Mycobacterium avium subsp. paratuberculosis lipophilic antigen causes Crohn’s disease-type necrotizing colitis in Mice
1 Research Area of Pathology and Pathophysiology, National Institute of Animal Health, 3-1-5 Kan-nondai, Tsukuba, 305-0856, Japan
2 Department of Veterinary Pharmacology Graduate School of Agriculture and Life Sciences, the University of Tokyo, Tokyo, 113-8657, Japan
3 Laboratories of Immunology, School of Life and Environmental Science, Azabu University, Fuchinobe 1-17-71, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
4 Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, the University of Tennessee, Knoxville, Tennessee, 37996-1071, USA
5 Department of Pathology, the Jikei University School of Medicine, Minato-ku, Tokyo, Japan
SpringerPlus 2012, 1:47 doi:10.1186/2193-1801-1-47Published: 8 November 2012
Background: A 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced murine colitis model was developed to investigate the pathogenesis and to evaluate a method of treating human Crohn’s disease. This experimental model rapidly induces colitis similar to human Crohn’s disease lesion in a reproducible manner. However, natural exposure of the human digestive tract to TNBS is unrealistic. A novel animal model based on realistic data is eagerly anticipated in future research on pathogenesis of CD. Method: We evaluated the potency of Map antigen molecules in an effort to develop a novel colitis model using a more realistic source than TNBS. We prepared the Map antigen by ethanol extraction and developed a mouse model in a manner similar to that of the well-known TNBS-induced colitis in mice. In the experiment, seven days after subcutaneous (SC) injection of the antigen into normal C57BL/6 mice, the same antigen in 50% ethanol was injected into the colon by the transanal route with a fine cannula. Results: On the fifth day after the transanal injection, histopathological examination revealed full-thickness necrotizing colitis with erosion and ulcers; severe infiltration with neutrophils, lymphocytes, macrophages, and perforation. However, no change was detected with each single Map-antigen injection. Conclusion: The present results provide a novel animal model for research on CD and may be the key to clarifying the relationship between CD and Map. This is the first evidence that mycobacterium antigen induces necrotizing colitis.