Spatial and Temporal Mapping of Human Innate Lymphoid Cells Reveals Elements of Tissue Specificity

Innate lymphoid cells (ILCs) play an increasingly well recognised role in the immunology of mucosal sites. Murine studies have demonstrated strict compartmentalisation of ILC subsets between tissues and functional differences of phenotypically similar ILCs between different tissues. However, relatively little data is available on human ILCs and their relative localisation and function between tissues, including mucosal surfaces.

Here, Yudanin et al detail the phenotypic and transcriptional profile of ILCs from different mucosal, lymphoid and metabolic human tissues. Substantial differences were observed in ILC population frequencies between tissues; indeed there was even pronounced variation between individual areas of the gut, highlighting the different compartmentalisation of ILCs in mucosal tissues. However, it was noted that this compartmentalisation was less pronounced than that described in mice. There was considerable transcriptional heterogeneity within ILC-subsets between tissues, where ILC1s in particular were more transcriptionally heterogenous in mucosal sites.