Fig. 2

Cytotoxic functions of adaptive NK cells after challenge with FV-induced target cells. C57BL/6 mice were infected with FV and treated as indicated in box (a). Naïve mice were also depleted for CD8⁺ T cells and injected i. p. with CFSE⁺ FBL-3 cells. After 48 h incubation, peritoneal lavage was performed and cells were counted. CFSE⁺ FBL-3 cells were measured at flow cytometer. The percentage of NK cell-mediated lysis of FBL-3 cells was calculated and is displayed in (b) (± SEM). FBL-3 cell killing in NK cell-depleted mice was used for calculations. Statistically significant differences were analyzed by an unpaired t test. At least eleven animals from three independent experiments were used for the analysis. Peritoneal lavage was performed after 0, 6, 24 and 48 h after FBL-3 cell injection into naïve and FV-infected mice (pooled data). NK cell numbers were determined and are shown in (c) (± SEM). Statistically significant differenced were analyzed by Kruskal–Wallis test. NK cells from peritoneum were also analyzed for the expression of the cytokines IFNγ, TNFα, the cytotoxicity-associated FasL and the proliferation marker KI-67 (d). At least six animals from two independent experiments were used for the analysis. Statistically significant differences were analyzed by an unpaired t test and were indicated as follows: *p < 0.05; **p < 0.01 and ***p < 0.001