Figure 6. IL-7-Driven Glycerol Metabolism and TAG Synthesis Are Critical for Memory CD8+ T Cell Survival.
(A and B) Purified memory P14 CD8+ T cells from 50–70 dpi were (A) transferred to Il7+/+ and Il7−/− mice and 5 days later the donor cells were stained with Bodipy493/503 and analyzed by flow cytometry or (B) stimulated with IL-7 for 12 hr and then TAG levels were measured as described in Experimental Procedures.
(C) Purified naive or memory P14 CD8+ T cells (from 50–70 dpi) were stimulated with IL-7 for 12 hr and then TAG levels were measured using Bodipy493/503 staining and flow cytometry.
(D) P14 chimeric mice containing memory P14 CD8+ T cells from 40–60 dpi were injected with IL-7/anti IL-7 (M25) complex. At 3 days later, TAG levels in donor P14 cells in the spleen and bone marrow were measured using Bodipy493/503 staining and flow cytometry.
(E) Memory P14 CD8+ T cells purified at 50–150 dpi were stained with Bodipy493/503, Ki-67, and Bcl-2 and analyzed by flow cytometry. The bar graphs show Bodipy493/503 MFI in the indicated cell populations.
(F) Memory P14 CD8+ T cells (from 30–40 dpi) overexpressing Gyk, Dgat1, Gpat1, Mogat1, or EV were adoptively transferred into Il7−/− mice. For comparison, the EV-transduced cells were also transferred into Il7+/+ mice (open circles). At 2–4 weeks later, donor RV+ P14 CD8+ T cells were enumerated and stained with Bodipy493/503. Values were normalized to those of EV-transduced cells in Il7+/+ mice (open circles).
Data shown are cumulative of two (D), three (A–C), and four (F) independent experiments or representative of five independent experiments (E) (n = 5–20 mice/group): *p < 0.05 and **p < 0.01 (see also Figure S4).