Chemokines in the inflammatory bowel diseases

Ulcerative colitis and Crohn's disease are characterized by chronic intesti nal inflammation. Intestinal bacteria initiate the activation of intestinal inflammatory processes, which are mediated by proinflammatory cytokines an d chemokines. In inflammatory bowel disease, intestinal inflammation is not downregulated, in part due to defective or absent inhibitory processes. St udies to date have demonstrated that IL-8, MCP-1, and ENA-78 are highly exp ressed in the intestinal mucosa in areas of active Crohn's disease and ulce rative colitis. Neutrophils and macrophages in the inflamed intestine synth esize and secrete large amounts of chemokines in patients with inflammatory bowel disease. Increased chemokine expression has also been observed in ep ithelial cells, endothelial cells, and smooth muscle cells. Future trials o f specific agents capable of inhibiting chemokine synthesis and secretion o r blocking chemokine-chemokine receptor interaction will be important to st udy in patients with ulcerative colitis and Crohn's disease.