Identification of a specific receptor for interleukin-1 in vascular smooth muscle cells: regulation by interleukin-1 and interleukin-6

Abstract A flourescently labeled ligand was utilized to establish the existence of an interleukin-1 (IL-1) receptor in vascular smooth muscle. The binding of the phycoerythrin-labeled IL-1β to the murine T cell line, EL-4, was examined as a positive control. The phycoerythrin-labeled IL-1β identified a specific IL-1 receptor in the EL-4 cells. Vascular smooth muscle cells were also positively stained by the fluorescent ligand. The binding of phycoerythrin-labeled IL-1β to these cells was saturable and reversed by 100-fold excess unlabeled IL-1β. Incubation of the vascular smooth muscle cells positively with IL-gb (25 ng/ml) or IL-6 (250 ng/ml) for 18 h increased and decreased, respectively, the percentage of cells positively stained by phycoerythrin-labeled IL-1β which suggest these cytokines regulate IL-1 receptor expression in these cells. These data indicate a specific receptor for IL-1 exists in vascular smooth muscle cells.