Figure S4.

IL-15-STAT5 signaling positively regulates YTHDF2 expression, and Ythdf2 deficiency does not affect the expression of IL-15 receptor components, the PI3K–AKT pathway, and the MEK–ERK pathway in NK cells.(A) qPCR showing the expression of Ythdf2 in NK cells at indicated time points following stimulation of IL-15. (B) qPCR showing the expression of Ythdf2 in NK cells in the presence of STAT5 inhibitor and IL-15 stimulation. (C and D) Representative histograms (C) and quantification (D) of intracellular staining showing the YTHDF2 protein levels in splenic NK cells from Stat5^WT and Stat5^ΔNK mice under the stimulation of IL-15. (E–G) Mice were treated with IL-15 (2 µg/d) for 5 d (n = 3 per group). The representative plots (E), percentages (F), and absolute numbers (G) of NK cells in the spleen are shown. (H–J) Representative plots of Ki67⁺ NK cells (H), BrdU⁺ NK cells (I), and annexin V⁺ NK cells (J) from IL-15–treated mice. (K) Representative histograms of CD122 and CD132 levels in splenic NK cells from Ythdf2^WT and Ythdf2^ΔNK mice. (L and M) Representative histograms (L) and quantification (M) of indicated molecules in splenic NK cells from Ythdf2^WT and Ythdf2^ΔNK mice after stimulation of IL-15. Data are shown as mean ± SD and were analyzed by unpaired two-tailed t test (M) or one-way ANOVA with Šídák post-test (A, D, F, and G). Data are representative of at least two independent experiments. *, P < 0.01; **, P < 0.01; ***, P < 0.001. MFI, median fluorescence intensity.