Title:Isolation of the neutralization ScFvs against HBV infection from the immunized population
VOLUME: 16 ISSUE: 10
Author(s):Yin Bai, Yanmin Chen, Nan Zhang, Xiaochen Guo, Jingzhuang Zhao, Fuxiang Wang, Pengfei Xu, Qingyan Yuan, Jianying Qi, Wenfei Wang, Deshan Li and Guiping Ren
Affiliation:Biopharmaceutical Lab, College of Life Science, Northeast Agricultural University, Harbin, China, 150030., Biopharmaceutical Lab, College of Life Science, Northeast Agricultural University, Harbin, China, 150030., Biopharmaceutical Lab, College of Life Science, Northeast Agricultural University, Harbin, China, 150030.
Keywords:HBV, ScFv antibody, bacterial antibody display, pre-S1 protein, Neutralizing activity, FACS.
Abstract:For a long time, researchers have attempted to replace human plasmaderived
immunoglobulin against HBV with recombinant HBV antibodies for therapeutic purposes, but
failed to develop the products. One of the reasons may be lack of high throughput antibody screening
tool. In this study, we screened an antibody library from immunized subjects by a powerful bacterial
display technology. The capacity of the ScFv library was 109, 117 individual clones against HBV pre-
S1 were initially selected and sequenced, the homology of these clones ranged from 59.7% -68.7%.
Ten clones were randomly selected based on florescence intensity by FACS. The ScFv antibodies were
expressed in E.coli and purified to examine their neutralization ability. First, we tested the ability of
these clones to block the binding of the pre-S1 polypeptide to the HBV sensitive cells Chang liver cells
and HepG2 cells, then, we examined the ability of these clones to inhibit the infection of the Change
liver cells by HBV released from HepG2.2.15 cells by detection of viral DNA and hepatitis B virus e
antigen (HBeAg) in the supernatant of Chang liver cells. Results showed that 4 (clone 3, 7, 9 and 31) out of the ten clones
could significantly reduce the binding of pre-S1 polypeptide to Chang liver cells in a dose-dependent manner. Treatment
with the same clones (clone 3, 7, 9 and 31) could dramatically reduce the contents of HBV DNA in the media of the infected
Chang liver cells by 29.4, 7.89, 58.8, 76.9, respectively, and the amount of HBeAg by 60.2%, 32.6%, 66.1% and
68.1%, respectively. These results suggest that these clones can neutralize HBV infection and have the potential to become
therapeutic antibodies against HBV infection to replace the human plasma-derived immunoglobulin
