Key role for Runx3 in effector CTL differentiation. (A) Western analysis of Runx3, Eomes, T-bet, and perforin expression in Runx3+/+ versus Runx3-/- CD8+ SP T cells differentiated for 6 d. beta-Actin was used as a loading control. (B) Northern blot analysis of Prf1 mRNA expression in Runx3+/+ versus Runx3-/- CD8+ T cells differentiated for 6 d. beta-Actin was used as a loading control. (C) Expression of granzyme B, IFN-gamma, TNF, and IL-2 by resting or restimulated (6 h) Runx3+/+ versus Runx3-/- CD8+ SP T cells differentiated for 6 d. The vertical gray line indicates the granzyme B MFI for WT GFP+ cells. Results in A-C are representative of two independent experiments. (D) ChIP analysis of binding of endogenous Runx3 and Eomes to the Prf1 locus. Enrichment of the indicated genomic regions was evaluated by real-time PCR of DNA from immunoprecipitated and input chromatin. The data are the means of duplicate measurements from two chromatin preparations from two independent CD8+ T cell differentiations. The efficiency of recovery of input for the -1-kb region of Prf1 was 0.97% for the Runx3 ChIP and 0.5% for the Eomes ChIP. 
