Enhancing CAR-T cell metabolism to overcome hypoxic conditions in the brain tumor microenvironment

• DOI: 10.1172/jci.insight.177141
• Publication Date: 2024-02-22T17:00:37Z
• Authors: Ryusuke Hatae; Keith Kyewalabye; Akane Yamamichi; Tiffany Chen; Su Phyu; Pavlina Chuntova; Takahide Nejo; Lauren S. Levine; Matthew H. Spitzer; Hideho Okada
• Keywords: Biomedical and clinical sciences; T-Lymphocytes; Oncology and Carcinogenesis; Immunology; 610; Cancer immunotherapy; Otology; AMP-Activated Protein Kinases; Brain cancer; Cell Line; Mice; Rare Diseases; Clinical Research; 616; Genetics; Tumor Microenvironment; Humans; Animals; Hypoxia; Cancer; Tumor; Biomedical and Clinical Sciences; TOR Serine-Threonine Kinases; Neurosciences; Brain; Health sciences; Gene Therapy; Glioma; Xenograft Model Antitumor Assays; 3. Good health; Brain Disorders; Brain Cancer; Orphan Drug; Immunotherapy; Biotechnology; Research Article

AbstractThe efficacy of chimeric antigen receptor (CAR)-T therapy has been limited against brain tumors to date. CAR-T cells infiltrating syngeneic intracerebral SB28-EGFRvIII glioma revealed impaired mitochondrial ATP production and a markedly hypoxic status compared to ones migrating to subcutaneous tumors. Drug screenings to improve metabolic states of T cells under hypoxic conditions led us to evaluate the combination of AMPK activator Metformin and the mTOR inhibitor Rapamycin (Met+Rap). Met+Rap-pretreated mouse CAR-T cells showed activated PPAR-gamma coactivator 1α (PGC-1α) through mTOR inhibition and AMPK activation, and a higher level of mitochondrial spare respiratory capacity than those pretreated with individual drugs or without pretreatment. Moreover, Met+Rap-pretreated CAR-T cells demonstrated persistent and effective anti-glioma cytotoxic activities in the hypoxic condition. Furthermore, a single intravenous infusion of Met+Rap-pretreated CAR-T cells significantly extended the survival of mice bearing intracerebral SB28-EGFRvIII gliomas. Mass cytometric analyses highlighted increased glioma-infiltrating CAR-T cells in the Met+Rap group with fewer Ly6c+ CD11b+ monocytic myeloid-derived suppressor cells in the tumors. Finally, human CAR-T cells pretreated with Met+Rap recapitulated the observations with murine CAR-T cells, demonstrating improved functions in vitro hypoxic conditions. These findings advocate for translational and clinical exploration of Met+Rap-pretreated CAR-T cells in human trials.