Of mice and men: Interaction of Corynebacterium diphtheriae strains with murine and human phagocytes

Journal article

Publication Details

Author(s): Weerasekera D, Fastner TA, Lang R, Burkovski A, Ott L
Journal: Virulence
Publication year: 2019
Volume: 10
Journal issue: 1
Pages range: 414-428
ISSN: 2150-5594
eISSN: 2150-5608


Seven non-toxigenic C. diphtheriae strains and one toxigenic strain were analyzed with regard to their interaction with murine macrophages (BMM) and human THP-1 macrophage-like cells. Proliferation assays with BMM and THP-1 revealed similar intracellular CFUs for C. diphtheriae strains independent of the host cell. Strain ISS4060 showed highest intracellular CFUs, while the toxigenic DSM43989 was almost not detectable. This result was confirmed by TLR 9 reporter assays, showing a low signal for DSM43989, indicating that the bacteria are not endocytosed. In contrast, the non-pathogenic C. glutamicum showed almost no intracellular CFUs independent of the host cell, but was recognized by TLR9, indicating that the bacteria were degraded immediately after endocytosis. In terms of G-CSF and IL-6 production, no significant differences between BMM and THP-1 were observed. G-CSF production was considerably higher than IL-6 for all C. diphtheriae strains and the C. glutamicum did not induce high cytokine secretion in general. Furthermore, all corynebacteria investigated in this study were able to induce NFκB signaling but only viable C. diphtheriae strains were able to cause host cell damage, whereas C. glutamicum did not. The absence of Mincle resulted in reduced G-CSF production, while no influence on the uptake of the bacteria was observed. In contrast, when MyD88 was absent, both the uptake of the bacteria and cytokine production were blocked. Consequently, phagocytosis only occurs when the TLR/MyD88 pathway is functional, which was also supported by showing that all corynebacteria used in this study interact with human TLR2.

FAU Authors / FAU Editors

Burkovski, Andreas Prof. Dr.
Professur für Mikrobiologie
Fastner, Tamara Antonia
Professur für Mikrobiologie
Lang, Roland Prof. Dr.
Professur für Angeborene Immunität und Pathogenerkennung
Weerasekera, Dulanthi
Professur für Mikrobiologie

How to cite

Weerasekera, D., Fastner, T.A., Lang, R., Burkovski, A., & Ott, L. (2019). Of mice and men: Interaction of Corynebacterium diphtheriae strains with murine and human phagocytes. Virulence, 10(1), 414-428. https://dx.doi.org/10.1080/21505594.2019.1614384

Weerasekera, Dulanthi, et al. "Of mice and men: Interaction of Corynebacterium diphtheriae strains with murine and human phagocytes." Virulence 10.1 (2019): 414-428.


Last updated on 2019-22-07 at 07:30