CONTROL IG HEAVY CHAIN CLASS SWITCHING

控制 IG 重链类别切换

• 批准号: 2633400
• 负责人: JOHN P MANIS
• 金额: $ 8.8万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-30 至 1999-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2633400
• 关键词: B lymphocyte; animal genetic material tag; cell differentiation; cytokine; gene deletion mutation; gene rearrangement; genetic regulatory element; genetically modified animals; humoral immunity; immunoglobulin genes; laboratory mouse; nucleic acid sequence; phosphorylcholine; tissue /cell culture; transcription factor

The mechanism of regulation of immunoglobulin heavy chain class switching remains unknown. Recent work from the laboratory of Dr. Fred Alt revealed the importance of sequences found 3' of the mouse heavy chain locus. B cells with a neomycin resistance gene replacing the 3' IgH enhancer were generated, and found to display an altered regulation in immunoglobulin isotype switching. The finding of this major regulatory element of IgH constant region genes may provide a key for understanding physiologic and pathologic aspects of immunoglobulin production. We propose to generate mice with a targeted germline deletion of the 3' IgH enhancer. This would create a model to study how this 5kb element exerts control over a l20kb portion of the IgH locus, addressing fundamental questions about how tissue specific gene expression is maintained, and subsequently changed during differentiation. The role of B cell activation signals and cytokines on IgH class switching, as well as mechanisms influencing IgH gene somatic hypermutation will be studied with this model. Importantly, these topics are directly relevant to human diseases such as the Ig deficiencies, immediate type hypersensitivities, and lymphomas involving translocations with c-myc. In the first phase of this proposal, the candidate will focus on learning the theory, approaches, and techniques used in current molecular biology. Phase 2 will focus on applying these techniques to make significant contributions in the understanding of B cell differentiation. The overall objective of this proposal is twofold; first to offer the candidate an intense training in molecular and cellular biology in preparation for an independent research position. Secondly, to provide important, clinically relevant insights in molecular immunology.

免疫球蛋白重链类别转换的调控机制 仍然未知。 Fred Alt 博士实验室的最新研究揭示了 小鼠重链基因座 3' 端发现的序列的重要性。乙 具有新霉素抗性基因取代 3' IgH 增强子的细胞 产生，并发现免疫球蛋白的调节发生改变 同种型转换。 IgH 这一主要调控元件的发现 恒定区基因可能为理解生理和 免疫球蛋白产生的病理方面。 我们建议生成具有 3' 区定向种系删除的小鼠 IgH 增强剂。这将创建一个模型来研究这个 5kb 元素如何 对 IgH 基因座的 l20kb 部分进行控制，解决 关于组织特异性基因表达如何进行的基本问题 保持不变，随后在分化过程中发生变化。的作用 B 细胞激活信号和细胞因子对 IgH 类别转换的影响，以及 将研究影响 IgH 基因体细胞超突变的机制 这个模型。重要的是，这些主题与人类直接相关 免疫球蛋白缺乏症、速发型超敏反应等疾病， 以及涉及 c-myc 易位的淋巴瘤。 在该提案的第一阶段，候选人将重点学习 当前分子生物学中使用的理论、方法和技术。 第二阶段将侧重于应用这些技术来取得重大成果 对 B 细胞分化的理解做出了贡献。整体 该提案的目标是双重的；首先向候选人提供 分子和细胞生物学方面的强化培训，为 独立研究职位。其次，提供重要的临床 分子免疫学的相关见解。