| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Veterinary Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
Mycobacterium avium subsp. paratuberculosis is the causative agent of Johne's disease, a chronic granulomatous enteritis of wild and domestic ruminants. During a long subclinical period, the organism persists in the intestine despite systemic cellular and humoral immune responses. To explore the mucosal immune response in Johne's disease, we isolated mononuclear leukocytes from the ileum of cows naturally infected with M. avium subsp. paratuberculosis and from cows that were not infected. We evaluated the immunophenotype of these cells and the proliferative responses after the addition of M. avium subsp. paratuberculosis sonicate or B-cell or T-cell mitogens. Although the percentage of T cells was increased in infected cows, these cells consisted mostly of memory (CD2+CD62L) and regulatory (CD4+CD25+) T cells. Further evidence of immune hyporesponsiveness included a decrease in the percentage of T cells with an activated phenotype and a decrease in cells expressing major histocompatibility factor class II (MHC class II). Unlike the spleen, ileal lymphocytes from infected cows failed to proliferate in response to M. avium subsp. paratuberculosis sonicate. Additionally, ileal lymphocytes from infected cows proliferated poorly in response to concanavalin A and pokeweed mitogen, suggesting generalized T cell and B cell hyporesponsiveness. These results indicate that a state of tolerance may exist in the intestine of cows subclinically infected with M. avium subsp. paratuberculosis organisms in subclinically infected cows. This effect may be induced, at least in part, by proliferation of regulatory T cells that nonspecifically suppress mucosal immune responsiveness.
Key words: Bovine monocytes; Johne's disease; mucosal immunology; Mycobacterium avium subsp. paratuberculosis; regulatory T cells.
Request reprints from Dr. D J Weiss, University of Minnesota, 1971 Commonwealth Ave, St. Paul, MN 55108 (USA). E-mail: weiss005{at}umn.edu
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Facebook
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
D. J. Weiss and C. D. Souza REVIEW PAPER: Modulation of Mononuclear Phagocyte Function by Mycobacterium avium subsp. paratuberculosis Vet. Pathol., November 1, 2008; 45(6): 829 - 841. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Scanu, T. J. Bull, S. Cannas, J. D. Sanderson, L. A. Sechi, G. Dettori, S. Zanetti, and J. Hermon-Taylor Mycobacterium avium Subspecies paratuberculosis Infection in Cases of Irritable Bowel Syndrome and Comparison with Crohn's Disease and Johne's Disease: Common Neural and Immune Pathogenicities J. Clin. Microbiol., December 1, 2007; 45(12): 3883 - 3890. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-w. Wu, M. Livesey, S. K. Schmoller, E. J. B. Manning, H. Steinberg, W. C. Davis, M. J. Hamilton, and A. M. Talaat Invasion and Persistence of Mycobacterium avium subsp. paratuberculosis during Early Stages of Johne's Disease in Calves Infect. Immun., May 1, 2007; 75(5): 2110 - 2119. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |