Class I colocalizes in MIICs. (A) Ultrathin cryosections
of immature CD34-derived LCs were double immunolabeled for MHC class II
(rabbit anti-human HLA-DR, small gold) and MHC class I (rabbit
anti-heavy chain serum, large gold). PM, plasma membrane.
(B–D) Endosomes, double immunolabeled with class I
(small gold), together with HLA-DR (large gold) (B),
class I (large gold) together with CD63 (small gold)
(C), and mannose-6-phosphate receptor (small gold)
(D). Large gold particles are 15 nm and small gold
particles (arrows) 5 nm; size bars represent 200 nm.