Expression of a major piroplasm surface protein of Theileria sergenti in sporozoite stage.

A 32 kilodalton major piroplasm surface protein (MPSP) is expressed abundantly on the surface of intraerythrocytic piroplasms of Theileria sergenti and is considered to be a candidate antigen for vaccine development against piroplasmosis. In this study, transcripts of MPSP gene were detected in an expression cDNA library prepared from T. sergenti-infected tick salivary glands. Expression of MPSP in the sporozoite stage was also confirmed by immunoblot analysis. Its expression at the sporozoite and intraerythrocytic stages gives scope for possible induction of protective immunity being targeted at both stages by immunization with recombinant MPSP.