This project involves the development and testing of a novel MHC based vaccine designed to provide both humoral and cellular immunity against viral attack. Such vaccines have particular relevance for protection against AIDS. These vaccines are based on linking viral epitopes through a tether to B2-microglobulin. This tripartite construct can replace normal peptides present in MHC-l binding sites, leading to the generation of virus-specific T-cell responses. Initial studies with a model mouse Sendai virus construct have provided proof of principle for this approach. This includes the cloning, refolding and purification of the vaccine and demonstration that it binds/exchanges with B2-microglobulin on cell surfaces, upregulates MHC expression on cells expressing empty class I MHC and stimulates T-cell hybridomas that are reactive to the Sendai virus epitopes present on the vaccine. The proposed studies involve: A. Further studies with the Sendai virus model including 1) additional investigation with the Beta2-linker-Sendai epitope construct to determine the effect of different linker sizes on binding to the MHC and on subsequent CFL responses 2) development and testing of a DNA version of the vaccine construct 3) determining whether vaccination of mice with these constructs will provide protection against challenge with the Sendai virus. As part of these studies the optimization of the route, dosage and duration of effectiveness will be determined. B. Development and testing of AIDS MHC-vaccine constructs, including I) using a p17 (Gag) sequence 2) using a Pol sequence 3) using a Nef sequence. These epitopes were chosen because of their highly conserved nature, their cross-clade reactivity, and their role in the spread of the disease.
