Evaluating the Immunoprotective and Diagnostic Potential of Schistosoma mansoni Epitopes from Sm050890 and Sm141290 Proteins Identified Through Reverse Vaccinology

Purpose

Schistosomiasis remains a parasitic disease affecting millions of people worldwide, requiring interventions like vaccination. In previous work, our group used reverse vaccinology to identify two epitopes from the Schistosoma mansoni proteins, Sm050890 (44–58) and Sm141290 (225–239). This study evaluated the immune response profile and protection induced by peptides, as a mixture of immunogens, in murine vaccination trials. Additionally, the diagnostic potential of these peptides was assessed on immunoassays.

Methods

Mice were immunized with a formulation containing the mixture of the peptides, subsequently infected, and perfused for worm burden recovery and quantification. Liver and blood samples from animals were used to evaluate the effect of immunization on the formation of granulomas and specific anti-peptide antibodies (IgG). Additionally, cytokine measurement was performed in splenocyte cultures from immunized mice, and peripheral blood serum from individuals infected with S. mansoni was used to assess the recognition of the peptides by IgG antibodies.

Results

The vaccine stimulated an increase in the production of IgG and IgG2c antibodies, associated with a significant reduction of 44 − 29% in worm burden. Although the vaccine did not reduce liver pathology, it enhanced the production of IFN-γ while decreasing IL-10 production by splenocytes. Furthermore, the peptides Sm050890 (44–58) and Sm141290 (225–239) were not recognized by IgG antibodies in the serum from infected individuals.

Conclusion

Overall, our data suggest that the peptides Sm050890 (44–58) and Sm141290 (225–239) are promising vaccine candidates against schistosomiasis and can be used to compose a multiepitope/chimeric vaccine in future studies.