Figure 7. Mitochondrial FAO enhances T cell survival and promotes CD8⁺ T_M cell development.

OVA peptide activated OT-I cells transduced with control (empty vector) or CPT1a expressing (EX) retrovirus were intravenously injected into congenic recipients (n = 5 per group), and (A) organs were harvested 2 days later, dot plots show percentages (top panels), or total numbers (bottom panels) of donor cells (mean ± SEM); *P < 0.0001 (top left), < 0.0001 (top right), 0.03 (bottom left), and 0.0006 (bottom right), or (B) mice were infected with LmOVA, and peripheral blood CD8⁺ T cells were analyzed by K^bOVA tetramer (line graphs) and GFP for retroviral expression (contour plots) at the peak of the response (T_E cells, day 7) and after contraction (T_M cells, day 14). Contour plots and bar graphs show the frequency of transduced (GFP⁺) cells within the CD8⁺ and K^bOVA tetramer positive gate in blood (left bar graph; *P = 0.0003), absolute numbers of transduced (GFP⁺) cells/ml blood (middle bar graph, data are normalized to control T_E cells; P = 0.02, numbers above bars indicate fold contraction), and absolute numbers of transduced (GFP⁺) cell in spleen (right bar graph, data are normalized to control T_E cells). Data are shown as mean ± SEM and are representative of at least 2 independent experiments with at least 5 mice per group. (C) OT-I cells transduced with control (empty vector) or CPT1a expressing (EX) retrovirus were intravenously injected into IL-15 deficient recipients (n = 5 per group) and mice were infected with LmOVA. Bar graphs show the frequency of transduced (GFP⁺) cells within the K^bOVA tetramer gate at the peak of the response (T_E cells, day 7), after contraction (T_M cells, day 14) and after challenge (recall, day 5 post challenge); *P = 0.01. Data are shown as mean ± SEM and are representative of 2 independent experiments. See also Figure S6.