Immune response to Schistosoma mansoni calreticulin in schistosomiasis resistant individuals.

The major strategy to reduce the impact of schistosomiasis is the development of a defined antigen vaccine. It has recently been reported that the 62-kDa antigen known as S. mansoni calreticulin (SmCaR), is a good T- and B-cell antigen and represents a potential vaccine candidate. In the present study the immune response to SmCaR was evaluated in individuals resistant to schistosomiasis. Lymphoproliferative response and cytokine production to SmCaR was assessed in 30 schistosomiasis resistant and healthy individuals. Only 10% of the schistosomiasis resistant individuals showed significant proliferative response to SmCaR while all of them showed significant proliferative response to soluble adult warm antigen (SAWA). On the other hand, 20-30% of the schistosomiasis resistant individuals showed detectable levels of IL-2, IL-4 and IFN-gamma after stimulation with SmCaR, and 59% of them showed had anti SmCaR IgM specific antibodies. These findings suggest that SmCaR might be a potential vaccine antigen.