HIV-specific cytotoxic T lymphocyte (CTL) response in seronegative Ugandan volunteers vaccinated with HIV-ALVAC vCP 205: result of the phase I HIVNET 007 vaccine study.
Int Conf AIDS 2000 Jul 9-14; 13:22 (abstract no.. LbOr24)
Cao H, Flores J, Sentongo E, Allen M, El Habib R, Sheppard H, Mbidde E, Mugyenyi P, Wilson S, Hom D Massachusetts General Hospital, AIDS Research Center, Charlestown, MA 02129. Fax: 617-726-5411, E-mail: cao@helix.mgh.harvard.edu.
The first prophylactic HIV-1 vaccine study in Africa aimed to evaluate the safety and immunogenicity of the ALVAC-HIV vCP205 in seronegative Ugandan volunteers. Forty individuals were randomized to receive the live canarypox vector in a double-blinded fashion at months 0, 1, 3 and 6. HIV-specific cellular immune responses were assessed after each immunization, and at day 182. We report here the CTL responses elicited by this clade B-based immunogen in a region where clade A and D viruses predominate. Freshly isolated PMBCs were stimulated in vitro with clade B antigens and subsequently tested for cytolytic activity using target cells infected with recombinant vaccinia viruses expressing clade A, B and D Gag and Env antigens in the standard chromium release assay. Confirmatory assays with the elispot method were performed on cryopreserved PBMCs with overlapping synthetic peptides. Immunogenicity and CTL activity were detected in this study population. HIV-specific activity to clade A and D antigens was also demonstrated, suggesting that vCP205 elicited cross-clade CD8+ T cell responses. Fine mapping and HLA restriction of identified epitopes will b performed and compared to known epitopes HIV-1 infected population.
Keywords: AEGIS, T-Lymphocytes, Cytotoxic, HIV Infections, HIV-1, AIDS Vaccines, HIV Seropositivity, CD8-Positive T-Lymphocytes, Vaccines, Antineoplastic Combined Chemotherapy Protocols, Vaccinia virus, Vaccines, Synthetic, Africa, COP protocol 2, In Vitro, immunology, AIDS
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