来源于H5N1患者的VH1-2编码广谱抗体的筛选与功能研究

Characterization and analysis of VH1-2-encoded heterosubtypic antibodies isolated from an avian H5N1 patient

目的从禽流感H5N1患者体内筛选分离抗流感病毒血凝素（Hemagglutinin，HA）广谱中和性抗体。方法通过B细胞体外培养、抗体可变区基因筛选及表达等技术，建立H5N1患者外周血中交叉反应性B细胞及H5N1假病毒中和活性B细胞的抗体基因文库。利用293T细胞表达系统体外表达抗体库，使用ELISA及假病毒中和试验筛选潜在的广谱抗体，并鉴定其功能。结果获得由VH1-2编码的抗体基因，其编码抗体可广谱结合H1，H5，H6，H9及H7亚型，并对GX-H5N1假病毒有良好的中和能力，该类抗体轻链为Vκ3-20/Jκ4和Vκ3-20/Jκ5。结论H5N1病毒感染可诱导产生广谱反应性抗体。

Objective To isolate the cross-reactive antibodies against hemagglutinin of influenza virus and identify its biological function. Methods The antibodies gene reservoir of cross-reactive and H5N1 pseudotype particles neutralizing B cell circulating in peripheral blood of a human H5N1 case was recovered by in vitro B cell culture, screening, RT-PCR and expression vector cloning techniques. The Ab gene pairing was screened by transient transfeetion of human kidney 293T cells and detected using ELISA and neutralization test. The heterosubtypic antibodies were prepared and characterized. Results We discovered the VH1-2-based heterosubtypic antibodies from two B cell lineages could neutralize GX-H5N1 pseudotype particles and have broader binding with Group 1 （including HI, H5, H6 and H9） and H7 subtype. Conclusions Cross-reactive antibodies can be induced by H5N1 infection.