Induction and persistence of Mycobacterium avium in myeloid derived suppressor cells
Final Report Abstract
Alongside Mycobacterium bovis, M. avium is probably the most important mycobacterial species with veterinary relevance. It has long been known that strains of the subspecies Mycobacterium avium subsp. avium (MAA) are more virulent in mice after infection than Mycobacterium avium subsp. hominissuis (MAH) or Mycobacterium avium subsp. paratuberculosis strains. Our own studies show that the formation of MAA harboring, nitric oxide (NO) producing, monocyte myeloid-derived suppressor cells (mMDSC) contributed to increased virulence of MAA. These cells influence the immune response of the mouse and contribute to the worsening of the course of infection. The aim of the proposed project was to determine how the formation of mMDSCs and the survival of MAA in mMDSCs occur. The project results show that not all mMDSC populations have uniform effects on mouse immunity. Crucial for the growth and immunosuppression of MAA44156 in mice seems to be an early availability of NO during the infection process, which is favorable for the proliferation of MAA44156. Infections of mice with different M. avium strains showed that induction of mMDSC and persistence of M. avium in them is not a virulence property of a subspecies. Virulent strains can adapt metabolically to an anaerobic environment in the mouse and efficiently combat stress through radical nitrogen species (RNS). It is possible that the RNS stress tolerance of M. avium increases virulence - induction and persistence in suppressor cells - but that tolerance is achieved in different strains by different ways.
Publications
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“Induction and persistence of Mycobacterium avium in myeloid-derived suppressor cells”. 75th Annual Meeting of the German Society for Hygiene and Microbiology (DGHM), 18-20 September 2023, Lübeck, Germany.
Sisay Girma Worku, Katrin Ehrhardt, Maren Schenke, Andreas Beineke, Guntram Grassl & Ralph Goethe
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“Induction and persistence of Mycobacterium avium in myeloid-derived suppressor cells in the mouse model”. 7th Joint Microbiology & Infection Conference of the German Society for Hygiene and Microbiology (DGHM) and the Association for General and Applied Microbiology (VAAM) from 02–05 June 2024 in Würzburg, Germany.
Sisay Girma Worku, Andreas Pich, Stefan Lienenklaus, Elke Goethe, Andreas Beineke, Guntram Grassl & Ralph Goethe
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“Induction and persistence of Mycobacterium avium in myeloid-derived suppressor cells”. American Society for Microbiology (ASM) 2024 Conference in Atlanta, Georgia, USA, from June 13-17
Sisay Girma Worku, Andreas Pich, Stefan Lienenklaus, Elke Goethe, Andreas Beineke, Guntram Grassl & Ralph Goethe
