title: Staphylococcus aureus - induced tumor necrosis factor - related apoptosis - inducing ligand expression mediates apoptosis and caspase-8 activation in infected osteoblasts.
abstract: BACKGROUND
  Staphylococcus aureus infection of normal osteoblasts induces expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL).
  
  
  RESULTS
  Normal osteoblasts were incubated in the presence of purified bacterial products over a range of concentrations. Results demonstrate that purified surface structures and a selected superantigen present in the extracellular environment are not capable of inducing TRAIL expression by osteoblasts. Osteoblasts were co-cultured with S. aureus at various multiplicities of infection utilizing cell culture chamber inserts. Results of those experiments suggest that direct contact between bacteria and osteoblasts is necessary for optimal TRAIL induction. Finally, S. aureus infection of osteoblasts in the presence of anti-TRAIL antibody demonstrates that TRAIL mediates caspase-8 activation and apoptosis of infected cells.
  
  
  CONCLUSIONS
  Collectively, these findings suggest a mechanism whereby S. aureus mediates bone destruction via induction of osteoblast apoptosis.
authors.affiliation: Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA. ehalexan@zoo.uvm.edu
authors.forename: Emily H
authors.initials: EH
authors.lastname: Alexander
authors.forename: F Andrea
authors.initials: FA
authors.lastname: Rivera
authors.forename: Ian
authors.initials: I
authors.lastname: Marriott
authors.forename: Juan
authors.initials: J
authors.lastname: Anguita
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Bost
authors.forename: Michael C
authors.initials: MC
authors.lastname: Hudson
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism*; D002478:Cells, Cultured; D004789:Enzyme Activation; D006801:Humans; D008024:Ligands; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000502:physiology; D051379:Mice; D010006:Osteoblasts / Q000201:enzymology / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000737:chemistry / Q000502:physiology*; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000378:metabolism* / Q000502:physiology
chemical_list: D051017:Apoptosis Regulatory Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C505530:CASP8 protein, human; C505526:Casp8 protein, mouse; D053181:Caspase 8; D020169:Caspases