Mucin-Like Associated Surface Protein: Potential Vaccine Candidate Against Chagas Disease

Trypanosoma cruzi is the etiological agent that causes Chagas’ disease.  It currently affects 11-16 million people in Latin America.  It is an emerging disease throughout the world because of immigration and lack of screening.  There is an urgent need to develop a vaccine to be able to control this parasitic infection. In our study we have used a mucin-associated surface protein (MASP) as synthetic peptide-based vaccine candidate in combination with different adjuvants, α-galactosylceramide, aluminum hydroxide, and/or synthetic trypomastigote glycosylphosphophatidylinositol (tGPI).  Thirteen groups were immunized with combination of the peptide and different adjuvants. The combination of adjuvants was administered to monitor any effects that they create on their own. The mice received 4 doses and ten days after the last immunization, were infected with a lethal dose of 1 X 10⁴ trypomastigote Y strain.  The survival and parasitemia of the mice were followed.   In order to determine if the synthetic peptide stimulated a CD4⁺/CD8⁺ T- cell response the IFN-γ was measured. IFN-γ is a known to protect upon challenge. Spleen cells were harvested for 24 hours in a 96 well plate.  The cells were stimulated with the synthetic peptide for 24 hours, supernatant was collected and IFN-γ was measured. The immunized mice that provided a good protection against T. cruzi were MASP/Alum and MASP/tGPI groups. The group with MASP/Alum also showed to stimulate CD4⁺/CD8⁺ T- cells. The results that immunized mice with MASP/Alum and MASP/tGPI are able to keep a low parasitemia seem to correlate with our hypothesis.