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: 8690404
• 负责人: Diane E Griffin
• 金额: $ 35.44万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8690404
• 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; Gene Expression Profile; Genetic; Health; Hippocampus (Brain); Immune; Immune response; Immune system; Immunoassay; Immunohistochemistry; In Vitro; Inbred BALB C Mice; Individual; Infection; Inflammatory Response; Interferons; 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; neutralizing antibody; prevent; prototype; receptor; transcription factor

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（由申请方提供）：辛德毕斯病毒（SINV）是甲病毒的原型，可引起小鼠脑脊髓炎，并为研究虫媒病毒脑脊髓炎的发病机制提供了模型。我们以前对SINV的研究表明，生存取决于宿主和病毒因素，包括年龄和遗传背景，病毒的毒力和宿主免疫反应。神经适应性SINV（NSV）对成年C57 BL/6（B6）小鼠具有毒性，是成熟动物中病毒诱导的致死性脑脊髓炎的模型。感染NSV的小鼠在7-10天内发展为瘫痪和死亡。病毒在感染后5-6天开始从大脑和脊髓中清除，与神经系统疾病的发作一致。虽然抗病毒免疫应答对于病毒清除至关重要，但它也可能导致致命疾病。我们已经证明，在T细胞缺陷小鼠和炎症反应的药理学抑制小鼠中，NSV感染后的存活率得到改善。因此，病毒特异性免疫细胞进入中枢神经系统（CNS）有助于神经元损伤，但在致命性脑脊髓炎期间引起神经元死亡的机制和免疫因素尚不清楚。在初步研究中，我们已经确定，缺乏重要的调节细胞因子白细胞介素（IL）-10加速致命的NSV诱导的麻痹性疾病的发病。加速性疾病与CNS中产生IL-17的CD 4 + T细胞（Th 17细胞）的早期增加和病毒清除延迟有关。确定Th 17细胞在NSV诱导的免疫病理学中的作用并鉴定它们影响结果的机制对于开发干预措施和鉴定对严重疾病易感性的宿主决定因素是重要的。该提案的具体目标是：（1）确定在致命性病毒性脑脊髓炎期间进入CNS的Th 17细胞是否具有或演变为“致病”表型。将使用流式细胞术表征IL-10-/-和野生型（WT）B6小鼠中的Th 17细胞的转录因子、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Th 17细胞的CNS环境。将测定病毒诱导的CNS Th 17细胞的转录组。(2)确定Th 17细胞是否负责病毒诱导的免疫病理学疾病。Th 17细胞和结果将在缺乏Th 1和Th 17分化所需因子的小鼠、遗传抗性BALB/c小鼠、感染SINV无毒力株的小鼠和通过抗病毒抗体从致命性脑炎中拯救的小鼠中进行研究。(3)确定CD 4 + T细胞介导的神经元损伤的机制并测试候选疗法。将使用遗传缺陷小鼠鉴定效应子， 抗体、免疫组织化学和CNS切片培养，随后鉴定预防免疫病理学CNS损伤的疗法。(4)确定延迟病毒清除的机制。将测量CNS中IFN-γ和E2抗体的产生以及IL-17和其他Th 17效应分子对IFN-γ和抗E2抗体的抗病毒作用的影响。