Role of the innate immune response in canine distemper virus neuropathogenesis

犬瘟热病毒（CDV）在广泛的食肉动物中引起严重的全身性疾病。 此外，高达30%的狗的经验参与中枢神经系统（CNS），使CDV非常适合的麻疹病毒诱导的神经病理机制的表征。在CNS中，CDV引起急性和慢性脱髓鞘病变，其部分是免疫病原性起源的。由于CDV V蛋白在抑制抗病毒反应中起着重要作用，我假设CDV相关的炎性CNS病变和随后的脱髓鞘是由于急性疾病阶段先天免疫反应对感染控制不足所致。为了验证这一假设，我提出了一个研究计划，有两个具体目标：（a）为了评估CDV抑制不同原代鼬鼠和犬细胞类型中干扰素（IFN）信号级联的能力，和（B）表征野生型和V-缺失病毒在鼬科动物器官型脑切片培养物中的传播、靶细胞和局部先天性免疫应答。对于（a），我将确定不同原代鼬科动物和犬CNS细胞类型、原代上皮细胞和外周血单核细胞中的复制效率。我还将测量I型IFN生产使用VSV-生物测定，以研究复制效率与先天免疫激活程度之间的相关性。对于（B），我将首先通过免疫组织化学比较两种病毒的扩散和靶细胞，并通过VSV生物测定和使用实时RT-PCR和Western印迹分析的细胞因子表达水平评估先天免疫激活。然后，将通过组织切片的双重染色来鉴定表达组氨酸的细胞。总之，拟议的工作将促进我们对麻疹病毒相关神经系统并发症的宿主反应贡献的理解，并将构成开发靶向预防性治疗的基础。

Canine distemper virus (CDV) causes a severe systemic disease in a broad range of carnivores. In addition, up to 30% of dogs experience involvement of the central nervous system (CNS), making CDV well suited for the characterization of Morbillivirus-induced neuropathogenetic mechanisms. In the CNS, CDV causes acute and chronic demyelinating lesions, which are partially of immunopathogenic origin. Since the CDV V-protein plays an essential role in the inhibition of antiviral responses, I hypothesize that CDV-associated inflammatory CNS lesions and subsequent demyelination result from an insufficient infection control by the innate immune response during the acute disease phase.To test this hypothesis, I am proposing a research plan with two specific aims:(a) To assess the ability of CDV to inhibit the interferon (IFN) signaling cascade in different primary mustelid and canine cell types, and (b) to characterize the dissemination, target cells, and the local innate immune response of wild type and V-deleted viruses in mustelid organotypic brain slice cultures.For (a) I will determine the replication efficiency in different primary mustelid and canine CNS cell types, primary epithelial cells, and peripheral blood mononuclear cells. I will also measure the type I IFN production using a VSV-bioassay to investigate a correlation between replication efficiency with the extent of innate immune activation. For (b) I will first compare the spread and target cells of the two viruses by immunohistochemistry, and assess the innate immune activation by VSV-bioassay and cytokine expression levels using real-time RT-PCR and Western blot analysis. The cytokine-expressing cells will then be identified by double-staining of tissue sections.Summarized, the proposed work will advance our understanding of the host response contribution to morbillivirus-associated neurologic complications and will constitute the basis for the development of a targeted preventative therapy.