Project description:CD8+ cytotoxic T cells play essential roles in anti-tumor immune responses. Here, we performed in vivo screens in CD8+ T cells and identified regulators of tumor infiltration and killing, which are directly relevant to cancer immunotherapy. Unlike in vitro screens, the in vivo screen robustly re-identified canonical immunotherapy targets such as PD-1 and Tim-3, along with genes that have not been characterized in T cells. The infiltration and degranulation screens converged on an RNA helicase Dhx37. Dhx37 knockout enhanced the efficacy of antigen-specific CD8+ T cells against cancer in vivo. Immunological characterization in mouse and human CD8+ T cells revealed that DHX37 suppresses effector function, cytokine production, and T cell activation. Transcriptomic profiling and biochemical interrogation revealed a role for DHX37 in modulating the NF-kB pathway. These data demonstrated the power of high-throughput in vivo genetic screens for immunotherapy target discovery, and uncovered DHX37 as a functional regulator of CD8+ T cells.
Project description:CD8+ cytotoxic T cells play essential roles in anti-tumor immune responses. Here, we performed in vivo screens in CD8+ T cells and identified regulators of tumor infiltration and killing, which are directly relevant to cancer immunotherapy. Unlike in vitro screens, the in vivo screen robustly re-identified canonical immunotherapy targets such as PD-1 and Tim-3, along with genes that have not been characterized in T cells. The infiltration and degranulation screens converged on an RNA helicase Dhx37. Dhx37 knockout enhanced the efficacy of antigen-specific CD8+ T cells against cancer in vivo. Immunological characterization in mouse and human CD8+ T cells revealed that DHX37 suppresses effector function, cytokine production, and T cell activation. Transcriptomic profiling and biochemical interrogation revealed a role for DHX37 in modulating the NF-kB pathway. These data demonstrated the power of high-throughput in vivo genetic screens for immunotherapy target discovery, and uncovered DHX37 as a functional regulator of CD8+ T cells.
Project description:Sequencing data related to our manuscript "Systematic identification of general and context-specific regulators of phagocytosis using magnetic genome-wide CRISPR screens"
Project description:The cellular processes that govern tumor resistance to immunotherapy remain poorly understood. To gain insight into these processes, we perform a genome-scale CRISPR activation screen for genes that enable human melanoma cells to evade cytotoxic T cell killing. Overexpression of four top candidate genes (CD274 (PD-L1), MCL1, JUNB, and B3GNT2) confer resistance in diverse cancer cell types and mouse xenografts. By investigating the resistance mechanisms, we find that MCL1 and JUNB modulate the mitochondrial apoptosis pathway. JUNB encodes a transcription factor that downregulates FasL and TRAIL receptors, upregulates the MCL1 relative BCL2A1, and activates the NF-B pathway. B3GNT2 encodes a poly-N-acetyllactosamine synthase that targets >10 ligands and receptors to disrupt interactions between tumor and T cells and reduce T cell activation. Inhibition of candidate genes sensitize tumor models to T cell cytotoxicity. Our results demonstrate that systematic gain-of-function screening can elucidate resistance pathways and identify potential targets for cancer immunotherapy.
Project description:<p>Due to the paucity of patient derived models in rare cancers, identification of therapeutic targets remains challenging. We developed a patient derived model, CLF-PED-015-T, from a patient with an undifferentiated sarcoma. From this model, we performed pooled RNAi and CRISPR-Cas9 negative selection screens and integrated that with a small molecule screen. Integration of these data identified CDK4 and XPO1 as potential therapeutic targets.</p>
Project description:Tumor Infiltrating Lymphocyte (TIL) therapy have shown promise in the treatment of patients with refractory solid tumors, with improvement in response rates and durability of responses nevertheless sought. To identify targets capable of enhancing the anti-tumor activity of T cell therapies, large-scale in vitro and in vivo CRISPR/Cas9 screens were performed, with the suppressor of cytokine signaling 1 (SOCS1) gene identified as a top T cell-enhancing target. In murine CD8 T cell therapy models, SOCS1 served as a critical checkpoint in restraining the accumulation of T central memory cells in lymphoid organs as well as intermediate (Texint) and effector (Texeff) exhausted T cell subsets derived from progenitor exhausted T cell (Texprog) cells in tumors. A comprehensive CRISPR tiling screen of the SOCS1 coding region identified sgRNAs targeting the SH2 domain of SOCS1 as the most potent, with a sgRNA with minimal off-target cut sites used to manufacture KSQ-001, an engineered TIL therapy with SOCS1 inactivated by CRISPR/Cas9. KSQ-001 possessed increased responsiveness to cytokine signals and enhanced in vivo anti-tumor function in mouse models. These data demonstrate the use of CRISPR/Cas9 screens in the rational design of T cell therapies.
Project description:Tumor Infiltrating Lymphocyte (TIL) therapy have shown promise in the treatment of patients with refractory solid tumors, with improvement in response rates and durability of responses nevertheless sought. To identify targets capable of enhancing the anti-tumor activity of T cell therapies, large-scale in vitro and in vivo CRISPR/Cas9 screens were performed, with the suppressor of cytokine signaling 1 (SOCS1) gene identified as a top T cell-enhancing target. In murine CD8 T cell therapy models, SOCS1 served as a critical checkpoint in restraining the accumulation of T central memory cells in lymphoid organs as well as intermediate (Texint) and effector (Texeff) exhausted T cell subsets derived from progenitor exhausted T cell (Texprog) cells in tumors. A comprehensive CRISPR tiling screen of the SOCS1 coding region identified sgRNAs targeting the SH2 domain of SOCS1 as the most potent, with a sgRNA with minimal off-target cut sites used to manufacture KSQ-001, an engineered TIL therapy with SOCS1 inactivated by CRISPR/Cas9. KSQ-001 possessed increased responsiveness to cytokine signals and enhanced in vivo anti-tumor function in mouse models. These data demonstrate the use of CRISPR/Cas9 screens in the rational design of T cell therapies.
