Plasmadium vivax: Cloning and Expression of a Major Blood-Stage . Surface Antigen

Abstract

Plasmodium vivax is a highly prevalent malaria pathogen of man; the following report is the first to describe the cloning and expression of a major asexual erythrocytic stage antigen of this species. The screening of a genomic DNA expression lilrary with a monoclonal antibody directed against a 200-kDa surface component (Pv200) of the more mature schizonts of P. vivax led to the selection of a recombinant bacterial clone which produced a fusion protein. Mouse and rabbit immune sera raised against the purified fusion protein recognized the 200-kDa parasite antigen on Western blots and reacted with the surface of segmenters by immunofluorescence. Sequencing of the 1.9-kb P. vivax DNA insert coding for this fusion protein revealed a 4547Vo homology at the nucleotide level with the P . falciparum gene of a parasite surface antigen,Pflgs, which has been shown to be a promising candidate for a malaria vaccine in primates and in man