Studies on the murine interleukin-1 receptor.

The multiple biological actions of interleukin-1 (IL-1) on its diverse range of target tissues is consequent upon interaction of the cytokine with specific, high affinity cell surface receptors. In this report we describe the covalent crosslinking of natural porcine IL-1 and recombinant human IL-1 to intact cells of the murine EL-4 6.1 [NOB-1] thymoma subline, and the solubilization of functional receptors from these cells. Crosslinking studies revealed the existence of two polypeptides, of 100 Kda and 80 Kda, which are involved in IL-1 recognition. Chromatographic studies and ligand-blotting of the soluble receptor demonstrated that the smaller of these two polypeptides, which appears to be a glycoprotein, is capable of interaction with both forms of IL-1.