Objective The fine and complex regulation of CD4 immune response is important in cancer, autoimmune diseases, inflammatory disorders and viral infection. If signals orchestrating productive CD4 T-cell responses are well documented, the contraction of antigen (Ag)-specific CD4 T-cell populations following the resolution of primary immune response is however not molecularly understood. It has been demonstrated that a negative feedback loop can regulate CD4 T cell proliferation through direct T-T interactions, leading to the preferential exclusion of Ag-experienced T cells. This T cell intrinsic mechanism limits the expansion of effector CD4 T cells and may then interfere with therapeutic vaccine efficacy. Using Cas9-(constitutive/inducible)-expressing Dby-reactive T cells (from a TCR Transgenic RAG-/- mouse strain named Marilyn) coupled to a sgRNA library and an in vivo selection strategy, we will extensively identify the negative regulators of CD4 T cells migration and priming in an ongoing primary immune response. As a proof of concept, we will first inactivate candidate genes (already known to be involved in CD4 T cells negative regulation: TGF-b receptor,IFN-γ receptor, PD-1 and PD-L1) in Ag-experienced memory CD4 T cells, which will be enriched for their proliferative capacity in vivo and used as a second cohort in immunized mice. Then, we will develop a genome-wide screen approach to generate a library of knockout Ag-experienced T cells as a second cohort. We expect that further insight into CD4 suppressive mechanisms, which dampen efficient antitumor immune responses, will allow optimization of cancer immunotherapy. Fields of science medical and health sciencesbasic medicineimmunologyautoimmune diseasesmedical and health sciencesbasic medicinepharmacology and pharmacypharmaceutical drugsvaccinesmedical and health sciencesclinical medicineoncologymedical and health sciencesbasic medicinephysiologymedical and health sciencesbasic medicineimmunologyimmunotherapy Keywords CD4 T cells proliferation inhibition CRISPR genome wide screen 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-2016 - Individual Fellowships Call for proposal H2020-MSCA-IF-2016 See other projects for this call Funding Scheme MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF) Coordinator INSTITUT CURIE Net EU contribution € 185 076,00 Address Rue d ulm 26 75231 Paris France See on map Region Ile-de-France Ile-de-France Paris Activity type Research Organisations 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 Other funding € 0,00
