Immunogenicity of recombinant adeno-associated virus type 2 expressing Hepatitis B virus envelope large protein gene

  Objective  To investigate the immunogenicity of recombinant adeno I2associated virus type 2(rAAV-2)expressing Hepatitis Bvirus envelope large protein(rAAV-2-LP)in vivo.

  Methods  One single dose of rAAV222LP(5×10¹¹ virus particles)was inculoated to Balb/c mice via intramuscular injection.At 30^th day, cDNAfragment of large protein in liver tissue was amplified by RT2PCR.The HBsAg antibody(Anti-HBs)in sera was assayed by radioimmunoassay(RIA).Cytotoxic Tlymphocyte(CTL)assays were performed with ⁵¹Cr release assay.

  Results  Exogenous large protein gene can be integrated into the hepatocellular chromosomal DNA.At 20^th day after inoculation with rAAV-LP, specific CTLactivity can be detected in mice.At 30^th day, Anti-HBs in sera can be detected.

  Conclusion  rAAVmediated exogenous HBVenvelope large protein gene can be tran sferred into cells in liver tissue, rAAV-2-LPcan induced both humoral and cellular immune response.The

  results  indicated that the rAAV-2-LPcan be used as a promising candidate for hepatitis Bvaccine, particularly as a thera-peutic vaccine for chronic hepatitis B.