BAD-LAMP is detected specifically in pDCs. (A) Detection of BAD-LAMP in human lymphoid tissue. Paraffin human spleen sections were stained with mAbs against CD123 (red) and BAD-LAMP (green). Overlay shows that BAD-LAMP⁺ cells are also CD123⁺ (merge, yellow). Bar indicates 20μm. Paraffin-fixed human tonsil sections were stained for immunohistochemistry (bottom right). BAD-LAMP⁺ cells display a pDC morphology (arrows, ×800) next to HEV. (B) Intracellular FACS staining on human PBMCs. A rare cell population can be isolated based on BAD-LAMP expression (left). BAD-LAMP⁺ cells were identified as pDCs based on BDCA-4 expression (right). (C) BAD-LAMP staining on purified pDCs. Cells stained in intracellular FACS (left) are homogenously BAD-LAMP⁺ (solid line) compared with isotype control background (filled graph). BAD-LAMP is localized in intracellular membrane compartments of BDCA-4⁺ pDCs, as shown by confocal microscopy (green, right). Nucleus (Nu) staining is shown in blue. Bar indicates 20μm.