Isolation of Mycobacterium avium Subspecies paratuberculosis Reactive CD4 T Cells from Intestinal Biopsies of Crohn’s Disease Patients

Authors

Ingrid Olsen, National Veterinary Institute, Oslo & University of Oslo and Rikshospitalet University HospitalFollow
Stig Tollefsen, University of Oslo and Rikshospitalet University Hospital
Claus Aagaard, Statens Serum Institut, Copenhagen
Liv J. Reitan, National Veterinary Institute, Oslo
J. P. Bannantine, USDA-ARS, National Animal Disease CenterFollow
Peter Andersen, Statens Serum Institut, Copenhagen
Ludvig M. Sollid, University of Oslo and Rikshospitalet University Hospital
Knut E.A. Lundin, University of Oslo and Rikshospitalet University Hospital & Rikshospitalet University Hospital, Oslo

Date of this Version

2009

Citation

Olsen I, Tollefsen S, Aagaard C, Reitan LJ, Bannantine JP, et al. (2009) Isolation of Mycobacterium avium Subspecies paratuberculosis Reactive CD4 T Cells from Intestinal Biopsies of Crohn’s Disease Patients. PLoS ONE 4(5): e5641. doi:10.1371/journal.pone.0005641

Abstract

Background: Crohn’s disease (CD) is a chronic granulomatous inflammation of the intestine. The etiology is unknown, but an excessive immune response to bacteria in genetically susceptible individuals is probably involved. The response is characterized by a strong Th1/Th17 response, but the relative importance of the various bacteria is not known.

Methodology/Principal Findings: In an attempt to address this issue, we made T-cell lines from intestinal biopsies of patients with CD (n = 11), ulcerative colitis (UC) (n = 13) and controls (n = 10). The T-cell lines were tested for responses to various bacteria. A majority of the CD patients with active disease had a dominant response to Mycobacterium avium subspecies paratuberculosis (MAP). The T cells from CD patients also showed higher proliferation in response to MAP compared to UC patients (p,0.025). MAP reactive CD4 T-cell clones (n = 28) were isolated from four CD patients. The T-cell clones produced IL-17 and/or IFN-c, while minimal amounts of IL-4 were detected. To further characterize the specificity, the responses to antigen preparations from different mycobacterial species were tested. One T-cell clone responded only to MAP and the very closely related M. avium subspecies avium (MAA) while another responded to MAP, MAA and Mycobacterium intracellulare. A more broadly reactive T-cell clone reacted to MAP1508 which belongs to the esx protein family.

Conclusions/Significance: The presence of MAP reactive T cells with a Th1 or Th1/Th17 phenotype may suggest a possible role of mycobacteria in the inflammation seen in CD. The isolation of intestinal T cells followed by characterization of their specificity is a valuable tool to study the relative importance of different bacteria in CD.