TLR4-mediated activation of dendritic cells by the heat shock protein DnaK from Francisella tularensis
TLR4-mediated activation of dendritic cells by the heat shock protein DnaK from Francisella tularensis
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DOI：
10.1189/jlb.0308215
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发表时间：
2008-12-01
影响因子：
5.5
通讯作者：
Michalek, Suzanne M.
中科院分区：
文献类型：
--
作者：
Ashtekar, Amit R.;Zhang, Ping;Michalek, Suzanne M.
土拉热弗朗西斯菌是土拉菌病的病原体，土拉菌病是人类和其他哺乳动物的严重的使人衰弱的疾病。由于这种微生物也被归类为“A类病原体”和潜在的生物战剂，因此需要有效的疫苗。F.包括热休克蛋白DnaK在内的土拉热菌的蛋白质已被提议用于潜在的亚单位疫苗中。在这项研究中，我们的特点是小鼠骨髓来源的树突状细胞（DC）的天然免疫反应，以F。土拉菌DnaK.使用细菌表达系统产生重组DnaK，并使用亲和层析、离子交换层析和尺寸排阻层析纯化。DnaK诱导DC中MAPKs和NF-κ B的活化以及促炎细胞因子IL-6、TNF-α和IL-12 p40以及低水平IL-10的产生。DnaK诱导DC表型成熟，共刺激分子CD 40，CD 80和CD 86的上调表明。DnaK通过TLR 4和衔接子MyD 88和Toll/IL-1 R结构域诱导IFN-β（TRIF）介导差异反应刺激DC。DnaK以MyD 88或TRIF依赖性方式诱导MAPK和NF-κ B B的活化。然而，MyD 88和TRIF依赖性信号通路的存在对于DC中DnaK诱导的最佳细胞因子应答至关重要。相反，DnaK以TRIF依赖性、MyD 88独立性的方式诱导DC成熟。这些结果提供了深入了解F的免疫显性抗原之间的分子相互作用。土拉菌和宿主免疫细胞，这对于合理设计和开发针对土拉菌的安全有效的疫苗至关重要。J. Leukoc. 84：1434-1446; 2008.
Francisella tularensis is the causative agent of tularemia, a severe, debilitating disease of humans and other mammals. As this microorganism is also classified as a "category-A pathogen" and a potential biowarfare agent, there is a need for an effective vaccine. Several antigens of F. tularensis, including the heat shock protein DnaK, have been proposed for use in a potential subunit vaccine. In this study, we characterized the innate immune response of murine bone marrow-derived dendritic cells ( DC) to F. tularensis DnaK. Recombinant DnaK was produced using a bacterial expression system and purified using affinity, ionexchange, and size-exclusion chromatography. DnaK induced the activation of MAPKs and NF-kappa B in DC and the production of the proinflammatory cytokines IL-6, TNF-alpha, and IL-12 p40, as well as low levels of IL-10. DnaK induced phenotypic maturation of DC, as demonstrated by an up-regulation of costimulatory molecules CD40, CD80, and CD86. DnaK stimulated DC through TLR4 and the adapters MyD88 and Toll/IL-1R domain-containing adaptor-inducing IFN-beta (TRIF) that mediated differential responses. DnaK induced activation of MAPKs and NF-kappa B in a MyD88- or TRIF-dependent manner. However, the presence of MyD88-and TRIF-dependent signaling pathways was essential for an optimal, DnaK-induced cytokine response in DC. In contrast, DnaK induced DC maturation in a TRIF-dependent, MyD88-independent manner. These results provide insight about the molecular interactions between an immunodominant antigen of F. tularensis and host immune cells, which is crucial for the rational design and development of a safe and efficacious vaccine against tularemia. J. Leukoc. Biol. 84: 1434-1446; 2008.