CD1 and major histocompatibility complex II molecules follow a different course during dendritic cell maturation.
The maturation of dendritic cells is accompanied by the redistribution of major histocompatibility complex (MHC) class II molecules from the lysosomal MHC class II compartment to the plasma membrane to mediate presentation of peptide antigens. Besides MHC molecules, dendritic cells also express CD1 molecules that mediate presentation of lipid antigens. Herein, we show that in human monocyte-derived dendritic cells, unlike MHC class II, the steady-state distribution of lysosomal CD1b and CD1c isoforms was unperturbed in response to lipopolysaccharide-induced maturation. However, the lysosomes in these cells underwent a dramatic reorganization into electron dense tubules with altered lysosomal protein composition. These structures matured into novel and morphologically unique compartments, here termed mature dendritic cell lysosomes (MDL). Furthermore, we show that upon activation mature dendritic cells do not lose their ability of efficient clathrin-mediated endocytosis as demonstrated for CD1b and transferrin receptor molecules. Thus, the constitutive endocytosis of CD1b molecules and the differential sorting of MHC class II from lysosomes separate peptide- and lipid antigen-presenting molecules during dendritic cell maturation.
van der Wel
Nicole N
NN
The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.
Sugita
Masahiko
M
Fluitsma
Donna M
DM
Cao
Xaiochun
X
Schreibelt
Gerty
G
Brenner
Michael B
MB
Peters
Peter J
PJ
D017951:Antigen Presentation / Q000276:immunology; D018949:Antigens, CD1 / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology*; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002478:Cells, Cultured; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D003001:Cloning, Molecular; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology; D004705:Endocytosis / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008247:Lysosomes / Q000378:metabolism* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D009000:Monocytes / Q000166:cytology* / Q000276:immunology; D011990:Receptors, Transferrin / Q000378:metabolism
D018949:Antigens, CD1; D000949:Histocompatibility Antigens Class II; D008070:Lipopolysaccharides; D011990:Receptors, Transferrin