Identification of a cross-neutralizing antibody that targets the receptor binding site of H1N1 and H5N1 influenza viruses

This research paper describes a chimeric monoclonal antibody, C12H5, which neutralizes seasonal and pandemic H1N1 viruses and offers cross-protection against some H5N1 viruses. C12H5 exhibits broad neutralizing activity by controlling virus entry and egress, offering *in vivo* protection. Structural analyses reveal that C12H5 binds to hemagglutinin (HA) at an epitope overlapping the receptor-binding site (RBS) and covering the 140-loop. Eight highly conserved residues crucial for broad H1N1 recognition were identified, and the antibody’s tolerance for Asp or Glu at position 190 contributes to its cross-neutralization potential. These results may aid in the development of antiviral drugs and broad-protection influenza vaccines.

Tingting Li, Junyu Chen, Qingbing Zheng, Wenhui Xue, Limin Zhang, Rui Rong, Sibo Zhang, Qian Wang, Minqing Hong, Yuyun Zhang, Lingyan Cui, Maozhou He, Zhen Lu, Zhenyong Zhang, Xin Chi, Jinjin Li, Yang Huang, Hong Wang, Jixian Tang, Dong Ying, Lizhi Zhou, Yingbin Wang, Hai Yu, Jun Zhang, Ying Gu, Yixin Chen, Shaowei Li, Ningshao Xia