Project description:CRISPR-Cas9 genome editing has enabled advanced T cell therapies, but occasional loss of the targeted chromosome remains a safety concern. To investigate whether Cas9-induced chromosome loss is a universal phenomenon and evaluate its clinical significance, we conducted a systematic analysis in primary human T cells. Arrayed and pooled CRISPR screens revealed that chromosome loss was generalizable across the genome and resulted in partial and entire loss of the chromosome, including in pre-clinical chimeric antigen receptor T cells. T cells with chromosome loss persisted for weeks in culture, implying the potential to interfere with clinical use. A modified cell manufacturing process, employed in our first-in-human clinical trial of Cas9-engineered T cells, dramatically reduced chromosome loss while largely preserving genome editing efficacy. Expression of p53 correlated with protection from chromosome loss observed in this protocol, suggesting both a mechanism and strategy for T cell engineering that mitigates this genotoxicity in the clinic.
Project description:CRISPR-Cas9 genome editing has enabled advanced T cell therapies, but occasional loss of the targeted chromosome remains a safety concern. To investigate whether Cas9-induced chromosome loss is a universal phenomenon and evaluate its clinical significance, we conducted a systematic analysis in primary human T cells. Arrayed and pooled CRISPR screens revealed that chromosome loss was generalizable across the genome and resulted in partial and entire loss of the chromosome, including in pre-clinical chimeric antigen receptor T cells. T cells with chromosome loss persisted for weeks in culture, implying the potential to interfere with clinical use. A modified cell manufacturing process, employed in our first-in-human clinical trial of Cas9-engineered T cells, dramatically reduced chromosome loss while largely preserving genome editing efficacy. Expression of p53 correlated with protection from chromosome loss observed in this protocol, suggesting both a mechanism and strategy for T cell engineering that mitigates this genotoxicity in the clinic.
Project description:CRISPR-Cas9 genome editing has enabled advanced T cell therapies, but occasional loss of the targeted chromosome remains a safety concern. To investigate whether Cas9-induced chromosome loss is a universal phenomenon and evaluate its clinical significance, we conducted a systematic analysis in primary human T cells. Arrayed and pooled CRISPR screens revealed that chromosome loss was generalizable across the genome and resulted in partial and entire loss of the chromosome, including in pre-clinical chimeric antigen receptor T cells. T cells with chromosome loss persisted for weeks in culture, implying the potential to interfere with clinical use. A modified cell manufacturing process, employed in our first-in-human clinical trial of Cas9-engineered T cells, dramatically reduced chromosome loss while largely preserving genome editing efficacy. Expression of p53 correlated with protection from chromosome loss observed in this protocol, suggesting both a mechanism and strategy for T cell engineering that mitigates this genotoxicity in the clinic.
Project description:We showed that iPSC-derived GD2-CART therapy for SCLC was more effective than peripheral blood-derived GD2-CART. Here, we investigated the molecular difference between iPSC-derived GD2-CARTs and peripheral blood-derived GD2-CARTs.
Project description:Cocaine and amphetamine-regulated transcript (CART) is expressed in pancreatic islet cells and neuronal elements. We have previously established insulinotropic actions of CART in human and rodent islets. The receptor for CART in the pancreatic beta cells is unidentified. We used RNA sequencing of Cartpt knock down (KD) INS-1 832/13 cells and identified GPR162 as the most Cartpt-regulated receptor. We therefore tested if GPR162 mediates the effects of CART in beta cells. Binding of CART to GPR162 was established using proximity ligation assay, radioactive binding and co-immunoprecipitation, and KD of Gpr162 mRNA caused reduced binding. Gpr162 KD cells had blunted CARTp-induced exocytosis, and reduced CARTp-induced insulin secretion. Furthermore, we identified a hitherto undescribed GPR162-dependent role of CART as a regulator of cytoskeletal arrangement. Thus, our findings provide mechanistic insight into the effect of CART on insulin secretion and show that GPR162 is the CART receptor in beta cells.
Project description:Cocaine and amphetamine-regulated transcript (CART) is expressed in pancreatic islet cells and neuronal elements. We have previously established insulinotropic actions of CART in human and rodent islets. The receptor for CART in the pancreatic beta cells is unidentified. We used RNA sequencing of Cartpt knock down (KD) INS-1 832/13 cells and identified GPR162 as the most Cartpt-regulated receptor. We therefore tested if GPR162 mediates the effects of CART in beta cells. Binding of CART to GPR162 was established using proximity ligation assay, radioactive binding and co-immunoprecipitation, and KD of Gpr162 mRNA caused reduced binding. Gpr162 KD cells had blunted CARTp-induced exocytosis, and reduced CARTp-induced insulin secretion. Furthermore, we identified a hitherto undescribed GPR162-dependent role of CART as a regulator of cytoskeletal arrangement. Thus, our findings provide mechanistic insight into the effect of CART on insulin secretion and show that GPR162 is the CART receptor in beta cells.