Role of bacterial intimin in colonic hyperplasia and inflammation

L M Higgins1, G Frankel, I Connerton

  • 1Department of Paediatric Gastroenterology, St. Bartholomews and the Royal London School of Medicine and Dentistry, London EC1A 7BE, UK.

Science (New York, N.Y.)
|July 27, 1999
PubMed

Enteropathogenic Escherichia coli (EPEC) cells adhere to gut epithelial cells through intimin alpha: the ligand for a bacterially derived epithelial transmembrane protein called the translocated intimin receptor. Citrobacter rodentium colonizes the mouse colon in a similar fashion and uses a different intimin: intimin beta. Intimin alpha was found to costimulate submitogenic signals through the T cell receptor. Dead intimin beta+ C. rodentium, intimin alpha-transfected C. rodentium or E. coli strain K12, and EPEC induced mucosal hyperplasia identical to that caused by C. rodentium live infection, as well as a massive T helper cell-type 1 immune response in the colonic mucosa. Mutation of cysteine-937 of intimin to alanine reduced costimulatory activity in vitro and prevented immunopathology in vivo. The mucosal changes elicited by C. rodentium were interferon-gamma-dependent. Immunopathology induced by intimin enables the bacteria to promote conditions that are favorable for increased microbial colonization.

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