Experimental mouse models of T cell-dependent inflammatory bowel disease.

Inflammatory bowel diseases (IBD) represent idiopathic chronic inflammatory disorders of the intestinal tract that are associated with aberrant immune responses against intestinal bacteria. Here, we describe two T cell-dependent models of experimental murine IBD. In the "T cell transfer" model, lymphopenic (scid or Rag (-/-) ) mice develop colitis upon adoptive transfer of naïve CD4(+) T cells. This model has also been extensively employed to identify mechanisms through which CD4(+)CD25(+) regulatory T cells suppress intestinal inflammation in vivo. We also describe a model of T cell-dependent IBD in immunocompetent mice, induced by infection with the intestinal bacterium Helicobacter hepaticus and concomitant treatment with a blocking αIL-10R mAb, which leads to the development of chronic inflammation of the caecum and colon (typhlocolitis). Both models reproduce many facets of human IBD pathology, including epithelial hyperplasia, goblet cell depletion, and leukocyte infiltration. These models provide reliable and tractable systems for the analyses of the induction and regulation of chronic inflammation in the gut.