AMPK: A metabolic switch for CD8+ T‐cell memory

Adenosine monophosphate‐activated protein kinase (AMPK) is a serine/threonine kinase and is crucial for cellular energy homeostasis. The exact role of AMPK during memory CD8⁺ T‐cell differentiation, a process that changes from the metabolically active state of effector T cells to one of quiescence in memory cells is not well understood; however, a report by Cantrell and colleagues [Eur. J. Immunol. 2013. 43: 889‐896] in this issue of the European Journal of Immunology shows that AMPK, by sensing glucose stress, is an important upstream molecule of mammalian target of rapamycin (mTOR) complex 1 for memory CD8⁺ T‐cell differentiation. This study provides new insights into how AMPK monitors energy stress to control effector and memory CD8⁺ T‐cell formation as discussed in this Commentary.