Figure 3: The phagocytic receptors and the costimulatory molecules on granuloma cells from the spleens (S/) of mice that were infected with the BCG vaccine in vivo for two months (/2) and after ex vivo culture for a few days. Scale bars: 10 μm. Different parts of granulomas are shown. ((a)-(b)) The immunochemical localization of the leukocyte surface markers CD11b, CD11c, CD14, and CD16/CD32 on granuloma cells and control mouse peritoneal macrophages, respectively. The brown color of the cell membranes indicates the presence of the receptors in these regions. Black and red arrows indicate macrophages and megakaryocytes stained for cell surface markers, respectively; red stars indicate neutrophils specifically stained for the receptors; black stars indicate fibroblasts without the antigen. ((c)-(d)) The confocal immunofluorescent localization of the cell surface receptors CD11b (red signal), CD11c and CD16/CD32 (green signals), and CD80 and CD86 (red signals) in granuloma cells. Colocalization of the receptors on confocal images of cells (yellow signal). Staining nuclei with DAPI (blue signal). (c) On the right panel is the same granuloma part that is on the left panel, but it is restained to acid-fast BCG-mycobacteria by Ziehl-Neelsen method. Macrophages and dendritic cells with BCG-mycobacteria are indicated by black arrows and stars, respectively. ((d), top panels) A part of a granuloma with a Langhans giant cell.