Abstract
ILC2s were originally identified as IL-5 and IL-13 secreting “natural helper cells” present within the fat-associated lymphoid clusters of the mesenteries in both mouse and man. The presence of ILCs in adipose tissue has more recently expanded to include all ILC groups. Since their initial discovery, our knowledge of these cells and their role in adipose immune responses has expanded significantly. In this review we summarize the current literature on the role that ILC2s play in orchestrating adipose tissue function in both lean and obese states. We go on to address new data detailing interactions of adipose ILCs with innate like B-cells (IBC) and discuss how this interaction results in localized protection of mucosal sites during infection and inflammation via the production of innate antibodies.
Highlights
Innate lymphoid cells are the newest kids on the block in terms of innate immune cell function, the previous 8 years have revealed a wealth of information on these previously enigmatic lymphocyte like cells
Since their initial discovery 8 years ago, ILC2s have emerged as major regulators of type-2 immunity in adipose tissue where they co-ordinate eosinophil, macrophage, adipocyte and IBC function
fat-associated lymphoid clusters (FALCs) are specialized hubs that act as a second line of immune defense sitting behind the mucosal frontline
Summary
Innate lymphoid cells are the newest kids on the block in terms of innate immune cell function, the previous 8 years have revealed a wealth of information on these previously enigmatic lymphocyte like cells. Tbet dependent ILC1s which secrete IFNγ and TNFα, GATA3 dependent ILC2s which secrete IL-5/IL-13 [and can secrete IL-10 [1]], RORγt dependent ILC3s which secrete IL-17A/IL-22, and include a population of Lymphoid tissue inducer (LTi) cells which are critical for secondary lymphoid organ development [2] and Id3 dependent ILCregs which produce IL-10 and require autocrine TGF-β1 [3] In addition to these non-cytotoxic cell types, are the classical cytotoxic NK cells that are important for protection against viruses and cancer. It has become apparent that type 2 immune cells play a critical role in the maintenance of homeostasis in lean, healthy adipose tissue and that ILC2 are central regulators of this function. It would be interesting to know if the secretion of IL-5 and IL-13 or other important mediators such as methionine-enkephalin peptides by adipose tissue ILC2s fluctuates with food intake, allowing the synchronization of adipose tissue function with food intake via immune regulation
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call