蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.

Variable fragment of heavy chain antibody against the terminal protein region of hepatitis B virus polymerase introduced by Tat protein transduction domain inhibits the replication of hepatitis B virus in vitro