Frontline: Interferon regulatory factor-1 as a protective gene in intestinal inflammation: role of TCRγ δ T cells and interleukin-18-binding protein

The transcription factor IFN regulatory factor-1 (IRF-1) regulates production and activity of many inflammatory mediators and cells. Here, we investigated the role of IRF-1 in intestinal inflammation using clinical and histologic scores; inflammatory mediators were also measured in colonic tissue. Dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) was administered to wild-type (WT) or IRF-1 knockout (KO) mice. DSS or TNBS led to a dramatic increase in lethality and colitis severity in IRF-1 KO compared with WT mice. Reduced levels of IFN-γ and IL-18-binding protein (IL-18BP) were observed in the colon of IRF-1 KO mice, whereas levels of inducible nitric oxide synthase, cyc…