title: Osteoblasts express the inflammatory cytokine interleukin-6 in a murine model of Staphylococcus aureus osteomyelitis and infected human bone tissue.
abstract: Staphylococcus aureus is the single most common cause of osteomyelitis in humans. Incidences of osteomyelitis caused by S. aureus have increased dramatically in recent years, in part due to the appearance of community-acquired antibiotic resistant strains. Therefore, understanding the pathogenesis of this organism has become imperative. Recently, we have described the surprising ability of bone-forming osteoblasts to secrete a number of important immune mediators when exposed to S. aureus in vitro. In the present study, we provide the first evidence for the in vivo production of such molecules by osteoblasts during bacterial infection of bone. These studies demonstrate the expression of the key inflammatory cytokine interleukin-6 by osteoblasts in organ cultures of neonatal mouse calvaria, and in vivo using a mouse model that closely resembles the pathology of trauma-induced staphylococcal osteomyelitis, as determined by confocal microscopic analysis. Importantly, we have established the clinical relevancy of these findings in infected human bone tissue from patients with S. aureus-associated osteomyelitis. As such, these studies demonstrate that bacterial challenge of osteoblasts during bone diseases, such as osteomyelitis, induces cells to produce inflammatory molecules that can direct appropriate host responses or contribute to progressive inflammatory damage.
authors.affiliation: Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223, USA. imarriot@email.uncc.edu.
authors.forename: Ian
authors.initials: I
authors.lastname: Marriott
authors.forename: David L
authors.initials: DL
authors.lastname: Gray
authors.forename: Susanne L
authors.initials: SL
authors.lastname: Tranguch
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.forename: Martin
authors.initials: M
authors.lastname: Stryjewski
authors.forename: L
authors.initials: L
authors.lastname: Scott Levin
authors.forename: Michael C
authors.initials: MC
authors.lastname: Hudson
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Bost
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000096:biosynthesis*; D051379:Mice; D018613:Microscopy, Confocal; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000276:immunology*; D010019:Osteomyelitis / Q000209:etiology / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012886:Skull / Q000502:physiology; D013203:Staphylococcal Infections / Q000150:complications / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger