Analysis of the HIV-1 gp41 specific immune response using a multiplexed antibody detection assay

A fluorescence-based, multiplexed, antibody-binding and mapping assay was developed to characterize antibody responses in HIV-1-infected individuals to the ectodomain of the HIV-1 gp41 envelope glycoprotein. The antigen panel included intact recombinant gp41, the fusion peptide region, the polar region, the N-heptad region, the C-heptad region as well as overlapping epitopes in the 2F5 and 4E10 monoclonal antibody-bin ding regions. The panel included both native and constrained peptides specifically designed to mimic putative gp41 prefusion and fusion intermediates. The results of these analyses revealed a broad pattern of immune responses against the test antigens, suggesting that none of these gp41 regions are immunologically silent. The HIV-1-positive sera were also evaluated using infectivity inhibition assays. No correlation was evident between the breadth or magnitude of specific anti-gp41 reactivities and virus neutralization potency. These evaluations demonstrated the substantial potential of the multiplexed antibody binding and mapping assay for rapid and sensitive analysis of complex antibody responses. (C) 2004 Elsevier B.V. All rights reserved.