title: Selection of a novel gp41-specific HIV-1 neutralizing human antibody by competitive antigen panning.
abstract: The HIV envelope glycoprotein (Env) is composed of two non-covalently associated subunits: gp120 and gp41. Panning of phage-displayed antibody libraries against Env-based antigens has resulted mostly in selection of anti-gp120 antibodies. Native gp41 in the absence of gp120 is unstable. The use of gp41 fragments as antigens has resulted in selection of antibodies with only relatively modest neutralizing activity. To enhance selection of antibodies specific for gp41 in the context of the whole Env we developed a methodology termed competitive antigen panning (CAP). Using CAP, we identified a novel gp41-specific human monoclonal antibody (hmAb), m48, from an immune library derived from long-term nonprogressors with high titers of broadly cross-reactive neutralizing antibodies (bcnAbs). Selection of m48 was only successful using CAP and not through the conventional pre-incubation methodology. In assays based on spreading infection in peripheral blood mononuclear cells (PBMCs) m48 neutralized a panel of HIV-1 primary isolates from different clades more potently than the well-characterized broadly cross-reactive HIV-1-neutralizing antibodies IgG1 4E10 and Fab Z13. These results may have implications for the selection of novel gp41-specific bcnAbs and other antibodies, and for the development of HIV-1 inhibitors and vaccine immunogens.
authors.affiliation: Protein Interactions Group, CCRNP, CCR, NCI-Frederick, NIH, Frederick, Maryland 21702, USA. zhangm@ncifcrf.gov
authors.forename: Mei-Yun
authors.initials: MY
authors.lastname: Zhang
authors.forename: Vidita
authors.initials: V
authors.lastname: Choudhry
authors.forename: Igor A
authors.initials: IA
authors.lastname: Sidorov
authors.forename: Vladimir
authors.initials: V
authors.lastname: Tenev
authors.forename: Bang K
authors.initials: BK
authors.lastname: Vu
authors.forename: Anil
authors.initials: A
authors.lastname: Choudhary
authors.forename: Hong
authors.initials: H
authors.lastname: Lu
authors.forename: Gabriela M
authors.initials: GM
authors.lastname: Stiegler
authors.forename: Hermann W D
authors.initials: HW
authors.lastname: Katinger
authors.forename: Shibo
authors.initials: S
authors.lastname: Jiang
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Broder
authors.forename: Dimiter S
authors.initials: DS
authors.lastname: Dimitrov
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007158:Immunologic Techniques; D009500:Neutralization Tests / Q000379:methods; D019151:Peptide Library
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015700:HIV Envelope Protein gp41; D019151:Peptide Library