Project description:In order to investigate the population heterogeneity of CAR19TIF, we determined to profile the single cell RNA transcriptional status of CAR19TIF cells derived from spleens of recipient mice at 2-month post cell transfer. Furthermore, we determined to examine potential subsets among the CAR19TIF cells and critical gene expression levels.
Project description:In order to investigate the underlying mechanism, we determined to profile the transcriptional status of CAR19TIF cells and sgZcsh12a CAR T cells derived from spleens of recipient mice at Day-10 post cell transfer and CAR19TIF cells and endogenous CD8 T cells derived from spleens of recipient mice at 3-month post cell transfer.
Project description:Chimeric antigen receptor (CAR) T cell therapies have revolutionized B cell malignancy treatment, but subsets of patients with large B cell lymphoma (LBCL) experience primary resistance or relapse after CAR T cell treatment. To uncover tumor microenvironment (TME)-induced resistance mechanisms, we examined patients’ intratumoral immune infiltrates and observed that elevated levels of immunoregulatory macrophages in pre-infusion tumor biopsies are correlated with poor clinical responses. In murine models, CAR T cell-produced interferon-gamma (IFN-g) promotes the expression of inducible nitric oxide synthase (iNOS, NOS2) in immunoregulatory macrophages, impairing CAR T cell function. Mechanistically, proteomics analysis of CAR T cells revealed that iNOS-expressing macrophages promote the upregulation of genes mediating apoptosis and cell cycle arrest in CAR T cells, while downregulating ribosome biogenesis and protein synthesis. Furthermore, CAR T cell metabolism is compromised by the depletion of glycolytic intermediates and rewiring of the TCA cycle. Pharmacological inhibition of iNOS enhances the CAR T cell treatment efficacy in B cell tumor-bearing mice. Notably, elevated levels of iNOS+CD14+ monocytes were observed in leukaphereses of patients with non-durable response to CAR T cell therapy. These findings suggest that mitigating iNOS in tumor-associated macrophages (TAMs), potentially by modulating IFN-g expression in CAR T cells, could improve outcomes for LBCL patients.
Project description:Chimeric antigen receptor (CAR) T cell therapies have revolutionized B cell malignancy treatment, but subsets of patients with large B cell lymphoma (LBCL) experience primary resistance or relapse after CAR T cell treatment. To uncover tumor microenvironment (TME)-induced resistance mechanisms, we examined patients’ intratumoral immune infiltrates and observed that elevated levels of immunoregulatory macrophages in pre-infusion tumor biopsies are correlated with poor clinical responses. In murine models, CAR T cell-produced interferon-gamma (IFN-g) promotes the expression of inducible nitric oxide synthase (iNOS, NOS2) in immunoregulatory macrophages, impairing CAR T cell function. Mechanistically, proteomics analysis of CAR T cells revealed that iNOS-expressing macrophages promote the upregulation of genes mediating apoptosis and cell cycle arrest in CAR T cells, while downregulating ribosome biogenesis and protein synthesis. Furthermore, CAR T cell metabolism is compromised by the depletion of glycolytic intermediates and rewiring of the TCA cycle. Pharmacological inhibition of iNOS enhances the CAR T cell treatment efficacy in B cell tumor-bearing mice. Notably, elevated levels of iNOS+CD14+ monocytes were observed in leukaphereses of patients with non-durable response to CAR T cell therapy. These findings suggest that mitigating iNOS in tumor-associated macrophages (TAMs), potentially by modulating IFN-g expression in CAR T cells, could improve outcomes for LBCL patients.