Cellular and humoral immune responses to recombinant Smp17.7 Schistosoma mansoni antigen

To determine the immunological responses to S. mansoni antigen rSmp17.7, a total of 184 subjects, 174 patients from a schistosomiasis endemic area, and 10 controls were used. Proliferation, cytokine profile in culture supernatants from antigen-stimulated peripheral blood mononuclear cells and specific IgG1, IgG3, IgG4, IgA, IgM & IgE levels were assessed. The highest stimulation index to rSmp17.7 was detected in S. mansoni patients. The evaluation of the cytokine profile [IL-2, IL-4 & IFN-gamma] in response to this antigen showed a significant increase as demonstrated by ELISA. Specifically, IFN-gamma and IL-2 were significantly detected by flow cytometry. IgG1 and IgM were the only Igs which showed a significant increase. These results highlight the importance of rSmp17.7 as a candidate vaccine for schistosomiasis. The results pave the way to understand the mechanism of schistosome-vaccine efficacy.