IMMUNOGENICITY AND ANTIGENICITY OF THE N-TERM REPEAT AMINO-ACID-SEQUENCE OF THE PLASMODIUM-FALCIPARUM P126 ANTIGEN

The P126 protein, a parasitophorus vacuole antigen of Plasmodium falci parum has been shown to induce protective immunity in Saimiri and Aotu s monkeys. In the present work we investigated its immunogenicity. Our results suggest that the N-term of P126 is poorly immunogenic and the antibody response against the P126 could be under a MHC restricted co ntrol in C57BL/6(H-2b) mice, which could be problematic in terms of a use of the P126 in a vaccine program. However, we observed that a synt hetic peptide, copying the 6 octapeptide repeat corresponding to the N -term of the P126, induces an antibody response to the native molecule in C57BL/6 non-responder mice. Moreover, the vaccine-P126 recombinant induced antibodies against the N-term of the molecule in rabbits whil e the unprocessed P126 did not.