Characterization of P15 Antigen of Cryptosporidium parvum Expressed by a Recombinant Vaccinia Virus

Abstract

The gene encoding P15 of Cryptosporidium parvum (C. parvum) sporozoites was amplified from Mito strain isolated from calf in Japan, and inserted into the thymidine kinase gene of vaccinia virus LC16mO strain under the control of the early-late promoter for the vaccinia virus 7.5-kilodalton (kDa) polypeptide. The P15 expressed by recombinant vaccinia virus in mammalian cells (RK13) had apparent molecular masses of 18-22 kDa. The vaccinia virus expressed P15 was glycosylated and transported to the surface of infected cells. Mice inoculated with the recombinant vaccinia virus produced high titers of antibodies against sporozoites or merozoites of C. parvum. Our next step will be to examine the ability of the recombinant P15 as a potential subunit vaccine to control cryptosporidiosis in animals.