High-Dimensional Single-Cell Analysis Identifies Organ-Specific Signatures and Conserved NK Cell Subsets in Humans and Mice

Summary

Natural killer (NK) cells are innate lymphoid cells (ILCs) involved in antimicrobial and antitumoral responses. Several NK cell subsets have been reported in humans and mice, but their heterogeneity across organs and species remains poorly characterized. We assessed the diversity of human and mouse NK cells by single-cell RNA sequencing on thousands of individual cells isolated from spleen and blood. Unbiased transcriptional clustering revealed two distinct signatures differentiating between splenic and blood NK cells. This analysis at single-cell resolution identified three subpopulations in mouse spleen and four in human spleen, and two subsets each in mouse and human blood. A comparison of transcriptomic profiles within and between species highlighted the similarity of the two major subsets, NK1 and NK2, across organs and species. This unbiased approach provides insight into the biology of NK cells and establishes a rationale for the translation of mouse studies to human physiology and disease.

Graphical Abstract

Highlights

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  scRNA-seq on spleen and blood NK cells reveals organ-specific signatures

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  scRNA-seq reveals the heterogeneity of NK cells in the blood and spleen

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  scRNA-seq on NK cells defines NK1 as human CD56 ^dim and mouse CD27 ⁻CD11b ⁺ NK cells

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  scRNA-seq on NK cells defines NK2 as human CD56 ^bright and mouse CD27 ⁺CD11b ⁻ NK cells

Abstract

Several NK cell subsets have been reported in humans and mice, but their heterogeneity remains poorly characterized. Using high-throughput single-cell RNA-seq, Crinier et al. provide conserved tissue-specific gene signatures of NK cells from spleen and blood and identified two major NK cell subsets transcriptionally similar across organs and species.