Listerial species escape from the phagosomes of interleukin-4-deactivated human macrophages independent of listeriolysin

K. Neumann, E. Eppler, Luis Filgueira, P. Groscurth, E. Gasal, A. Schaffner, G. Schoedon, M. Schneemann

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)


    Listeria monocytogenes is the causative agent of infections like sepsis and meningitis, especially in immunocompromised hosts. Human macrophages are able to phagocytose and digest L. monocytogenes but IL-4 prevents human macrophages from killing the bacteria, the mechanisms of which are unknown. In the present study, we examined various listeria species and strains including wild-type and deletion mutants in human macrophages pretreated with IL-4. To analyse the IL-4-mediated deactivation process, we combined quantitative infection assays with various morphologic methods. IL-4 facilitates survival and escape of the pathogenic L. monocytogenes wild-type strain 10403S from the macrophage phagosomes. In untreated macrophages, the isogenic listeriolysin deletion mutant strain DP-L2161 was killed and did not escape from the phagolysosomes. However, after macrophage deactivation with IL-4 DP-L2161 survived and escaped from the phagosomes. This was also the case, but to a lesser extent, even for the naturally avirulent L. innocua. As detected by confocal laser-scanning fluorescence microscopy and electron microscopy, IL-4 permitted the escape of all listeria species tested, including DP-L2161 and L. innocua from the phagosomal compartment of the macrophages. We conclude that escape from the phagosome and survival of the listeria species tested in IL-4-deactivated human macrophages is independent of the virulence factor listeriolysin.
    Original languageEnglish
    Pages (from-to)431-439
    JournalImmunology and Cell Biology
    Publication statusPublished - 2003


    Dive into the research topics of 'Listerial species escape from the phagosomes of interleukin-4-deactivated human macrophages independent of listeriolysin'. Together they form a unique fingerprint.

    Cite this