The expression of Indoleamine 2, 3-dioxygenase (IDO) is reduced in granulomas from BCG vaccinated cattle compared to granulomas from unvaccinated controls after experimental challenge with Mycobacterium bovis

Authors Organisations
  • Waldo L. Garcia-Jimenez(Author)
    University of Surrey
  • Bernardo Villarreal-Ramos(Author)
    Animal and Plant Health Agency
  • Duncan Grainger(Author)
    University of Surrey
  • Glyn Hewinson(Author)
    Animal and Plant Health Agency
  • Hans M. Vordermeier(Author)
    Animal and Plant Health Agency
  • Francisco J. Salguero(Author)
    University of Surrey
    Animal and Plant Health Agency
Type Article
Original languageEnglish
Pages (from-to)52-56
Number of pages5
JournalVeterinary Immunology and Immunopathology
Early online date13 Aug 2018
Publication statusPublished - 01 Sep 2018
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Bovine tuberculosis (bTB), mainly caused by Mycobacterium bovis (M. bovis), is a major economic disease of livestock worldwide. Vaccination is considered as a potentially sustainable adjunct to the current control strategy. Cattle vaccination with the live attenuated M. bovis bacillus Calmette-Guerin (BCG) confers variable protection; the reasons for this variability are not understood. Indoleamine 2, 3-dioxygenase (IDO), through the catalysis of tryptophan, is thought to have an immunoregulatory role in the immune response to Mycobacterium tuberculosis (M. tuberculosis). In this work, we used immunohistochemistry and digital image analysis to evaluate the presence of IDO in granulomas at different stages of development in cattle that had been BCG-vaccinated or not and then challenged with M. bovis. Our results show that the expression of IDO in granulomas from non-vaccinated M. bovis challenged animals is higher than in granulomas from BCG-vaccinated M. bovis challenged animals. Thus, it is possible that vaccination with BCG prevents the induction of what are thought to be host immunosuppressive pathways by M. bovis, which contribute to pathology during the disease.


  • Bovine tuberculosis, IDO, Immunohistochemistry, Indoleamine 2,3-dioxygenase, Mycobacterium bovis