Structural and genetic basis for development of broadly neutralizing influenza antibodies - PubMed (original) (raw)

. 2012 Sep 27;489(7417):566-70.

doi: 10.1038/nature11371. Epub 2012 Aug 29.

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Structural and genetic basis for development of broadly neutralizing influenza antibodies

Daniel Lingwood et al. Nature. 2012.

Abstract

Influenza viruses take a yearly toll on human life despite efforts to contain them with seasonal vaccines. These viruses evade human immunity through the evolution of variants that resist neutralization. The identification of antibodies that recognize invariant structures on the influenza haemagglutinin (HA) protein have invigorated efforts to develop universal influenza vaccines. Specifically, antibodies to the highly conserved stem region of HA neutralize diverse viral subtypes. These antibodies largely derive from a specific antibody gene, heavy-chain variable region IGHV1-69, after limited affinity maturation from their germline ancestors, but how HA stimulates naive B cells to mature and induce protective immunity is unknown. To address this question, we analysed the structural and genetic basis for their engagement and maturation into broadly neutralizing antibodies. Here we show that the germline-encoded precursors of these antibodies act as functional B-cell antigen receptors (BCRs) that initiate subsequent affinity maturation. Neither the germline precursor of a prototypic antibody, CR6261 (ref. 3), nor those of two other natural human IGHV1-69 antibodies, bound HA as soluble immunoglobulin-G (IgG). However, all three IGHV1-69 precursors engaged HA when the antibody was expressed as cell surface IgM. HA triggered BCR-associated tyrosine kinase signalling by germline transmembrane IgM. Recognition and virus neutralization was dependent solely on the heavy chain, and affinity maturation of CR6261 required only seven amino acids in the complementarity-determining region (CDR) H1 and framework region 3 (FR3) to restore full activity. These findings provide insight into the initial events that lead to the generation of broadly neutralizing antibodies to influenza, informing the rational design of vaccines to elicit such antibodies and providing a model relevant to other infectious diseases, including human immunodeficiency virus/AIDS. The data further suggest that selected immunoglobulin genes recognize specific protein structural 'patterns' that provide a substrate for further affinity maturation.

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Conflict of interest statement

The authors declare no competing financial interests.

Figures

Figure 1

Figure 1. Somatic maturation of heavy chain confers HA reactivity.

a, Amino acid alignment of somatic CR6261 heavy-chain variable region (including the D and J regions) with JOINSOLVER predicted germline precursor (Kabat convention). Somatic mutations are shown in red. Those incorporated into germline variants are underlined. Mutations T28P and S30R are in close proximity to the Kabat-defined CDR H1 and are CR6261 contact residues, and therefore defined as CDR H1 somatic mutations in the remaining text. b, ELISA binding of somatic (sHsL, filled circles), respective germline (gHgL, open circles), and chimaeric (sHgL, half-filled circles) indicated HA-stem-specific antibodies to H1 1999 NC. OD, optical density. Error bars represent standard deviations of the mean for each antibody concentration. PowerPoint slide

Figure 2

Figure 2. CDR H1 maturation confers CR6261 neutralization activity.

a, CR6261 interaction with H1 A/South Carolina/1/1918 (1918 SC) HA stem (grey, PDB accession 3GBN). Side chains with at least 10 Å2 of interaction are depicted as sticks, with somatically mutated residues coloured red. b, ELISA binding and neutralization of H1 1999 NC by mature (filled circles) and sCDR H1/sFR3 germline-mutated CR6261 (filled squares) Error bars represent standard deviations of the mean for each antibody concentration. c, CDR H1 of CR6261 uncomplexed (blue) or with HA (light blue, PDB accession 3GBN) compared with unmutated CDR H1 from 47e (cyan, PDB accession 1RZI); mutated residues are in red (CR6261) or pink (47e). A non-crystallographic symmetry (NCS)-averaged electron density map (grey) is contoured at 1.0_σ_. PowerPoint slide

Figure 3

Figure 3. HA engages and activates membrane-presented germline antibody.

a, 293F cells expressing membrane IgMs (VRC01 (grey), IGHV1-69 germ lines (wild-type and Ile53Ala/Phe54Ala mutants, coloured lines)) exposed to HA with an N-linked glycan introduced to block the sialic-acid-binding site (ΔRBS) (red) and anti-light-chain expression controls (purple) analysed by flow cytometry. b, Unmodified HA trimer also engages germline (30 mM 6′-sialyllactose present) by flow cytometry. c, CR6261 CDR H2 interactions with 1918 SC HA stem (PDB accession 3GBN). d, HA proteoliposomes selectively activate tyrosine phosphorylation (pY) by CR6261 germline BCR (P < 0.0002, ANOVA); wild-type and mutant CDR H2 receptor activity differed for HA (asterisk) but not for anti-IgM (Tukey’s HSD, α = 0.05)). Presented are the mean values and standard errors of pY intensity. PowerPoint slide

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References

    1. Corti D, et al. Heterosubtypic neutralizing antibodies are produced by individuals immunized with a seasonal influenza vaccine. J. Clin. Invest. 2010;120:1663–1673. doi: 10.1172/JCI41902. - DOI - PMC - PubMed
    1. Wrammert J, et al. Broadly cross-reactive antibodies dominate the human B cell response against 2009 pandemic H1N1 influenza virus infection. J. Exp. Med. 2011;208:181–193. doi: 10.1084/jem.20101352. - DOI - PMC - PubMed
    1. Ekiert DC, et al. Antibody recognition of a highly conserved influenza virus epitope. Science. 2009;324:246–251. doi: 10.1126/science.1171491. - DOI - PMC - PubMed
    1. Sui J, et al. Structural and functional bases for broad-spectrum neutralization of avian and human influenza A viruses. Nature Struct. Mol. Biol. 2009;16:265–273. doi: 10.1038/nsmb.1566. - DOI - PMC - PubMed
    1. Sui J, et al. Wide prevalence of heterosubtypic broadly neutralizing human anti-influenza A antibodies. Clin. Infect. Dis. 2011;52:1003–1009. doi: 10.1093/cid/cir121. - DOI - PMC - PubMed

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