Induction of autoimmune colitis by Yersinia enterocolitica 60-kilodalton heat-shock protein

Many investigations of the relationship between ulcerative colitis (UC) and heat-shock protein (Hsp) 60 have been reported. We have already established an animal model exhibiting UC-like lesions caused by administration of Escherichia coli expressing Yersinia enterocolitica Hsp60. In this study, we therefore attempted to induce mouse colitis by purified Y. enterocolitica Hsp60.

Purified Y. enterocolitica Hsp60 was injected intraperitoneally into B10A/SgSn mice at a dose of 3 microg/0.2 ml once a week for 2 months, and morphological changes in the intestine were examined by light and electron microscopical analysis. Autoimmune responses were also examined.

The mice treated with Y. enterocolitica Hsp60 exhibited immune reaction between large intestine and autologous serum. Light and electron microscopically, degradation of glandular ducts, erosions, ulceration, crypt abscess-like formation, infiltration of inflammatory cells and absence of perivascular reticular fibers in lamina propria mucosae and subepithelial reticular layer were observed.

These findings indicate that administration of Y. enterocolitica Hsp60 induces UC-like lesions with autoimmune responses.