Structural Basis of Protection against H7N9 Influenza Virus by Human Anti-N9 Neuraminidase Antibodies

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Cell Host Microbe. 2019 Oct 24. pii: S1931-3128(19)30526-8. doi: 10.1016/j.chom.2019.10.002. [Epub ahead of print] Structural Basis of Protection against H7N9 Influenza Virus by Human Anti-N9 Neuraminidase Antibodies.

Zhu X¹, Turner HL¹, Lang S¹, McBride R², Bangaru S³, Gilchuk IM³, Yu W¹, Paulson JC², Crowe JE Jr⁴, Ward AB⁵, Wilson IA⁶.
Author information

1 Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. 2 Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA. 3 Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA. 4 Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA. 5 Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: andrew@scripps.edu. 6 Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA. Electronic address: wilson@scripps.edu.

Abstract

Influenza virus neuraminidase (NA) is a major target for small-molecule antiviral drugs. Antibodies targeting the NA surface antigen could also inhibit virus entry and egress to provide host protection. However, our understanding of the nature and range of target epitopes is limited because of a lack of human antibody structures with influenza neuraminidase. Here, we describe crystal and cryogenic electron microscopy (cryo-EM) structures of NAs from human-infecting avian H7N9 viruses in complex with five human anti-N9 antibodies, systematically defining several antigenic sites and antibody epitope footprints. These antibodies either fully or partially block the NA active site or bind to epitopes distant from the active site while still showing neuraminidase inhibition. The inhibition of antibodies to NAs was further analyzed by glycan array and solution-based NA activity assays. Together, these structural studies provide insights into protection by anti-NA antibodies and templates for the development of NA-based influenza virus vaccines and therapeutics.
Copyright ? 2019 Elsevier Inc. All rights reserved.


KEYWORDS:

H7N9 influenza virus; X-ray crystallography; antibody; cryo-electron microscopy; glycan array; inhibition mechanism; neuraminidase; neuraminidase-Fab structures

PMID: 31757767 DOI: 10.1016/j.chom.2019.10.002