FIGURE 5.

Gfi1 suppresses IL-7Rα expression and transcription in vivo. A, suppression of GFP reporter activity by overexpression of Gfi1. IL-7Rα transcriptional activities in individual thymocyte subpopulations were determined using the 7RIG-BAC^Tg on WT or Gfi1^Tg backgrounds. Contour plots are representative of four independent experiments with 4 WT and 5 Gfi1^Tg mice transgenic for 7RIG-BAC^Tg. Bar graph shows mean ± S.E. four independent experiments. B, IL-7Rα surface expression and transcription in Gfi1^Tg transgenic CD4 and CD8 LNT cells. The effect of Gfi1 was assessed in WT or Gfi1^Tg mice transgenic for 7RIG-BAC^Tg. Cell surface IL-7Rα and GFP expression were determined by flow cytometry. Bar graph shows mean ± S.E. from three independent experiments with 3 WT and 5 Gfi1^Tg7RIG-BAC^Tg mice. C, expression of γc cytokine receptor families on Gfi1^Tg CD8⁺ LNT cells. Surface expression of the indicated γc cytokine receptors were determined on gated CD8 T cells from WT and Gfi1^Tg mice. Data are representative of three independent experiments. D, Gfi1^Tg specifically suppresses IL-7Rα expression on CD8⁺ T cells. Surface cytokine receptor levels on Gfi1^Tg CD8⁺ T cells were quantified and normalized to levels on WT CD8⁺ T cells. Bar graph shows mean ± S.E. of three independent experiments.