This study will measure the immunologic and clinical effect of twelve weeks of treatment with a type I interferon administered to patients with active UC. The primary outcomes include documenting changes in immune parameters by measuring peripheral and lamina propria mononuclear cell cytokine release, expression levels of SOCS proteins in mononuclear cells, and changes in clinical parameters using the Short Clinical Colitis Activity Index and endoscopic and histologic scores. Secondary endpoints include the rate and severity of adverse events. Our short-term goal is to correlate changes in immune and biochemical parameters that accompany or predict clinical responses. The long-term goal of this study is to establish type I interferons as an effective alternative or adjunctive therapy with a low risk profile for the treatment of ulcerative colitis.