Recruitment of Ly6Chi monocytes to colon of CCR2 null mice. (a) Representative staining and mean percentage of CD115+ Ly6Chi monocytes within the CD11b+ fraction of blood leukocytes in wild-type (WT) or CCR2−/− mice. (b) Representative Ly6C and MHCII expression on live-gated CD45+ CD11b+SSClow colon leukocytes and the absolute numbers of P1, P2, and P3/P4 subsets from resting WT or CCR2−/− mice. Results representative of at least three individual experiments with 3–4 mice in each group. (**P<0.01 and ***P<0.001). (c) Donor-derived cells (CD45.1+/CD45.2+ CX3CR1+/gfp) within the live-gated CD45+ CD11b+ fraction of colonic LP cells of CCR2−/− mice, 24 h, 48 h, 96 h, and 7 days after transfer of 2 × 106 fluorescence-activated cell-sorted Ly6Chi BM monocytes. (d) Expression of Ly6C, MHCII, and F4/80 on donor-derived cells isolated from recipient CCR2−/− colon at 24 h, 48 h, 96 h, and 7 days after transfer of Ly6Chi monocytes, compared with live-gated CD45+ CD11b+SSClo cells from wild-type (WT) colon (left panel). (e) Expression of CX3CR1-green fluorescent protein (GFP) by donor-derived cells in colon at 24 h, 48 h, 96 h, and 7 days after transfer. Gates for identifying CX3CR1int and CX3CR1hi cells were set using CD11b+ cells from resting CX3CR1+/gfp colon. (f) Donor-derived cells (CD45.1+/CD45.2+ CX3CR1+/gfp) among live-gated CD45+ CD11b+ cells in bloodstream of CCR2−/− mice, 24 h, 48 h, 96 h, and 7 days after transfer of Ly6Chi monocytes and in phosphate-buffered saline (PBS)-treated controls. Results are representative of two individual experiments with two recipient mice at each time point.