About this Research Topic
Innate Lymphoid Cells (ILC) represent a relatively recently described group of lymphocytes that differ from conventional T cells due to their lack of genetically rearranged antigen receptors. ILCs share many phenotypic and functional properties of adaptive immune cells, and can be divided into three distinct lineages on the basis of their specific transcription factor expression: Group 1 (ILC-1) are dependent on T-bet and produce IFN-γ, Group 2 (ILC-2) express GATA-3 and produce IL-5, IL-4 and IL-13 and Group 3 (ILC-3) express RORγt and produce IL-17 and IL-22. These groups parallel the transcriptional and functional characteristics of T helper 1 (Th1), Th2 and Th17 conventional T cells, respectively. In contrast with their adaptive counterparts, ILC function is independent of antigen priming. Instead, ILCs are equipped to sense and respond to changes in their microenvironment. Due to their position at barrier surfaces, ILCs are poised to rapidly respond pathogens and tissue injury. ILCs are developmentally programmed to migrate, differentiate and populate mucosal tissues including the gut, lung and reproductive tract and associated lymphoid tissues.
Although ILCs are critical for tissue homeostasis and inflammatory processes, they are present only in very low numbers. Their scarcity belies their potency as ILCs are critical in regulating responses to pathogens, such as helminthic parasites, to maintain tissue integrity and promote immunological tolerance of T cells to commensal bacteria. Their dysregulation can lead to chronic inflammatory diseases including allergy and asthma and to autoimmune diseases such as colitis and Crohn’s disease. All ILC subsets have been shown to influence tumorigenesis, although their role to date appears highly ambiguous and are still requiring critical evaluation.
In this Research Topic, we aim to gather original cutting edge research covering aspects of the emerging field of ILCs in mucosal immunity and of the newly discovered role for ILCs in adipose tissue and metabolism. We welcome the submission of Original Research, Review and Perspective articles that address the following sub-topics:
1. ILC distribution and function at mucosal sites: gastrointestinal, respiratory and genitourinary.
2. ILCs and host:parasite interactions in gastrointestinal and respiratory sites.
3. ILCs and cancers at mucosal sites or in adipose tissue.
4. ILCs in human mucosal diseases.
5. ILCs in adipose tissue and metabolism.
6. ILCs and T cell crosstalk during mucosal immune responses.
We acknowledge the initiation and support of this Research Topic by the International Union of Immunological Societies (IUIS). We hereby state publicly that the IUIS has had no editorial input in articles included in this Research Topic, thus ensuring that all aspects of this Research Topic are evaluated objectively, unbiased by any specific policy or opinion of the IUIS.
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