title: Regulation of intracellular trafficking of human CD1d by association with MHC class II molecules.
abstract: CD1 family members are antigen-presenting molecules capable of presenting bacterial or synthetic glycolipids to T cells. Here we show that a subset of human CD1d molecules are associated with major histocompatibility complex (MHC) class II molecules, both on the cell surface and in the late endosomal/lysosomal compartments where class II molecules transiently accumulate during transport. The interaction is initiated in the endoplasmic reticulum with class II-invariant chain complexes and appears to be maintained throughout the class II trafficking pathway. A truncated form of CD1d which lacks its cytoplasmic YXXZ internalization motif is transported to late endosomal/lysosomal compartments in the presence of class II molecules. Furthermore, the same CD1d deletion mutant is targeted to lysosomal compartments in HeLa cells expressing class II molecules and invariant chain by transfection. The deletion mutant was also found in lysosomal compartments in HeLa cells expressing only the p33 form of the invariant chain. These data suggest that the intracellular trafficking pathway of CD1d may be altered by class II molecules and invariant chain induced during inflammation.
authors.affiliation: Section of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8011, USA.
authors.forename: Suk-Jo
authors.initials: SJ
authors.lastname: Kang
authors.forename: Peter
authors.initials: P
authors.lastname: Cresswell
mesh_terms: D000818:Animals; D018949:Antigens, CD1 / Q000235:genetics / Q000378:metabolism*; D055610:Antigens, CD1d; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001692:Biological Transport; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D019281:Dimerization; D006367:HeLa Cells; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D051379:Mice
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; D000944:Antigens, Differentiation, B-Lymphocyte; C526877:CD1D protein, human; D000949:Histocompatibility Antigens Class II; C045084:invariant chain