CD4 and helminthiasis: By making use of a complex of rIL-2:anti-IL-2 (IL-2C), previously shown to specifically expand Tregs in vivo,37, 48, 49 we demonstrate that boosting of CD4+Helios+Foxp3+ tTreg populations early following chronic helminth infection can dampen innate and adaptive type-2 responses and decrease worm expulsion, despite increasing the number of ILCs in the MLN.