Figure 2: Rgs1 deletion enhances monocyte–macrophage chemotaxis and impairs homologous desensitization.

Migration of peritoneal macrophages from ApoE^−/− and Rgs1^−/− ApoE^−/− mice through an 8-μm filter towards increasing concentrations of recombinant murine (a) CCL5, (b) CCL3 and (c) CCL2 placed in the lower chamber of a Boyden chamber. (d) Migration of peritoneal macrophages pretreated with 0, 0.1, 1 and 10 nM CCL5 and exposed to 1 nM CCL5. Quantification of migration is presented relative to results of untreated cells, set as 1. RPMI media was used as a negative control. Graphs indicate migration index±s.e.m. for each treatment group (triplicates; n=5–6 per group). In vivo chemotaxis was assessed by i.p. injection of 100 μg zymosan and recruited, peritoneal 7/4^hiLy6G⁻ monocytes quantified by flow cytometry at (e) 4 h and (f) 16 h after injection (n=2–4 for saline and n=6–11 for zymosan) (g) The expression of CCR5 on the surface of circulating monocytes after zymosan (n=6–7). Mean fluorescence intensity (MFI) is shown for CCR5 on monocytes at 4 h after zymosan above isotype control (grey). P<0.01 in a,b; P<0.05 in c,d calculated by two-way analysis of variance with significance at individual doses indicated by stars calculated by Bonferroni post-tests. P<0.05 in e–g calculated by Student’s t-test.