Intracellular cytokine analysis by flow cytometry. Health donor-derived PBMC (N = 4) were treated with PB-derived mitochondria at 200 µg/mL (N = 4) in duplicate for 3 days in the presence of T-cell activator CD3/CD28 Dynabeads. (A–H) There were no marked differences in the percentages of IL-1β (A), IL-4 (B), IL-5 (C), IL-10 (D), IL-13 (E), TGF-β1 (G), and TNF-α (H)-producing cells after the treatment with PB-derived mitochondria. (F) Downregulation of the percentage of IL-17A-positive cells after the treatment with PB-derived mitochondria. Data were given as mean ± SD (standard deviation, N = 4).