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bioRxiv · 10.1101/2023.11.13.566775

Enhancing CAR-T Cell Metabolism to Overcome Hypoxic Conditions in the Brain Tumor Microenvironment

Hatae, R.·Kyewalabye, K.·Yamamichi, A.·Chen, T.·Phyu, S.·Chuntova, P.·Nejo, T.·Levine, L. S.·Spitzer, M. H.·Okada, H.
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Abstract

The 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 1 (PGC-1) 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.

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Hatae, R., Kyewalabye, K., Yamamichi, A., Chen, T., Phyu, S., Chuntova, P., Nejo, T., Levine, L. S., Spitzer, M. H., Okada, H.. 2023-11-15. Enhancing CAR-T Cell Metabolism to Overcome Hypoxic Conditions in the Brain Tumor Microenvironment. https://doi.org/10.1101/2023.11.13.566775

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