B CELL DIFFERENTIATION IN IG TRANSGENIC SCID MICE

描述：这是第二次提交更新项目进行研究 免疫球蛋白转基因SCID小鼠B细胞分化的研究在……里面 在最近发表的初步实验中，研究人员发现 在转Ig重链基因的SCID小鼠中，B系细胞达到 前B细胞发育阶段，RAG1/2水平下调 亲B细胞阶段。在Ig重链和轻链基因转基因中，SCID B 谱系细胞可达到B细胞发育阶段和RAG1/2水平 在前B细胞阶段和前B细胞阶段都下调。数据来自 SCID/+和SCID转基因研究表明，仅重链基因就可以 阻止V-DJ加入活动(但不阻止DJ加入或V-Jkappa加入 事件)，而重链和轻链基因阻止V-DJ连接和 Kappa轻链基因的重组也是如此。世界银行的目标是 目前的应用是：1)确定组装的重链基因如何 下调原B细胞中RAG的表达(和V-DJ连接)。会是 确定了伪轻链是否在该信号传递中起作用 将尝试克隆与信号传递有关的基因。2) 确定某些u/kappa基因组合促进SCID B细胞的原因 发展，而其他国家则不是。需要检验的一个假设是，这是否 是Mu，kappa组合能够阻止DNA的功能 导致SCID细胞DNA未解决断裂的重组事件。3) 探索Mu、kappa组合的抗原特异性 决定它是否会下调DNA重组(和RAG 表达)。4)确定免疫球蛋白中B细胞的发育是否加速 转基因小鼠。5)评估SCID B细胞的功能活性 转基因动物。值得注意的是，这些动物缺乏T细胞，就像RAG-/-小鼠一样， 但它们仍然是“漏水的”，允许低频率的Ig基因重排 去做吧。关于Ig分泌细胞的性质的问题将被问及 在这些小鼠中产生的(例如，表达kappa转基因或内源性kappa 基因？)以及B细胞是否具有抗自身免疫球蛋白转基因(dsDNA特异性) 能够在这些动物体内发育。6)亩、卡帕之间的差异 已经观察到了转基因SCID小鼠：其中一些小鼠的B细胞 对有丝分裂原有反应，而其他B细胞则不起作用。尝试次数将是 克隆基因，当差异表达时，允许 有丝分裂原反应性或有丝分裂原无反应性。

DESCRIPTION: This is a second submission of a renewal project to study B-cell differentiation in immunoglobulin-transgenic scid mice. In preliminary experiments recently published, the investigator has found that in scid mice transgenic for Ig heavy chain genes, B lineage cells reach the pre-B-cell stage of development and that RAG1/2 levels are downregulated at the pro-B-cell stage. In Ig heavy and light chain gene transgenics, scid B lineage cells can reach the B-cell stage of development and RAG1/2 levels are down-regulated both at the pro-B and the pre-B-cell stages. Data from scid/+ and scid transgenics suggest that the heavy chain gene, alone, can prevent V-DJ joining events (but not DJ joining nor V-Jkappa joining events), while heavy and light chain genes prevent V-DJ joining and recombination at the kappa light chain locus, as well. The goals of the present application are to: 1) determine how an assembled heavy chain gene down-regulates RAG expression (and V-DJ joining) in pro-B-cells. It will be determined whether pseudo-light chain plays a role in this signaling and attempts will be made to clone genes involved in the signaling. 2) Determine why some mu/kappa gene combinations work to promote scid B-cell development while others do not. An hypothesis to be tested is whether this is a function of the mu,kappa combination's being able to arrest DNA recombination events which lead to unresolved breaks in scid cell DNA. 3) Explore the notion that the antigen-specificity of the mu,kappa combination determines whether it will down-regulate DNA recombination (and RAG expression). 4) Determine whether B-cell development is accelerated in Ig transgenic mice. 5) Assess the functional activity of scid B-cells in transgenic animals. Notably, these animals lack T-cells, like RAG-/- mice, but they remain "leaky," allowing low-frequency Ig gene rearrangements to take place. Questions will be asked about the nature of Ig-secreting cells that arise in these mice (e.g., express kappa transgene or endogenous kappa genes?) and whether B-cells with anti-self Ig transgenes (dsDNA-specificity) are able to develop in these animals. 6) Differences among mu,kappa transgenic scid mice have already been observed: the B-cells in some are responsive to mitogen while the B-cells in others are not. Attempts will be made to clone the genes that, when differentially expressed, allow for mitogen-responsiveness or mitogen-unresponsiveness, respectively.