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

ZILIANI, M; ALBA-SOTO, CD; SÁNCHEZ, DO; TEKIEL, V

Mendoza

Congreso; BIOCELL 2012, Vol. 36 (Suppl.): 1-140 ISSN 0327 - 9545 PRINTED IN ARGENTINA - SAIB - 48 Annual Meeting XLVIII Reunión Anual th Argentine Society for Biochemistry and Molecular Biology Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

SAIB

We have previously identified a group of 22 novel vaccine candidates for Chagas? disease by screening an epimastigote-subtracted 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 T. cruzi 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 T. cruzi 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.