Severe murine schistosomiasis results from disrupted CD4+ T-cell modulation by immunodominance of a single egg epitope.

OBJECTIVE

This study examined the correlation between immunodominance of the major egg antigen Sm-p40234-246, a robust Th1/Th17 anti-egg CD4 T-cell response, and severe liver immunopathology in experimental murine schistosomiasis. It serves as a platform to analyze how varying degrees of immunodominance affect CD4+ T cell modulation and disease outcomes.

METHODS

We used a murine model of schistosomiasis to investigate the effects of immunodominance. Infected mice were divided into two groups: one treated with a combination of epitopes targeting immunodominance of the major egg antigen Sm-p40 and the other with a mock mixture of non-immunogenic epitopes. Liver granuloma area, a hallmark of schistosomiasis pathology, was quantified using histological and morphometric analyses. The average granuloma areas between the treated and untreated groups were compared using one-way ANOVA with Tukey's multiple comparison test. Additionally, we isolated CD4+ T cells from mesenteric lymph nodes, stimulated them with specific egg antigens, and collected purified supernatants to assess their signature cytokine secretion profiles for each treatment group.

RESULTS

Results showed that strong immunodominance of a single egg epitope undermines effective CD4+ T-cell modulation, promoting a strongly polarized Th1/Th17 pathogenic response. Conversely, neutralizing this immunodominance produces the opposite restorative effect.

CONCLUSION

Immunodominance is an important pathogenic component that influences CD4+ T cell modulation in experimental murine schistosomiasis. Moreover, immunodominance can be used to treat these and other important CD4+ T cell-mediated diseases.