Description
Innate lymphoid cells (ILCs) serve as sentinels in mucosal tissues, sensing release of soluble inflammatory mediators, rapidly communicating danger via cytokine secretion, and functioning as guardians of tissue homeostasis. Although ILCs have been studied extensively in model organisms, little is known about these first responders in humans, especially their lineage and functional kinships to cytokine-secreting T helper cell (Th) counterparts. Here, we report gene regulatory circuitries for four human ILCTh counterparts derived from mucosal environments, revealing that each ILC subset diverges as a distinct lineage from Th and circulating natural killer cells, but shares circuitry devoted to functional polarization with their Th counterparts. Super-enhancers demarcate cohorts of cell identity genes in each lineage, uncovering new modes of regulation for signature cytokines, novel molecules that likely impart important functions to ILCs, and potential mechanisms for autoimmune disease SNP associations within ILCTh subsets.