Activated platelets and endothelial cell interaction with neutrophils under flow conditions.
OBJECTIVE
The mechanism of neutrophil adhesion to the endothelium during the earliest stages of acute inflammation, especially before the induction of adhesion molecules on endothelial cells, remains unknown. We studied the possible involvement of platelets in this process.


METHODS
Neutrophils were added to human umbilical vein-derived endothelial cells (HUVEC) with or without adherent platelets in the presence or absence of adhesion-blocking monoclonal antibodies (mAbs). Adhesion of neutrophils to HUVEC at dynamic flow conditions was assessed using a flow chamber.


RESULTS
1) Thrombin-activated platelets adhered to resting-HUVEC at dynamic flow conditions through platelet glycoprotein IIb/IIIa and RGD proteins. 2) Neutrophils tethered to P-selectin induced on thrombin-activated platelets, which were immobilized on HUVEC. 3) Activated neutrophils adhered, via LFA-1, to ICAM-1 on HUVEC. 4) Activated platelets induced interleukin (IL)-8 secretion by HUVEC.


CONCLUSIONS
Immobilized platelets on the vessel wall with induced P-selectin on the surface biochemically and functionally promote the adhesion of neutrophils to endothelial cells.
Mine
S
S
First Department of Internal Medicine, University of Occupational and Environmental Health, Japan, School of Medicine, Kitakyushu, Fukuoka.
Fujisaki
T
T
Suematsu
M
M
Tanaka
Y
Y
D000210:Acute-Phase Reaction / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000473:pathology*; D005340:Fibrinogen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D015539:Platelet Activation; D010975:Platelet Aggregation Inhibitors / Q000378:metabolism; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D014471:Umbilical Veins
D015815:Cell Adhesion Molecules; D005353:Fibronectins; D016209:Interleukin-8; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D005340:Fibrinogen