Role of endothelial MCP-1 in monocyte adhesion to inflamed human endothelium under physiological flow.
Monocyte chemoattractant protein-1 (MCP-1) is an essential chemokine involved in monocyte traffic across endo- and epithelial barriers both in vitro and in vivo. However, the contribution of endothelial MCP-1 signaling via its CCR2 receptor in monocyte adhesion to inflamed endothelium under flow is incompletely understood. A sensitive flow chamber assay was used to assess monocyte adhesion to TNF-alpha-activated primary human pulmonary artery endothelial cells (HPAEC) during physiological shear stress. Monocyte adhesion was markedly reduced ( approximately 45%) when HPAEC-derived MCP-1 was either neutralized with anti-MCP-1 mAb or inhibited by translational arrest of MCP-1 mRNA transcripts with MCP-1 antisense oligomers. Corresponding efficacy was observed for blockade of monocyte CCR2 receptor function by anti-CCR2 mAb or MCP-1 antagonists (9-76 analog). The impact of endothelial MCP-1 on monocyte-HPAEC adhesion occurred via beta(2)-integrin but not via beta(1)-integrin adhesion pathways. In this line, pretreatment of monocytes with MCP-1 but not RANTES provoked a rapid and transient neoepitope 24 expression on beta(2)-integrin alpha-chains, as analyzed by increased reporter mAb24 binding. Collectively, our data show an important cross talk of endothelial MCP-1 with monocyte CCR2 effecting monocyte firm adhesion to inflamed HPAEC under physiological flow conditions.
Maus
U
U
Department of Internal Medicine, Justus-Liebig University, Giessen 35392, Germany. Ulrich.A.Maus@med.uni-giessen.de
Henning
S
S
Wenschuh
H
H
Mayer
K
K
Seeger
W
W
Lohmeyer
J
J
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018821:CD18 Antigens / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000503:physiopathology*; D005434:Flow Cytometry; D018056:Hemorheology / Q000379:methods; D006801:Humans; D007249:Inflammation / Q000503:physiopathology*; D019012:Integrin beta1 / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D011651:Pulmonary Artery / Q000166:cytology; D020239:Receptor Cross-Talk / Q000187:drug effects; D054390:Receptors, CCR2; D019707:Receptors, Chemokine / Q000037:antagonists & inhibitors / Q000378:metabolism
D000911:Antibodies, Monoclonal; C515334:CCR2 protein, human; D018821:CD18 Antigens; D018932:Chemokine CCL2; D019012:Integrin beta1; D016376:Oligonucleotides, Antisense; D010446:Peptide Fragments; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; C106929:monocyte chemoattractant protein 1 (9-76)