MtDNA depletion and impaired immune functions and subsequent recovery in THP-1 cells following transfection with TFAM siRNA. A-G, Transfection with TFAM siRNA. A, TFAM proteins levels relative to β-actin during titration of TFAM siRNA, showing optimal knockdown of TFAM protein after transfection of THP-1 cells with 30 nmol/L siRNA for 8 days. B, Cell viability. C, Cell proliferation. D, The levels of the MT-CO1 and SDHA proteins relative to β-actin. D, OCR for different aspects of mitochondrial respiration and respiratory profile. E, Phagocytosis of E coli. Recovery 8 days after removal of TFAM siRNA. F, Levels of the MT-CO1 and SDHA proteins relative to β-actin. G, Oxygen consumption for different aspects of mitochondrial respiration. H, Bacterial phagocytosis. All experiments were carried out on 3 to 4 independent biological replicates and are presented as means ± SD. **P < .01 and ***P < .001.