Using pooled screens, Goodman and Azimi et al. assessed the impact of 40 distinct costimulatory domains on the function, persistence, and phenotype of CD19-directed CAR T cells in vitro. The BAFF-R, TACI, and CD40 intracellular domains resulted in similar or superior antigen-specific proliferation, activation, and (except CD40) cytokine production to stalwarts CD28 and 4-1BB, while KLRG1 dampened T cell functionality. BAFF-R CAR T cells were enriched in a cytotoxic phenotype associated with CAR T cell expansion and efficacy in patients. Compared to 4-1BB, BAFF-R costimulation in anti-BCMA CAR T cells extended survival in a multiple myeloma mouse model.
Contributed by Alex Najibi
ABSTRACT: Chimeric antigen receptors (CARs) repurpose natural signaling components to retarget T cells to refractory cancers but have shown limited efficacy in persistent, recurrent malignancies. Here, we introduce "CAR Pooling," a multiplexed approach to rapidly identify CAR designs with clinical potential. Forty CARs with signaling domains derived from a range of immune cell lineages were evaluated in pooled assays for their ability to stimulate critical T cell effector functions during repetitive stimulation that mimics long-term tumor antigen exposure. Several domains were identified from the tumor necrosis factor (TNF) receptor family that have been primarily associated with B cells. CD40 enhanced proliferation, whereas B cell-activating factor receptor (BAFF-R) and transmembrane activator and CAML interactor (TACI) promoted cytotoxicity. These functions were enhanced relative to clinical benchmarks after prolonged antigen stimulation, and CAR T cell signaling through these domains fell into distinct states of memory, cytotoxicity, and metabolism. BAFF-R CAR T cells were enriched for a highly cytotoxic transcriptional signature previously associated with positive clinical outcomes. We also observed that replacing the 4-1BB intracellular signaling domain with the BAFF-R signaling domain in a clinically validated B cell maturation antigen (BCMA)-specific CAR resulted in enhanced activity in a xenotransplant model of multiple myeloma. Together, these results show that CAR Pooling is a general approach for rapid exploration of CAR architecture and activity to improve the efficacy of CAR T cell therapies.
Author Info: (1) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 9
Author Info: (1) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA. (2) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. (3) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. (4) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. INSERM U976, Saint Louis Research Institute, Paris City University, Paris, France. (5) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. (6) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. (7) School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Department of Oral and Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA 94143, USA. Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA. (8) Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 03722, Korea. (9) Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. (10) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. (11) Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA. (12) Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA. Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. (13) Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA. Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Chan Zuckerberg Biohub, San Francisco, CA 94158, USA. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA 94143, USA. (14) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. (15) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA. Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Chan Zuckerberg Biohub, San Francisco, CA 94158, USA. Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA. (16) Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA. Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Sonoma Biotherapeutics, South San Francisco, CA 94080, USA. (17) Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. Parker Institute for Cancer Immunotherapy, San Francisco, CA 94143, USA. Gladstone UCSF Institute for Genetic Immunology, San Francisco, CA 94107, USA. Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA. Chan Zuckerberg Biohub, San Francisco, CA 94158, USA. UCSF Cell Design Institute, San Francisco, CA 94158, USA.
