Table 2.

Distribution of transmembrane proteins on the limiting membranes relative to the internal membranes of MIICs from IMDC

	% Internal membrane	% Limiting membrane	N
MHC class II	95	5	282
CD1b	15	85	117
CD1c	55	45	146
LAMP1	22	78	144
CD63	68	32	203

The immunogold labeling on multilaminar lysosomal MIICs from immature monocyte-derived dendritic cells was determined and the percentage of labeling on the limiting membranes and the internal membranes was quantified (N is the number of gold particles counted). MHC class II and CD63 molecules were detected mostly on the internal membranes and CD1b and LAMP1 on the limiting membranes. CD1c is nearly equally distributed amongst both membrane categories.