An American team has developed a new ileal CD model by infecting Nod2-deficient mice with Helicobacter hepaticus. These mice present granulomatous inflammation of the ileum similar to that observed during the course of CD. Nod2 is the most well known of the genes that predispose to CD. It is believed to be responsible for a defect in antimicrobial peptide synthesis by Paneth cells in the small intestinal crypts. This study also demonstrates that it is possible to suppress the observed phenotype by restoring secretion of a-defensin5 (an antimicrobial peptide) by the Paneth cells of these mice.

This model enables a more accurate characterization of ileal CD via localization of the inflammation, the presence of granulomas in the intestinal mucosa and the interaction of the mucosal immune system with flora of the digestive tract.

Reference:

Biswas A., Liu Y., Hao L., Mizoguchi A., Salzman N., Bevins C., and Kobayachi K. Induction and rescue of Nod2-dependent Th1-driven granulomatous inflammation of the ileum, Proc. Natl. Acad. Sci. , 2010 Aug 17, 107(33):14739-44.