Investigation of Schistosoma mansoni carboxypeptidase and sphingomyelinase as potential vaccine candidates

Abstract

Schistosomiasis is a chronic disease affecting more than 200 million people in 74 countries around the world, causing nearly 20 000 deaths per year. This important disease, usually is not detected in the early stages of infection, and becomes a threat for both men and women development during their most productive ages (Engels et al. 2002), being children the group with higher susceptibility. The development of a vaccine against this disease was established as one of the main goals of the World Health Organization (Bergquist et al. 2002)Genomic research, together with transcriptome and proteome approaches, provide information that can be used in the search of novel vaccine candidates. The information obtained from the Schistosoma mansoni transcriptome (Verjovski-Almeida et al. 2003) opened a window of opportunity for the development of novel vaccine candidates. Two genes have been selected, namely carboxypeptidase and sphingomyelinase, for investigation as vaccine candidates, due to their putative role in the parasites physiology and likely surface location exposed to the host’s immune system. We intend to clone these genes in the appropriate vectors for expression in E. coli, express them and purify the encoded proteins for specific antibody production in order to imunolocalize them in the parasite tissue. The ability for induction of both humoral and cellular immune responses against the recombinant proteins will be assessed by immunization of mice with the recombinant protein- and DNA-vaccine forms, and the results obtained will be correlated with the protection induced against challenge with S. mansoni cercariae. (AU)