Induction of Colitis by a CD4+T Cell Clone Specific for a Bacterial Epitope
It is now well established that the intestinal flora plays an important role in the pathogenesis of inflammatory bowel disease (IBD). However, whether bacteria serve as the sole target of the immune response in this process or whether they act indirectly by triggering an anti-self response is still...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 100; no. 26; pp. 15830 - 15835 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
23.12.2003
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | It is now well established that the intestinal flora plays an important role in the pathogenesis of inflammatory bowel disease (IBD). However, whether bacteria serve as the sole target of the immune response in this process or whether they act indirectly by triggering an anti-self response is still unclear. We have previously shown that specific pathogen-free IL-10-deficient (IL-10 KO) mice develop a T helper (Th1)-cytokine associated colitis after experimental infection with Helicobacter hepaticus. We here show that H. hepaticus Ag (SHelAg)-specific CD4+Th1 clones transfer disease to H. hepaticus-infected T cell-deficient RAG KO hosts. Importantly, uninfected recipients of the SHeIAg-specific clones did not develop intestinal inflammation, and a control Schistosoma mansoni-specific Th1 clone did not induce colitis upon transfer to infected RAG KO mice. The disease-inducing T cell clones recognized antigen(s) (Ag) specifically expressed by certain Helicobacter species as they responded when stimulated in vitro with H. hepaticus and Helicobacter typhlonius Ag, but not when cultured with Ag preparations from Helicobacter pylori, various non-helicobacter bacteria, or with cecal bacterial lysate from uninfected mice. Characterization of the Ag specificity of one of the clones showed that it reacts uniquely with a 15-mer peptide epitope on the flagellar hook protein (FlgE) of H. hepaticus presented by I-Ab. Together, our results demonstrate that colitis can be induced by clonal T cell populations that are highly specific for target Ag on intestinal bacteria, suggesting that an aberrant T cell response directed against gut flora is sufficient to trigger IBD. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AJ583505). Present address: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, D-30625 Hannover, Germany. This paper was submitted directly (Track II) to the PNAS office. Edited by Howard M. Grey, La Jolla Institute for Allergy and Immunology, San Diego, CA Abbreviations: Ag, antigen; FlgE, flagellar hook protein; IBD, inflammatory bowel disease; OMP, outer membrane protein; SHelAg, soluble Helicobacter hepaticus Ag; Treg, T regulatory cell; KO, knockout; Th1, T helper 1; TCR, T cell receptor; CBL, cecal bacterial lysate. To whom correspondence should be addressed. E-mail: mkullberg@niaid.nih.gov. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.2534546100 |