Figure 6. SREBP signaling is required for metabolic reprograming of activated CD8⁺ T cells.

(a) Basal oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) of quiescent and 24 h stimulated WT and Scap^fl/fl CD8⁺ T cells. (b) A schematic of OCR in basal condition and in response to sequential treatment with oligomycin (oligo: ATPase inhibitor), FCCP (uncoupling agent) and rotenone-myxothiazol (Rot-Myxo: electron transport chain inhibitor). Basal resp: basal respiration, ATP: ATP production, Max resp: maximal respiration, Non-mito resp: non-mitochondrial respiration, SRC: spare respiratory capacity (c) OCR of 24 h activated WT and Scap^fl/fl CD8⁺ T cells in basal state and in response to sequential treatment with oligomycin, FCCP and rotenone-myxothiazol. (d) Mitotracker staining of WT and Scap^fl/fl CD8⁺ T cells ex vivo and after 24h of activation with anti-CD3-28. (e) Glucose and glutamine consumption, and lactate production measurement in spent media from activated WT and Scap^fl/fl CD8⁺ T cell activated for 24 h with anti-CD3-28. (f) 2-deoxy-2-(¹⁸F)fluoro-D-glucose (FDG) uptake assay. CD8⁺ T cells were activated with anti-CD3-28 for indicated time. Cultures were pulsed with [¹⁸F]FDG for 60 min before analysis. (g) Cellular ATP levels in quiescent, 6 or 24 h activated WT and Scap^fl/fl CD8⁺ T cells (anti-CD3-28). Data are mean of triplicates with standard deviation and representative of two (c) or three (d) independent experiments. *p<0.05, **p<0.01, ***p<0.001 (two-tailed unpaired Student’s t-test).