7mem
CryoEM structure of monoclonal Fab 045-09 2B05 binding the lateral patch of influenza virus H1 HA
Structural highlights
FunctionC3W5S1_I09A0 Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization of about two third of the virus particles through clathrin-dependent endocytosis and about one third through a clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore (By similarity).[SAAS:SAAS013829_004_327643][RuleBase:RU003324] Publication Abstract from PubMedBroadly neutralizing antibodies are critical for protection against both drifted and shifted influenza viruses. Here, we reveal that first exposure to the 2009 pandemic H1N1 influenza virus recalls memory B cells that are specific to the conserved receptor-binding site (RBS) or lateral patch epitopes of the hemagglutinin (HA) head domain. Monoclonal antibodies (mAbs) generated against these epitopes are broadly neutralizing against H1N1 viruses spanning 40 years of viral evolution and provide potent protection in vivo. Lateral patch-targeting antibodies demonstrated near universal binding to H1 viruses, and RBS-binding antibodies commonly cross-reacted with H3N2 viruses and influenza B viruses. Lateral patch-targeting mAbs were restricted to expressing the variable heavy-chain gene VH3-23 with or without the variable kappa-chain gene VK1-33 and often had a Y-x-R motif within the heavy-chain complementarity determining region 3 to make key contacts with HA. Moreover, lateral patch antibodies that used both VH3-23 and VK1-33 maintained neutralizing capability with recent pH1N1 strains that acquired mutations near the lateral patch. RBS-binding mAbs used a diverse repertoire but targeted the RBS epitope similarly and made extensive contacts with the major antigenic site Sb. Together, our data indicate that RBS- and lateral patch-targeting clones are abundant within the human memory B cell pool, and universal vaccine strategies should aim to drive antibodies against both conserved head and stalk epitopes. First exposure to the pandemic H1N1 virus induced broadly neutralizing antibodies targeting hemagglutinin head epitopes.,Guthmiller JJ, Han J, Li L, Freyn AW, Liu STH, Stovicek O, Stamper CT, Dugan HL, Tepora ME, Utset HA, Bitar DJ, Hamel NJ, Changrob S, Zheng NY, Huang M, Krammer F, Nachbagauer R, Palese P, Ward AB, Wilson PC Sci Transl Med. 2021 Jun 2;13(596):eabg4535. doi: 10.1126/scitranslmed.abg4535. PMID:34078743[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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