Engineering 2nd generation 5MCARs to monitor and treat Type-I Diabetes

PROJECT SUMMARY This proposal is aimed at developing immune cell engineering approaches for the monitoring and treatment of T cell-mediated autoimmune diseases such as Type-I diabetes (T1D). The native 5-module receptor complexes that drive T cell responses to peptide antigens embedded in MHC molecules have evolved through an iterative process over the last ~435 million years to optimize T cell responses to a broad range of challenges. 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 kill autoimmune CD4+ T cells that mediate T1D in preclinical mouse models, resulting in significantly reduced disease incidence in 5MCAR-CTL-treated mice. Our proof-of-concept work supports the idea, echoed by the RFA to which we are responding, that engineered immune cell-based immunotherapies hold promise for the treatment of autoimmune diseases. Also as noted in the RFA, this area of investigation is in its infancy and requires support of exploratory engineering approaches to reach its full potential. Our foundational work provides us with a novel platform from which to continue the development of novel biomimetic engineering approaches for detecting and eliminating autoimmune T cell responses. Our goals here will be to develop novel applications using our 1st generation 5MCAR technology and to iterate on the 5MCAR platform through the engineering and testing of 2nd generation 5MCARs. Specifically, we will: 1) determine if using 5MCARs to redirect central memory CD8+ T cells, stem cell memory CD8+ T cells, or Tregs are most effective at preventing T1D in preclinical models; 2) use 5MCAR-CTLs as sentinels that can trafficking throughout the body and report on the presence of pathogenic autoimmune CD4+ T cells prior to clinical symptoms; and, 3) engineer and test 2nd generation 5MCARs that more closely mimic their native counterparts with the goal of improving 5MCAR performance. When completed, the proposed work will provide valuable pre-clinical data for the therapeutic potential of biomimetic 5MCAR-CTLs and 5MCAR-Tregs that are engineered based on evolution’s blueprint.