Apoptotic neutrophils containing Staphylococcus epidermidis stimulate macrophages to release the proinflammatory cytokines tumor necrosis factor-α and interleukin-6Visa övriga samt affilieringar
2008 (Engelska)Ingår i: FEMS Immunology and Medical Microbiology, ISSN 0928-8244, E-ISSN 1574-695X, Vol. 53, nr 1, s. 126-135Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
Staphylococcus epidermidis infections are usually nosocomial and involve colonization of biomaterials. The immune defense system cannot efficiently control the bacteria during these infections, which often results in protracted chronic inflammation, in which a key event is disturbed removal of neutrophils by tissue macrophages. While ingesting uninfected apoptotic neutrophils, macrophages release anti-inflammatory cytokines that lead to resolution of inflammation. In clinical studies, we have previously found elevated levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in synovial fluid from prostheses infected with coagulase negative staphylococci. We show that macrophages phagocytosing apoptotic neutrophils containing S. epidermidis released TNF-alpha and interleukin-6, whereas macrophages phagocytosing spontaneously apoptotic neutrophils did not. This difference was not due to dissimilar phagocytic capacities, because macrophages ingested both types of neutrophils to the same extent. The activation was induced mainly by the apoptotic neutrophils themselves, not by the few remaining extracellular bacteria. Macrophages were not activated by apoptotic neutrophils that contained paraformaldehyde-killed S. epidermidis. Proinflammatory reactions induced by clearance of apoptotic neutrophils containing S. epidermidis might represent an important mechanism to combat the infective agent. This activation of macrophages may contribute to the development of chronic inflammation instead of inflammation resolution.
Ort, förlag, år, upplaga, sidor
Oxford University Press, 2008. Vol. 53, nr 1, s. 126-135
Nyckelord [en]
Staphylococcus epidermidis infection; neutrophil; macrophage; chronic inflammation; phagocytosis; TNF-α; TNF-alpha
Nationell ämneskategori
Immunologi
Identifikatorer
URN: urn:nbn:se:hj:diva-5576DOI: 10.1111/j.1574-695X.2008.00412.xISI: 000255644300016PubMedID: 18400011Scopus ID: 2-s2.0-43349091469OAI: oai:DiVA.org:hj-5576DiVA, id: diva2:36396
2008-05-092008-05-092019-08-30Bibliografiskt granskad