Screening,identification and sequencing of human phage engineered antibody against HBsAg / 解放军医学杂志

ABSTRACT

Objective To screen and identify the human phage engineered antibodies against HBsAg, and to analyze their gene sequence. Methods The phage antibody library was constructed by phage surface display techniques, and then the antibody genes were isolated and amplified from human peripheral blood lymphocyte. The human phage engineered antibody against HBsAg was selected through bio-panning from the phage antibody library. The affinity and specificity of the phage antibody was identified by ELISA and inhibition ELISA assay. The genes of heavy chain and light chain of the phage antibody against HBsAg were analyzed by sequencing. Results 30 colonies were obtained after three rounds of bio-panning. One of them had the highest A490 (A490=1.47?0.08) with ELISA, and the inhibition rate was 76% with inhibition assay (A490=0.35?0.10), implying that the phage antibody against HBsAg was of high specificity. The findings of enzyme digestion demonstrated that the phage antibody included genes of heavy chain and light chain. Sequencing results indicated that the VH region of heavy chain belonged to VHI subgroup and the VL region of light chain belonged to V? Ⅰ and V? Ⅲ subgroup. Conclusions The specific human phage engineered antibody against HBsAg was selected successfully from the phage antibody library. These results suggest that screening and identification of human phage engineered antibody against HBsAg through the phage antibody library are technologically feasible. It lays a foundation for application of human engineered antibody against HBsAg to design new targeted therapy strategy for HBV.