期刊
JOURNAL OF INFECTIOUS DISEASES
卷 193, 期 7, 页码 1023-1028出版社
OXFORD UNIV PRESS INC
DOI: 10.1086/500948
关键词
-
Background. The dexamethasone (DEX) immunosuppressive effect on macrophage killing activity and cytokine production in response to Aspergillus fumigatus conidia is antagonized by granulocyte-macrophage colony-stimulating factor (GM-CSF). The molecular mechanism is unknown. We postulated that this antagonism is mediated by inhibitor kappa B (I kappa B) induction by DEX and is opposed by acceleration of I kappa B degradation by GM-CSF with or without conidia stimulation, with corresponding effects on translocation and activation of nuclear factor kappa B (NF-kappa B). Methods. We studied 2 types of cells, resident peritoneal macrophages from CD-1 mice and the murine macrophage RAW264.7 cell line. Cells were unstimulated or stimulated with conidia and simultaneously treated with DEX, GM-CSF, or DEX plus GM-CSF, for 2-4 hours. I kappa B degradation and NF-kappa B activation were assessed by Western blot. Results. Macrophages stimulated with conidia alone increased NF-kappa B translocation. DEX increased I kappa B levels in cytoplasm and blocked translocation of NF-kappa B to the nucleus in unstimulated and conidia-stimulated macrophages. Conversely, GM-CSF decreased I kappa B levels. GM-CSF reversed the effect of DEX on IkB levels. NF-kappa B levels were minimal in DEX-treated macrophage nuclear extracts, compared with those from GM-CSF-treated and GM-CSF plus DEX-treated macrophages. Conclusion. GM-CSF can reverse the DEX immunosuppressive effect by enhancing IkB degradation and promoting NF-kappa B translocation. This would allow macrophage production of proinflammatory cytokines, facilitating resistance to aspergillosis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据