title: Advanced glycation end products of human β₂ glycoprotein I modulate the maturation and function of DCs.
abstract: In chronic disorders related to endothelial cell dysfunction, plasma β₂ glycoprotein I (β₂GPI) plays a role as a target antigen of pathogenetic autoimmune responses. However, information is still lacking to clarify why β₂GPI triggers autoimmunity. It is possible that posttranslational modification of the protein, such as nonenzymatic glycosylation, leads to the formation of advanced glycation end products (AGEs). The aim of our study was to explore whether glucose-modified β₂GPI is able to interact and activate monocyte-derived immature dendritic cells (iDCs) from healthy human donors. SDS-PAGE and spectrofluorometric analyses indicated that β₂GPI incubated with glucose was sugar modified, and that this modification likely consisted of AGE formation, resulting in AGE-β₂GPI. AGE-β₂GPI caused phenotypical and functional maturation of iDCs involving the activation of p38 MAPK, ERK, and NF-κB. It also induced on DCs a significant up-regulation of RAGE, the receptor for AGEs. Evidence for RAGE involvement comes from blocking experiments with an anti-RAGE mAb, confocal analysis, and coimmunoprecipitation experiments. AGE-β₂GPI-stimulated DCs had increased allostimulatory ability and primed naive T lymphocytes toward a Th2 polarization. These findings might explain in part the interactive role of β₂GPI, AGEs, and DCs in chronic disorders related to endothelial cell dysfunction.
authors.affiliation: Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Brigitta
authors.initials: B
authors.lastname: Buttari
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Profumo
authors.forename: Antonella
authors.initials: A
authors.lastname: Capozzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Facchiano
authors.forename: Luciano
authors.initials: L
authors.lastname: Saso
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sorice
authors.forename: Rachele
authors.initials: R
authors.lastname: Riganò
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000276:immunology / Q000494:pharmacology; D015551:Autoimmunity; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000276:immunology; D004789:Enzyme Activation / Q000276:immunology; D005260:Female; D005947:Glucose / Q000276:immunology / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000276:immunology*; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology; D053482:beta 2-Glycoprotein I / Q000276:immunology* / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D017127:Glycation End Products, Advanced; D016328:NF-kappa B; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D053482:beta 2-Glycoprotein I; D048051:p38 Mitogen-Activated Protein Kinases; D005947:Glucose