IL-18 enhances the migratory potential of NK cells.

(a) Flow cytometric analysis of isolated cecal LP cells from 1:1 Il18r1^-/—CD45.2:WT-CD45.1 mixed bone marrow chimeric mice, Sm-pretreated and infected orally with 5x10⁷ CFU S.Tm for 12h (n = 9 per group). Single cells were gated on CD45⁺ CD3^- lymphocytes. Quantification of NK1.1⁺ cells from WT or Il18r1^-/- LP cells as distinguished by their congenic markers CD45.1 (WT) and CD45.2 (Il18r1^-/-). (b) Assessment of in vivo cell proliferation via EdU incorporation and flow cytometric analysis of isolated LP cells from C57BL/6 mice, either uninfected or infected orally with 5x10⁷CFU S.Tm for 12h (n = 5–6 per group). Quantification of EdU incorporation in CD3^- NK1.1⁺ cells. (c) 2D Transwell migration assay of splenic NK cells isolated by MACS and stimulated for 3h in presence or absence of 100ng/mL rIL-18. Migration was analyzed towards the indicated concentrations of CXCL9 (n = 4 per group). (d) Flow cytometric analysis of CXCR3 surface expression on splenic NK cells, stimulated for 3h in presence or absence of 100ng/mL rIL-18 (n = 4 per group). Data represent the mean ± SD and statistical analyses were performed using the Mann-Whitney-U test or ordinary one-way ANOVA (ns = not significant, * = p<0.05; ** = p<0.01; *** = p<0.001).