PROJECT SUMMARYThis proposal is aimed at developing immune cell engineering approaches for the monitoring and treatment ofT cell-mediated autoimmune diseases such as Type-I diabetes (T1D). The native 5-module receptorcomplexes that drive T cell responses to peptide antigens embedded in MHC molecules have evolved throughan iterative process over the last ~435 million years to optimize T cell responses to a broad range ofchallenges. Using a biomimetic approach we have developed a 5-module chimeric antigen receptor (5MCAR)and reported that cytotoxic T cells expressing 5MCARs (5MCAR-CTLs) can specifically target and killautoimmune CD4+ T cells that mediate T1D in preclinical mouse models resulting in significantly reduceddisease incidence in 5MCAR-CTL-treated mice. Our proof-of-concept work supports the idea echoed by theRFA to which we are responding that engineered immune cell-based immunotherapies hold promise for thetreatment of autoimmune diseases. Also as noted in the RFA this area of investigation is in its infancy andrequires support of exploratory engineering approaches to reach its full potential. Our foundational workprovides us with a novel platform from which to continue the development of novel biomimetic engineeringapproaches for detecting and eliminating autoimmune T cell responses. Our goals here will be to developnovel applications using our 1st generation 5MCAR technology and to iterate on the 5MCAR platform through theengineering and testing of 2nd generation 5MCARs. Specifically we will: 1) determine if using 5MCARs to redirectcentral memory CD8+ T cells stem cell memory CD8+ T cells or Tregs are most effective at preventing T1D inpreclinical models; 2) use 5MCAR-CTLs as sentinels that can trafficking throughout the body and report on thepresence of pathogenic autoimmune CD4+ T cells prior to clinical symptoms; and 3) engineer and test 2ndgeneration 5MCARs that more closely mimic their native counterparts with the goal of improving 5MCARperformance. When completed the proposed work will provide valuable pre-clinical data for the therapeuticpotential of biomimetic 5MCAR-CTLs and 5MCAR-Tregs that are engineered based on evolutions blueprint.