Abrogated lymphocyte infiltration and lowered CD14 in dextran sulfate induced colitis in mice treated with p65 antisense oligonucleotides

Background and aims: Dextran sulfate sodium (DSS) induced colitis exhibits a predominantly NF-kappaB dependent proinflammatory cytokine profile and shares similarities with human inflammatory bowel disease (IBD). Lamina propria macrophages of IBD patients display elevated levels of NF-kappaB p65. Knowing the role of NF-kappaB in IBD, we investigated the beneficial cellular mechanisms underlying the lasting effect of a single p65 antisense treatment in DSS-colitis mice. Methods: One local dose of p65 antisense oligonucleotides was administered in DSS colitis mice. Ten days later the mice were killed and examined at cellular and biochemical levels. The level of p65 in lamina propria cells was determined by electrophoretic mobility shift assay and by intracellular immunofluorescent staining of nuclear p65 levels, using laser scanning cytometer. Results: FACS analysis demonstrated a considerable drop in infiltrating lymphocytes and a drastic reduction in CD14+ cells in mice treated with p65 antisense oligonucleotides. Moreover, abrogation of inflammation extended all the way to the cecum in treated mice. Treatment was correlated with decreased DNA binding activity of NF-kappaB. Conclusions: Our data strongly support a model in which p65 antisense treatment possesses the capacity to disrupt the pathogenic autocrine loop propagated by NF-kappaB at the chronic phase of IBD.