Defense Mechanisms Against CMV Brain Infection

巨细胞病毒脑部感染的防御机制

• 批准号: 7201550
• 负责人: James R Lokensgard
• 金额: $ 27.01万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7201550
• 关键词: Betaherpesvirinae; CD19 molecule; SCID mouse; cellular immunity; chemokine receptor; cytotoxic T lymphocyte; enzyme linked immunosorbent assay; flow cytometry; gene expression; genetically modified animals; helper T lymphocyte; immune response; immunocytochemistry; interferon gamma; interleukin 10; leukocyte activation /transformation; natural killer cells; neuroimmunomodulation; neutralizing antibody; reporter genes; tumor necrosis factor alpha; virus replication; Betaherpesvirinae; CD19 molecule; SCID mouse; cellular immunity; chemokine receptor; cytotoxic T lymphocyte; enzyme linked immunosorbent assay; flow cytometry; gene expression; genetically modified animals; helper T lymphocyte; immune response; immunocytochemistry; interferon gamma; interleukin 10; leukocyte activation /transformation; natural killer cells; neuroimmunomodulation; neutralizing antibody; reporter genes; tumor necrosis factor alpha; virus replication

DESCRIPTION (provided by applicant): Cytomegalovirus is a significant opportunistic pathogen in AIDS patients as well as the most common infectious cause of congenital brain disorders. We have recently developed a model of murine cytomegalovirus (MCMV) encephalitis in which immunocompetent and immunodeficient mice are infected through the intracerebroventricular (icv) route. Analogous t o t he situation in humans, immunocompetent m ice a re not susceptible t o M CMV encephalitis, w whereas mice with a severe immune deficit develop uncontrolled brain infection similar to that seen in patients with advanced AIDS. Adoptive transfer of splenocytes from MCMV-primed mice protects immunodeficient animals and this protection is associated with elevated brain levels of several lymphocyte chemoattractants. In this proposal, the central hypothesis to be tested is that glial cell-produced CXCR3 ligands recruit lymphocytes that control the intracerebral spread of MCMV via the production of antiviral cytokines. To test this hypothesis, we will individually deplete splenic lymphocyte subpopulations (i.e., T lymphocytes [CD4+ and CD8+], NK cells, and B-cells) prior to adoptive transfer into immunodeficient mice and determine the effect on viral spread following subsequent icv infection. We will then examine how disruption of chemokine networks by administration of neutralizing antibodies to each of the CXCR3 ligands affects viral expression and lymphocyte trafficking. Additionally, we will examine the role of CXCR3 ligands in trafficking of lymphocytes into infected brains following adoptive transfer of splenocytes from CXCR3 knockout mice. The effect of lymphocytes on chemokine production by glial cells will be investigated by determining if adoptive transfer amplifies CXCR3 ligand levels and identifying which glial cell types produce these ligands in response to MCMV infection. Transfer of lymphocytes from interleukin-10 knockout mice will be performed to determine if this cytokine is used to dampen glial cell chemokine production in response to infection. The role of antiviral cytokines in inhibiting viral replication in the brain will be addressed by examining differences in tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma, levels in the brains of infected mice with and without adoptively transferred splenocytes. Finally, adoptive transfer of splenic lymphocyte subpopulations, from TNF-alpha and IFN-gamma knockout mice will be used to determine if these cytokines alter viral replication and spread within the brain. The in vivo MCMV brain-infection model presented in this grant application provides us with the ability to investigate neuropathogenesis and defense of the brain occurring during viral encephalitis. The studies proposed in this competitive renewal application will provide new insights into the role of CXCR3 ligand production by activated glial cells in the control of viral replication, chemokine-mediated trafficking of lymphocytes into the brain, and the generation of chemokine-induced cytokine networks.

描述（由申请人提供）：巨细胞病毒是AIDS患者以及先天性脑疾病最常见的传染病的重要机会病原体。我们最近开发了一种鼠巨细胞病毒（MCMV）脑炎的模型，其中免疫功能和免疫缺陷小鼠通过室内（ICV）途径感染。在人类中的情况类似，免疫能力不易受易感性的脑炎脑炎，而患有严重免疫缺陷的小鼠会形成不受控制的脑感染，类似于患有晚期艾滋病患者的小鼠。脾细胞从MCMV引发的小鼠中的收养转移可保护免疫缺陷的动物，并且这种保护与几种淋巴细胞化学吸引剂的大脑水平升高有关。在该提案中，要检验的中央假设是神经胶质细胞生产的CXCR3配体募集淋巴细胞，这些淋巴细胞通过产生抗病毒细胞因子来控制MCMV的脑内扩散。为了检验这一假设，我们将单独耗尽脾淋巴细胞亚群（即T淋巴细胞[CD4+和CD8+]，NK细胞和B细胞），NK细胞和B细胞），然后再传递到免疫缺陷型小鼠中，并确定随后ICV感染后对病毒的影响。然后，我们将通过对每种CXCR3配体中和抗体进行中和抗体的施用来研究趋化因子网络的破坏如何影响病毒表达和淋巴细胞运输。此外，我们将研究CXCR3配体在从CXCR3基因敲除小鼠中收养脾细胞后，将淋巴细胞在被感染的大脑中运输到感染的大脑中的作用。淋巴细胞对神经胶质细胞趋化因子产生的影响将通过确定是否会放大CXCR3配体水平并确定哪些神经胶质细胞类型会响应MCMV感染而产生这些配体。将进行白介素-10敲除小鼠的淋巴细胞转移，以确定该细胞因子是否用于响应感染来抑制神经胶质细胞趋化因子的产生。抗病毒细胞因子在抑制大脑中的病毒复制中的作用将通过检查肿瘤坏死因子（TNF）-Alpha和干扰素（IFN）-Gamma的差异来解决，而感染小鼠的大脑水平有和没有过养的脾细胞。最后，将使用TNF-Alpha和IFN-Gamma基因敲除小鼠的脾淋巴细胞亚群的过继转移，以确定这些细胞因子是否改变了病毒复制并在大脑内传播。本赠款应用中介绍的体内MCMV脑感染模型使我们能够研究病毒性脑炎期间发生的神经病发生和防御脑的神经病生成和防御。在这种竞争性更新应用中提出的研究将为激活的神经胶质细胞在控制病毒复制，趋化因子介导的淋巴细胞运输到大脑中的运输以及趋化因子诱导的细胞因子网络的运输方面提供新的见解。