title: Neutrophil survival and c-kit(+)-progenitor proliferation in Staphylococcus aureus-infected skin wounds promote resolution.
abstract: Polymorphonuclear neutrophils (PMNs) are critical for the formation, maintenance, and resolution of bacterial abscesses. However, the mechanisms that regulate PMN survival and proliferation during the evolution of an abscess are not well defined. Using a mouse model of Staphylococcus aureus abscess formation within a cutaneous wound, combined with real-time imaging of genetically tagged PMNs, we observed that a high bacterial burden elicited a sustained mobilization of PMNs from the bone marrow to the infected wound, where their lifespan was markedly extended. A continuous rise in wound PMN number, which was not accounted for by trafficking from the bone marrow or by prolonged survival, was correlated with the homing of c-kit(+)-progenitor cells from the blood to the wound, where they proliferated and formed mature PMNs. Furthermore, by blocking their recruitment with an antibody to c-kit, which severely limited the proliferation of mature PMNs in the wound and shortened mouse survival, we confirmed that progenitor cells are not only important contributors to PMN expansion in the wound, but are also functionally important for immune protection. We conclude that the abscess environment provides a niche capable of regulating PMN survival and local proliferation of bone marrow-derived c-kit(+)-progenitor cells.
authors.affiliation: Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616, USA.
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Kim
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Granick
authors.forename: Cindy
authors.initials: C
authors.lastname: Kwok
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Walker
authors.forename: Dori L
authors.initials: DL
authors.lastname: Borjesson
authors.forename: Fitz-Roy E
authors.initials: FR
authors.lastname: Curry
authors.forename: Lloyd S
authors.initials: LS
authors.lastname: Miller
authors.forename: Scott I
authors.initials: SI
authors.lastname: Simon
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002470:Cell Survival; D055879:Gene Knock-In Techniques; D042381:Granulocyte Precursor Cells / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009504:Neutrophils / Q000276:immunology / Q000502:physiology*; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D013207:Staphylococcal Skin Infections / Q000276:immunology*; D013211:Staphylococcus aureus / Q000502:physiology; D014945:Wound Healing / Q000276:immunology* / Q000502:physiology; D014946:Wound Infection / Q000276:immunology*
chemical_list: D019009:Proto-Oncogene Proteins c-kit