Sadikot Ruxana T, Zeng Heng, Yull Fiona E, Li Bo, Cheng Dong-sheng, Kernodle Douglas S, Jansen E Duco, Contag Christopher H, Segal Brahm H, Holland Steven M, Blackwell Timothy S, Christman John W
Department of Veterans Affairs and Division of Allergy, Pulmonary and Critical Care, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
J Immunol. 2004 Feb 1;172(3):1801-8. doi: 10.4049/jimmunol.172.3.1801.
We examined the role of redox signaling generated by NADPH oxidase in activation of NF-kappaB and host defense against Pseudomonas aeruginosa pneumonia. Using mice with an NF-kappaB-driven luciferase reporter construct (HIV-LTR/luciferase (HLL)), we found that intratracheal administration of P. aeruginosa resulted in a dose-dependent neutrophilic influx and activation of NF-kappaB. To determine the effects of reactive oxygen species generated by the NADPH oxidase system on activation of NF-kappaB, we crossbred mice deficient in p47(phox) with NF-kappaB reporter mice (p47(phox-/-)HLL). These p47(phox-/-)HLL mice were unable to activate NF-kappaB to the same degree as HLL mice with intact NADPH oxidase following P. aeruginosa infection. In addition, lung TNF-alpha levels were significantly lower in p47(phox-/-)HLL mice compared with HLL mice. Bacterial clearance was impaired in p47(phox-/-)HLL mice. In vitro studies using bone marrow-derived macrophages showed that Toll-like receptor 4 was necessary for NF-kappaB activation following treatment with P. aeruginosa. Additional studies with macrophages from p47(phox-/-) mice confirmed that redox signaling was necessary for maximal Toll-like receptor 4-dependent NF-kappaB activation in this model. These data indicate that the NADPH oxidase-dependent respiratory burst stimulated by Pseudomonas infection contributes to host defense by modulating redox-dependent signaling through the NF-kappaB pathway.
我们研究了NADPH氧化酶产生的氧化还原信号在激活核因子-κB（NF-κB）以及宿主抵御铜绿假单胞菌肺炎中的作用。利用携带由NF-κB驱动的荧光素酶报告基因构建体（HIV-LTR/荧光素酶（HLL））的小鼠，我们发现气管内给予铜绿假单胞菌会导致中性粒细胞呈剂量依赖性流入以及NF-κB的激活。为了确定NADPH氧化酶系统产生的活性氧对NF-κB激活的影响，我们将p47（phox）缺陷小鼠与NF-κB报告基因小鼠（p47（phox-/-）HLL）进行杂交。这些p47（phox-/-）HLL小鼠在感染铜绿假单胞菌后，无法像具有完整NADPH氧化酶的HLL小鼠那样程度地激活NF-κB。此外，与HLL小鼠相比，p47（phox-/-）HLL小鼠肺组织中肿瘤坏死因子-α（TNF-α）水平显著降低。p47（phox-/-）HLL小鼠的细菌清除能力受损。使用骨髓来源的巨噬细胞进行的体外研究表明，在用铜绿假单胞菌处理后，Toll样受体4对于NF-κB的激活是必需的。对来自p47（phox-/-）小鼠的巨噬细胞进行的进一步研究证实，在该模型中，氧化还原信号对于最大程度的Toll样受体4依赖性NF-κB激活是必需的。这些数据表明，铜绿假单胞菌感染刺激的NADPH氧化酶依赖性呼吸爆发通过NF-κB途径调节氧化还原依赖性信号传导，从而有助于宿主防御。
