Fig. 3: The MRTFs mediate signalling to SRF in the CD8+ T-cell immune response.

A Experimental protocol for analysis of OT-I Elk4^−/− CD8⁺ T cells. B Analysis by flow cytometry of expansion of 5000 adoptively co-transferred OT-I Elk4^−/− and OT-I WT CD8⁺ cells after infection, mean value ± SEM (n = 6 mice). C Top, representative profile of cell surface expression of KLRG1 and IL-7Rα, 7 days post-infection; bottom, quantification of SLEC and MPEC. Data are mean values ± SEM for n = 6 mice represented by datapoints infected on the same day. Paired two-tailed t test is used for p value determination. D Irradiated Rag2^−/− mice were reconstituted with bone marrow from OT-I WT TamCre or OT-I Mrtfa^−/−Mrtfb^f/f TamCre mice. Following reconstitution, chimeras were treated for 15 days with tamoxifen and OT-I WT (CD45.1) and OT-I Mrtfab^−/− (CD45.2) naive CD8⁺ T cells were purified and co-transferred 1:1 into CD45.1/CD45.2 recipients, followed by rLM-OVA infection the next day. E Immunoblot analysis before transfer reveals complete Mrtfb inactivation. Experiment has been done multiple times with similar results. F Analysis by flow cytometry of expansion of 5000 adoptively co-transferred OT-I WT and OT-I Mrtfab^−/− CD8⁺ T cells following infection. Data show mean numbers ± SEM in the blood (20 μl). Data are representative of 2 independent experiments with 5 mice each. Statistical significance, paired two-tailed t test. G Cell surface expression of CD44, CD62L, KLRG1 and IL-7Rα by flow cytometry as in Fig. 1D. Quantification of SLEC and MPEC. Data show mean values ± SEM; datapoints represent individual mice pooled from 2 independent experiments with 6 mice each. Statistical significance, paired two-tailed t test. Source data are provided as a Source Data file.