Figure 5.

CD200R1 blockade promotes neutrophil recruitment into the skin and is associated with increased CCL20, but reduced ROS production. (A) CD200R1 expression on inflamed skin neutrophils from skin treated with Aldara cream for the indicated days. (B−C), (F−I) Aldara cream‐induced skin inflammation with CD200R1 blockade or isotype control. Neutrophil: (B) apoptosis and cell death, (C) in vivo recruitment to intradermal CXCL1 administration. (D) CD200R1 expression on bone marrow neutrophils. (E) BM neutrophil migration towards CXCL1 in transwell assays. “Input” is cells recovered from a well lacking a transwell chamber. CXCL1 was added to the top chamber as a negative migration control, or to the bottom chamber to stimulate migration in the presence of the isotype control, or anti‐CD200R1. (F−G) Skin chemokines measured by cytometric bead array. (H) S100A8 ELISA on skin extracts. (I) Neutrophil ROS production. Filled histogram‐fluorescence minus one control, black line‐isotype, red line‐CD200R1 blockade. (J) Neutrophil ROS in the intradermal IL‐23 injection model. MFI, median fluorescence intensity. Data are pooled from 2 to 4 independent experiments (n = 6−10). Mean and SD shown. Analyzed using unpaired t‐test (for two groups of data, [B−D], [F−J]) or Brown−Forsythe and Welch analysis of variance (for >2 groups of data), (E) with Dunnett's multiple comparison test. *p < .05, **p < .01, ***p < .001.