Important contributions of P-selectin glycoprotein ligand-1-mediated secondary capture to human monocyte adhesion to P-selectin, E-selectin, and TNF-alpha-activated endothelium under flow in vitro.
In this study, an in vitro flow model and a blocking mAb to P-selectin glycoprotein ligand-1 (PSGL-1) were used to define the role of PSGL-1 in monocyte attachment and rolling on E- and P-selectin and in attachment and accumulation on 6-h TNF-alpha-activated HUVEC. KPL1, an adhesion-blocking mAb directed against the tyrosine sulfate motif of PSGL-1, abolished monocyte-adhesive interactions with P-selectin, but only partially blocked monocyte interaction with E-selectin. Further analysis showed that on E-selectin, KPL1 blocked only secondary (i.e., monocyte/monocyte) interactions, but did not block primary (i.e., monocyte/E-selectin) interactions, with secondary adhesion accounting for 90% of the total adhesive interactions on either E- or P-selectin. On cytokine-activated HUVEC, monocytes initially attached and formed linear strings of adherent cells, which involved both primary and secondary adhesion. PSGL-1 or L-selectin mAb reduced string formation, and the combination of PSGL-1 and L-selectin mAb prevented monocyte strings and inhibited 86% of accumulation. Monocyte attachment and rolling on purified adherent monocytes were also critically dependent on PSGL-1 on the adherent monocytes. These studies document that secondary interactions between monocytes, mediated by PSGL-1, are crucial for monocyte initial attachment, rolling, and accumulation on activated endothelium under laminar shear flow.
Lim
Y C
YC
Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.
Snapp
K
K
Kansas
G S
GS
Camphausen
R
R
Ding
H
H
Luscinskas
F W
FW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000276:immunology; D016466:CHO Cells; D002448:Cell Adhesion / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D006224:Cricetinae; D015194:Diffusion Chambers, Culture; D019040:E-Selectin / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D008024:Ligands; D008562:Membrane Glycoproteins / Q000502:physiology*; D009000:Monocytes / Q000378:metabolism / Q000502:physiology*; D019007:P-Selectin / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D014471:Umbilical Veins
D000911:Antibodies, Monoclonal; D019040:E-Selectin; D008024:Ligands; D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein; D014409:Tumor Necrosis Factor-alpha