FIG 2.

CCR2-dependent recruitment of IMs to peripheral tissues and localization of these cells to Yersinia infection foci. C57BL/6, CCR2^−/−, or CCR2-GFP mice were orally infected with 5 × 10⁷ CFU of 32777. (A to C) Cells were isolated from bone marrow (BM) or spleen at 7 or 14 dpi, stained with anti-Ly6G and anti-CD11b, and analyzed by flow cytometry. Dead cells were excluded from the analysis. (A) Representative dot plots of Ly6C and CD11b signals of cells isolated from either BM or spleen of C57BL/6 (top) or CCR2^−/− (bottom) mice at 7 dpi. The gate indicates CD11b⁺ Ly6C^hi IMs. (B and C) The numbers of IMs from BM (B) or spleen (C) in mice left uninfected (UI) or at the indicated number of days postinfection calculated from the flow cytometry data are plotted. Data shown are the means and standard errors of data from individual animals combined from at least two independent experiments. P values were calculated with a Mann-Whitney test, and P values of <0.05 are indicated. (D) Tissues from CCR2-EGFP mice after infection were fixed, and frozen sections were prepared and stained with DAPI, anti-Yersinia polyclonal antibody, and anti-CD11c antibody followed by fluorescently labeled species-specific secondary antibodies for confocal microscopy. Representative confocal immunofluorescence microscopic images of individual and overlaid fluorescent signals, as indicated, from one spleen at 3 dpi are shown.