Development of a malaria T-cell vaccine for blood stage immunity.

We have defined a strategy for the development of a T-cell vaccine for blood stage immunity, taking into consideration the central role of T cells and MHC restriction in malaria immune responses. We have used the AMPHI computer algorithm to identify putative T-cell epitopes from conserved regions of 11 Plasmodium falciparum asexual stage proteins. Ten of the eleven proteins are currently candidates for vaccine development. Using this algorithm we selected 22 putative T-cell epitope peptides and 8 control peptides. These peptides were used to test the T-cell responses of three defined populations of Caucasians who have (1) recovered from P. falciparum malaria, (2) been exposed, but never clinically infected, (3) never been exposed or infected. Preliminary analysis of our data shows population differences in T-cell responses to putative T-cell epitope peptides. Ultimately, these studies will help to identify those T epitopes that can be incorporated into a T-cell vaccine for protective immunity.