Fig. 5.

AMPK activation in T cells. (A) AMPK is activated in T cells in one of two ways: by energy deprivation via LKB1 kinase or by TCR activation via CAMKK2. AMPK activation causes an increase in ATP-generating metabolic processes while decreasing ATP-consuming processes. (B) Within minutes of TCR signaling, AMPK activity is up-regulated, and ATP is most likely generated via oxidative phosphorylation. Within a few hours, Glut1 can be trafficked to the cell surface, and new Glut1 protein is expressed such that glucose uptake stimulates aerobic glycolysis.