Production of Granulocyte/Macrophage and Macrophage Colony-Stimulating Factors by Human Thyrocytes in Culture

Monocytes/macrophages can be activated by the colony-stimulating factors (CSFs), granulocyte/macrophage CSF and macrophage CSF, and play a pivotal role in immune and inflammatory responses. We examined whether human thyrocytes can produce these CSFs. Interleukin-1 (IL-1) strongly up-regulated the gene and protein expression of the two CSFs. Interferon-γ stimulated M-CSF expression but inversely suppressed GM-CSF expression in either basal or IL-1-stimulated condition. Thyrocytes prepared from Graves’ thyroid tissues produced relatively larger amounts of GM-CSF in response to IL-1 and M-CSF in both basal and IL-1-stimulated conditions when compared to those obtained from normal and adenomatous goiter thyroid tissues. Thyrotropin attenuated M-CSF, but not GM-CSF, production. The present finding indicates that human thyrocytes themselves produce both GM-CSF and M-CSF, and thus may participate in immune and inflammatory responses through these CSFs production.