The L.E.A.P.S. approach to vaccine development.

The Ligand Epitope Antigen Presentation System (L.E.A.P.S.) approach to vaccine development utilizes immune peptides to promote the immunogenicity and influence the type of immune response generated towards epitopes in peptides which may be too small to elicit an immune response. The covalent attachment of these immune peptides to the antigenic peptide promotes the interaction of the epitope with T cells (T cell binding ligand (TCBL)) or antigen presenting cells (immune cell binding ligand (ICBL)) and ultimately promotes binding with the T cell receptor on CD4 or CD8 T cells. The, J, ICBL/TCBL peptide derived from the beta-2-microglobulin chain of MHC I molecules promotes Th1 type responses to the antigenic peptide while the, G, ICBL/TCBL peptide derived from the beta chain of MHC II molecules promotes Th2 types of responses. The efficacy of this approach has been demonstrated by characterization of the immune responses to L.E.A.P.S. vaccines and by elicitation of protection from infectious challenge with herpes simplex virus and other pathogens. The protection studies show that the L.E.A.P.S. approach allows customization of the immune response appropriate for inducing protection from disease. The theory, background, examples and studies of the mechanism of action of the L.E.A.P.S. vaccines will be discussed.