Antagonism of Vaccine-Induced HIV-1-Specific CD4 T Cells by Primary HIV-1 Infection: Potential Mechanism of Vaccine Failure

Abstract

Prior immunity to HIV-1 elicited by vaccination may modify subsequent responses upon exposure to infectious HIV-1. An HIV-1-uninfected person entered in a vaccine trial that included immunizations to HIV-1LAI envelope with a recombinant vaccinia vector and recombinant protein developed envelope-specific CD4+ T cell responses, including proliferative and cytolytic responses, but was not protected from a high risk HIV-1 exposure. CD4+ T cell clones derived from blood at the peak of vaccine-induced immunity recognized and lysed autologous target cells expressing four distinct regions within the HIV-1LAI envelope region; three of these CTL clones also recognized targets expressing envelope from ..