FIGURE 3.

Differential expression of CXCR4/7 on monocytes and macrophages with different phenotypes. A, detection of CXCR4- or CXCR7-positive cells in monocytes versus macrophages. THP-1 monocytes, PMA-driven THP-1 macrophages, primary monocytes and their differentiated macrophages (100 ng/ml IFN-γ+1 μg/ml LPS) were stained with CXCR4 or CXCR7 antibodies and their respective isotype-matched IgG controls before analyzed by flow cytometry assays. Flow cytometry plots are representative results from three independent experiments. B, summarized quantitative data for panel A. *, p < 0.05; **, p < 0.01. C, CXCR7 expression in M1 versus M2 macrophages. Human primary monocytes were differentiated into M1 or M2 phenotype by IFN-γ+LPS (M1) or IL-4(M2), respectively for 48 h. Then, the cells were stained with CD68, CD206(mannose receptor) or CXCR7 antibodies and the respective isotype-matched IgG controls before analyzed by a standard flow cytometry assay. Macrophages were identified and gated by their forward and side scatter characteristics. Flow cytometry plots are representative results from three independent experiments showing fluorescence intensity of isotype control antibodies (black line) compared with the CD68, CD206, or CXCR7-selective antibodies (blue or red line). D, differential change of cell surface CXCR4 versus CXCR7 during monocyte-to-macrophage differentiation. Cell surface CXCR4 or CXCR7 antigen levels were determined by flow cytometry assays after the human primary monocytes were differentiated into macrophages by indicated reagents for 48 h. Mean fluorescence intensity for CXCR4 or CXCR7 antigen was determined after normalization with respective IgG controls. (n = 5), *, p < 0.05; **, p < 0.01.