Fig. 4

Antiviral activity of NKT cells and NKT cell activating therapy. Mice were infected with FV and splenocytes as well as bone marrow cells were used for adoptive transfer experiments. NKT cells were isolated and 1 × 10⁵ NKT cells were transferred i.v. into acutely FV-infected mice (a). At 3 dpi, viral loads were determined in the recipient mice. At least four mice from two different experiments were used. In b–f, one group of mice was injected with αGalCer at 0 dpi (FV + αGalCer) for stimulation of NKT cells. Absolute numbers of NKT cells per organ are shown in b. A representative histogram of the NKT cell activation of FV-infected mice after αGalCer stimulation is displayed in c. Effector function were measured by the apoptosis-inducing FasL and analyzed by flow cytometry. Data were collected from at least three independent experiments. At least eight animals per group were used for analysis. Viral loads after αGalCer treatment were examined by infectious centers assay at 3 dpi (e) and 7 dpi (f). Mean (±SEM) values of percentages are indicated by bars. A minimum of nine mice out of three independent experiments (b, d, e) or at least four mice from two different experiments were used for f. Statistically significant differences between groups were analyzed with the Mann–Whitney test (a, e, f) or the Kruskal–Wallis test (b, d) and are indicated by single asterisk for p < 0.05; double asterisk for p < 0.01 or triple asterisk for p < 0.001. ns not significant