MHCII-Mediated Dialog between Group 2 Innate Lymphoid Cells and CD4+ T Cells Potentiates Type 2 Immunity and Promotes Parasitic Helminth Expulsion

• DOI: 10.1016/j.immuni.2014.06.016
• Publication Date: 2014-07-31T15:46:18Z
• Authors: Christopher J. Ol...; You Yi Hwang; Jennifer A. Walker; Maryam Salimi; See Heng Wong; James M. Brewer; Alexandros Englez...; Jillian L. Barlow; Emily Hams; Seth T. Scanlon; Graham S. Ogg; Padraic G. Fallon; Andrew N.J. McKenzie
• Keywords: Innate lymphoid cell; Nippostrongylus brasiliensis; Thymic stromal lymphopoietin

Group 2 innate lymphoid cells (ILC2s) release interleukin-13 (IL-13) during protective immunity to helminth infection and detrimentally during allergy and asthma. Using two mouse models to deplete ILC2s in vivo, we demonstrate that T helper 2 (Th2) cell responses are impaired in the absence of ILC2s. We show that MHCII-expressing ILC2s interact with antigen-specific T cells to instigate a dialog in which IL-2 production from T cells promotes ILC2 proliferation and IL-13 production. Deletion of MHCII renders IL-13-expressing ILC2s incapable of efficiently inducing Nippostrongylus brasiliensis expulsion. Thus, during transition to adaptive T cell-mediated immunity, the ILC2 and T cell crosstalk contributes to their mutual maintenance, expansion and cytokine production. This interaction appears to augment dendritic-cell-induced T cell activation and identifies a previously unappreciated pathway in the regulation of type-2 immunity.