In the current study we identified that both HES and infection with H. polygyrus induced ST2 expression on CD4+ T cells and interestingly in the IL-4Rα−/− mice, which were not protected with H. polygyrus, there was very little expression of ST2 suggesting that IL-33 signaling may also play a role in EAE protection in this model. This evidence concerns the gene IL33 and infection.