Expression and in vitro activity of a neutralizing antibody against West Nile virus that reduces antibody-dependent enhancement
10.3760/cma.j.cn112309-20230328-00075
- VernacularTitle:一株降低了抗体依赖性增强效应的西尼罗病毒中和抗体的表达与体外活性研究
- Author:
Xiangjun HAO
1
;
Nan CHEN
;
Wanlu ZHU
;
Jing WANG
;
Guojiang CHEN
;
Chunxia QIAO
;
Xinying LI
;
Beifen SHEN
;
Jiannan FENG
;
Lihui CHAI
;
He XIAO
Author Information
1. 军事科学院军事医学研究院毒物药物研究所，北京 100850
- Keywords:
Neutralizing antibody;
West Nile virus;
Antibody-dependent enhancement effect
- From:
Chinese Journal of Microbiology and Immunology
2024;44(1):44-49
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To establish an antibody expression system to reduce the antibody-dependent enhancement (ADE) effect of target antibody.Methods:Site-directed mutagenesis was used to mutate the 234 and 235 sites of the Fc region of the mammalian cell antibody expression vector-L234A and L235A to establish the antibody expression vector pFRT-IgG1κ-FcM. An antibody Wt-WNV with significant ADE effect obtained in previous work was selected and expressed by the pFRT-IgG1κ-FcM system to obtain mutant antibody FcM-WNV. The binding ability of FcM-WNV to target antigen West Nile virus envelope protein-DⅢ (WNV E-DⅢ) was detected by ELISA, and the its binding ability to human high-affinity IgG Fc receptor hFcγRⅠ (hCD64 ) was analyzed by flow cytometry. The neutralizing activity of FcM-WNV in vitro was detected by pseudovirus infection of host cells (BHK21 and K562). Results:The expression levels of FcM-WNV and Wt-WNV were comparable, and FcM-WNV could recognize and bind to WNVE-DIII in a concentration-dependent manner. Compared with Wt-WNV, the binding ability of FcM-WNV to hCD64 was significantly weakened, showing a significant decrease in fluorescence intensity. Consistent with the previous experimental results, Wt-WNV at a concentration of 5 μg/ml significantly enhanced the infection of K562 by WNV pseudovirus, while FcM-WNV at a concentration of 5 μg/ml could effectively block pseudovirus infection in both K562 and BHK21 cells.Conclusions:The established antibody expression system can effectively reduce the ADE effect of the target antibody.
