Four cross-linked HIV Gag peptides prime the immune response to HIV proteins in mice

The functional help provided by four cross-linked synthetic peptides from HIV-1 Gag structural proteins was investigated in the mouse model. These peptides, selected upon non-self-criteria, are not predicted as T epitopes by classical prediction methods such as the Rothbard consensus or the amphipathy rule. Priming mice with these peptides allows the enhancement of the antibody response to HIV-1 Gag proteins (p55, p18, p24) given in the viral particle form. Furthermore, all of them also induce spleen and lymph node cells from primed mice to proliferate in vitro, in a MHC class II restricted context. This approach may help to identify relevant immunogenic viral epitopes that may be involved in a vaccinal strategy.