A Murine Intestinal Intraepithelial NKp46-Negative Innate Lymphoid Cell Population Characterized by Group 1 Properties

• Main Authors: Aline Van Acker, Konrad Gronke, Aindrila Biswas, Liesbet Martens, Yvan Saeys, Jessica Filtjens, Sylvie Taveirne, Els Van Ammel, Tessa Kerre, Patrick Matthys, Tom Taghon, Bart Vandekerckhove, Jean Plum, Ildiko Rita Dunay, Andreas Diefenbach, Georges Leclercq
• Format: Article
• Language: English
• Published: Elsevier 2017-05-01
• Series: Cell Reports
• Subjects: intestinal; intraepithelial; ILC1; Ly49E; NKp46-negative; IFN-γ
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124717305971

The Ly49E receptor is preferentially expressed on murine innate-like lymphocytes, such as epidermal Vγ3 T cells, intestinal intraepithelial CD8αα+ T lymphocytes, and CD49a+ liver natural killer (NK) cells. As the latter have recently been shown to be distinct from conventional NK cells and have innate lymphoid cell type 1 (ILC1) properties, we investigated Ly49E expression on intestinal ILC populations. Here, we show that Ly49E expression is very low on known ILC populations, but it can be used to define a previously unrecognized intraepithelial innate lymphoid population. This Ly49E-positive population is negative for NKp46 and CD8αα, expresses CD49a and CD103, and requires T-bet expression and IL-15 signaling for differentiation and/or survival. Transcriptome analysis reveals a group 1 ILC gene profile, different from NK cells, iCD8α cells, and intraepithelial ILC1. Importantly, NKp46−CD8αα−Ly49E+ cells produce interferon (IFN)-γ, suggesting that this previously unrecognized population may contribute to Th1-mediated immunity.