title: Effect of tumor necrosis factor-alpha on intracellular Staphylococcus aureus in vascular endothelial cells.
abstract: Although tumor necrosis factor-alpha (TNF-alpha) is an important host factor against intracellular bacteria, little is known about the effect of TNF-alpha on the persistence of intracellular Staphylococcus aureus in vascular endothelial cells. It was investigated whether recombinant human TNF-alpha influences the survival of intracellular S. aureus (ATCC 29213) in human umbilical vein endothelial cells (HUVEC) under a condition with an antistaphylococcal agent, and its mechanism. The HUVECs were incubated with TNF-alpha, oxacillin, or both in 24-well plates for up to 48 h following internalization of S. aureus (10(6) CFU well(-1)) into HUVECs for 1 h. TNF-alpha (1 ng mL(-1)) significantly reduced the number of intracellular S. aureus in HUVECs, and TNF-alpha plus oxacillin eliminated more intracellular S. aureus in HUVEC than oxacillin alone. The LDH viability assay and quantification of apoptosis using photometric enzyme-immunoassay showed that TNF-alpha preferentially induced cell death and apoptosis of HUVECs infected with S. aureus compared with noninfected HUVECs. These results indicate that TNF-alpha helps antistaphylococcal antibiotics to eliminate intracellular S. aureus in vascular endothelial cells, partly because TNF-alpha preferentially induces apoptosis of endothelial cells infected by S. aureus.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Chongro-Gu, Seoul, Korea.
authors.forename: Wan Beom
authors.initials: WB
authors.lastname: Park
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Jeon
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Sung Han
authors.initials: SH
authors.lastname: Kim
authors.forename: Nam Joong
authors.initials: NJ
authors.lastname: Kim
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Kim
authors.forename: Myoung-Don
authors.initials: MD
authors.lastname: Oh
authors.forename: Kang Won
authors.initials: KW
authors.lastname: Choe
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017209:Apoptosis; D002460:Cell Line; D015169:Colony Count, Microbial; D042783:Endothelial Cells / Q000382:microbiology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D050296:Microbial Viability; D010068:Oxacillin / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D000900:Anti-Bacterial Agents; D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase; D010068:Oxacillin