Viral tools for studying NG2 cells

描述（由申请人提供）：少突胶质细胞是中枢神经系统的髓磷脂形成细胞，由鉴定的前体细胞发育而来，即少突胶质细胞祖细胞（OPCs）、多突胶质细胞或NG2细胞。这些细胞大约在妊娠中期出现在啮齿动物发育中的中枢神经系统内的特定位置，广泛迁移，随着迁移而增殖，然后缓慢分化为髓磷脂形成细胞。令人惊讶的是，大部分OPC细胞不能完全分化，并在成人中枢神经系统中持续存在，作为一种缓慢分裂的细胞，可以被认为是第四种胶质细胞类型。这些成年OPCs的功能还没有被很好地理解，部分原因是它们不同寻常地混合了胶质和神经元的特性。主要的问题仍然是：1)这些细胞在发育和成年动物以及损伤后的表型可塑性；2)电兴奋性在OPC发育和功能中的作用。本提案的目标是开发新的基于病毒的工具来分析NG2+ opc的发展和特性。我们的策略利用了细胞类型特异性诱导cre小鼠驱动系的可用性和最近开发的“翻转”载体，其中串联突变的loxP位点允许将选定的基因从反义方向倒置到义方向。这种策略允许对标记抗原、功能蛋白和RNAi的表达进行时间控制。这里开发的工具可以广泛用于研究中枢和周围神经系统内的其他胶质细胞类型。

DESCRIPTION (provided by applicant): Oligodendrocytes, the myelin forming cells of the CNS, develop from identified precursor cells known alternately as oligodendrocyte progenitor cells (OPCs), polydendrocytes, or NG2 cells. These cells appear about midgestation in rodents at specific locations within the developing CNS, migrate extensively, proliferate as they migrate, and then slowly differentiate into myelin-forming cells. Surprisingly, a large fraction of the OPC population fails to fully differentiate and persists throughout the adult CNS as a slowly dividing cell that can be considered an fourth glial cell type. The functions of these adult OPCs are not well understood, in part, because of their unusual mixture of glial and neuronal properties. Major questions remain regarding 1) the phenotypic plasticity of these cells in developing and adult animals and after injury and 2) the role of electrical excitability in OPC development and function. The goal of this proposal is to develop new viral-based tools for analyzing the development and properties of NG2+ OPCs. Our strategy takes advantage of the availability of cell-type specific inducible cre mouse driver lines and recently developed "flip" vectors in which tandem mutant loxP sites allow for inversion of selected genes from an anti-sense to sense orientation. This strategy allows for temporal control of the expression of marker antigens, functional proteins and RNAi. The tools to be developed here can be used widely to study other glial cell types within the central and peripheral nervous system. PUBLIC HEALTH RELEVANCE: Oligodendrocytes, the myelin-forming cells of the CNS, develop from an identified precursor cell that has an unusual mixture of neuronal and glial properties. Their functional role(s) in CNS homeostasis is unknown. The new tools to be developed here will help us to understand the unusual properties of these cells and how those properties relate to the responses of these cells to injury and demyelination.