Fig. 5

Increased apoptosis and decreased BCL2 expression as well as increased cytokine withdrawal-induced cell death in Stat5 DKI NK cells. a, b Freshly isolated total spleen cells were stained with anti-CD3, anti-CD122, anti-NK1.1, Annexin V, and 7AAD. Apoptotic NK cells were identified as CD3⁻CD122⁺NK1.1⁺Annexin V⁺, and dead NK cells were identified as CD3⁻CD122⁺NK1.1⁺Annexin V⁺7AAD⁺ (lower panels of a). Percentages of apoptotic and dead cells in splenic NK cells from 7 WT (open bars) and 7 Stat5 DKI (filled bars) mice b. c, d BCL2 expression (MFI) of bone marrow (c) and spleen (d) NK cells. e Time course of BCL2 expression in splenic NK cells cultured with 20 ng ml⁻¹ IL-15; BCL2 levels were determined by flow cytometry. Isotype control antibody (shaded in grey) and BCL2 antibody staining of WT (blue) and Stat5 DKI (red) NK cells are shown. f BCL2 expression levels (MFI) in IL-15-stimulated splenic NK cells from 3 WT (open bars) and 3 Stat5 DKI (red bars) mice. The experiment was performed twice. Error bars in b, c, d and f are means ± SEM and statistical analyses were performed by grouped multiple t-test using Prism 7.0b