International immunopharmacology
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Int. Immunopharmacol. · Nov 2010
Loxoribine, a selective Toll-like receptor 7 agonist, induces maturation of human monocyte-derived dendritic cells and stimulates their Th-1- and Th-17-polarizing capability.
Recently, a guanosine analog, 7-allyl-7,8-dihydro-8-oxo-guanosine (loxoribine), has been identified as a selective Toll-like receptor (TLR)7 agonist. Bearing in mind the controversy regarding the expression of TLR7 by human myeloid dendritic cells (DCs) and its significance for functions of these cells, the goal of this study was to investigate the effect of loxoribine on differentiation, maturation and functions of human monocyte-derived (Mo)DCs. Immature MoDCs were obtained by cultivation of monocytes for 6 days with recombinant granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4. ⋯ Allogeneic CD4(+)T cells in co-culture with loxoribine-treated MoDCs proliferated more strongly, at lower DC/CD4(+)T-cell ratio (1:80), and secreted significantly higher levels of IL-17 and IFN-γ compared to the cultures with control MoDCs. The stimulatory effect of loxoribine on T helper (Th)1 polarization capability of MoDCs was further potentiated by ligation of CD40. In conclusion, our results show that loxoribine stimulated differentiation, maturation, allostimulatory as well as Th1 and Th17 polarization capability of human MoDCs and suggests that these effects might be associated with up-regulation of TLR7 expression, but not increased IFN-β production.
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Neutrophils are the first line of innate immune defense against infectious diseases. However, since their discovery by Elie Metchnikoff, they have always been considered tissue-destructive cells responsible for inflammatory tissue damage occurring during acute infections. Now, extensive research in the field of neutrophil cell biology and their role skewing the immune response in various infections or inflammatory disorders revealed their importance in the regulation of immune response. ⋯ Activated neutrophils provide signals for the activation and maturation of macrophages as well as dendritic cells. Neutrophils are also involved in the regulation of T-cell immune response against various pathogens and tumor antigens. Thus, the present review is intended to highlight the emerging role of neutrophils in the regulation of both innate and adaptive immunity during acute infectious or inflammatory conditions.
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Int. Immunopharmacol. · Nov 2010
Anti-asthmatic effect of schizandrin on OVA-induced airway inflammation in a murine asthma model.
Asthma comprises a triad of reversible airway obstruction, bronchial smooth muscle cell hyperreactivity to bronchoconstrictors, and chronic bronchial inflammation. Clinical and experimental findings have established eosinophilia as a sign of allergic disorders. In the present investigation, we evaluated the anti-asthmatic effects of schizandrin and its underlying mechanisms in an in vivo murine asthmatic model. ⋯ Additionally, schizandrin suppresses the production of reactive oxygen species (ROS) in a dose-dependent manner, and inhibits goblet cell hyperplasia and inflammatory cell infiltration in lung tissue. Thus, schizandrin has anti-asthmatic effects, which seem to be partially mediated by reduction of oxidative stress and airway inflammation, in a murine allergic asthma model. These results indicate that schizandrin may be an effective novel therapeutic agent for the treatment of allergic asthma.