Chronic schistosomiasis during pregnancy epigenetically reprograms T cell differentiation in offspring of infected mothers.

Schistosomiasis is a non-transplacental helminth infection. Chronic infection during pregnancy suppresses allergic airway responses in offspring. We addressed the question whether in utero exposure to chronic schistosome infection (Reg phase) in mice affects B cell and T cell development. Therefore, we focused our analysis on T cell differentiation capacity induced by epigenetic changes in promoter regions of signature cytokines in offspring. Here we show that naïve T cells from offspring of schistosome infected female mice had a strong capacity to differentiate into TH 1 cells, whereas TH 2 differentiation was impaired. In accordance, reduced levels of histone acetylation of the IL-4 promoter regions were observed in naïve T cells. To conclude, our mouse model revealed distinct epigenetic changes within the naïve T cell compartment affecting TH 2 and TH 1 cell differentiation in offspring of mothers with chronic helminth infection. These findings could eventually help understand how helminths alter T cell driven immune responses induced by allergens, bacterial or viral infections, as well as vaccines