Official websites use. Share sensitive information only on official, secure websites. Author contributions: E. H performed the statistical analyses and generated tables and figures.
All authors contributed to discussions about the results and critically revised the manuscript. Frahm gatesmri. T cell responses have been implicated in reduced risk of HIV acquisition in uninfected persons and control of viral replication in HIV-infected individuals.
HIV Gag-specific T cells have been predominantly associated with post-infection control, whereas Env antigens are the target for protective antibodies; therefore inclusion of both antigens is common in HIV vaccine design. Yet, inclusion of multiple antigens may provoke antigenic competition, reducing the potential effectiveness of the vaccine.
Therefore, T cell based vaccine strategies should aim at choosing a minimalist set of antigens to reduce interference of individual vaccine components with the induction of the maximally achievable immune response. Env-specific broadly neutralizing antibodies 1 or Env V2-specific antibodies able to effectively promote Fc receptor-mediated functions 2 , 3 are highly desirable, and most of the current vaccine concepts include an Env component to allow for their elicitation.
Nevertheless, the induction of T cell responses remains an important goal for several vaccine candidates [reviewed in 4 ], specifically those targeting Gag 5 , based on numerous studies suggesting that T cells targeting epitopes within Gag are particularly important in the host defense against HIV-1 6 — Several challenges remain for the induction of a protective cellular immune response 11 , as highlighted by the lack of efficacy of the Step Study and HVTN 12 — One of the proposed reasons for the lack of efficacy in the Step Study was the inability of the MRKAd5 HIV vaccine to induce T cell responses of appropriate epitope breadth to provide recognition of potential infecting virus strains.
