Differential Modulation of Human Innate Lymphoid Cell (ILC) Subsets by IL-10 and TGF-\u03b2

Sandra Bonne-Année,Mabel C Bush,Thomas B Nutman

doi:10.1038/s41598-019-50308-8

Abstract

Using multiparameter flow cytometry human innate lymphoid cell (ILC) subsets can be detected in the circulation, in relatively low frequencies. Despite the low frequency of ILCs in circulation, ex vivo experiments have demonstrated that these ILCs release extremely large per cell quantities of signature ILC cytokines following activation. To determine how activated ILC cytokine production is regulated, ILC subsets were activated in the presence or absence of the immunoregulatory cytokines IL-10 and TGF-β. An examination of circulating ILC subsets revealed surface expression of IL-10Rα and mRNA expression of both IL-10Rα and TGF-βR1 for all ILC subsets. Stimulated ILC1 production of IFN-γ was decreased by TGF-β and not IL-10. Interestingly, ILC2s stimulated in the presence of IL-10 had a marked reduction in cytokine production of IL-5 and IL-13 while TGF-β had no effect on ILC2 cytokine production. Ex vivo activated ILC1 and ILC2 subsets were also found to be a source of the immunoregulatory cytokine IL-10, raising the potential for ILC-mediated regulation of immune cells. These findings demonstrate the differential effects of immunoregulatory cytokines IL-10 and TGF-β on activated ILC1 and ILC2 populations ex vivo.

Highlights

Innate lymphoid cells (ILCs) can be found in both tissues and in peripheral blood in healthy individuals, but changes in their frequencies and composition have been associated with a variety of human diseases[1]
By first gating on the total ILC population, these cells could be divided into their respective ILC subsets as follows: ILC1s (CD45+ Lin− CD127+ cKit-NKp44−), ILC2s (CD45+ Lin-CD127+ CRTH2+) and ILC3s (CD45+ Lin− CD127+ cKit+ NKp44−/+)
The GM number of total ILCs per million CD45+ cells found in the circulation was 246.7 a number that translated to a geometric mean (GM) frequency of 0.09%, of total CD45+ cells (Fig. 1C)

Summary

Introduction

Innate lymphoid cells (ILCs) can be found in both tissues and in peripheral blood in healthy individuals, but changes in their frequencies and composition have been associated with a variety of human diseases[1]. Total ILCs and ILC subsets were isolated from the blood of healthy adult donors and stimulated ex vivo to determine the cytokine potential of the various cell types under different conditions. Stimulation of ILC3s with IL-1β/ IL-23 did not result in a statistically significant production of ILC3 signature cytokines IL-17A or IL-22, a 7- and 2-fold increase was observed for both cytokines respectively when compared to ILC3s cultured without www.nature.com/scientificreports

Results

Conclusion