Fig. 4.

Chemo-irradiation results in activation of NK cells. NK cell activation was measured by increased CD69 and TRAIL expression and by increased degranulation (cell surface CD107a expression) of splenic NK cells at different time points after treatment of 4T1 tumor-bearing B6CBAF1 mice with CY+TBI, as indicated. NK cells were identified as CD3-negative and CD49b-positive lymphocytes. a The percentages (and SEM) of NK cells positive for CD69, CD107a, and TRAIL of five mice per time point: 9 days after 4T1 tumor induction without treatment with CY+TBI, and at successive time points after CY+TBI. ^§ p < 0.05, ^£ p < 0.01, *p < 0.001 compared with 9 days after 4T1 tumor induction without chemo-irradiation. b Examples of FACS plots of CD69, CD107a, and TRAIL expression of splenic NK cells of individual 4T1 tumor-bearing mice at the time points indicated