Presence of High Affinity Receptor for Interleukin-1 (IL-1) on Cultured Porcine Thyroid Cells

Summary

Using ¹²⁵I-interleukin-1β (¹²⁵I-IL-1β) as a ligand, a specific receptor of high affinity dissociation constant (1.1 ± 0.2 × 10^-10 M) with binding sites (350 ± 40/cell) for interleukin-1β (IL-1β) has been demonstrated on cultured porcine thyroid cells. IL-1α Almost equally cross-reacted with the receptor (Kd = 1.2 ± 0.3 × 10^-10 M and 350 ± 50 binding sites/cell). TSH, IL-2 and other peptide hormones did not inhibit the binding of ¹²⁵I-IL-1β to thyroid cells.

Crosslinking study revealed a major band (∼ 95 kD) with a corrected molecular mass of ∼ 78 kD. Moreover, both IL-1β and IL-1α stimulated prostaglandin E₂ production of cultured porcine thyroid cells, although the potency of IL-1α was slightly greater than that of IL-1β. These results suggest that IL-1 may be involved in the regulation of thyroid cell function.

Key words

Interleukin-1 - Receptor - Thyroid cells - Prostaglandin E₂