Figure 6.
Contribution of IL-15 to generation of CD8 lineage cells. (A) Thymocyte profiles resulting from E8IIICre-mediated deletion of IL-7Rα alone or in combination with IL-4Rα or IL-15 germline deficiency. Total thymocytes were analyzed for expression of CD8α, CD4, and TCR-β from Cre− control (black), germline IL-15−/− (olive green), E8IIICre IL-7R–cKO (blue), IL-7R–cKO combined with germline IL-4R−/− (brown) or IL-15−/− (bright green) mice. Data are representative of at least three independent experiments. (B) Total thymocyte number and frequency of TCR-βhi CD8SP thymocytes from mice in A shown in comparison to γc-cKO mice (red). γc-cKO– and IL-7Rα–cKO-derived cells were specifically gated for those that were γc- or IL-7Rα–deleted. Data represent the means after pooling at least six individual mice from at least three independent experiments. (C) Relative frequency of TCR-βhi CD8SP thymocytes after E8IIICre-mediated deletion of IL-7Rα alone (blue line) or in combination with germline deletion of IL-4Rα (brown line) or IL-15 (green line). IL-7Rα–deleted TCR-βhi CD8SP thymocyte frequencies were analyzed from total thymocytes. Data are shown as frequencies normalized to Cre− controls. Data represent the mean after pooling at least eight individual mice from at least two independent experiments. (D) Relative frequency of IL-7Rα–deleted TCR-βhi CD8SP thymocytes resulting from deletion of IL-7Rα alone (blue line) or in combination with IL-15 (green line) compared with frequency of γc-deleted TCR-βhi CD8SP thymocytes from γc-cKO mice (red line). Data were obtained as for Fig. 6 C. Data represent the mean of at least six individual mice from at least three independent experiments. (B–D) Error bars represent SEM. All statistically significant changes are marked with asterisks: *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Any comparisons not marked with asterisks were not significant.