Effect of IFN-γ on expression of Fas and MHC class I on EL4 cells and susceptibility of EL4 cells to the cytotoxicity of allogeneic CD8 T cells.
(A) IFN-γ up-regulates Fas and MHC class I expression on EL4 cells. Surface expression of Fas and MHC class I on EL4 cells cultured in the absence (dotted histograms) or the presence of IFN-γ (6.25 ng/mL; solid histograms) is shown. (B) Killing of EL4 cells by alloreactive CTLs. Spleen cells from WT or GKO BALB/c mice were stimulated with irradiated B6 splenocytes for 5 days, and the killing activity against untreated EL4 (○) or EL4 cells that were cultured with IFN-γ (6.25 or 12.5 ng/mL for 12-14 hours) (●) was measured by a 51Cr-release assay. Data are presented as the average (percent specific lysis) of triplicates. Results from one representative experiment of at least 3 independent experiments are shown.
