title: Common tolerance mechanisms, but distinct cross-reactivities associated with gp41 and lipids, limit production of HIV-1 broad neutralizing antibodies 2F5 and 4E10.
abstract: Developing an HIV-1 vaccine has been hampered by the inability of immunogens to induce broadly neutralizing Abs (BnAbs) that protect against infection. Previously, we used knockin (KI) mice expressing a prototypical gp41-specific BnAb, 2F5, to demonstrate that immunological tolerance triggered by self-reactivity of the 2F5 H chain impedes BnAb induction. In this study, we generate KI models expressing H chains from two other HIV-1 Abs, 4E10 (another self-/polyreactive, anti-gp41 BnAb) and 48d (an anti-CD4 inducible, nonpolyreactive Ab), and find a similar developmental blockade consistent with central B cell deletion in 4E10, but not in 48d VH KI mice. Furthermore, in KI strains expressing the complete 2F5 and 4E10 Abs as BCRs, we find that residual splenic B cells arrest at distinct developmental stages, yet exhibit uniformly low BCR densities, elevated basal activation, and profoundly muted responses to BCR ligation and, when captured as hybridoma mAb lines, maintain their dual (gp41/lipid) affinities and capacities to neutralize HIV-1, establishing a key role for anergy in suppressing residual 2F5- or 4E10-expressing B cells. Importantly, serum IgGs from naive 2F5 and 4E10 KI strains selectively eliminate gp41 and lipid binding, respectively, suggesting B cells expressing 2F5 or 4E10 as BCRs exhibit specificity for a distinct spectrum of host Ags, including selective interactions by 2F5 BCR(+) B cells (i.e., and not 4E10 BCR(+) B cells) with those mimicked by its gp41 neutralization epitope.
authors.affiliation: Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
authors.forename: Kwan-Ki
authors.initials: KK
authors.lastname: Hwang
authors.forename: Hilary
authors.initials: H
authors.lastname: Bouton-Verville
authors.forename: Shi-Mao
authors.initials: SM
authors.lastname: Xia
authors.forename: Amanda
authors.initials: A
authors.lastname: Newman
authors.forename: Ying-Bin
authors.initials: YB
authors.lastname: Ouyang
authors.forename: Barton F
authors.initials: BF
authors.lastname: Haynes
authors.forename: Laurent
authors.initials: L
authors.lastname: Verkoczy
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D057134:Antibodies, Neutralizing / Q000096:biosynthesis / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D000080908:Broadly Neutralizing Antibodies; D002454:Cell Differentiation; D003429:Cross Reactions; D055879:Gene Knock-In Techniques; D015483:HIV Antibodies / Q000096:biosynthesis / Q000276:immunology*; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology; D007108:Immune Tolerance; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008055:Lipids / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism
chemical_list: C558560:2F5 monoclonal antibody; C558559:4E10 monoclonal antibody; D016915:AIDS Vaccines; D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000080908:Broadly Neutralizing Antibodies; D015483:HIV Antibodies; D015700:HIV Envelope Protein gp41; D007074:Immunoglobulin G; D008055:Lipids; D011947:Receptors, Antigen, B-Cell