Bovine Staphylococcus aureus Secretes the Leukocidin LukMF' To Kill Migrating Neutrophils through CCR1.

Autor:	Vrieling M, Koymans KJ; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., Heesterbeek DA; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., Aerts PC; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., Rutten VP; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands., de Haas CJ; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., van Kessel KP; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., Koets AP; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands., Nijland R; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands., van Strijp JA; Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands j.vanstrijp@umcutrecht.nl.
Jazyk:	angličtina
Zdroj:	MBio [mBio] 2015 Jun 04; Vol. 6 (3), pp. e00335. Date of Electronic Publication: 2015 Jun 04.
DOI:	10.1128/mBio.00335-15
Abstrakt:	Unlabelled: Although Staphylococcus aureus is best known for infecting humans, bovine-specific strains are a major cause of mastitis in dairy cattle. The bicomponent leukocidin LukMF', exclusively harbored by S. aureus of ruminant origin, is a virulence factor associated with bovine infections. In this study, the molecular basis of the host specificity of LukMF' is elucidated by identification of chemokine receptor CCR1 as its target. Bovine neutrophils, the major effector cells in the defense against staphylococci, express significant cell surface levels of CCR1, whereas human neutrophils do not. This causes the particular susceptibility of bovine neutrophils to pore formation induced by LukMF'. Bovine S. aureus strains produce high levels of LukMF' in vitro. In culture supernatant of the mastitis field isolate S1444, LukMF' was the most important cytotoxic agent for bovine neutrophils. In a fibrin gel matrix, the effects of the in situ secreted toxins on neutrophils migrating toward S. aureus were visualized. Under these physiological ex vivo conditions, bovine S. aureus S1444 efficiently killed approaching neutrophils at a distance through secretion of LukMF'. Altogether, our findings illustrate the coevolution of pathogen and host, provide new targets for therapeutic and vaccine approaches to treat staphylococcal diseases in the cow, and emphasize the importance of staphylococcal toxins in general. Importance: This study explains the mechanism of action of LukMF', a bicomponent toxin found in bovine lineages of S. aureus that is associated with mastitis in cattle. At a molecular level, we describe how LukMF' can specifically kill bovine neutrophils. Here, we demonstrate the contribution of toxins in the determination of host specificity and contribute to the understanding of mechanisms of coevolution of pathogen and host. Our study provides new targets that can be used in therapeutic and vaccine approaches to treat staphylococcal diseases in the cow. We also demonstrate the importance of toxins in specific elimination of immune cells, which has broader implications, especially in human infections. (Copyright © 2015 Vrieling et al.)
Databáze:	MEDLINE
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