Involvement of p38-mitogen-activated protein kinase in staphylococcus aureus-induced neutrophil apoptosis
2001 (English)In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 70, no 4, 642-648 p.Article in journal (Refereed) Published
Apoptosis occurred in human neutrophils within an hour of exposure to viable serumopsonized Staphylococcus aureus, as indicated by appearance of cells with condensed nuclei, fragmented DNA, and increased phosphatidylserine exposure. In contrast, serum-opsomized, heat-killed S. aureus did not induce apoptosis. This discrepancy could not be explained by differences in bacterial uptake or total NADPH-oxidase activity. Suppressing phagocytosis by pretreating the neutrophils with cytochalasin b or by using nonopsonized bacteria did not prevent apoptosis. A supernatant from bacteria grown for 2 h in nutrient broth had a strong proapoptotic influence that was abrogated by heat treatment. Exposure to viable S. aureus or supernatant also led to activation of p38-mitogen-activated protein kinase in the neutrophils. Inhibition of this kinase with SB203580 reduced the apoptosis-inducing capacity of both bacteria and supernatant. We conclude that S. aureus activates p38-mitogen-activated protein kinase in neutrophils and induces apoptosis, probably mediated by a bacteria-derived soluble factor(s).
Place, publisher, year, edition, pages
2001. Vol. 70, no 4, 642-648 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-27857Local ID: 12617OAI: oai:DiVA.org:liu-27857DiVA: diva2:248409