Browsing by Author "Foulger, Andrew."

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Isolation of a human anti-HIV gp41 membrane proximal region neutralizing antibody by antigen-specific single B cell sorting.
(Plos., 2011) Morris, Lynn.; Chen, Xi.; Alam, Shabnam Munir.; Tomaras, Georgia D.; Zhang, Ruijun.; Marshall, Dawn J.; Chen, Bing.; Parks, Robert J.; Foulger, Andrew.; Jaeger, Frederick H.; Donathan, Michele.; Bilska, Mira.; Gray, Elin Solomonovna.; Abdool Karim, Salim Safurdeen.; Kepler, Thomas B.; Whitesides, John.; Montefiori, David Charles.; Moody, Michael Anthony.; Liao, Hua-Xin.; Haynes, Barton F.
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.
Isolation of a Monoclonal Antibody That Targets the Alpha-2 Helix of gp120 and Represents the Initial Autologous Neutralizing-Antibody Response in an HIV-1 Subtype C-Infected Individual.
(American Society for Microbiology., 2011) Gray, Elin Solomonovna.; Moody, Michael Anthony.; Wibmer, Constantinos Kurt.; Chen, Xi.; Marshall, Dawn J.; Amos, Joshua.; Moore, Penelope L.; Foulger, Andrew.; Yu, Jae-Sung.; Lambson, Bronwen Elizabeth.; Abdool Karim, Salim Safurdeen.; Whitesides, John.; Tomaras, Georgia D.; Haynes, Barton F.; Morris, Lynn.; Liao, Hua-Xin.
The C3-V4 region is a major target of autologous neutralizing antibodies in HIV-1 subtype C infection. We previously identified a Center for AIDS Program of Research in South Africa (CAPRISA) participant, CAP88, who developed a potent neutralizing-antibody response within 3 months of infection that targeted an epitope in the C3 region of the HIV-1 envelope (P. L. Moore et al., PLoS Pathog. 5:e1000598, 2009). Here we showed that these type-specific antibodies could be adsorbed using recombinant gp120 from the transmitted/founder virus from CAP88 but not by gp120 made from other isolates. Furthermore, this activity could be depleted using a chimeric gp120 protein that contained only the C3 region from the CAP88 viral envelope engrafted onto the unrelated CAP63 viral envelope (called 63-88C3). On the basis of this, a differential sorting of memory B cells was performed using gp120s made from 63-88C3 and CAP63 labeled with different fluorochromes as positive and negative probes, respectively. This strategy resulted in the isolation of a highly specific monoclonal antibody (MAb), called CAP88-CH06, that neutralized the CAP88 transmitted/founder virus and viruses from acute infection but was unable to neutralize CAP88 viruses isolated at 6 and 12 months postinfection. The latter viruses contained 2 amino acid changes in the alpha-2 helix of C3 that mediated escape from this MAb. One of these changes involved the introduction of an N-linked glycan at position 339 that occluded the epitope, while the other mutation (either E343K or E350K) was a charge change. Our data validate the use of differential sorting to isolate a MAb targeting a specific epitope in the envelope glycoprotein and provided insights into the mechanisms of autologous neutralization escape.
Structural constraints of vaccine-induced tier-2 autologous HIV neutralizing antibodies targeting the receptor-binding site.
(Cell Press., 2016) Bradley, Todd.; Fera, Daniela.; Bhiman, Jinal N.; Eslamizar, Leila.; Lu, Xiaozhi.; Anasti, Kara.; Zhang, Ruijun.; Sutherland, Laura L.; Scearce, Richard M.; Bowman, Cindy M.; Stolarchuk, Christina.; Lloyd, Krissey E.; Parks, Robert.; Eaton, Amanda.; Foulger, Andrew.; Nie, Xiaoyan.; Abdool Karim, Salim Safurdeen.; Barnett, Susan.; Kelsoe, Garnett.; Kepler, Thomas B.; Alam, Shabnam Munir.; Montefiori, David Charles.; Moody, Michael Anthony.; Liao, Hua-Xin.; Morris, Lynn.; Santra, Sampa.; Harrison, Stephen C.; Haynes, Barton F.
Abstract available in pdf.