Investigating CXCR3 Blockade as Precision Therapy for Cardiac Sarcoidosis using Single-Cell Multi-omics and TCR Phenotyping

PROJECT SUMMARY/ABSTRACT Sarcoidosis, characterized by non-caseating granulomas, is a multi-organ inflammatory disease disproportionately affecting black patients in the United States. Although cardiac sarcoidosis occurs in 20-30% of all patients with sarcoidosis, it contributes to 85% of deaths by causing heart failure, ventricular arrhythmias, and sudden cardiac death. The lack of therapeutic targets for cardiac sarcoidosis remains a significant gap in clinical care. My prior work has focused on utilizing single-cell multi-omics and mass cytometry (CyTOF) to identify pathogenic antigen-specific T-cell subsets in myocarditis due to cancer immunotherapy. Now, I am excited to pivot my research direction and extend these innovative methods to investigate cardiac sarcoidosis, with the goal of bringing my prior experience with deep immunophenotyping tools to help bridge the translational gap in cardiac inflammatory diseases. Dysregulation in CD4 T-helper cell (Th) subsets, particularly Th17.1 expressing C-X-C Motif Chemokine Receptor 3 (CXCR3), has been associated with a number of inflammatory diseases, including sarcoidosis. I hypothesize that cardiac sarcoidosis is associated with recruitment of CXCR3+ Th17.1 cells to the heart, which can be therapeutically targeted with CXCR3 blockade. To test this, I will utilize a mouse model of cardiac sarcoidosis and biobank samples from patients with cardiac and non-cardiac pulmonary-only sarcoidosis compared to healthy controls. In Aim 1, I will perform single-cell RNA-seq, TCR-seq, and CITE-seq on tissue (heart, blood, lymphoid organs, lungs) isolated from Tsc2fl/fl CD11c Cre+ mice with cardiac sarcoidosis. In Aim 2, I will conduct single-cell multi-omics and deep T-cell phenotyping on specimens biobanked from patients with cardiac sarcoidosis compared to pulmonary-only sarcoidosis and healthy control patients. In Aim 3, I will explore the therapeutic effects of CXCR3+ blockade on T-cell migration. Specifically, Aim 3a, I will investigate the mechanistic effects of blocking CXCR3 and its ligands, CXCL9/10, on macrophage- mediated Th17.1 cell migration and function in an in vitro transwell system, while in Aim 3b I will treat Tsc2fl/fl CD11c Cre+ mice with CXCR3 blockade to assess for reduced cardiac granuloma formation and Th17.1 cell migration to the heart assessed by single-cell multi-omics. By completing this project, I will define key pathogenic T-cell subsets and interactions between adaptive and innate immunity that drive cardiac sarcoidosis, and test a potential therapeutic pathway for precision medicine. In doing so, I hope to pave the way for the development of adjuvant therapies for treatment and prevention of cardiac sarcoidosis. This Katz R01 will be instrumental in launching my change in research direction within cardio-immunology.