Type II interleukin-1 receptor is not expressed in cultured endothelial cells and is not involved in endothelial cell activation.
Interleukin-1 (IL-1) profoundly affects a number of functions of endothelial cells (EC). It was previously shown that EC express the type I 80-Kd IL-1 receptor (IL-1 RI). In this study we define the expression and functional significance of the type II IL-1R (IL-1 RII) in EC. Human umbilical vein EC did not express appreciable levels of IL-1 RII mRNA as assessed by Northern analysis or reverse transcription and polymerase chain reaction. Exposure to various cytokines (including IL-4, which augments IL-1 RII in neutrophils) failed to induce IL-1 RII mRNA. The binding of radiolabeled IL-1 beta to EC was blocked by antitype I (M4) but not by antitype II (M22) monoclonal antibodies (MoAbs). MoAbs directed against the IL-1 RI (M1 and M4) inhibited the induction of IL-6 and adhesion molecules in EC by IL-1, whereas an anti-IL-1 RII (M22) was inactive. The human IL-1 receptor antagonist (IL-1ra) preferentially interacts with IL-1 RI versus IL-1 RII in the mouse. IL-1 ra inhibited the response of mouse endothelial cells to IL-1. We conclude that EC selectively express the IL-1 RI and that this is involved in the response of this cell type to IL-1.
Colotta
F
F
Centro Daniela e Catullo Borgomainerio, Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy.
Sironi
M
M
Borrè
A
A
Pollicino
T
T
Bernasconi
S
S
Boraschi
D
D
Mantovani
A
A
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000737:chemistry* / Q000166:cytology / Q000502:physiology; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D017472:Receptors, Interleukin-1 / Q000032:analysis* / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal; D016207:Cytokines; D007375:Interleukin-1; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1