Chemotactic factors regulate lectin adhesion molecule 1 (LECAM-1)-dependent neutrophil adhesion to cytokine-stimulated endothelial cells in vitro.
Monoclonal antibodies recognizing CD18, CD11a, CD11b, and neutrophil lectin adhesion molecule 1 (LECAM-1), i.e., the human homologue of the murine MEL-14 antigen, were used to assess the relative contribution of these glycoproteins to neutrophil-endothelial adhesion. Under static conditions, the adhesion of neutrophils to IL-1-stimulated human umbilical vein endothelial cell (HUVEC) monolayers was inhibited by antibodies to CD18, CD11a, and the neutrophil LECAM-1, and the effect of combining anti-LECAM-1 and anti-CD11a was almost additive. Under flow at a wall shear stress 1.85 dyn/cm2, a condition where CD18-dependent adhesion is minimal, anti-LECAM-1 inhibited adhesion by greater than 50%. Chemotactic stimulation of neutrophils induced a rapid loss of LECAM-1 from the neutrophil surface, and the level of neutrophil surface LECAM-1 was closely correlated with adhesion under flow. Neutrophils contacting the activated endothelial cells for 30 min lost much of their surface LECAM-1, a phenomenon induced by a soluble factor or factors released into the medium by the stimulated monolayers, and a high percentage migrated through the HUVEC monolayer. This migration was almost completely inhibited by anti-CD18, but was unaffected by antibodies to neutrophil LECAM-1. These results support the concept that LECAM-1 is a neutrophil adhesion molecule that participates in the adherence of unstimulated neutrophils to cytokine-stimulated endothelial cells under conditions of flow, and is then lost from the neutrophil surface coincident with the engagement of CD18-dependent mechanisms leading to transendothelial migration.
Smith
C W
CW
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030.
Kishimoto
T K
TK
Abbassi
O
O
Hughes
B
B
Rothlein
R
R
McIntire
L V
LV
Butcher
E
E
Anderson
D C
DC
Abbass
O
O
D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D002448:Cell Adhesion / Q000187:drug effects*; D002630:Chemotactic Factors / Q000494:pharmacology*; D016207:Cytokines / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects; D010972:Platelet Activating Factor / Q000494:pharmacology; D016201:Receptors, Lymphocyte Homing / Q000502:physiology*
D000911:Antibodies, Monoclonal; D002630:Chemotactic Factors; D016207:Cytokines; D016209:Interleukin-8; D010972:Platelet Activating Factor; D016201:Receptors, Lymphocyte Homing