Figure 1. CD8⁺ T_M cells have substantial mitochondrial spare respiratory capacity.

Spleens and lymph nodes were harvested from naive and LmOVA infected mice, and T_N, T_E, and T_M cells were isolated. (A) O₂ consumption rates (OCR) were measured in real time under basal conditions and in response to indicated mitochondrial inhibitors; P < 0.0001 after FCCP injection. Data are representative of 4 independent experiments. (B) Extracellular acidification rates (ECAR) were measured under basal conditions; *P < 0.01 for T_E versus T_N cells, and < 0.01 for T_E versus T_M cells. Data are representative of 2 independent experiments. (C-F) OT-I cells were activated with OVA peptide for 3 days, and subsequently cultured in either IL-2 or IL-15 to generate IL-2 T_E and IL-15 T_M cells, respectively. Basal extracellular acidification rate (ECAR) (D), basal OCR/ECAR ratio (E), and OCR under basal conditions and in response to indicated mitochondrial inhibitors (F) in IL-2 T_E and IL-15 T_M cells are shown; *P < 0.0001 (D), < 0.0001 (E), <0.0001 (F after FCCP). Data are representative of at least 3 independent experiments. Data are shown as mean ± SEM. See also Figure S1.