DNA-immunization with a V2 deleted HIV-1 envelope elicits protective antibodies in macaques

Rhesus macaques immunized with the HIV-1 SF162 Delta V2 gp140 envelope usin g the DNA-prime plus protein-boost vaccination methodology, developed HIV e nvelope-specific T-cell lymphoproliferative responses and potent neutralizi ng antibodies. To evaluate the protective potential of these antibodies dur ing acute infection, the animals were depleted of their CD8 + T lymphocytes using specific monoclonal antibodies and subsequently challenged intraveno usly with the pathogenic SHIVSF162P4 isolate. As compared to non-vaccinated animals (one of which died from AIDS 16 weeks post-exposure) the vaccinate d macaques had lower levels of peak viremia, rapidly cleared virus from the periphery and developed delayed seroconversion to SIV core antigens. (C) 2 001 Elsevier Science B.V. All rights reserved.