ILC1 lineage identity is determined by a cis-regulatory element marked by a novel lncRNA [RNA-seq]

Innate lymphoid cells (ILCs) comprise three groups of recently identified tissue resident immune cell lineages that play critical roles in protective immune responses and tissue homeostasis. While significant progress has been made in defining the key protein mediators of ILC development and function, how cis-acting epigenetic regulatory elements or long non-coding RNAs (lncRNAs) regulate ILCs is unknown. Herein, we describe a cis-regulatory element demarcated by a novel lncRNA that controls the maturation, function and lineage identity of group 1 ILCs while being dispensable for early ILC development and homeostasis of mature ILC2s and ILC3s. We named this ILC1-restricted lncRNA Rroid. The Rroid locus controls the functional specification and lineage identity of ILC1 by promoting chromatin accessibility and STAT5 deposition at the promoter of its neighboring gene, Id2, in response to the ILC1-specific cytokine IL-15. RNA-seq for gene expression in mouse NK cells