Interferon Inhibits Prostaglandin E 2 Synthesis and Stimulates (2′-5′)Oligoadenylate Synthetase Activity in Peripheral Blood Mononuclear Cells of Inflammatory Bowel Disease Patients

The effect of interferon (IFN) on prostaglandin E₂ (PGE₂) synthesis by peripheral blood mononuclear cells of normal subjects and patients with inflammatory bowel disease was studied. Exposure of peripheral blood mononuclear cells, isolated from normal subjects and patients with active ulcerative colitis and Crohn's disease, to IFN reduced the release of PGE₂ in a dose-dependent manner. The inhibitory effect was observed for at least 24 h after the removal of IFN. To correlate the effect of IFN on PGE₂ synthesis with a known activity of IFN, the induction of (2′-5′)oligoadenylate synthetase (OAS) was also studied in the same mononuclear cells. Low basal levels of this enzyme were detected in mononuclear cells isolated from normal subjects and patients with active ulcerative colitis and Crohn's disease. Moreover, IFN treatment in vitro resulted in a similar induction of this enzyme in patients and controls. There results indicate that peripheral blood mononuclear cells of patients with active ulcerative colitis and Crohn's disease have normal response to IFN. In addition, our data do not suggest that IFN has an important role in the pathogenesis of these diseases.