Multiple antigen peptide mimetics containing gp41 membrane-proximal external region elicit broad neutralizing antibodies against human immunodeficiency virus type 1 in guinea pigs

Eliciting a broadly neutralizing antibody response against the HIV-1 membrane-proximal external region (MPER) mimicking the activity of 4E10 and 2F5 monoclonal antibodies remains a major challenge. In this study, two novel tetra-branched peptide immunogens, 4E10- and 2F5-MAP4, were designed and synthesized using a MAP system. Guinea pigs were immunized with either of these two synthetic immunogens emulsified in an oil-phase adjuvant at 3-week intervals. After four immunizations, epitope-specific antibody responses were induced successfully, and moderate neutralizing activities against tier 1 (clades B, BC, AE) and tier 2 (clade C) HIV-1 pseudoviruses were detectable in unfractionated sera and purified IgGs. The synthetic gp41 membrane-proximal external region peptide mimetics, 4E10- and 2F5-MAP4, assisted by an appropriate adjuvant, are promising prophylactic vaccine candidates potentially capable of eliciting broadly neutralizing antibody responses against HIV-1. Copyright (c) 2013 European Peptide Society and John Wiley & Sons, Ltd.