Role of phorbol ester receptors in the 12-0-tetradecanoyl-phorbol-13-acetate (TPA)-induced down-regulation of colony-stimulating factor (CSF-1) binding to murine peritoneal exudate macrophages

✍ Scribed by Ben D.-M. Chen; Kimberly L. Wilkins

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 915 KB
• Volume: 124
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041240221

✦ Synopsis

Treatment of murine peritoneal exudate macrophages (PEM) by tumor-prornoting phorbol esters (TPA) results in a rapid loss of binding activity to radioactive-labeled colony-stimulating factor ([1251]-CSF-1) on the cell surface. The inhibitory effect of TPA on PEM i s transient; treated cells recover full [1251]-CSF-1 binding activity in less than 6 hr at 37OC either in the presence or after the removal of added TPA. The role of phorbol ester receptors in the induction of [1251]-CSF-1 binding inhibition was studied. The biologically active ligand [3H]-phorbol 12,13-dibutyrate (t3H]-PDBu) bound specifically to cultured murine PEM. At OOC, stable and equilibrium binding occurred after 2-3 hr. Scatchard analysis revealed linear plots with a dissociation constant and receptor number per cell of 20.9 n M and 3.9 x 105/cell, respectively. Treatment of PEM with biolo ically active phorbol esters at 37OC rapidly inhibited