Global depletion of NK cells lead to increased bacterial titres of <i>Y</i>. <i>pseudotuberculosis</i> in the mLNs.

<p>7-week old female C57BL/6 mice were injected with 100 μg of anti NK1.1 antibody i. p. 24 hours prior to infection. Mice were challenged with 2 x 10⁷ CFU of <i>Y</i>. <i>pseudotuberculosis</i> strain YPIII. (A) Three days post infection mLNs were excised and homogenates were plated onto selective plates. Data from three independent experiments were pooled. Bacterial loads were compared using a Mann-Whitney U test (**, p < 0.01). (B) Three days post infection mLNs were excised and single cell suspensions were stained with Live/Dead, CD3, CD4, CD8, CD19, NK1.1, CD11b, CD11c, CD49b, F4/80, Ly6C, Ly6G. Living cell numbers of macrophages, neutrophils, inflammatory monocytes, B cells, DCs, monocytes, pDCs, TH cells, CTL, NKT-, and NK cells were assessed. Cross striped bars represent undepleted mice, black bars represent NK depleted mice. Data from three independent experiments were pooled and analyzed with a Student’s t-test (**p < 0.01; ***, p < 0.001). DCs: dendritic cells, TH: T helper cells, CTL: cytotoxic lymphocytes, NKT: natural killer T-cells, NK: natural killer cells.