Abstract 1120: Bioenergetics of T cells in the context of adoptive immunotherapy

Abstract

Abstract Tumor-specific T cell therapy has been used as an experimental approach for an anti-tumor therapy (Sadelain M 2003, Gattinoni L 2006). Adoptive T cell transfer therapies rely on ex vivo T cell isolation, transduction, activation and expansion of autologous tumor-reactive T cell populations prior to patient administration (Yee C 2002, Dudley ME 2003, Bollard CM 2004). The metabolic changes occurring in modified T-cells are the object of growing interest. For example, it has been shown that quiescent T cells display low energetic and biosynthetic demands, generating ATP through the TCA cycle and OXPHOS (oxidative phosphorylation). Activated T cells undergo conversion from a resting to an active state and ATP production switches from OXPHOS to high glycolysis. Our objective was to assess T cell metabolism and evaluate changes in glycolytic and mitochnodrial function that occur during transduction and expansion, prior to administration of T-cells in adoptive immunotherapy protocols. Methods. Human T-cells were isolated from buffy coat using ficoll separation. 48 hours after phytohemagglutinin (PHA) stimulation, cells were transduced with the retroviral vector bearing chimeric antigen receptor (CAR) targeting PSMA (Maher, Brentjens et al. 2002), and transduction efficacy was assessed by FACS. T-cells further were stimulated by exposure to antigen-presenting cells, APC. The metabolic profiles were determined at different steps of T cell stimulation and transduction. A Seahorse XF96 Analyzer was used to measure glycolysis (extracellular acidification rate, ECAR) and the oxygen consumption rate (OCR), a measure of oxidative phosphorylation (OXPHOS). Results: Glycolysis and oxygen consumption was low in resting non-stimulated cells. Both CAR-transduced and non-transduced T cells increased glycolysis (5-fold), oxygen consumption (3-fold) and ATP-linked OCR following PHA stimulation. No significant metabolic differences were observed between CAR-transduced and non-transduced T cells. High glycolytic activity was maintained by T cells over the 25 day course of T cell transduction and expansion. Mitochondrial function (oxygen consumption) declined during this period. Restimulation by exposure to antigen-presenting cells resulted in a small mitochondrial response in transduced T cells, whereas glycolysis remained high and showed no additional response. Conclusion: Glycolysis (ECAR) remains high, whereas oxygen consumption (OCR and OXPHOS) declines during T cell preparation for adoptive T cell therapy. Whether the specific changes in glucose metabolism and mitochondria respiration can influence cytotoxic function remains to be elucidated. Citation Format: Ekaterina Moroz, Maxim Moroz, Inna Serganova, Juan Zurita, Jason Lee, Nisargbhai Shah, Vladimir Ponomarev, Ronald Blasberg. Bioenergetics of T cells in the context of adoptive immunotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1120. doi:10.1158/1538-7445.AM2014-1120