Structural basis for a potent human neutralizing antibody targeting a conserved epitope on the H7 hemagglutinin head

J Junxin Li (Shenzhen Key Laboratory of Human Antibody Engineering, Center for Protein and Cell-Based Drugs, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences) M Min Wang Y Yang Yang L Limin Zhang (Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Center for Quantum Technology Research and School of Physics) L Lvyan Liu (Institute of Maternal and Child Medicine, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University) W Wei Yang Y Yun Peng (State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology) X Xu Zhang B Bin Yuan Q Qi Peng (The MOE Basic Research and Innovation Center for the Targeted Therapeutics of Solid Tumors, School of Basic Medical Sciences, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, China.) X Xiaolu Yang (Department of Cancer Biology and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania) Y Yixin Chen G George F. Gao Y Yi Shi (School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Functional Biomaterials Engineering Technology Research Center) X Xiaochun Wan (Shenzhen Key Laboratory of Human Antibody Engineering, Center for Protein and Cell-Based Drugs, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences)

Abstract

Zoonotic H7N9 avian influenza virus infection remains a global concern because of its pandemic potential. Therefore, developing effective antibodies and vaccines against H7N9 is vital for preventing and controlling major outbreaks. Here, we isolated a human VH3-30 gene-encoded antibody, designated 6Y13, from a survivor of H7N9 infection. This antibody recognized the hemagglutinins (HAs) of the representative H7 subtype zoonotic viruses spanning two decades of antigenic evolution and potently neutralized epidemic H7N9 viruses in vitro. Moreover, 6Y13 conferred complete protection in mice against lethal H7N9 challenge in both prophylactic and therapeutic experiments. Structural analysis by cryoelectron microscopy indicated that 6Y13 binds to a unique conserved site on the HA head, distinct from the receptor-binding site and lateral patch. Nevertheless, 6Y13 efficiently blocked viral receptor binding without interfering with HA receptor binding, independent of Fc-mediated steric hindrance. Our findings provide a promising therapeutic candidate against pan-H7 subtype viruses and are beneficial for the design of H7 subtype influenza vaccine immunogens.

Article Details

Volume / Issue Vol. 122, Issue 45
Published November 11, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (15)

J

Junxin Li

Shenzhen Key Laboratory of Human Antibody Engineering, Center for Protein and Cell-Based Drugs, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences

M

Min Wang

Y

Yang Yang

L

Limin Zhang

Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Center for Quantum Technology Research and School of Physics

L

Lvyan Liu

Institute of Maternal and Child Medicine, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University

W

Wei Yang

Y

Yun Peng

State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology

X

Xu Zhang

B

Bin Yuan

Q

Qi Peng

The MOE Basic Research and Innovation Center for the Targeted Therapeutics of Solid Tumors, School of Basic Medical Sciences, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, China.

X

Xiaolu Yang

Department of Cancer Biology and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania

Y

Yixin Chen

G

George F. Gao

Y

Yi Shi

School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Functional Biomaterials Engineering Technology Research Center

X

Xiaochun Wan

Shenzhen Key Laboratory of Human Antibody Engineering, Center for Protein and Cell-Based Drugs, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences