Increased secretion of granulocyte-macrophage colony-stimulating factor in mucosal lesions of inflammatory bowel disease

Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-3 transmit a same signal needed for growth and activation in granulocytes and macrophages, because these receptors utilize a common beta chain. Little is known about growth factors for intestinal myeloid cells in lesions of inflammatory bowel disease (IBD). Aim: To find out whether GMCSF is produced by the intestinal cells in IBD patients and controls. Methods: We measured levels of GM-CSF, tumor necrosis factor (TNF), and IL-3 in the media of organ culture and lamina propria mononuclear cells (LPM Cs) cu Itu re of colonic mucosa from the patients with IBD. Next, we have investigated GM-CSF production of colonic epithelial cell lines. Results: Spontaneous secretion of GM-CSF was increased in inflamed mucosa, while secretion of IL-3 was not detected. Release of GM-CSF was enhanced in LPMCs from inflamed mucosa. Mucosal GM-CSF production was correlated to TNF-alpha production. Colonic epithelia[ cell line and T cell produced GMCSF with superantigen stimulation. Conclusion: We revealed pivotal production of GM-CSF but not IL-3 in intestinal lesion of IBD. Increased secretion of GM-CSF might lead to chronic gut inflammation. Copyright (C) 2001 S. Karger AG, Basel.