Type 2 innate lymphoid cells–new members of the “type 2 franchise” that mediate allergic airway inflammation

Abstract

Type 2 innate lymphoid cells (ILC2s) are members of an ILCfamily, which contains NKcells and Rorγt⁺ ILCs, the latter including lymphoid tissue inducer (LTi) cells and ILCs producing IL‐17 and IL‐22. ILC2s are dedicated to the production of IL‐5 and IL‐13 and, as such, ILC2s provide an early and important source of type 2 cytokines critical for helminth expulsion in the gut. Several studies have also demonstrated a role for ILC2s in airway inflammation. In this issue of the European Journal of Immunology, Klein Wolterink et al. [Eur. J. Immunol. 2012. 42: 1106‐1116] show that ILC2s are instrumental in several models of experimental asthma where they significantly contribute to production of IL‐5 and IL‐13, key cytokines in airway inflammation. This study sheds light over the relative contribution of ILC2s versus T helper type 2 cells (Th2) in type 2 mediated allergen‐specific inflammation in the airways as discussed in this commentary.