Project description:To characterize the phenotype of human HIT T-cells endowed with a novel synthetic co-stimulatory molecule isolated from a mouse xenograft model compared to a control.
Project description:The local mechanisms regulating exhaustion of tumor-infiltrating lymphocytes (TILs) and responsiveness to PD-1 blockade remain partly elucidated. In human ovarian cancer we show that tumor-reactive intraepithelial (ie)CD8+ TILs engaged by antigen are polyfunctional and upregulate PD-1, which restrains their effectiveness. PD-1+ TILs exhibit a continuum of TCR-engaged/exhausted states with variable effector fitness related to CD28 costimulation, which they receive in intraepithelial niches involving myeloid antigen-presenting cells (mAPC). Following PD-1 blockade, activation of TILs requires CD28 costimulation mediated in situ by tumor mAPCs, which is locally enhanced by CTLA-4 blockade. CD40 ligand also amplifies TIL responses in situ, especially in tumors in which mAPCs are not activated. Thus, dysfunctional and exhausted TILs, in a state of TCR engagement but without proper CD28 costimulation by mAPCs in situ, are unlikely to fully benefit from PD-1 blockade.
Project description:Engagement of CD27 during naïve CD8+ T (TN) cell activation is critical for T cell memory generation through poorly understood mechanisms. To examine the effects of CD27 signaling during TN cell activation we designed a synthetic trimeric CD70 ligand. In conjunction with T cell receptor (TCR) stimulation, ligation of CD27 resulted in immediate receptor internalization, recruitment of TRAF2/SHP-1, and modulation of Lck and ERK/AKT signaling in cells receiving concurrent CD28 costimulation. Independent of this modulatory effect on CD28 costimulated T cells, CD27 signaling enhanced ATF2, FOXO1, and FOXP1 transcription factor circuits, which induced T cell memory rather than the effector associated gene programs observed with CD28 costimulation alone. CD27-costimulated T cells engineered with a chimeric antigen receptor (CAR) exhibited improved tumor control. CD27 signaling during TN cell activation modulates activation strength and directs memory T cell properties that may benefit therapeutic T cells engineered with CARs or T cell receptors.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.
Project description:Chronic stimulation can cause T cell dysfunction and limit efficacy of cellular immunotherapies. CRISPR screens have nominated gene targets for engineered T cells, but improved methods are required to compare large numbers of synthetic knockin sequences to reprogram cell functions. Here, we developed Modular Pooled Knockin Screening (ModPoKI), an adaptable platform for modular construction of DNA knockin libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors. Over 30 ModPoKI screens across human TCR and CAR T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically-stimulated CAR T cells and anti-cancer function in vitro and in vivo. ModPoKI’s modularity allowed us to generate a ~10,000-member library of TF combinations. Non-viral knockin of a combined BATF-TFAP4 polycistronic construct further enhanced function. ModPoKI facilitates discovery of complex gene constructs to program cellular functions.