In Vivo Modelling of Hepatitis B Virus Subgenotype A1 Replication Using Adeno-Associated Viral Vectors
Shonisani Wendy Limani,
Njabulo Mnyandu,
Abdullah Ely,
Reubina Wadee,
Anna Kramvis,
Patrick Arbuthnot,
Mohube Betty Maepa
Affiliations
Shonisani Wendy Limani
Wits/SAMRC Antiviral Gene Therapy Research Unit, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
Njabulo Mnyandu
Wits/SAMRC Antiviral Gene Therapy Research Unit, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
Abdullah Ely
Wits/SAMRC Antiviral Gene Therapy Research Unit, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
Reubina Wadee
Department of Anatomical Pathology, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050 and National Health Laboratory Services, P.O. Box 1038, Johannesburg 2000, South Africa
Anna Kramvis
Hepatitis Virus Diversity Research Unit, Health Sciences Faculty, School of Clinical Medicine, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
Patrick Arbuthnot
Wits/SAMRC Antiviral Gene Therapy Research Unit, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
Mohube Betty Maepa
Wits/SAMRC Antiviral Gene Therapy Research Unit, Health Sciences Faculty, School of Pathology, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg 2000, South Africa
The paucity of animal models that simulate the replication of the hepatitis B virus (HBV) is an impediment to advancing new anti-viral treatments. The work reported here employed recombinant adeno-associated viruses (AAVs) to model HBV subgenotype A1 and subgenotype D3 replication in vitro and in vivo. Infection with subgenotype A1 is endemic to parts of sub-Saharan Africa, and it is associated with a high risk of hepatocellular carcinoma. Recombinant AAV serotype 2 (AAV2) and 8 (AAV8) vectors bearing greater-than-genome-length sequences of HBV DNA from subgenotype A1 and D3, were produced. Transduced liver-derived cultured cells produced HBV surface antigen and core antigen. Administration of AAV8 carrying HBV subgenotype A1 genome (AAV8-A1) to mice resulted in the sustained production of HBV replication markers over a six-month period, without elevated inflammatory cytokines, expression of interferon response genes or alanine transaminase activity. Markers of replication were generally higher in animals treated with subgenotype D3 genome-bearing AAVs than in those receiving the subgenotype A1-genome-bearing vectors. To validate the use of the AAV8-A1 murine model for anti-HBV drug development, the efficacy of anti-HBV artificial primary-microRNAs was assessed. Significant silencing of HBV markers was observed over a 6-month period after administering AAVs. These data indicate that AAVs conveniently and safely recapitulate the replication of different HBV subgenotypes, and the vectors may be used to assess antivirals’ potency.
