Potential role for toll-like receptor 4 in mediating Escherichia coli maltose-binding protein activation of dendritic cells
Potential role for toll-like receptor 4 in mediating Escherichia coli maltose-binding protein activation of dendritic cells
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DOI：
10.1128/iai.00486-06
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发表时间：
2007-03-01
影响因子：
3.1
通讯作者：
Sun, Wellington
中科院分区：
文献类型：
--
作者：
Fernandez, Stefan;Palmer, Dupeh R.;Sun, Wellington
大肠杆菌麦芽糖结合蛋白（MBP）用于增加细菌蛋白表达系统中蛋白的稳定性和溶解性，并且越来越多地用于促进针对各种病原性细菌和病毒的亚单位疫苗的生产和递送。MBP标签被认为是惰性的，对标记蛋白的生物活性或其生物分布的影响最小。然而，很少有研究表征MBP的免疫学属性。在这里，我们分析了MBP处理的树突状细胞（DC）的表型和功能结果，并表明MBP诱导DC活化和促炎细胞因子（白细胞介素-1 β [IL-1 β]，IL-6，IL-8，肿瘤坏死因子α和IL-12 Ⅱ 70）的产生在24小时内，并强烈增加I κ β磷酸化处理的细胞。有趣的是，通过加入抗人Toll样受体4（TLR 4）抗体，I κ β的磷酸化在很大程度上被消除，表明MBP通过TLR 4激活DC成熟的信号传导。与该假设一致，MBP激活了表达TLR 4的细胞系293-hTLR 4A，但不激活对照培养物以分泌IL-8。观察到的数据是独立的脂多糖污染和支持TLR 4介导的MBP的影响的作用。这些结果提供了深入了解MBP可能增强对疫苗融合蛋白的免疫应答的机制。
The Escherichia coli maltose-binding protein (MBP) is used to increase the stability and solubility of proteins in bacterial protein expression systems and is increasingly being used to facilitate the production and delivery of subunit vaccines against various pathogenic bacteria and viruses. The MBP tag is presumed inert, with minimum effects on the bioactivity of the tagged protein or its biodistribution. However, few studies have characterized the immunological attributes of MBP. Here, we analyze the phenotypic and functional outcomes of MBP-treated dendritic cells (DCs) and show that MBP induces DC activation and production of proinflammatory cytokines (interleukin-1 beta [IL-1 beta], IL-6, IL-8, tumor necrosis factor alpha, and IL-12II70) within 24 h and strongly increases I kappa beta phosphorylation in treated cells. Interestingly, phosphorylation Of I kappa beta was largely abrogated by the addition of anti-human Toll-like receptor 4 (TLR4) antibodies, indicating that MBP activates signaling for DC maturation via TLR4. Consistent with this hypothesis, MBP activated the TLR4-expressing cell line 293-hTLR4A but not control cultures to secrete IL-8. The observed data were independent of lipopolysaccharide contamination and support a role for TLR4 in mediating the effects of MBP. These results provide insight into a mechanism by which MBP might enhance immune responses to vaccine fusion proteins.