(A–D) Activated OT-1 CD8⁺ T cells in the presence of OVA-I, anti-CD28, and GSH were treated with or without Lip-1, A2ARi, or a combination of both. RNA-Seq was performed in activated T cells, and GSEA plot showed the enriched pathway of oxidative phosphorylation in the combination of both compared with single treatment alone (A). Activated CD8⁺ T cells were fixed and observed by transmission electron microscopy (B). The number (C) and length (D) of cristae in mitochondria were measured and summarized. (E and F) Activated CD8⁺ T cells were stained with MTR and MTG to measure the mitochondrial membrane potential and mitochondrial mass, respectively (E). The ratio of MTR^hiMTG^lo to MTR^loMTG^hi was calculated (F). (G and H) The oxygen consumption rate (OCR) of activated OT-1 CD8⁺ T cells treated as indicated in the presence of OVA-I, anti-CD28, and GSH under normoxic (N) or hypoxic (H) conditions was measured by the Seahorse MitoStress Test with injections of oligomycin, FCCP, and antimycin A/rotenone (G). Basal OCR (H) was calculated from these activated CD8⁺ T cells cultured under hypoxic conditions. (I and J) Activated CD8⁺ T cells were stained with BODIPY and mBBr to measure neutral lipid by PE signal and GSH, respectively (I). The ratio of PE^hiGSH^hi to PE^loGSH^lo was calculated (J). Results are representative of 2 (A–D) or 3 (E, F, I, and J) independent experiments. Data were analyzed by 2-way ANOVA (C, D, F, H, and J). Data plotted are mean ± SEM from biological replicates. *P < 0.05, **P < 0.01, ***P < 0.001.