E-protein inhibition in ILC2 development shapes the function of mature ILC2s during allergic airway inflammation

E-protein transcription factors (TFs) limit group 2 innate lymphoid cell (ILC2) development while promoting T cell differentiation from common lymphoid progenitors (CLPs). Inhibitors of DNA-binding (Id) proteins block E-protein DNA binding in CLPs to allow ILC2 development. However, whether E-proteins influence ILC2 function upon maturity and activation remains unclear. Mice that overexpress Id1 under control of the thymus-restricted proximal Lck promoter (Id1tg/WT) have a large pool of primarily thymus-derived ILC2s in the periphery that develop in the absence of E-protein activity. We used these mice to investigate how the absence of E-protein activity affects ILC2 function and genomic landscape in response to house dust mite (HDM) allergens. Id1tg/WT mice had increased Klrg1- ILC2s in the lung compared to wild type (WT, Id1WT/WT) mice in response to HDM, but Id1tg/WT ILC2s had an impaired capacity to produce type 2 cytokines. Analysis of WT ILC2 accessible chromatin suggested that AP-1 and C/EBP TFs but not E-proteins were associated with ILC2 inflammatory gene programs. Instead, E-protein binding sites were enriched at functional genes in ILC2s during development that were later dynamically regulated in allergic lung inflammation, including genes that control ILC2 response to cytokines and interactions with T cells. Finally, ILC2s from Id1tg/WT compared to WT mice had fewer regions of open chromatin near functional genes that were enriched for AP-1 factor binding sites following HDM treatment. These data show that E-proteins shape the chromatin landscape during ILC2 development to dictate the functional capacity of mature ILC2s during allergic inflammation in the lung. Overall design: Accesibility profiles by ATAC-seq for ILC2 and T-cells from WT mice lungs and for ILC2 from both WT and Id1tg mice lungs, in response to IN administration of house dust mite (HDM). Additional grant information for this study: 1DP2 OD024087