The IIb-IIIa glycoprotein complex that mediates platelet aggregation is directly implicated in leukocyte adhesion.
Evidence is presented that the IIb-IIIa glycoprotein complex, which functions as the receptor for fibrinogen on platelets and is central to platelet aggregation, is expressed on the surface of leukocytes where it may function as a receptor for fibronectin. F(ab')2 fragments of a monoclonal antibody, 25E11, raised against activated large granular lymphocytes, inhibited killing by natural killer cells, blocked the binding of fibronectin-coated particles by monocytes, and stimulated neutrophils to exhibit increased antibody-dependent killing. Immunoprecipitation studies of leukocytes and platelets, and the ability of 25E11 to inhibit platelet aggregation, identified the antigen as an epitope on the IIb-IIIa complex. This glycoprotein thus constitutes the first example of a receptor mediating both platelet aggregation and leukocyte adhesion.
Burns
G F
GF
Cosgrove
L
L
Triglia
T
T
Beall
J A
JA
López
A F
AF
Werkmeister
J A
JA
Begley
C G
CG
Haddad
A P
AP
d'Apice
A J
AJ
Vadas
M A
MA
D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D002448:Cell Adhesion; D002648:Child; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D007962:Leukocytes / Q000166:cytology*; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface / Q000502:physiology*; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000378:metabolism; D013915:Thrombasthenia / Q000276:immunology / Q000473:pathology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D005353:Fibronectins; D007140:Immunoglobulin Fab Fragments; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic