title: Two Escape Mechanisms of Influenza A Virus to a Broadly Neutralizing Stalk-Binding Antibody.
abstract: Broadly neutralizing antibodies targeting the stalk region of influenza A virus (IAV) hemagglutinin (HA) are effective in blocking virus infection both in vitro and in vivo. The highly conserved epitopes recognized by these antibodies are critical for the membrane fusion function of HA and therefore less likely to be permissive for virus mutational escape. Here we report three resistant viruses of the A/Perth/16/2009 strain that were selected in the presence of a broadly neutralizing stalk-binding antibody. The three resistant viruses harbor three different mutations in the HA stalk: (1) Gln387Lys; (2) Asp391Tyr; (3) Asp391Gly. The Gln387Lys mutation completely abolishes binding of the antibody to the HA stalk epitope. The other two mutations, Asp391Tyr and Asp391Gly, do not affect antibody binding at neutral pH and only slightly reduce binding at low pH. Interestingly, they enhance the fusion ability of the HA, representing a novel mechanism that allows productive membrane fusion even in the presence of antibody and hence virus escape from antibody neutralization. Therefore, these mutations illustrate two different resistance mechanisms used by IAV to escape broadly neutralizing stalk-binding antibodies. Compared to the wild type virus, the resistant viruses release fewer progeny viral particles during replication and are more sensitive to Tamiflu, suggesting reduced viral fitness.
authors.affiliation: Infectious Diseases Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Ning
authors.initials: N
authors.lastname: Chai
authors.affiliation: Infectious Diseases Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Lee R
authors.initials: LR
authors.lastname: Swem
authors.affiliation: Pathology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Mike
authors.initials: M
authors.lastname: Reichelt
authors.affiliation: Bioinformatics & Computational Biology Department, Genentech, South San Francisco, California, United States of America.|Cancer Immunology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Haiyin
authors.initials: H
authors.lastname: Chen-Harris
authors.affiliation: Protein Chemistry Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Luis
authors.affiliation: Translational Immunology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Summer
authors.initials: S
authors.lastname: Park
authors.affiliation: Infectious Diseases Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Ashley
authors.initials: A
authors.lastname: Fouts
authors.affiliation: Structural Biology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lupardus
authors.affiliation: Bioinformatics & Computational Biology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Wu
authors.affiliation: Development Sciences Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Olga
authors.initials: O
authors.lastname: Li
authors.affiliation: Development Sciences Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: McBride
authors.affiliation: Bioinformatics & Computational Biology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Lawrence
authors.affiliation: Translational Immunology Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.affiliation: Infectious Diseases Department, Genentech, South San Francisco, California, United States of America.
authors.forename: Man-Wah
authors.initials: MW
authors.lastname: Tan
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology; D015153:Blotting, Western; D004285:Dogs; D004352:Drug Resistance, Microbial / Q000276:immunology*; D005434:Flow Cytometry; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology*; D006801:Humans; D057131:Immune Evasion / Q000276:immunology*; D007150:Immunohistochemistry; D009980:Influenza A virus / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000276:immunology; D016133:Polymerase Chain Reaction
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus