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Group 2 Innate Lymphoid Cells: New Players in Human Allergic Diseases


Doherty TA, Broide DH

Department of Medicine, University of California, La Jolla, USA

J Investig Allergol Clin Immunol 2015; Vol. 25(1): 1-11



Allergic diseases are characterized by tissue eosinophilia, mucus secretion, IgE production, and activation of mast cells and TH2 cells. Production of TH2 cytokines including IL-4, IL-5, IL-9, and IL-13 has mainly been attributed to CD4+ TH2 cells. However, the recent discovery of group 2 innate lymphoid cells (ILC2s) in humans and findings from experimental disease models have challenged conventional concepts associated with the contribution of specific cells to type 2 inflammation in allergic diseases. ILC2s produce high levels of TH2 cytokines and have been detected in human lung tissue, peripheral blood, the gastrointestinal tract, skin, and sinonasal tissue, suggesting that ILC2s could contribute to chronic rhinosinusitis, asthma, atopic dermatitis, and gastrointestinal allergic disease. Moreover, depletion of ILC2s in animal models suggests a role for these cells in atopic dermatitis and asthma. This review will focus on the role of ILC2s in human allergy and asthma and provide a mechanistic insight from animal models.

Key words: ILC2. ILC2s. Group 2 innate lymphoid cells. Allergy. Asthma. Atopic dermatitis. Chronic rhinosinusitis. Allergic rhinitis.