Role of CD40 and B7 costimulators in inflammatory bowel diseases.

We analyse the costimulating role of CD40/CD40 ligand and B7/CD28 in inflammatory bowel diseases (IBD) as a potential target of antibody therapy. CD40, expressed by lamina propria B lymphocytes in gut mucosa, interacts with CD40 ligand on T cell. This interaction is implicated in the pathogenesis of IBD. In some animal models of colitis the anti-CD40L therapy demonstrated to be effective. Phase II trials on Crohn's disease are ongoing. B7.1 and B7.2, expressed by macrophages, interact with CD28, on T cell. B7.2 resulted implicated in ulcerative colitis, determining a Th2 pattern, whereas B7.1, a major Th1 stimulator, could be involved in Crohn's disease. In some animal models of colitis anti-B7.1, but not anti-B7.2, was effective. Anti B7 therapy was not yet tested in humans.