OMIP‐066: Identification of Novel Subpopulations of Human Group 2 Innate Lymphoid Cells in Peripheral Blood

Abstract

This 14-color flow cytometry panel was designed to identify newly described subpopulations within human group 2 innate lymphoid cells (ILC2s) and other ILC subsets. This panel also allowed to identify recently reported subpopulations of peripheral blood CRTH2 − c-Kit + ILCs. We validated this panel mostly in human peripheral blood but also confirmed that the same panel and gating strategy works well in human tonsillar cells. The panel contains a few markers indicating the activation status of ILCs. In addition, phycoerythrin (PE) channel is available for the markers of interest in each study. In the validation studies described here, PE channel was used to test the expression of some markers. These features make this panel applicable for immunophenotyping of ILCs in various disease states.

Full Spectrum Flow Cytometry for High-Dimensional Immunophenotyping of Mouse Innate Lymphoid Cells

“…Given their extensive roles in both immunity and inflammation, ILC2s are known to display dynamic expression of extracellular markers associated with pro-inflammatory functions, exemplified via variations in IL-33 receptor (ST2) and KLRG1 expression depending on the inflammatory signal initiating the primary response 13,34,35 . Moreover, the inflammation-dependent plasticity of ILC2s has been demonstrated in both mouse lungs and human peripheral blood, whereby stimulation with IL-1, IL-12 and IL-18 promotes ILC2s to adopt an ILC1-like transcriptional and functional profile associated with the expression of T-bet (Tbx21) and production of IFN-     Similarly, human ILC2s, in response to IL-1 and IL-23 stimulation, transdifferentiate into a subset exhibiting ILC3-like characteristics, evidenced by upregulation of the ILC3 signature transcription factor RORt and production of IL-17 8,37 . ILC3s are a heterogeneous subset and contribute broad roles in combating against extracellular microbes, including fungi and bacteria, via the production of IL-17A and IL-22 following IL-1 and IL-23-mediated activation [38][39][40] . Representing the dominant ILC subset within the steady state siLP 41 , ILC3s are strictly reliant upon RORt (encoded by Rorc) expression for development and function 39,42,43 .…”

“…Moreover, the inflammation-dependent plasticity of ILC2s has been demonstrated in both mouse lungs and human peripheral blood, whereby stimulation with IL-1β, IL-12 and IL-18 promotes ILC2s to adopt an ILC1-like transcriptional and functional profile associated with the expression of T-bet ( Tbx21 ) and production of IFN-γ 5, 6, 34, 36 . Similarly, human ILC2s, in response to IL-1β and IL-23 stimulation, transdifferentiate into a subset exhibiting ILC3-like characteristics, evidenced by upregulation of the ILC3 signature transcription factor RORγt and production of IL-17 8, 37 .…”

Role of ILC2s in Solid Tumors: Facilitate or Inhibit?

“…Recent study has classified hILC2s into more detailed subsets. According to the expression of CCR10, c-Kit (CD117) and CCR6, hILC2s was divided into 3 subgroups: CCR10 + ILC2s, c-Kit + ILC2s and c-Kit − ILC2s (50). The phenotype of c-Kit + hILC2s can switch to ILC3-like cells when exposed to IL-1b and IL-23 in some pathological conditions.…”

Cord-Blood-Derived Professional Antigen-Presenting Cells: Functions and Applications in Current and Prospective Cell Therapies

“…Though scarce, the discussed ILC subsets can also be identified in healthy peripheral pediatric and adult blood through strenuous gating strategies involving the exclusion of cell-surface markers identifying other immune cells [ 35 , 147 ]. Still, ILCs have been shown to be involved both in promoting and suppressing tumor growth, highlighting both the need for further investigations and the potential for cell therapy approaches [ 146 ].…”