Richter Cornelia, Juan Martina Herrero San, Will Jutta, Brandes Ralf P, Kalinke Ulrich, Akira Shizuo, Pfeilschifter Josef M, Hultqvist Malin, Holmdahl Rikard, Radeke Heinfried H
pharmazentrum frankfurt/Center for Drug Research, Development, and Safety, Clinic of J. W. Goethe University, Frankfurt, Germany.
J Immunol. 2009 Apr 1;182(7):4183-91. doi: 10.4049/jimmunol.0800795.
Permanent exposure to pathogens requires decisions toward tolerance or immunity as a prime task of dendritic cells. The molecular mechanisms preventing uncontrolled immune responses are not completely clear. We investigated the regulatory function of Ncf1, an organizing protein of NADPH oxidase, in the signaling cascade of Toll-like receptors. TLR9-stimulated spleen cells from both Ncf1-deficient and B10.Q mice with a point mutation in exon 8 of Ncf1 exhibited increased IL-12p70 secretion compared with controls. This finding was restricted to stimulatory CpG2216 and not induced by CpG2088. Because only CpG/TLR9-induced IL-12p70 was regulated by Ncf1, we used TRIF(-/-) and MyD88(-/-) cells to show that TLR9/MyD88 was primarily affected. Interestingly, additional experiments revealed that spleen cells from NOX2/gp91(phox)-deficient mice and the blocking of electron transfer by diphenylene iodonium had no influence on CpG-induced IL-12p70, confirming an NADPH oxidase-independent function of Ncf1. Finally, proving the in vivo relevance CpG adjuvant-guided OVA immunization resulted in a strong augmentation of IL-12p70-dependent Th1 IFN-gamma response only in Ncf1-deficient mice. These data suggest for the first time an important role for Ncf1 in the fine tuning of the TLR9/MyD88 pathway in vitro and in vivo that is independent of its role as an activator of NOX2.
长期暴露于病原体需要树突状细胞做出耐受或免疫的决定，这是其首要任务。防止免疫反应失控的分子机制尚不完全清楚。我们研究了NADPH氧化酶的组织蛋白Ncf1在Toll样受体信号级联反应中的调节功能。与对照组相比，来自Ncf1缺陷小鼠和Ncf1第8外显子有一个点突变的B10.Q小鼠的TLR9刺激的脾细胞表现出IL-12p70分泌增加。这一发现仅限于刺激性CpG2216，而非由CpG2088诱导。因为只有CpG/TLR9诱导的IL-12p70受Ncf1调节，我们使用TRIF(-/-)和MyD88(-/-)细胞来表明TLR9/MyD88主要受到影响。有趣的是，进一步的实验表明，来自NOX2/gp91(phox)缺陷小鼠的脾细胞以及二苯碘鎓对电子传递的阻断对CpG诱导的IL-12p70没有影响，证实了Ncf1具有不依赖NADPH氧化酶的功能。最后，为了证明体内相关性，CpG佐剂引导的OVA免疫仅在Ncf1缺陷小鼠中导致IL-12p70依赖性Th1 IFN-γ反应的强烈增强。这些数据首次表明Ncf1在体外和体内对TLR9/MyD88途径的微调中起重要作用，且该作用独立于其作为NOX2激活剂的作用。
