Interferon Expression in Crohn's Disease Patients: Increased Interferon-γ and -α mRNA in the Intestinal Lamina Propria Mononuclear Cells

Abstract

The in vivo interferon (IFN) activation in Crohn's disease was evaluated by measuring the relative amounts of IFN-α and -γ mRNA in freshly isolated human lamina propria mononuclear cells (LPMC) from patients with Crohn's disease and controls. Both IFN-γ and IFN-α mRNA, as estimated by dot blot analysis, were increased in Crohn's disease (LPMC), although the relative amounts of IFN mRNA appeared to differ among patients. Appreciable amounts of IFN-γ mRNA were found in Crohn's disease peripheral blood mononuclear cells (PBMC) extracts, whereas the same cells were negative for IFN-α mRNA. Only minute amounts of IFN-γ RNA were found sporadically in control LPMC while no IFN-α was detected. Control PBMC were shown to be virtually negative for both IFN-α and IFN-γ mRNA. These data suggest that IFN induction in the normal human gut is a well-controlled function and that in Crohn's disease tissues, both IFN-γ and IFN-α production are dysregulated. The increased IFN activity may represent a major feature in the induction and perpetuation of the chronic inflammatory process in Crohn's disease.