Expression of viral infectivity factor protein of human immunodificiency viruses and its biological function / 中华传染病杂志

ABSTRACT

Objectives To analyze the characteristic of HIV-1 viral infectivity factor (Vif) gene variants isolated from Shanghai. To construct the prokaryotic expression vector of HIV-1 vif gene and understand its immunogenieity. Methods HIV-1 vii genes were amplified and sequenced from 23 serum samples of HIV-1 infected patients in Shanghai and then compared with the international standard HIV-1 strain. Subsequently, these amplified Vif fragments were sub cloned into pETS2b(+)expression vector. The recombinant prokaryotie plasmids pETS2b (+)-HIV-1/Vif were then transferred into BL21DS(Star)cells for expressing and purifying HIV-1 Vif protein. HIV-1 Viff rat polyclonal antibody was then preparing by injecting the purified Vif proteins into the mice. ELISA was used to determine the purity of Vif proteins and the immunogenicity of its polyclonal antibodies. Results The nucleotide acid mutation rate of HIV-1 vif gene in Shanghai AIDS patient was (0. 179±0. 006)% compared with the international standard HIV-1 strain. Some similar mutations in vif gene were found in HIV-1 strains isolated from Shanghai while the amino acid sequence between 151 and 240 in Vif protein was conserved. The construction of HIV-1 Vif prokaryotic expression plamids and the preparation of Vif polyclonal antibodies were successfully done in this study. The reaction between recombinant HIV-1 Vif protein and the serum from HIV-1 infected patient was not significantly different from that between the recombinant protein and healthy control serum(P＞0.05). HIV-1 Vif polyclonal antibody reacted differently with recombined HIV-1 Vif protein compared with healthy control serum samples (t=178.61, P＜0.01). Conclusions The Vif gene mutation rate is high in HIV-1 strains isolated from Shanghai compared with international standard HIV-1 strain. The prokaryotic expression plasmids of HIV-1 vif antigen are successfully constructed and Vif polyclonal antibodies are prepared well.