Initial study of the dendritic cell response to SeV DI particles

描述(由申请人提供)：树突状细胞(DC)对病原体的反应成熟是有效的免疫介导的感染控制和防止后续再次感染的关键。致病病毒已经开发出通过对抗负责有效DC成熟的细胞机制来逃避免疫识别的策略。另一方面，当遇到具有绕过DC激活能力的病原体时，DC利用多个互补系统来确保完全成熟。这些互补机制主要以I型IFN为代表，它为抗病毒基因的表达和DC的完全成熟提供信号。仙台病毒(SeV)株坎特尔(C)有效地触发完全的DC成熟，而不考虑功能性病毒拮抗剂的存在。我们的数据表明，SeV-C是通过细胞内螺旋酶RIG-I和MDA5在DC中检测到的。与通过这些解旋酶感知的其他病毒不同，SeV-C对DC的完全成熟是快速的，并且不依赖于细胞因子反馈。我们已经确定病毒库中存在的SeV缺陷干扰(DI)颗粒是SeV-C非常有效地诱导DC成熟的原因。目前尚不清楚与细胞因子互补无关的导致SeV-C感染的DC有效应答的具体信号通路。这项建议的目标是在我们的实验室中实施标准的方法，以确定参与对SeV DI颗粒的直接反应的信号通路。我们将使用这些技术进行研究，以评估转录因子IRFs3和7、NF-kB和AP-1及其激活途径在诱导完整功能的DC成熟程序中的作用，以响应SeV-C，独立于I型IFN。已知这些转录因子参与相关DC成熟基因的转录。这项研究的结果将作为设计未来全面研究的指导，旨在表征SeV DI颗粒直接触发DC完全成熟的机制。这些机制的特征可能构成对非致病性病毒的主要威慑，可能导致新的免疫刺激方式。公共卫生相关性：缺陷干扰(DI)颗粒为SeV股票提供了一种独特的刺激，可触发树突状细胞(DC)有效、快速和完全成熟，而不依赖于补充对其他病毒的反应所需的细胞因子反馈。这笔赠款将允许我们在实验室实施必要的技术，以对对SeV DI颗粒的非凡反应负责的细胞机械进行初步研究。这些研究对于全面描述有效应对病毒感染的DC机制至关重要，并应为免疫刺激分子的发展提供新的见解。

DESCRIPTION (provided by applicant): The maturation of dendritic cells (DCs) in response to a pathogen is essential for effective immune-mediated control of the infection and protection from subsequent re-infections. Pathogenic viruses have developed strategies to evade immune recognition by antagonizing the cellular machinery responsible for effective DC maturation. DCs, on the other hand, utilize multiple complementary systems to ensure complete maturation when encountering pathogens with the ability to bypass DC activation. These complementary mechanisms are primarily represented by type I IFNs which signal for the expression of anti-viral genes and for the complete maturation of DCs. Sendai virus (SeV) strain Cantell (C) efficiently triggers complete DC maturation irrespective of the presence of functional viral antagonists. Our data have demonstrated that SeV-C is detected in DCs by the intracellular helicases RIG-I and MDA5. Differently from other viruses sensed by these helicases, complete DC maturation in response to SeV-C is fast and independent of cytokine feedback. We have identified SeV defective interfering (DI) particles present in the viral stocks as the responsible for the extraordinarily effective induction of DC maturation by SeV-C. The specific signaling pathways responsible for the potent DC response to SeV-C infection, independently of cytokine complementation, are not known. The goal of this proposal is to implement in our laboratory standard methodology to identify the signaling pathways that participate in the direct response to SeV DI particles. We will use these techniques to perform studies to asses the role of the transcription factors IRFs 3 and 7, NF-kB, and AP-1 and their activation pathways in the induction of a fully functional DC maturation program in response to SeV-C independently of type I IFNs. These transcription factors are known to participate in the transcription of relevant DC maturation genes. The results form this investigation will be used as a lead to design future comprehensive studies aimed to characterize the mechanisms responsible for the direct triggering of complete maturation of DCs by SeV DI particles. The characterization of these mechanisms, which likely constitute the main deterrent for non pathogenic viruses, could lead to novel ways of immune stimulation. PUBLIC HEALTH RELEVANCE: Defective interfering (DI) particles provide SeV stocks with a unique stimulus that triggers potent, fast, and complete maturation of dendritic cells (DCs) independently of the cytokine feedback that is needed to complement the response to other viruses. This grant will allow us to implement in our lab the technology necessary to perform initial studies of the cellular machinery responsible for the extraordinary response to SeV DI particles. These studies are crucial for the comprehensive characterization of the DC mechanisms that efficiently respond to virus infection and should provide novel insights for the development of immunostimulatory molecules.