Expression of tumor necrosis factor receptors on human monocytes and internalization of receptor bound ligand.

摘要: Tumor necrosis factor (TNF) is a polypeptide produced by monocytes and macrophages. Although TNF receptors have been identified on variety of cell types, previous studies not determined whether these also exist monocytes. In the present work, highly purified recombinant was labeled with 125I. The 125I-labeled bound specifically to human monocyte membrane preparations. A curvilinear Scatchard plot indicated presence TNF-binding sites two different affinities. results indicate that receptor-bound rapidly internalized then degraded intracellularly. These findings are in concert recent demonstrating immunomodulates function an autocrine mechanism.