MicroRNA regulation of type 2 innate lymphoid cell homeostasis and function in allergic inflammation. Mus musculus

MicroRNAs (miRNAs) exert powerful effects on immunity through coordinate regulation of multiple target genes in a wide variety of cells. Group 2 innate lymphoid cells (ILC2s) are tissue sentinel mediators of allergic inflammation. We established the physiological requirements for miRNAs in ILC2 homeostasis and immune function, and compared the global miRNA repertoire of resting and activated ILC2s and T helper type 2 (TH2) cells. Mice lacking the miR-17~92 cluster in ILC2s displayed reduced lung inflammation following exposure to the natural allergen papain. Moreover, miR-17~92-deficient ILC2s exhibited defective growth and cytokine expression in response to IL-33 and TSLP in vitro. The miR-17~92 cluster member miR-19a promoted IL-13 production and inhibited expression of several target genes, including SOCS1 and A20, signaling inhibitors that limit IL-13 production. These findings establish miRNAs as important regulators of ILC2 biology, reveal overlapping but non-identical miRNA-regulated gene expression networks in ILC2s and TH2 cells, and reinforce the therapeutic potential of targeting miR-19 to alleviate pathogenic allergic responses . Overall design: Gene expression analysis of ILC2 and Th2 cells in vitro and ex vivo isolated from the lung.