CNS Pathobiology of IFN-inducible non-ELR CXC Chemokines

描述(申请人提供)：三种趋化因子，CXCL9，CXCL10和CXCL11，组成干扰素诱导的非ELR CXC趋化因子亚群。这些趋化因子与共同的受体CXCR3和可能的附加受体结合，参与白细胞的运输，但具有其他重叠和不同的功能。在这里，我们假设，由于受体的可用性和用途以及他们自己的差异基因表达，这个趋化因子亚群的成员在多发性硬化症和病毒性脑膜脑炎等炎症性神经疾病的发病机制中发挥着多种不同的作用。我们和其他人广泛研究的CXCL10是局部诱导的(例如在星形胶质细胞中)，并参与从感染性脑膜脑炎到免疫性炎症性脱髓鞘等多种中枢神经系统疾病的白细胞运输。尽管如此，我们对以下方面知之甚少：(1)CXCL9、CXCL10和CXCL11或CXCR3在上述和其他中枢神经系统炎症性疾病病理机制中的时空协调调节；(2)这三种趋化因子在这个亚群中可能发挥的中枢神经系统功能的谱；(3)CXCR3与其他可能的受体在中枢神经系统中介导这些趋化因子生物学作用的相对作用。因此，在这项建议的第一个具体目标中，我们将定义CXCL9、10和L 1和CXCR3在不同的神经炎性病理中的协调调控和时空表达，包括：(I)内毒素血症，(Ii)病毒感染(即淋巴细胞性脉络膜脑膜炎和MHV脑脊髓炎)，(Iii)髓鞘少突胶质细胞多肽(MOG)免疫诱导的实验性自身免疫性脑脊髓炎(EAE)。此外，这些疾病范例将在缺乏干扰素-γ基因的小鼠身上进行研究，以确定这一关键细胞因子的调节作用。在第二个具体目标中，我们将评估CXCL9、CXCL10和CXCL11在活体中枢神经系统中的功能后果和作用机制。每产生一种针对星形胶质细胞的趋化因子，就会产生转基因小鼠。这些所谓的GF-CXCL转基因小鼠将接受中枢神经系统自发和疾病诱导的改变的评估。此外，我们还将阐明这些趋化因子在中枢神经系统中的血管抑制功能。为此，我们将把GF-CXCL小鼠与脑中有慢性血管生成的GF-IL-6转基因小鼠杂交。在最终的特定目标中，我们将利用最近开发的缺乏CXCR3受体的突变小鼠来确定该受体或其他假定的受体在介导CXCL10的生物学行为中的作用。CXCR3缺陷小鼠将在CNS病毒感染或诱导MOG-EAE以及与GF-CXCL10转基因小鼠杂交后接受神经病理结果检查。我们的研究结果将填补我们目前知识的巨大空白，并为干扰素-γ诱导的非ELR CXC趋化因子的中枢神经系统病理生物学提供重要的新信息。

DESCRIPTION (provided by applicant): Three chemokines, CXCL9, CXCL10 and CXCL11, comprise the IFN-inducible non-ELR CXC chemokine subgroup. These chemokines bind to a common receptor CXCR3 and possibly additional receptors and are involved in leukocyte trafficking but have other overlapping as well as distinct functions. Here we hypothesize that as dictated by receptor availability and usage as well as through their own differential gene expression, members of this chemokine subgroup play multiple and diverse roles in the pathogenesis of inflammatory neurological diseases such as multiple sclerosis and viral meningoencephalitis.CXCL10 which is widely studied by us, as well as others, is induced locally (e.g. in astrocytes) and implicated in leukocyte trafficking in a variety of CNS diseases ranging from infectious meningoencephalitides to immunoinflammatory demyelinating pathologies. Despite this, we know very little about: (1) the coordinate spatial and temporal regulation of CXCL9, CXCL10 andCXCL11 or CXCR3 in these and other CNS inflammatory disease pathologies, (2) the spectrum of possible CNS functions performed by all three chemokines in this subgroup, and (3) the relative role of CXCR3 versus other putative receptors inmediating the biological actions of these chemokines in the CNS. Accordingly, in the first specific aim of this proposal we will define the coordinate regulation and temporal and spatial expression of CXCL9, 10 &l 1 and CXCR3 in distinct neuroinflammatory pathologies including: (i) LPS-induced endotoxemia, (ii) virus infection (i.e. lymphocytic choriomeningitis and MHV encephalomyelitis), and (iii) myelin oligodendrocyte peptide (MOG) immunization-induced experimentalautoimmune encephalomyelitis (EAE). Further, these disease paradigms will be studied in mice lacking the IFN-gamma gene in order to establish the regulatory role of this key cytokine. In the second specific aim, we will assess the in vivo functional consequences and mechanisms of action of CXCL9, CXCL10 and CXCL11 in the living CNS. Transgenic mice will be generated with the production of each these chemokines targeted to the astrocyte. These so-called GF-CXCL transgenicmice will be assessed for spontaneous as well as disease-induced alterations in the CNS. In addition, we will elucidate the angiostatic functions of these chemokines in the CNS. For this purpose we will interbreed GF-CXCL mice with GF-IL-6transgenic mice that have chronic angiogenesis in the brain. In the final specific aim we will make use of recently developed mutant mice that lack the CXCR3 receptor to determine the role of this or other putative receptors in mediating the biological actions of CXCL10. CXCR3 deficient mice will be examined for neuropathologic outcomes following CNS viral infection or induction of MOG-EAE as well as in intercrosses with the GF-CXCL10 transgenic mice. The results from our studies will fill in large gaps in our current knowledge and provide important new information as to the CNS pathobiology of the IFN-gamma-inducible non-ELR CXC chemokines.