exMito treated APCs increase allogeneic T-cell activation and proliferation in MLR. In vitro MLR between C57BL/6J responder T cells and BALB/c T-cell–depleted splenocytes was set up as described in “Methods.” (A) Cells were stained with a CD69 antibody and representative dot plots for the expression of CD69 on green fluorescent protein (GFP)-expressing responder T cells after 48 hours of MLR (S/R: 0.5 to 1; left) and the mean percentage CD69⁺ T cells (right) are shown. (B) Representative histograms after 120 hours of MLR with the indicated treatments showing the percentage of proliferate responder T cells (left) and relative proliferation index (RPI) calculated using the equation: RPI = (stimulated T cells with or without mitochondrial treatment − nonstimulated T cells)/stimulated T cells without mitochondrial treatment (right) is shown (n = 3). (C) CD25 expression on CD4⁺ and CD8⁺ allogeneic T cells after 48 hours presented as MFI relative fold change (n = 6). (D) Percent of naïve (CD44⁻CD62L⁺), central memory (CM; CD44⁺CD62L⁺), and effector (CD44⁺CD62L⁻) CD4⁺ and CD8⁺ T cells after 48 hours in a MLR (n = 4-6). ∗P < .05, ∗∗P < .01, and ∗∗∗P < .001; n, number of independent experiments. S/R, Stimulator/Responder.