Th1 cells are considered the major CD4+T helper subset responsible for the control of intracellular pathogens, including Trypanosoma cruzi, the protozoan parasite of Chagas disease. Th17 cells are known for their involvement in autoimmunity and the defense against some extracellular organisms, but are generally not believed to have a significant function during intracellular infections. In contrast, we show that Th17 cells are highly protective against the intracellular pathogen T. cruzi.
