Detection of HO-1⁺ and HO-1^- DCs in human tissues. (A) Confocal micrographs of cryostat sections from human skin show HO-1⁺ cells (green fluorescence), DC-SIGN⁺ cells (red fluorescence), and merged images with dual labeling. Dermal iDCs show complete overlap of HO-1 and DC-SIGN expression. The epidermis (^*) shows very low or absent expression of both HO-1 and DC-SIGN. (objective, × 40/1.0). (B) Confocal micrographs of cryostat sections from a chronically infected human tonsil show few weakly HO-1⁺ cells (green fluorescence, arrow), DC-LAMP⁺ cells (red fluorescence), and merged images with dual labeling. Tonsil mature DCs expressing DC-LAMP do not express HO-1 (objective, × 63/1.4). Results are representative of 3 different skin and tonsils analyzed in the same way.