Bioinformatic identification of vaccine and diagnostic candidates of Cryptosporidium parvum.

TOMAZIC MARIELA LUJÁN; RODRÍGUEZ ANABEL ELISA; FLORIN-CHRISTENSEN MÓNICA; SCHNITTGER LEONHARD

México

Congreso; CONGRESS OF PARASITOLOGY 2014; 2014

BACKGROUND: Bovine cryptosporidiosis is mainly caused by the zoonotic apicomplexan Cryptosporidium parvum. The disease is responsible for a considerable morbidity and mortality of pre-weaned calves around the world. Infected animals excrete large amounts of the infective stage, the oocyst, into the environment. In humans, the infection is known to be a major cause of infant death in developing countries and considered emergent in industrialized ones. So far there are neither fully effective treatments nor vaccines available. Glycosylphosphatidylinositol (GPI) anchored proteins have been shown to be involved in invasion of protozoan parasites and are often immunodominant. In this work we identified GPI-anchored antigens of C. parvum in order to characterize their potential as components of a subunit vaccine and/or serology-based diagnostic tools.METHODS: A reverse vaccinology approach was followed by screening the C. parvum proteome using a combination of signal peptide- and five GPI-anchor predictive bioinformatic tools. Cryptosporidium-specific antigens were determined by a reverse BLASTp procedure and the Interpro database was used to determine predicted functions of antigen domains.RESULTS: Of the 3805 proteins of the C. parvum proteome, altogether 13 proteins were identified as being GPI-anchored. These proteins include GP40/15, which has experimentally been demonstrated to possess a GPI-anchor, supporting the validity of our approach. Three candidates were selected based on i) the highest score of prediction, ii) presence of a domain reported to be involved in parasite invasion, and iii) their Cryptosporidium-specificity, and recombinant forms were produced.CONCLUSIONS: Ongoing research is verifying whether selected GPI-anchored proteins constitute valid vaccine candidates and diagnostic antigens.Financed by CONICET, INTA (PNSA-1115053) and ANPCyT (PICT2012-0695)