Figure 4.

CCR5 expression by macrophages in the human rectum and colon. A: Representative 20x pseudo-color images in one individual of CD68 (white) and CCR5 (red) co-staining in the rectum and colon. Tissue sections were stained as described in Methods. Mouse IgG isotype controls for CCR5 staining are shown in Figure 2A. Corresponding dot plots are shown next to each image and depict CCR5 mean and maximum fluorescence intensities of cells that were first gated to stain positive for CD68. Thus, cells within the upper right quadrants of the dot plots co-express CD68 and CCR5. The numbers of CD68⁺ CCR5⁺ cells in the upper right quadrants and their corresponding cell densities are specified in each plot. Also given is the percentage of CD68⁺ macrophages co-expressing CCR5. B: Summary of percentages (left y axis) of CD68⁺ macrophages co-expressing CCR5 and their cell densities (right y axis) in all biopsies analyzed. Paired samples, i.e., where the data were derived from a colon and rectum biopsy obtained from the same individual at the same time point (n=18), are connected by lines. Differences going against the prevailing trend are indicated by solid lines, others by dotted lines.