The present invention provides a composition for suppressing an inflammatory immune response comprising the excretory/secretory (ES) component of Fasciola hepatica or a fraction thereof. The composition has particular utility in the treatment or prophylaxis of T cell mediated inflammatory immune responses, and in particular autoimmune disease. The invention further extends to methods for modulating a T cell mediated immune response wherein a therapeutically effective amount of the excretory/secretory (ES) component from Fasciola hepatica is administered to a subject in need of such treatment in order to suppress the development of the response.
