Figure 5. Infiltrating macrophages or microglia were involved in the peak of disease at 14 dpi. CD11b (green) was stained as the β-integrin marker of microglia or mature macrophages. DAPI (blue) was applied to counterstain the cell nuclei. To determine the involvement of infiltrating or resident microglia, CD11b expression was examined in the retina during the course of EAU. Detectable CD11b-positive staining (green) was only observed at 14 dpi but not at other stages of disease (data not shown). The positive staining indicated that CD11b was a cell-surface molecule (CD11b, middle column 40×). The size bar (left panels) represents 200 μm (10×) and the size bar (right panels) represents 50 μm (40×).