Molecular characterization of woodchuck CD4 (wCD4) and production of a depletion monoclonal antibody against wCD4

Chinese woodchucks with different susceptibility to WHV infection differ in their genetic background exemplified by cytochrome B and MHC-DRB molecules

BACKGROUND

Chinese woodchucks (M. himalayana) were recently found to be susceptible to woodchuck hepatitis virus (WHV) infection. In this study, we aimed to determine the susceptibility to WHV infection of M. himalayana from different areas and their association with the animal genetic background exemplified by cytochrome B and MHC-DRB molecules.

METHODS

Animals from four different areas in Qinghai province were inoculated with WHV59 strains. The virological markers including WHV surface antigen (WHsAg), WHV core antibody (WHcAb), and WHV DNA in serum were measured by ELISA and Real-time PCR, respectively. The sequences of cytochrome B gene and MHC-DRB molecules were obtained and sorted with Clustalx software. The nucleotide variation sites were identified using MEGA5 software.

RESULTS

The animals from four different areas had different susceptibility to WHV infection. Animals from TR and TD areas had a high level of long-lasting viremia, while those from GD and WL areas had a low level of transient viremia after WHV inoculation. All of the animals belong to the same subspecies M. himalayana robusta identified by cytochrome B gene sequences. Based on their nucleotide variation pattern, 8 alleles of cytochrome B gene were identified, and 7 MHC-DRB alleles were identified. Allele A of cytochrome B and Allele Mamo-DRB1*02 of MHC-DRB was found to be frequent in animals from TR and TD areas, while Allele H of cytochrome B and Allele Mamo-DRB1*07 of MHC-DRB was predominant in animals from GD and WL areas.

CONCLUSION

Chinese woodchucks from different areas differed in their susceptibility to WHV infection, though they belong to the same subspecies M. himalayana robusta. The genetic background exemplified by cytochrome B and MHC-DRB differed in Chinese woodchucks with different susceptibility to WHV infection.

Animal models for the study of hepatitis B virus infection

Even with an effective vaccine, an estimated 240 million people are chronically infected with hepatitis B virus (HBV) worldwide. Current antiviral therapies, including interferon and nucleot(s)ide analogues, rarely cure chronic hepatitis B. Animal models are very crucial for understanding the pathogenesis of chronic hepatitis B and developing new therapeutic drugs or strategies. HBV can only infect humans and chimpanzees, with the use of chimpanzees in HBV research strongly restricted. Thus, most advances in HBV research have been gained using mouse models with HBV replication or infection or models with HBV-related hepadnaviral infection. This review summarizes the animal models currently available for the study of HBV infection.