title: Priming effects of tumor necrosis factor-α on production of reactive oxygen species during Toxoplasma gondii stimulation and receptor gene expression in differentiated HL-60 cells.
abstract: Neutrophils are among the principal effector cells that protect against infectious agents, in part by producing reactive oxygen species (ROS) via the actions of tumor necrosis factor-α (TNF-α). In this study, we investigated whether HL-60 cells that had been differentiated into neutrophil-like cells by all-trans retinoic acid could be primed with TNF-α similar to human neutrophils. Our results showed that when differentiated HL-60 (dHL-60) cells were primed with TNF-α for 10 min, ROS production induced by zymosan A or phorbol myristate acetate (PMA) was enhanced in a TNF-α-dose-dependent manner. In addition, when dHL-60 cells were stimulated with live tachyzoites of Toxoplasma gondii after TNF-α priming, ROS production was also enhanced. Thus, dHL-60, similar to neutrophils, produced ROS after PMA, zymosan A, or T. gondii stimulation. Furthermore, we examined gene expression in dHL-60 cells after TNF-α treatment. The pro-inflammatory cytokine IL-6 was up-regulated more than 1.6-fold by 0.1 ng/mL TNF-α. Endogenous TNF-α was down-regulated by priming. IL-8 receptors genes were not affected by priming with 0.1 ng/mL or 1 ng/mL TNF-α. Complement receptor (CR) 1 and CR3 gene expression was not affected by TNF-α priming for 10 min. However, when the priming period was extended to 1 h, CR1 and CR3 genes were up-regulated 1.3 and 1.4-fold, respectively. Expression of the cell-surface CR3 (CD11b) was not significantly affected by TNF-α for 15 min but was slightly enhanced after priming for 2 h. These results suggest that dHL-60 cells may be used as a substitute for neutrophils when evaluating the effects of cytokines or immunomodulator agents.
authors.affiliation: Department of Immunology and Microbiology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan, takane@med.teikyo-u.ac.jp.
authors.forename: Takane
authors.initials: T
authors.lastname: Kikuchi-Ueda
authors.forename: Tsuneyuki
authors.initials: T
authors.lastname: Ubagai
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ono
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D018922:HL-60 Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D014122:Toxoplasma / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D014123:Toxoplasmosis / Q000382:microbiology; D014212:Tretinoin; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D015850:Interleukin-6; D017382:Reactive Oxygen Species; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D014212:Tretinoin