1. Isolation of a Human Anti-HIV gp41 Membrane Proximal Region Neutralizing Antibody by Antigen-Specific Single B Cell Sorting
- Author
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Morris, Lynn, Chen, Xi, Alam, Munir, Tomaras, Georgia D., Zhang, Ruijun, Marshall, Dawn J., Chen, Bing, Parks, Robert, Foulger, Andrew, Jaeger, Frederick, Donathan, Michele, Bilska, Mira, Gray, Elin S., Abdool Karim, Salim, Kepler, Thomas B., Whitesides, John, Montefiori, David, Moody, M. Anthony, Liao, Hua-Xin, and Haynes, Barton F.
- Subjects
Virology ,FOS: Clinical medicine ,Immunology ,virus diseases ,3. Good health - Abstract
Broadly neutralizing antibodies are not commonly produced in HIV-1 infected individuals nor by experimental HIV-1 vaccines. When these antibodies do occur, it is important to be able to isolate and characterize them to provide clues for vaccine design. CAP206 is a South African subtype C HIV-1-infected individual previously shown to have broadly neutralizing plasma antibodies targeting the envelope gp41 distal membrane proximal external region (MPER). We have now used a fluoresceinated peptide tetramer antigen with specific cell sorting to isolate a human neutralizing monoclonal antibody (mAb) against the HIV-1 envelope gp41 MPER. The isolated recombinant mAb, CAP206-CH12, utilized a portion of the distal MPER (HXB2 amino acid residues, 673-680) and neutralized a subset of HIV-1 pseudoviruses sensitive to CAP206 plasma antibodies. Interestingly, this mAb was polyreactive and used the same germ-line variable heavy (VH1-69) and variable kappa light chain (VK3-20) gene families as the prototype broadly neutralizing anti-MPER mAb, 4E10 (residues 672-680). These data indicate that there are multiple immunogenic targets in the C-terminus of the MPER of HIV-1 gp41 envelope and suggests that gp41 neutralizing epitopes may interact with a restricted set of naive B cells during HIV-1 infection.