Objective The maintenance of intestinal homeostasis has local and systemic implications for the host health and depends on a balance regulated by interactions between the immune system and the gut microbiota. Recently, it has become clear that a newly identified group of cells, innate lymphoid cells (ILCs), have a crucial role in intestinal homeostasis and host defence. ILCs respond rapidly to changes in the gut microenvironment and produce several cytokines that regulate intestinal inflammation. Although the pathways responsible for ILCs’ development and differentiation are only starting to be elucidated, the transcription factor T-bet has emerged as a key regulator of these processes.This proposal aims to clarify the molecular mechanisms involved in the T-bet-dependent development and function of ILCs and how these processes can be modulated by the intestinal microbiota. First, we propose to use a novel lineage-tracing mouse model that uses dual fluorescence reporters to differentiate between cells that currently express T-bet from cells that used to express T-bet, in order to distinguish between the mechanisms responsible for ILCs development from the mechanisms involved in ILCs function. In addition, we aim to uncover novel T-bet associated pathways that are active on intestinal ILCs, and understand how these pathways are regulated by the gut microbiome. Moreover, we aim to develop a novel in vitro co-culture system of ILCs in intestinal organoids, which will facilitate our studies and benefit future studies investigating the development and functions of intestinal lymphocytes. The detailed study of ILCs development, differentiation and function and the identification of novel T-bet and microbiota associated pathways will open new possibilities in the modulation of ILC’s functions and inform on how to divert these cells away from their pathogenic phenotypes that are responsible for gut inflammation and could have a significant impact on the field of intestinal immunity. Fields of science medical and health sciencesclinical medicinegastroenterologyinflammatory bowel diseasemedical and health sciencesbasic medicineimmunologymedical and health sciencesmedical biotechnologycells technologiesstem cellsmedical and health sciencesbasic medicinephysiologyhomeostasismedical and health scienceshealth sciencesnutritionobesity Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2014-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2014 See other projects for this call Funding Scheme MSCA-IF-EF-ST - Standard EF Coordinator KING'S COLLEGE LONDON Net EU contribution € 183 454,80 Address Strand WC2R 2LS London United Kingdom See on map Region London Inner London — West Westminster Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 183 454,80