tailieunhanh - Báo cáo khoa học: Differential post-translational modification of CD63 molecules during maturation of human dendritic cells

The capacity of dendritic cells to initiate T cell responses is related to their ability to redistribute MHC class II mole-cules from the intracellular MHC class II compartments to the cell surface. This redistribution occurs during dendritic cell development as they are converted from an antigen capturing, immature dendritic cell into an MHC class II-peptide presenting mature dendritic cell. During this matu-ration, antigen uptake and processing are down-regulated and peptide-loaded class II complexes become expressed in a stable manner on the cell surface. . | Eur. J. Biochem. 270 2412-2420 2003 FEBS 2003 doi Differential post-translational modification of CD63 molecules during maturation of human dendritic cells Anneke Engering1 3 Lotte Kuhn1 2 Donna Fluitsma3 Elisabeth Hoefsmit3 and Jean Pieters1 2 1 Basel Institute for Immunology Basel Switzerland 2Biozentrum University of Basel Basel Switzerland 3Department of Cell Biology and Immunology Vrije Universiteit Amsterdam The Netherlands The capacity of dendritic cells to initiate T cell responses is related to their ability to redistribute MHC class II molecules from the intracellular MHC class II compartments to the cell surface. This redistribution occurs during dendritic cell development as they are converted from an antigen capturing immature dendritic cell into an MHC class II-peptide presenting mature dendritic cell. During this maturation antigen uptake and processing are down-regulated and peptide-loaded class II complexes become expressed in a stable manner on the cell surface. Here we report that the tetraspanin CD63 that associates with intracellularly localized MHC class II molecules in immature dendritic cells was modified post-translationally by poly N-acetyl lactosamine addition during maturation. This modification of CD63 was accompanied by a change in morphology of MHC class II compartments from typical multivesicular organelles to structures containing densely packed lipid moieties. Post-translational modification of CD63 may be involved in the functional and morphological changes of MHC class II compartments that occur during dendritic cell maturation. Keywords antigen presentation poly N-acetyl lactosamine addition dendritic cells tetraspanins MHC class II. Dendritic cells have the unique feature to induce T cell responses in lymphoid organs against antigens captured in peripheral tissues for review see 1 2 . Immature tissue dendritic cells use several mechanisms to internalize a broad array of antigens via the .