Heterogeneity of plasma cell states is regulated by the dynamics of IRF4 expression

项目总结 保护性抗体反应依赖于分泌的免疫球蛋白。这是在一个 B细胞分化为浆细胞(PC)的阶段特异性方式 关于IRF4和Blimp-1转录因子的顺序上调。在一起，他们 协调浆细胞基因计划，其中包括对 免疫球蛋白转录本与大量分泌重要基因的调控 免疫球蛋白的调节，即转录后调节和翻译后调节。尽管 这种理解，在阐述在活体中观察到的 PC在细胞寿命、增殖率、组织趋向性、表型等方面的异质性 记号笔和分泌率。具体地说，人们不知道这种分级监管是如何 机制使PC国家多样化，即是否有其他监管机构参与，或者 网络的动态控制着不同的PC状态。我们发现，将IRF4基因拷贝减半 导致PC异构性的因素表明，网络的动态使PC状态多样化。 这一建议旨在阐明IRF4表达的动态机制 控制PC结果。此外，我们将使用新开发的记者鼠标， 能够同时检测分泌和膜免疫球蛋白表达的细胞 独特的荧光蛋白。重要的是，我们希望这个记者系统像一部小说一样发挥作用 和分化阶段无偏见的方法来研究细胞经历IgH表达的变化 水平和3‘端用途。共同理解PC表型和Ig的分子基础 使用异构性将使未来的方法能够在不同的环境中测试它们的相关性 它们可能会随着感染或病理状态的不同而变化。

PROJECT SUMMARY Protective antibody responses depend upon secreted immunoglobulin. This is regulated in a stage-specific manner upon the differentiation of B cell blasts into plasma cells (PC) and depends on the sequential upregulation of the IRF4 and Blimp-1 transcription factors. Together, they orchestrate the plasma cell gene program that includes alternative processing of the immunoglobulin transcript and the regulation of genes important for secretion of large quantities of immunoglobulin, i.e. post-transcriptional and post-translational regulation, respectively. Despite this understanding, a gap in knowledge exists in what elaborates the observed in vivo heterogeneity of PC in regards to cell longevity, proliferative rates, tissue tropism, phenotypic markers, and secretory rates. Specifically, it is not understood how this hierarchical regulatory mechanism diversifies PC states, i.e. whether other regulators are engaged or whether the dynamics of the network control distinct PC states. We have found that halving Irf4 gene copies contributes to PC heterogeneity suggesting that the dynamics of the network diversifies PC states. This proposal aims to elucidate the mechanisms whereby the dynamic of IRF4 expression controls PC outcome. Furthermore, we will employ a newly developed reporter mouse that enables simultaneous detection of cells expressing secretory and membrane Ig by two spectrally distinct fluorescent proteins. Importantly, we expect this reporter system to function as a novel and differentiation-stage-unbiased approach to study cells undergoing changes in IgH expression levels and 3'end usage. Together, understanding the molecular basis of PC phenotypic and Ig usage heterogeneity will enable future methodologies to test their relevance in diverse settings which likely vary as a function of infection or pathologic states.