Do viruses cause CD?

"D'oh! Genes and Environment Cause Crohn's Disease" in Cell (2010)Preview:  "Information obtained from genome-wide association studies has cracked open the biology of common chronic diseases by identifying genes that predispose individuals to these disorders. Cadwell et al., 2010 now demonstrate that a viral infection, a toxic insult to the gut, commensal bacteria, and a Crohn's disease susceptibility gene collude to cause inflammatory disease in the mouse gut."

"Virus-Plus-Susceptibility Gene Interaction Determines Crohn's Disease Gene Atg16L1 Phenotypes in Intestine" in Cell (2010)
Highlights:

• Mice with mutations in the Crohn's disease gene Atg16L1 display intestinal disease
• Disease requires murine norovirus (MNV) infection together with Atg16L1 mutation
• Viral triggering of disease is dependent on virus strain and timing of infection
• Disease in response to mucosal injury involves cytokines and commensal bacteria

"Crohn's disease: Genes, viruses and microbes" in Nature (2010)
Abstract:  "Variations in several genes can increase an individual's susceptibility to complex disorders. But what tips the balance to cause the full-blown disease? For Crohn's disease, viruses could provide part of the answer."