Cytokine gene deleted mice in the study of gastrointestinal inflammation

The major experimental and intellectual advance in gastroenterology in recent years has been the observation that mice with deletions in specific cytokine genes develop a spontaneous inflammatory bowel disease. Inflammatory bowel disease has also been seen in a number of other mouse strains with perturbed immune responses. The driving force for disease in a number of these models is the normal bacterial flora. These studies show that the gut immune system is in homeostasis with the antigens of the flora, but inappropriate T-helper 1 (Th1)-type responses to the flora cause severe gut injury and since the antigenic stimulus persists, the consequence is chronic inflammation.