Role of CD4 T cells in fatal alphavisus encephalomyelitis

CD4 T 细胞在致死性甲状病毒脑脊髓炎中的作用

• 批准号: 9278654
• 负责人: Diane E Griffin
• 金额: $ 8.15万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-10 至 2017-06-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9278654
• 关键词: Address; Adult; Age; Alphavirus; Antibodies; Antiviral Agents; Brain; CD4 Positive T Lymphocytes; Cells; Cervical lymph node group; Cessation of life; Culicidae; Disease; Effector Cell; Encephalitis; Encephalomyelitis; Environment; Evolution; Experimental Autoimmune Encephalomyelitis; Flow Cytometry; Genetic; Health; Hippocampus (Brain); Immune; Immune response; Immune system; Immunoassay; Immunohistochemistry; In Vitro; Inbred BALB C Mice; Individual; Infection; Inflammatory Response; Interferon Type II; Interleukin-10; Interleukin-17; Intervention; Knowledge; Lead; Measures; Mediating; Mediator of activation protein; Modeling; Mus; Nervous System Trauma; Neuraxis; Neurologic; Neurons; Outcome; Paralysed; Pathogenesis; Phenotype; Population; Predisposition; Production; Research; Resistance; Role; Sindbis Virus; Slice; Spinal Cord; Study models; Surface; T-Lymphocyte; Testing; Therapeutic; Viral; Viral Antibodies; Virulence; Virulent; Virus; Virus Diseases; base; cytokine; disability; immunopathology; improved; lymph nodes; mature animal; nervous system disorder; neuron loss; neutralizing antibody; prevent; prototype; receptor; transcription factor; transcriptome

DESCRIPTION (provided by applicant): Sindbis virus (SINV), the prototype alphavirus, causes encephalomyelitis in mice and provides a model for studying the pathogenesis of arboviral encephalomyelitis. Our previous studies with SINV have shown that survival is dependent on host and viral factors that include age and genetic background, virulence of the virus and the host immune response. Neuroadapted SINV (NSV) is virulent for adult C57BL/6 (B6) mice and is a model for virus-induced fatal encephalomyelitis in mature animals. NSV-infected mice develop weakness that progresses to paralysis and death within 7-10 days. Virus clearance from the brain and spinal cord begins 5-6 days after infection and is coincident with the onset of neurological disease. Although the antiviral immune response is essential for virus clearance, it can also contribute to fatal disease. We have shown that survival after NSV infection is improved in T cell-deficient mice and in mice with pharmacologic inhibition of the inflammatory response. Therefore, virus-specific immune cells entering the central nervous system (CNS) contribute to neuronal damage, but the mechanisms and immune factors that cause neuronal death during fatal encephalomyelitis are not known. In preliminary studies, we have determined that deficiency of the important regulatory cytokine interleukin (IL)-10 accelerates the onset of fatal NSV-induced paralytic disease. Accelerated disease is associated with an early increase in the CNS of CD4+ T cells producing IL-17 (Th17 cells) and a delay in virus clearance. Determination of the role of Th17 cells in NSV-induced immunopathology and identification of the mechanism(s) by which they influence outcome is important for developing interventions and for identifying host determinants of susceptibility to severe disease. The specific aims of the proposal are: (1) Determine whether Th17 cells entering the CNS during fatal viral encephalomyelitis have or evolve a "pathogenic" phenotype. Th17 cells in IL-10-/- and wild type (WT) B6 mice will be characterized for expression of transcription factors, cytokines and surface receptors using multicolor flow cytometry. The CNS environment for Th17 cells will be assessed using qRT-PCR and immunoassays. The transcriptome of virus- induced CNS Th17 cells will be determined. (2) Determine whether Th17 cells are responsible for virus- induced immunopathologic disease. Th17 cells and outcome will be studied in mice deficient in factors required for Th1 and Th17 differentiation, genetically resistant BALB/c mice, mice infected with an avirulent strain of SINV and mice rescued from fatal encephalitis by antiviral antibody. (3) Determine the mechanism of CD4+ T cell-mediated neuronal damage and test candidate therapeutics. Effectors will be identified using genetically deficient mice, neutralizing antibodies, immunohistochemistry and CNS slice cultures followed by identification of therapies that prevent immunopathologic CNS damage. (4) Determine the mechanism for delayed virus clearance. Production of IFN-γ and E2 antibody in the CNS and the effect of IL-17 and other Th17 effector molecules on the antiviral effects of IFN-γ and anti-E2 antibody will be measured.

描述（由应用提供）：Sindbis病毒（SINV），原型α病毒，导致小鼠的脑脊髓炎，并提供了研究弧病毒性脑脊髓炎发病机理的模型。我们先前对SINV的研究表明，存活取决于宿主和病毒因素，包括年龄和遗传背景，病毒病毒和宿主免疫反应。神经适应的SINV（NSV）对于成年C57BL/6（B6）小鼠是有毒的，并且是成熟动物中病毒诱发的致命性脑脊髓炎的模型。 NSV感染的小鼠会在7-10天内发展为瘫痪和死亡的弱点。感染后5-6天，大脑和脊髓的病毒清除开始，与神经系统疾病的发作相吻合。尽管抗病毒免疫响应对于病毒清除至关重要，但它也可能导致致命疾病。我们已经表明，在T细胞缺陷小鼠和具有炎症反应的药物抑制的小鼠中，NSV感染后的生存得到了改善。因此，进入中枢神经系统（CNS）的病毒特异性免疫细胞有助于神经元损害，但是在致命性脑脊髓炎期间导致神经元死亡的机制和免疫因子尚不清楚。在初步研究中，我们确定重要的调节性细胞因子白介素（IL）-10的缺乏会加速致命NSV诱发的麻痹性疾病的发作。加速疾病与产生IL-17（Th17细胞）的CD4+ T细胞的中枢神经系统提前增加和病毒清除率有关。测定Th17细胞在NSV诱导的免疫病理学中的作用以及影响结果的机制的鉴定对于制定干预措施和确定对严重疾病易感性的宿主决定者很重要。该提案的具体目的是：（1）确定在致命病毒性脑脊髓炎期间TH17细胞是否进入中枢神经系统，或发展为“致病性”表型。 IL-10 - / - 和野生型（WT）B6小鼠中的Th17细胞将使用多色流式细胞仪来表达转录因子，细胞因子和表面受体的表达。将使用QRT-PCR和免疫测定法评估TH17细胞的CNS环境。将确定病毒诱导的CNS Th17细胞的转录组。 （2）确定TH17细胞是否负责病毒诱导的免疫病理疾病。 TH17细胞和结果将在缺乏Th1和Th17分化所需因素的小鼠中，遗传抗性BALB/C小鼠，被抗病毒抗体从致命性脑炎中救出的sinv菌株和小鼠感染的小鼠。 （3）确定CD4+ T细胞介导的神经元损伤和测试候选治疗的机制。将使用遗传缺陷的小鼠识别效应子，中和 抗体，免疫组织化学和中枢神经系统切片培养物，然后鉴定预防免疫病理中心损伤的疗法。 （4）确定延迟病毒清除率的机制。将测量CNS中IFN-γ和E2抗体的产生，以及IL-17和其他TH17效应子分子对IFN-γ和抗E2抗体抗病毒药作用的影响。