The Schistosoma mansoni cyclophilin A epitope 107-121 induces a protective immune response against schistosomiasis

In this study, we characterized the cyclophilin A (SmCyp), initially described as Smp17.7, analyzed its allergenic potential using in vitro functional assays, and evaluated its ability to induce protection in mice when administered as an antigen using different vaccine formulations and strategies. Results indicated that SmCyp could be successfully expressed by mammalian cells and bacteria. The recombinant protein did not promote IgE-reporter system activation in vitro, demonstrating its probable safety for use in vaccine formulations. T and B-cell epitopes were predicted in the SmCyp sequence, with two of them located within the active isomerase site. The most immunogenic antigen, SmCyp (107–121), was then used for immunization protocols. Immunization with the SmCyp gene or protein failed to reduce parasite burden but induced an immune response that modulated the granuloma area. In contrast, immunization with the synthetic peptide SmCyp (107–121) significantly reduced worm burden (48–50%) in comparison to control group, but did not regulate liver pathology. Moreover, the protection observed in mice immunized with the synthetic peptide was associated with the significant production of antibodies against the SmCyp (107–121) epitope. Therefore, in this study, we identified an epitope within the SmCyp sequence that induces a protective immune response against the parasite, thus representing a promising antigen that could be used for vaccine formulation against schistosomi...
Source: Molecular Immunology - Category: Allergy & Immunology Source Type: research