Figure 1. TGF-β signaling represses NK1.1⁺ CD8⁺ T cell differentiation.

(a) Flow cytometry analysis of TGF-(βRII and NK1.1 expression at the surface of either CD8⁺ T cell splenocytes or CD4⁺ T cell splenocytes 8 days after LCMV infection of B6 mice. Data are representative of 4 experiments with 3–4 animals per group. (b–c) T cell- depleted bone marrow (BM) cells from CD4-Cre; Stop^fl/fl Tgf-/βRI^CA Thy1.2 B6 mice (TGF- βRI^CA) or Thy 1.1 B6 mice (TGF-βRI^WT) were mixed at a 1:1 ratio and transferred into irradiated rag2^KO mice (RAG^KO). Chimeras were infected with LCMV 5 weeks later and splenocytes analyzed by flow cytometry 8 days post-infection for the BM origin of NK1.1⁺ CD8⁺ T splenocytes. (c) Graph illustrating the absolute number of NK1.1⁺ CD8⁺ T cells and NK1.1⁻ CD8⁺ T splenocytes derived from each BM donor (mean + SD, n=3 representative of 2 experiments). (d) Graph illustrating the percentage of both LCMV specific H2-D^b(NP_396–404) tetramer⁺ CD8⁺ splenocytes and LCMV specific H2-D^b(GP_33–41) tetramer⁺ CD8⁺ splenocytes expressing high levels of TGF-(βRII at different times after LCMV infection. (e) Graph illustrating absolute numbers of LCMV specific H2-D^b(NP_{396– 404}) and LCMV specific H2-D^b(GP_33–41) tetramer⁺ CD8⁺ splenocytes expressing NK1.1 at different times after LCMV infection. Data are representative of three experiments and shown as mean + SD n=5 per point. (f–g) Naïve (CD44^low CD62L^high) OT-1 T cells were adoptively transferred into B6 mice, infected the following day by Lm-Ova. The graphs illustrate the percentage of OT-1 splenocytes expressing high levels of TGF-(βRII (f) and the absolute numbers of NK1.1⁺ OT-1 T cells at different times after Lm-Ova infection (g). Data are representative of 3 experiments and shown as mean + SD n=3 per point.