Molecular Analyses of the individual function of the transcriptional Co-Activator BOB.1/OBF.1 in B versus T lymphocytes and its specific contribution to the Germinal Center Reaction

B 淋巴细胞与 T 淋巴细胞中转录共激活因子 BOB.1/OBF.1 个体功能的分子分析及其对生发中心反应的具体贡献

• 批准号: 397031396
• 负责人: Professorin Dr. Cornelia Brunner
• 金额: --
• 依托单位: Forschungsbereich Onkologie / Tumorimmunologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/397031396?language=en
• 关键词: Molecular; Analyses; individual; function; transcriptional

BOB.1/OBF.1 was originally described as a B cell specific transcriptional co-activator. BOB.1/OBF.1 itself has only very weak affinity to DNA but is recruited by the transcription factors Oct1 and Oct2 to the so called Octamer motif and thereby enhances Octamer-dependent transcription. BOB.1/OBF.1-deficient mice show severe defects at different stages of B cell development, but also in certain T cell populations, like TH1, TH2 or follicular T-helper cells (TFH). The main characteristic of BOB.1/OBF.1-deficient mice is the complete absence of germinal centers and consequently also of germinal center derived B cells, like plasma and memory B cells. However, the question is not fully understood, whether the lack of germinal centers is caused exclusively by the BOB.1/OBF.1 deficiency in B cells or if in addition an inefficient T cell help, provided particularly by TFH, also contributes to this severe phenotype. Because of the lack of appropriate tools to regulate BOB.1/OBF.1 expression in these terminal cell differentiation stages so far we were not able to define the exact impact of BOB.1/OBF.1 to the germinal center reaction by precise molecular analyses. Furthermore, there were only limited options to study BOB.1/OBF.1 deficiency in T cells in the presence of wildtype B cells and vice versa.We have now generated mice bearing floxed BOB.1/OBF.1 alleles. Such a mouse system allows the conditional deletion of BOB.1/OBF.1 expression and therefore the precise analyses of B- as well as T-cell differentiation and function in the absence of the transcriptional co-activator. Using our conditional system together with appropriate Cre expressing mouse lines we are now able to analyze the specific need of BOB.1/OBF.1 expression in early and also in late stages of B-cell development as well as the requirement of BOB.1/OBF.1 for the function of specific T cell subpopulations. A main focus of our project is the identification and further characterization of BOB.1/OBF.1 target genes in order to understand the influence of BOB.1/OBF.1 on B-cell development and function under physiological conditions. Moreover, these analyses allow us to understand how BOB.1/OBF.1 affects germinal center reaction if it is exclusively deleted in defined B and T cell subpopulations. Additionally, due to our newly generated system we are now able to characterize the individual relevance of BOB.1/OBF.1 under immune-pathological conditions and thus to further elucidate the role of BOB.1/OBF.1 in autoimmune processes. Therefore, the aim of the here proposed study is the identification of molecular mechanisms in which the transcriptional co-activator BOB.1/OBF.1 is involved during B and T cell development and differentiation as well as new functions of BOB.1/OBF.1 in those processes under physiological and also immune-pathological conditions.

Bob.1/obf.1最初被描述为B细胞特异性转录共激活因子。 Bob.1/obf.1本身对DNA的亲和力仅非常弱，但被转录因子Oct1和Oct2募集到所谓的八聚体基序，从而增强了八聚体依赖性转录。 Bob.1/obf.1缺陷小鼠在B细胞发育的不同阶段显示出严重的缺陷，但在某些T细胞群体（如Th1，Th2或滤泡T-TH2或卵泡T-helper细胞（TFH））中也显示出严重的缺陷。 BOB.1/obf.1缺陷小鼠的主要特征是完全不存在生发中心，因此也没有生发中心衍生的B细胞，例如血浆和记忆B细胞。但是，这个问题尚未完全理解，是否缺乏生发中心是仅由BOB.1/obf.1 B细胞中的缺乏引起的，还是另外是否尤其是由TFH提供的低效率T细胞帮助也会导致这种严重的表型。由于缺乏调节BOB的适当工具。1/obf.1在这些末端细胞分化阶段的表达到目前为止，我们无法通过精确的分子分析来定义BOB.1/OBF.1对生发中心反应的确切影响。此外，研究BOB.1/obf.1在存在Wildtype B细胞的情况下，T细胞缺乏症的选择有限，反之亦然。现在，我们已经产生了带有bob.1/obf.1等位基因的小鼠。这种小鼠系统允许有条件地删除BOB.1/obf.1表达，因此在没有转录共激活因子的情况下，B-以及T细胞分化和功能的精确分析。使用条件系统以及适当的CRE表达小鼠线，我们现在能够分析BOB.1/OBF.1早期和B细胞发育后期的表达以及BOB.1/obf.1在特定T细胞亚种的功能中的需求。我们项目的主要重点是BOB.1/obf.1靶基因的识别和进一步表征，以了解BOB.1/obf.1对生理条件下B细胞发育和功能的影响。此外，这些分析使我们能够理解BOB.1/obf.1如果在定义的B和T细胞亚群中仅删除了生发中心反应。此外，由于我们新生成的系统，我们现在能够表征BOB.1/obf.1在免疫病理条件下的个人相关性，从而进一步阐明了Bob.1/obf.1在自身免疫过程中的作用。因此，此处提出的研究的目的是鉴定分子机制，其中转录共激活因子BOB.1/obf.1在B和T细胞发育和分化过程中涉及BOB.1/OBF.1在生理和免疫病理条件下的这些过程中的新功能。