Altered expression of maturation markers in HPS2 DCs. (A) moDCs from HPS2 patients and control were induced to mature by culture with LPS for 24 hours, seeded on glass, and permeabilized with methanol. DCs were stained with moAbs against DC-LAMP (red) or HLA-DR (green) (top panels), and with anti-CD83 (green) and DAPI (blue) (bottom panels). Images were acquired using a confocal microscope (LSM 510 META; Carl Zeiss Inc.) with a ×100/1.3 oil objective. Images were acquired sequentially using separate laser excitations to avoid crosstalk between the fluorophore signals. (B-C) IHC on formalin-fixed paraffin-embedded sections obtained from lymph nodes of Pt1, Pt2, and control. In the lymph nodes from HPS2-patients, DC-LAMP reactivity is diffused in the cytoplasm, whereas in control, DC-LAMP reactivity is limited to the classical paranuclear dot (B, inserts). By double IHC (C), DC-LAMP⁺ cells (brown) coexpress CD1a (41% of DC-LAMP⁺ cells), Langerin (45%), and S100 protein (62%) (blue). CTR, control; DAPI, 4′,6-diamidino-2-phenylindole; MHC, major histocompatibility complex; Pt, patient.