Figure 2. SLAT is not required for CD8⁺ T cell differentiation into primary effector CTLs.

Mice were primed with 5 × 10⁶ Act-mOVA/K^b−/− splenocytes. On day 7, OVA_257–264/K^b-specific CD8⁺ T cells were stained with H-2K^b-OVA tetramer and IFN-γ and TNF-α -producing CD8⁺ T cells were assessed by ICS following restimulation with OVA peptide for 5 h. A, Expression of T-Bet and Eomes within the OVA_257–264/K^b-specific CD8⁺ T cell population. B, Expression of KLRG1 and CD127 on OVA/K^b-specific CD8⁺ T cells. KLRG-1^high CD127^low CD8⁺ T cells are referred to as short-lived effector cells (SLEC) whereas KLRG-1^low CD127^high CD8⁺ T cells are referred to as memory precursor effector cells (MPEC). C, Frequency of IFN-γ and TNF-α-producing CD8⁺ T cells within the IFN-γ⁺ CD8⁺ T cells. Each graph represents the mean of 6 mice/group and is representative of at least two independent experiments. D, In vivo cytolytic activity of Ag-specific CD8⁺ T cells from WT vs. KO mice 6 days after priming with Act-mOVA/K^b−/− splenocytes. Data are presented as the frequency of tetramer⁺ cells (numbers above outlined areas in first and third panels from left) and killing of target cells pulsed with OVA_257–264 peptide and loaded with high concentration of the cytosolic dye CFSE (OVA) vs. control target cells pulsed with an irrelevant peptide and loaded with a low concentration of CFSE (Ski9) (second and fourth panels from left). Cytotoxicity was determined 16 h after adoptive transfer of target cells. Numbers in plots indicate percentage ± SEM of specific killing of CFSE^high, OVA-loaded cells). Data are representative of five independent experiments.