Antigenicity and protective capacity of novel vaccine candidates for Trypanosma cruzi.

ZILIANI MARIA; ALBA SOTO CATALINA D; SANCHEZ DANIEL O; TEKIEL VALERIA

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2012

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

We have previously identified a group of 22 novel vaccine candidates for Chagas’ disease by screening an epimastigotesubtracted trypomastigote cDNA expression library. Of these, we selected 3 genes for further studies: G2, a hypothetical protein (TcCLB.507003.70), A12, a putative lysosomal membrane glycoprotein (TcCLB.510825.30), and A11, a TcTASV-C surface antigen (TcCLB.511675.3). In this work we analyzed the antigenicity of these proteins in the course of experimental and natural infection with and evaluated the protective capacity of TcTASV-C. Sera obtained from humans and infected animals reacted against the recombinant proteins, suggesting that these genes are expressed in the parasite stages that infect the definitive host and validate them as vaccine candidates. To test the protective capacity of TcTASV-C, we employed a prime and boost vaccination schedule (2 doses of DNA+ GM-CSF/mouse and 2 doses of protein + alum/ mouse; TcTASV-C: n=6; controls: n=6). Fifteen days after the last dose, animals were challenged with the highly virulent RA strain (lineage VI). Vaccinated animals presented lower levels of both circulating parasites and mortality (50% vs 100% at 30 d.p.i.) than controls, suggesting that TcTASV-C induces a partially protective response.