Regulatory T cells in cattle and their potential role in bovine paratuberculosis

• Published in: Comparative immunology, microbiology and infectious diseases Vol. 35; no. 3; pp. 233 - 239
• Main Authors: Coussens, Paul M., Sipkovsky, Sue, Murphy, Brooke, Roussey, Jon, Colvin, Christopher J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2012
• Subjects: Allergy and Immunology; Animals; antigens; Antigens, Bacterial - immunology; bacteria; blood serum; Bovine leukemia virus; Bovine leukosis; cattle; Cattle - immunology; Cattle - microbiology; Cattle - virology; Cattle Diseases - immunology; Cattle Diseases - microbiology; CD25 antigen; CD4 antigen; CD4-positive T-lymphocytes; Coinfection; Data processing; Effector cells; Enteritis; Enzootic Bovine Leukosis - pathology; Enzootic Bovine Leukosis - virology; Foxp3; gamma -Interferon; Immunity, Cellular; Immunoglobulin G; Immunoregulation; Infectious Disease; Inflammation; interferon-gamma; Interferon-gamma - immunology; Interleukin 10; Interleukin-10 - immunology; Intestine; intestines; Johne's disease; Leukemia Virus, Bovine - immunology; Leukemia Virus, Bovine - pathogenicity; Lymph Nodes - microbiology; Lymph Nodes - pathology; Lymphocytes T; Macrophages; Macrophages - immunology; Macrophages - microbiology; Monocytes; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Mycobacterium avium subsp. paratuberculosis - immunology; Mycobacterium avium subsp. paratuberculosis - pathogenicity; neutralization; Paratuberculosis; Paratuberculosis - immunology; Paratuberculosis - microbiology; Paratuberculosis - pathology; Regulatory T cells; Reviews; Ruminantia; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - microbiology; Regulatory T cells; Foxp3; Paratuberculosis; Bovine leukemia virus; Johne's disease
• ISSN: 0147-9571; 1878-1667; 1878-1667
• DOI: 10.1016/j.cimid.2012.01.004

The intracellular bacterium Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne's disease in wild and domestic ruminants. Johne's disease presents as a chronic enteritis with severe inflammation of intestinal tissues, characterized by widespread infiltration of macrophages, the target cell of MAP. Clinical signs of Johne's disease are typically accompanied by a loss of peripheral CD4+ T cell responses to MAP antigens and an increase in anti-MAP serum IgG levels. Recently, it was proposed that regulatory T cells might develop over the lengthy course of subclinical MAP infection. In the past five years, significant progress in defining bovine regulatory T cells has been made. These studies grew out of observations that IL-10 is produced by PBMCs in response to MAP antigen stimulation and that neutralization of this IL-10 could enhance IFN-γ production from MAP-antigen reactive effector T cells. Depletion studies revealed that MAP responsive cell populations producing IL-10 were largely CD4+ and CD25+, although monocytes have also been shown to produce IL-10 in response to MAP. In addition, evidence for a regulatory population of γδ T cells has also begun to accumulate. We summarize current thinking regarding regulatory T cells in MAP infection and provide data suggesting a potential link between regulatory T cells, bovine leukemia virus, and MAP.