-anti-HBc declined significantly in CHB patients with response to Peg-IFN (p<0.001) and in NUC-treated patients (p<0.001); the lowest levels (median 2.68, range 2.12-3.08 Log10 IU/ml) were found in long-term responders who cleared HBsAg subsequently. During spontaneous and therapy-induced fluctuations of CHB (remissions and reactivations) total- and IgM-anti-HBc correlated with ALT (p<0.001, r=0.351 and p=0.008, r=0.185 respectively). Total-anti-HBc qualifies as a useful marker of HBV-induced-liver-disease that might help to discriminate major phases of chronic HBV infection and to predict sustained response to antivirals.
Background and Aims
The clinical utility of two biomarkers, hepatitis B virus (HBV) RNA and hepatitis B core‐related antigen (HBcrAg), as compared to conventional markers of HBV replication and ...disease activity, is unclear.
Approach and Results
Untreated participants in the North American Hepatitis B Research Network Adult Cohort Study were categorized by chronic hepatitis B (CHB) phases based on HBsAg and HBeAg status and HBV DNA and alanine aminotransferase (ALT) levels. HBV RNA and HBcrAg were measured (Abbott HBV pgRNA Research Assay and Fujirebio Lumipulse Immunoassay, respectively), and cross‐sectional associations with conventional CHB markers were tested. Among 1,409 participants across all CHB phases, median HBV DNA was 3.8 log10 IU/mL and ALT was 34 U/L. HBV RNA was quantifiable in 99% of HBeAg+ and 58% of HBeAg− participants; HBcrAg was quantifiable in 20% of HBeAg+ (above linear range in the other 80%) and 51% of HBeAg− participants. Both markers differed across CHB phases (P < 0.001), with higher levels in the HBeAg+ and HBeAg− immune active phases. HBV RNA and HBcrAg correlated moderately strongly with HBV DNA in both HBeAg+ and HBeAg− phases (HBV RNA: e+ ρ = 0.84; e− ρ = 0.78; HBcrAg: e+ ρ = 0.66; e− ρ = 0.56; P for all, <0.001), but with HBsAg levels among HBeAg+ phases only (HBV RNA: e+ ρ = 0.71; P < 0.001; e− ρ = 0.18; P = 0.56; HBcrAg: e+ ρ = 0.51; P < 0.001; e− ρ = 0.27; P < 0.001). Associations of higher HBV RNA and HBcrAg levels with higher ALT, APRI, and Fibrosis‐4 levels were consistent in HBeAg−, but not HBeAg+, phases.
Conclusions
Despite clear relationships between HBV RNA and HBcrAg levels and CHB phases, these markers have limited additional value in differentiating CHB phases because of their strong association with HBV DNA and, to a lesser extent, with clinical disease indicators.
At least 600000 individuals worldwide annually die of hepatitis B virus(HBV)-related diseases,such as chronic hepatitis B(CHB),liver cirrhosis(LC),and hepatocellular carcinoma(HCC).Many viral ...factors,such as viral load,genotype,and specific viral mutations,are known to affect disease progression.HBV reverse transcriptase does not have a proofreading function,therefore,many HBV genotypes,sub-genotypes,mutants,and recombinants emerge.Differences between genotypes in response to antiviral treatment have been determined.To date,10 HBV genotypes,scattered across different geographical regions,have been identified.For example,genotype A has a tendency for chronicity,whereas viral mutations are frequently encountered in genotype C.Both chronicity and mutation frequency are common in genotype D.LC and progression to HCC are more commonly encountered with genotypes C and D than the other genotypes.Pathogenic differences between HBV genotypes explain disease intensity,progression to LC,and HCC.In conclusion,genotype determination in CHB infection is important in estimating disease progression and planning optimal antiviral treatment.
Infection with hepatitis B virus (HBV) may lead to acute or chronic hepatitis. HBV infections were previously much more frequent but there are still 240 million chronic HBV carriers today and ca. ...620,000 die per year from the late sequelae liver cirrhosis or hepatocellular carcinoma. Hepatitis B was recognized as a disease in ancient times, but its etiologic agent was only recently identified. The first clue in unraveling this mystery was the discovery of an enigmatic serum protein named Australia antigen 50 years ago by Baruch Blumberg. Some years later this was recognized to be the HBV surface antigen (HBsAg). Detection of HBsAg allowed for the first time screening of inapparently infected blood donors for a dangerous pathogen. The need to diagnose clinically silent HBV infections was a strong driving force in the development of modern virus diagnostics. HBsAg was the first infection marker to be assayed with a highly sensitive radio immune assay. HBV itself was among the first viruses to be detected by assay of its DNA genome and IgM antibodies against the HBV core antigen were the first to be selectively detected by the anti-μ capture assay. The cloning and sequencing of the HBV genome in 1978 paved the way to understand the viral life cycle, and allowed development of efficient vaccines and drugs. Today’s hepatitis B vaccine was the first vaccine produced by gene technology. Among the problems that still remain today are the inability to achieve a complete cure of chronic HBV infections, the recognition of occult HBV infections, their potential reactivation and the incomplete protection against escape mutants and heterologous HBV genotypes by HBV vaccines.
Hepatitis B virus (HBV) infection is a serious nosocomial infection that affects patients undergoing hemodialysis (HD). However, certain HBV variants are not detected by routine serological tests in ...Egyptian dialysis units because of mutations that change important viral antigens (Ags). Of note, these mutations can result in the appearance of different HBV variants with different clinical manifestations. Thus, the present study aimed to assess different clinical forms of HBV infections and viral genotypes among patients undergoing HD in the Ismailia governorate of Egypt. To this end, serum samples were collected from 150 patients undergoing HD and screened for HBV‐DNA using a nested PCR technique. Positive samples were then screened for HBV serological markers (hepatitis B core antibody HBcAb, hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen and hepatitis B e antibody) using ELISA and the HBV viral load quantitated by qPCR. HBV genotypes were detected by direct sequencing of the partial surface (S) gene. The most common clinical form of HBV infection in our study cohort was overt HBV infection (10%); followed by seropositive occult hepatitis B infection (7.3%), most of whom had an isolated HBcAb. The least common form was the precore mutant (1.3%). All HBV isolates were genotype D. This study reveals the importance of HBcAb and PCR in screening for HBV, especially for detection of occult hepatitis B infection.
MicroRNAs (miRNAs) are a class of small, single-stranded, noncoding, functional RNAs. Hepatitis B virus (HBV) is an enveloped DNA virus with virions and subviral forms of particles that lack a core. ...It was not known whether HBV encodes miRNAs. Here, we identified an HBV-encoded miRNA (called HBV-miR-3) by deep sequencing and Northern blotting. HBV-miR-3 is located at nucleotides (nt) 373 to 393 of the HBV genome and was generated from 3.5-kb, 2.4-kb, and 2.1-kb HBV in a classic miRNA biogenesis (Drosha-Dicer-dependent) manner. HBV-miR-3 was highly expressed in hepatoma cell lines with an integrated HBV genome and HBV
hepatoma tumors. In patients with HBV infection, HBV-miR-3 was released into the circulation by exosomes and HBV virions, and HBV-miR-3 expression had a positive correlation with HBV titers in the sera of patients in the acute phase of HBV infection. More interestingly, we found that HBV-miR-3 represses HBsAg, HBeAg, and replication of HBV. HBV-miR-3 targets the unique site of the HBV 3.5-kb transcript to specifically reduce HBc protein expression, levels of pregenomic RNA (pgRNA), and HBV replication intermediate (HBV-RI) generation but does not affect the HBV DNA polymerase level, thus suppressing HBV virion production (replication). This may explain the low levels of HBV virion generation with abundant subviral particles lacking core during HBV replication, which may contribute to the development of persistent infection in patients. Taken together, our findings shed light on novel mechanisms by which HBV-encoded miRNA controls the process of self-replication by regulating HBV transcript during infection.
Hepatitis B is a liver infection caused by the hepatitis B virus (HBV) that can become a long-term, chronic infection and lead to cirrhosis or liver cancer. HBV is a small DNA virus that belongs to the hepadnavirus family, with virions and subviral forms of particles that lack a core. MicroRNA (miRNA), a small (∼22-nt) noncoding RNA, was recently found to be an important regulator of gene expression. We found that HBV encodes miRNA (HBV-miR-3). More importantly, we revealed that HBV-miR-3 targets its transcripts to attenuate HBV replication. This may contribute to explaining how HBV infection leads to mild damage in liver cells and the subsequent establishment/maintenance of persistent infection. Our findings highlight a mechanism by which HBV-encoded miRNA controls the process of self-replication by regulating the virus itself during infection and might provide new biomarkers for diagnosis and treatment of hepatitis B.
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