KLRG1 and NKp46 expressing CD117+ human innate lymphoid cell precursors are biased to ILC2 and ILC3, respectively

Recently, circulating multi- and uni-potent human ILC precursors (ILCP) have been found in a lymphocyte population that expresses CD117 and CD127 but lacks CRTH2 and NKp44. However, these ILCPs have not been extensively characterized. We performed an unbiased Hierarchical Stochastic Neighbor Embedding (HSNE) analysis of the phenotype of peripheral blood CD117+ ILCPs which revealed the presence of three major subsets: the first expressed NKp46, the second expressed both NKp46 and CD56, while the third expressed KLRG1. Analysis of their differentiation potential on bulk and clonal levels, cytokine production and the transcriptome revealed that the NKp46+ ILCPs contain high frequencies of ILC3 precursors whereas a minority can differentiate into ILC1/NK-like cells. In contrast, KLRG1+ ILCPs are biased to the ILC2 lineage, but are highly plastic and epigenetically primed to differentiate into other ILC subsets depending on the activation signals they receive. Overall design: biological replicate (n=3) ATAC-Seq experiments