No abstract

Genetic variability has significant impacts on biological characteristics and pathogenicity of hepatitis B virus (HBV), in which the N-terminal sequence of the presurface 1 (preS1) region of HBV large surface protein (LHBs) displays genotype (GT) dependent genetic heterogeneity. However, the influence of this heterogeneity on its biological roles is largely unknown. By analyzing 6560 full-length genome sequences of GTA-GTH downloaded from HBVdb database, the preS1 N-terminal sequences were divided into four representative types, namely C-type (representative of GTA, GTB, and GTC), H-type (GTF and GTH), E-type (GTE and GTG), and D-type (GTD), respectively. We artificially substituted the preS1 N-termini of GTC and GTD plasmids or viral strains with each sequence of the four representative types. The roles of preS1 N-terminus on HBV replication, secretion and infectivity were investigated using HepG2 or HepG2-NTCP cells. In the transfection experiments, the results showed that the extracellular HBsAg levels and HBsAg secretion coefficients in D- and E-type strains were significantly higher than those in C- and H-type strains. D-type strain produced more extracellular HBV DNA than C-type strain. We further observed that D-, H-, and E-type strains increased the levels of intracellular replicative HBV DNAs, comparing with C-type strain. In the infection experiments, the levels of extracellular HBeAg, intracellular HBV total RNA and pgRNA/preC mRNA in D- and E-type strains were markedly higher than C and H-type ones. Our data suggest that the preS1 N-termini affect HBV replication, secretion and infectivity in a genotype dependent manner. The C- and H-type strains prefer to attenuate HBsAg secretion, while the strains of D- and E-type promoted infectivity. The existence and function of the intergenotypic shift of preS1 in naturally occurring recombination requires further investigation, as the data we acquired are mostly related to recombinant preS1 region between N-terminus of preS1 from genotypes A-H and the remaining preS1 portion of GTC or GTD.

Background: The serum hepatitis B virus (HBV) RNA is suggested as a potential new biomarker of HBV infection. However, it is not fully understood. Objectives: The current study aimed at characterizing serum HBV RNA in patients with untreated chronic hepatitis B (CHB) and genotype B and C HBV infection. Methods: A large cohort of 483 patients with hepatitis B e antigen (HBeAg)-positive and -negative was performed. The routine serum biomarkers of HBV infection were tested. HBV genotyping was carried out by direct sequencing. Serum HBV RNA levels were quantified using a method described in the authors' previous study (lower limit of detection: 66.7 IU/mL). Results: Serum HBV RNA was detected in 92.5% (394/426) of the patients with HBeAg-positive and 31.6% (18/57) of HBeAg-negative ones; a positive association was observed between HBeAg and HBV RNA statuses in the subjects. Alanine aminotransferase (ALT), HBV DNA, and genotype were the independent predictors in patients with HBeAg-positive CHB (P = 0.024, 0.001 and 0.014, respectively), while it was HBV DNA in the negative ones (P = 0.000) for serum HBV RNA detectability. Serum HBV RNA was positively correlated with ALT, aspartate transaminase (AST) and HBV DNA, regardless of HBeAg status, and with hepatitis B surface antigen (HBsAg) in HBeAg-positive ones (P < 0.05). Conclusions: Serum HBV RNA may be affected by HBeAg status, serum HBV DNA, HBsAg levels, HBV genotype, ALT, and AST levels. There might be some similarities between the characteristics of serum HBV RNA, and serum HBV DNA and HBsAg, regardless of its distinctive features. The roles of serum HBV RNA in viral replication, infection, survival, disease progression, and antiviral responses need to be investigated in further studied.

PurposeThis study aimed to investigate the HIV and hepatitis B virus (HBV) co-infection in three HIV high endemic areas with different modes of HIV transmission and explore the HBV nucleos(t)ide analogue resistance (NUCr) substitutions in this cohort receiving antiretroviral therapy (ART).Patients and methodsThe enrolled 705 HIV-infected patients were from three different regions in China and received lamivudine-based ART for at least 1 year. After screening for hepatitis B surface antigen (HBsAg), the hepatitis B e antigen (HBeAg), and antibody against hepatitis B core antigen (anti-HBc and anti-HBc IgM), HBV DNA in plasma of patients positive for HBsAg was tested. The reverse transcriptase (RT) sequences of HBV were analyzed by direct sequencing.ResultsThe overall HBsAg-positive rate was 7.1% (50/705) (Guangxi [25/170, 14.7%], Xinjiang [13/257, 5.1%], and Henan [12/278, 4.3%]). The age, transmission route, and ethnic status were found to be associated with HIV/HBV co-infection. We obtained 23 HBV RT sequences belonging to genotypes B (9/23, 39.1%), C (13/23, 56.5%), and D (1/23, 4.4%). About 65.2% (15/23) of RT sequences harbored NUCr substitutions, all of which had combination substitution patterns. Patients with HBV NUCr had significantly higher HBV DNA level and ratio of HBeAg-positive than those without NUCr. None of the patients was found to have both lamivudine-resistant HBV and HIV.ConclusionOur results suggested that HBsAg-positive rate in the studied patients was similar to that of the general population in each of the studied regions, where the age, transmission route, and ethnic status might also play roles in HIV/HBV co-infection. The HBV combination NUCr substitutions were common in co-infected patients under ART. Monitoring of HBV infection and NUCr substitutions in HIV-infected patients would help in providing better clinical decisions and management, thus lowering patients’ risks to develop end-stage liver diseases.