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）响应病原体的成熟对于有效的免疫介导的感染控制和防止随后的再感染至关重要。病原性病毒已经开发出通过拮抗负责有效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。这些互补机制主要由I型IFN代表，其为抗病毒基因的表达和DC的完全成熟发出信号。仙台病毒（SeV）株Cantell（C）有效地触发完全DC成熟，而不管功能性病毒拮抗剂的存在。我们的数据表明，SeV-C在DC中通过细胞内解旋酶RIG-I和MDA 5检测到。与由这些解旋酶感知的其他病毒不同，响应于SeV-C的完全DC成熟是快速的并且不依赖于细胞因子反馈。我们已经鉴定了病毒储备物中存在的SeV缺陷型干扰（DI）颗粒是SeV-C非常有效地诱导DC成熟的原因。负责对SeV-C感染的有效DC应答的特异性信号传导途径，独立于细胞因子互补，尚不清楚。该提案的目标是在我们的实验室中实施标准方法，以确定参与对SeV DI颗粒的直接响应的信号通路。我们将使用这些技术进行研究，以评估转录因子IRFs 3和7，NF-κ B和AP-1及其激活途径在诱导一个完全功能的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。这项研究的结果将被用作设计未来综合研究的线索，旨在表征负责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，可能导致免疫刺激的新方法。公共卫生相关性：缺陷干扰（DI）颗粒为SeV原种提供独特的刺激，其独立于补充对其他病毒的应答所需的细胞因子反馈而触发树突状细胞（DC）的有效、快速和完全成熟。这笔赠款将使我们能够在实验室中实施必要的技术，以进行对SeV DI粒子异常反应的细胞机制的初步研究。这些研究对于全面表征有效响应病毒感染的DC机制至关重要，并应为免疫刺激分子的开发提供新的见解。

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.