Influence of novel CD4 binding-defective HIV-1 envelope glycoprotein immunogens on neutralizing antibody and T-cell responses in nonhuman primates.

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TitleInfluence of novel CD4 binding-defective HIV-1 envelope glycoprotein immunogens on neutralizing antibody and T-cell responses in nonhuman primates.
Publication TypeJournal Article
Year of Publication2010
AuthorsDouagi, I, Forsell, MNE, Sundling, C, O'Dell, S, Feng, Y, Dosenovic, P, Li, Y, Seder, R, Loré, K, Mascola, JR, Wyatt, RT, Hedestam, GBKarlsson
JournalJ Virol
Volume84
Issue4
Pagination1683-95
Date Published2010 Feb
ISSN1098-5514
KeywordsAIDS Vaccines, Animals, Antibodies, Neutralizing, Antigens, CD4, B-Lymphocytes, Binding Sites, HIV Antibodies, HIV Envelope Protein gp120, HIV-1, Immunologic Memory, Macaca mulatta, Models, Molecular, Mutagenesis, Site-Directed, Protein Binding, Protein Structure, Quaternary, T-Lymphocytes
Abstract

The high-affinity in vivo interaction between soluble HIV-1 envelope glycoprotein (Env) immunogens and primate CD4 results in conformational changes that alter the immunogenicity of the gp120 subunit. Because the conserved binding site on gp120 that directly interacts with CD4 is a major vaccine target, we sought to better understand the impact of in vivo Env-CD4 interactions during vaccination. Rhesus macaques were immunized with soluble wild-type (WT) Env trimers, and two trimer immunogens rendered CD4 binding defective through distinct mechanisms. In one variant, we introduced a mutation that directly disrupts CD4 binding (368D/R). In the second variant, we introduced three mutations (423I/M, 425N/K, and 431G/E) that disrupt CD4 binding indirectly by altering a gp120 subdomain known as the bridging sheet, which is required for locking Env into a stable interaction with CD4. Following immunization, Env-specific binding antibody titers and frequencies of Env-specific memory B cells were comparable between the groups. However, the quality of neutralizing antibody responses induced by the variants was distinctly different. Antibodies against the coreceptor binding site were elicited by WT trimers but not the CD4 binding-defective trimers, while antibodies against the CD4 binding site were elicited by the WT and the 423I/M, 425N/K, and 431G/E trimers but not the 368D/R trimers. Furthermore, the CD4 binding-defective trimer variants stimulated less potent neutralizing antibody activity against neutralization-sensitive viruses than WT trimers. Overall, our studies do not reveal any potential negative effects imparted by the in vivo interaction between WT Env and primate CD4 on the generation of functional T cells and antibodies in response to soluble Env vaccination.

DOI10.1128/JVI.01896-09
Alternate JournalJ. Virol.
PubMed ID19955308
PubMed Central IDPMC2812383