Increasing AMPK activity supports enhanced oxidative metabolism, proliferation, and in vitro recovery of human CD4+ T cells

Abstract

Abstract Background In adoptive immunotherapy, treatment success correlates with the in vivo expansion and subsequent persistence of transferred cells. In T cells, survival and memory formation are both enhanced when cells exhibit higher levels of oxidative metabolism. AMP-activated protein kinase (AMPK) is a master regulator of metabolism, promoting oxidative phosphorylation when nutrients are scarce. We hypothesized that enhanced AMPK signaling would improve T cell therapeutic potential by increasing their oxidative potential and prolonging their persistence. Results Jurkat and primary human T cells were transduced with a lentiviral construct encoding either AMPKγ2 or an empty vector. All AMPKγ2 transduced cells showed increased activation of the AMPK pathway, with AMPK-transduced Jurkat T cells exhibiting increased baseline and maximal oxygen consumption as measured on a Seahorse Metabolic Analyzer. Furthermore, they were able to maintain this enhanced oxidative metabolism despite prolonged nutrient starvation. In addition, AMPK-transduced primary human T cells increased their mitochondrial density and improved their in vitro proliferation, with significantly increased recovery of CD4+ T cells. Discussion Increasing AMPK activity by over-expressing AMPKγ2 increases the in vitro oxidative potential, proliferation, and recovery of human T cells, particularly CD4+ T cells. These changes are all attractive features for subsequent adoptive immunotherapy. Further work will evaluate the mechanism underlying the phenotype and metabolome of AMPK-transduced cells and will assess their metabolic activity and persistence in vivo.