Endothelial cells as a target for antiphospholipid antibodies: role of anti-beta 2 glycoprotein I antibodies.
OBJECTIVE
To investigate the role of the plasma cofactor for antiphospholipid antibodies in antibody binding to endothelial cells.


METHODS
a) Evaluation of endothelial cell binding of polyclonal and monoclonal anti-beta 2 glycoprotein I antibodies; and b) study of the effects of antibody binding: adhesion molecule expression, leukocyte adhesion, and interleukin-1 beta secretion.


RESULTS
Anti-beta 2 glycoprotein I antibodies bind endothelial cell monolayers in vitro by reacting with the cofactor adhered to the cell membranes. Antibody binding induces an up-regulation of adhesion molecules, favours leukocyte adherence, and increases interleukin-1 beta secretion. Interleukin-1 beta plays an active role to mediate adhesion molecule expression through an autocrine loop, as shown by the inhibitory effect of interleukin 1 receptor antagonist.


CONCLUSIONS
Antiphospholipid antibodies do react with endothelium through the co-factor adhered to their cell membranes and induces a pro-adhesive cell phenotype.
Del Papa
N
N
Istituto di Medicina Interna, Malattie Infettive & Immunopatologia, IRCCS Policlinico, University of Milan, Italy.
Raschi
E
E
Catelli
L
L
Khamashta
M A
MA
Ichikawa
K
K
Tincani
A
A
Balestrieri
G
G
Meroni
P L
PL
D000818:Animals; D017152:Antibodies, Antiphospholipid / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000209:etiology / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D001777:Blood Coagulation / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D013927:Thrombosis / Q000209:etiology / Q000276:immunology; D053482:beta 2-Glycoprotein I
D017152:Antibodies, Antiphospholipid; D001323:Autoantibodies; D015815:Cell Adhesion Molecules; D006023:Glycoproteins; D053482:beta 2-Glycoprotein I