Figure 3. Mature DCs are associated with large clusters of CD4+ T-cells in chronic periodontitis. Fluorescence images (0.25-µ optical sections) were acquired by confocal laser scanning microscopy, with the use of an epifluorescence microscope (Nikon E800, Japan) integrated to a confocal laser scanning system (BioRad Radiance 2000, Hercules, CA, USA). Shown are the CD4+ T-cells (green, panels A1, B1, C1), CD83+ mature DCs (red, panels A2, B2, C2), and merged channels (yellow, panels A3, C3), indicating co-localization of T-cells and DCs. Also shown is a mature DC alone (panels B2, B3). Final magnification (optical and digital): 400x (A); 1500X (B, C)