Activated platelets express IL-1 activity.
Suspensions of washed human platelets express IL-1 activity after activation with agents such as thrombin, collagen, ADP, or epinephrine as judged by the ability of the platelet suspensions to support the growth of a T cell line, D10.G4.1, which exhibits a growth requirement for IL-1. Unactivated platelets express little IL-1 activity. The IL-1 activity expressed by activated platelets appears to be entirely associated with the platelet surface. No IL-1 activity was detected in supernatants derived from suspensions of activated platelets. A mAb specific for IL-1 beta inhibited 90% of the activity expressed by thrombin-activated platelets, whereas a mAb specific for IL-1 alpha inhibited approximately 20% of the activity. A control mAb was without an effect. These results indicate that activated platelets express surface-associated IL-1 activity. Platelet surface IL-1 may provide a mechanism for altering in an extremely localized and rapid manner the properties of IL-1 responsive cells with which platelets come in direct contact during processes of inflammation and vessel wall damage.
Hawrylowicz
C M
CM
Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110.
Santoro
S A
SA
Platt
F M
FM
Unanue
E R
ER
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000918:Antibody Specificity; D001792:Blood Platelets / Q000032:analysis / Q000276:immunology*; D002460:Cell Line; D003594:Cytoplasmic Granules / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation; D051379:Mice; D015539:Platelet Activation; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D007375:Interleukin-1