Eosinophils and Th2 immunity: contemporary insights

Eosinophils, innate immune leukocytes elicited by Th2 cells, have long been associated with the effector arm of Th2 immune responses. However, accumulating data over the past decade reveal a much more dynamic picture of Th2 immunity, where eosinophils are present very early in response to Th2‐inducing agents and function in the initiation of Th2 immunity. Here we discuss recent data showing immune functions of eosinophils distinct from their previously appreciated tissue‐ and helminth‐destructive capacities, providing strong evidence for a new paradigm of Th2 immunity defined by a dynamic interplay between eosinophils and T cells.