Plasmodium chabaudi: polymorphic and nonpolymorphic epitopes of the antigen Pch105/RESA

The localization in the erythrocyte membrane of Pch105/RESA, the ring stage-infected erythrocyte surface antigen of Plasmodium chabaudi, the proposed analog to the vaccine candidate Pf155/RESA in P. falciparum, is here confirmed by the use of the immunogold technique in electron microscopy. Furthermore, a number of monoclonal antibodies to other P. chabaudi erythrocyte membrane antigens in the same molecular weight range as Pch105 were compared in different test systems. Data from immunoblotting of native and recombinant antigen as well as an inhibition ELISA indicate that Pch105 is identical to Pc96 and two other described antigens of 105 and 110 kDa. Pch105 could also be shown to have polymorphic epitopes, varying between different strains of P. chabaudi, without impact on the molecular weight.