Evaluation of envelope vaccines derived from the South African subtype C human immunodeficiency virus type 1 TV1 strain
Chiron Corporation, Emeryville, CA 94608, United States; University of Stellenbosch, Tygerberg Hospital, Cape Town, South Africa; University of California, Davis, CA 95616, United States; Duke University Medical Center, Durham, NC 27710, United States; Genetronics/Inovio, Inc., San Diego, CA 92121, United States; Chiron Corp., 4560 Horton St., Emeryville, CA 94608, United States; Food and Drug Laboratory, Richmond, CA 94804, United States; Department of Medical Virology, Tswane Academic Division, University of Pretoria, Pretoria, South Africa
Human immunodeficiency virus type 1 (HIV-1) subtype C infections are on the rise in Sub-Saharan Africa and Asia. Therefore, there is a need to develop an HIV vaccine capable of eliciting broadly reactive immune responses against members of this subtype. We show here that modified HIV envelope (env) DNA vaccines derived from the South African subtype C TV1 strain are able to prime for Immoral responses in rabbits and rhesus macaques. Priming rabbits with DNA plasmids encoding V2-deleted TV1 gp140 (gp140TV1ΔV2), followed by boosting with oligomeric protein (o-gp140TV1ΔV2) in MF59 adjuvant, elicited higher titers of env-binding and autologous neutralizing antibodies than priming with DNA vaccines encoding the full-length TV1 env (gp160) or the intact TV1 gp140. Immunization with V2-deleted subtype B SF162 env and V2-deleted TVl env together using a multivalent vaccine approach induced high titers of oligomeric env-binding antibodies and autologous neutralizing antibodies against both the subtypes B and C vaccine strains, HIV-1 SF162 and TV1, respectively. Low-level neutralizing activity against the heterologous South African subtype C TV2 strain, as well as a small subset of viruses in a panel of 13 heterologous primary isolates, was observed in some rabbits immunized with the V2-deleted vaccines. Immunization of rhesus macaques with the V2-deleted TV1 DNA prime/protein boost also elicited high titers of env-binding antibodies and moderate titers of autologous TV1 neutralizing antibodies. The pilot-scale production of the various TV1 DNA vaccine constructs and env proteins described here should provide an initial platform upon which to improve the immunogenicity of these subtype C HIV envelope vaccines. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
binding protein; DNA vaccine; Human immunodeficiency virus vaccine; neutralizing antibody; unclassified drug; virus envelope protein; virus envelope vaccine; animal cell; antibody response; antibody titer; article; cytotoxic T lymphocyte; derivatization; evaluation; human; human cell; Human immunodeficiency virus 1; Human immunodeficiency virus 1 subtype c; immune response; immunogenicity; nonhuman; priority journal; South Africa; virus envelope; virus isolation; virus strain; AIDS Vaccines; Amino Acid Sequence; Animals; Drug Evaluation, Preclinical; Gene Deletion; Gene Products, env; HIV Antibodies; HIV Envelope Protein gp160; HIV Infections; HIV-1; Immunization, Secondary; Injections, Intramuscular; Macaca mulatta; Molecular Sequence Data; Mutation; Neutralization Tests; Rabbits; Sequence Alignment; South Africa; Vaccination; Vaccines, DNA; Human immunodeficiency virus 1; Macaca mulatta; Oryctolagus cuniculus