Fig. 4

LPS promotes NK cell accumulation after LCMV infection. B6 mice were infected with LCMV, injected with LPS or PBS one day later and analyzed at day 4 p.i.. a Percentage and absolute numbers (#) of NK cells (CD3^–NK1.1⁺) in spleens. Data are pooled from five independent experiments (n = 5–16) with 2–4 mice per group. b Specific lysis of YAC-1 target cells by NK cells. Results are displayed as total splenocyte-to target cell-ratio (left, n = 15) or as NK cell-to-target cell-ratio (right, n = 7). Data are pooled from 2 to 6 independent experiments with 2–4 mice per group. Dots represent mean values, error bars the SEM. c Expression of CD11b, CD27 and KLRG1, gated at the indicated NK cell subsets. Pooled data from five independent experiments (n = 11) with 2–4 mice per group and representative contour plots and histograms are shown. Numbers indicate means ± SEM. d CFSE-labeled wild-type (wt) or TLR2/4^–/– NK cells were transferred into B6 recipient mice. One day later, recipient mice were infected with LCMV and another day later injected with LPS or PBS. At day 4 p.i., cell division of the transferred NK cells (CD45.2⁺CD3^–NK1.1⁺) in spleen was analyzed by CFSE dye dilution. Representative histograms are shown, numbers indicate mean values ± SEM; dots represent values of individual mice. The positions of the gates were determined by the utmost right peak of the CFSE dilution histograms which represents undivided cells. The gates include all cells with lower fluorescence intensity when compared to the undivided CSFE^high cells. Data are derived from five independent experiments with 1–3 mice per group (for wt NK cells, n = 7) and two independent experiments with two mice per group (for TLR2/4^–/– NK cells, n = 4). *p < 0.05, **p < 0.01, ***p < 0.001; ANOVA with Tukey-Kramer post-test (a, left); Kruskal-Wallis with Dunn’s post-Test (a, right); unpaired t-test with Welch-correction (d)