IMMUNOGENICITY OF RECOMBINANT PLASMODIUM-FALCIPARUM RHOPTRY ASSOCIATED PROTEIN-1 AND PROTEIN-2

Mice and rabbits immunized with recombinant forms of malaria vaccine c andidate antigens rhoptry-associated proteins 1 and 2 (RAP-1, RAP-2 an d rRAP-1, rRAP-2) produce antibodies at titres equivalent to monoclona l antibody ascites fluid raised against the native proteins. Sera from animals immunized with rRAP-1 contain antibodies which recognize the native protein by indirect immunofluorescence and immunoblotting, part ially inhibit erythrocyte invasion in vitro and are long lasting. Epit ope mapping shows these antibodies predominantly recognize epitopes in the N-terminal third of rRAP-1, some of which coincide with the targe ts of inhibitory monoclonal antibodies. By contrast, sera from animals immunized with rRAP-2 contain antibodies which recognize the recombin ant but not the native protein.