Signaling pathways that interface with Klf2 to regulate B cell migration

描述（由申请人提供）：人类B细胞耗竭疗法以及来自动物模型的累积证据表明，B淋巴细胞有助于引发几种自身免疫性疾病，包括关节炎、狼疮和1型糖尿病。最近的临床试验表明，限制淋巴细胞迁移可以改善自身免疫性疾病，提高了B细胞循环可以作为治疗自身反应性的手段的可能性。一个主要 实现这一目标的障碍是缺乏关于B细胞归巢受体调节的机制知识。该R21项目基于申请人的发现，即Kruppel样因子2（Klf 2）是控制成熟B细胞迁移模式的关键转录因子。此外，Klf 2在B细胞区室内的切除导致狼疮样形式的自身免疫，其进一步支持改变的B细胞迁移和疾病进展之间的联系。目前拨款提案的前提是Klf 2控制几个重要的归巢受体，通过定义与Klf 2相互作用的基因和蛋白质，将揭示协调B细胞运输的分子机制。为了实现这一目标，Aim 1研究将首先使用定量质谱（MS）技术来鉴定促进Klf 2功能的相互作用蛋白。平行的MS研究将确定与Klf 2调节的归巢受体的启动子区结合的蛋白质复合物。总之，这些实验将揭示Klf 2相互作用蛋白的子集，其以谱系特异性方式直接形成B细胞迁移。在Aim 2研究中，将使用DNA微阵列和染色质免疫沉淀结合高通量DNA测序（ChIP-Seq）方法捕获Klf 2控制下调节B细胞运输的基因。这些结果将确定Klf 2的遗传足迹，从而提供涉及B细胞稳态和自身耐受的分子靶点的缓存。获得缺乏Klf 2的原代B细胞谱系为所提出的生化和遗传实验提供了理想的对照。从拟议的项目中出现的总体结果将提供第一次深入了解如何保持成熟的B细胞循环模式。反过来，这些发现可能会促进新疗法的合理设计，以控制B细胞运输作为改善疾病的手段。

DESCRIPTION (provided by applicant): B cell-depletion therapies in humans as well as accumulating evidence from animal models indicate that B lymphocytes help initiate several autoimmune disorders including arthritis, lupus, and type 1 diabetes. Recent clinical trials have shown that restricting lymphocyte migration can ameliorate autoimmune diseases, raising the possibility that B cell circulation can be targeted as a means of treating auto reactivity. A major barrier towards achieving this goal is the dearth of mechanistic knowledge concerning the regulation of B cell homing receptors. This R21 project is predicated on the applicant's discovery that Kruppel-like factor 2 (Klf2) is a key transcription factor that controls mature B cel migration patterns. Moreover, Klf2 excision within the B cell compartment results in a lupus-like form of autoimmunity that further supports the link between altered B cell migration and disease progression. The premise of the current grant proposal is that Klf2 controls several important homing receptors and that by defining the genes and proteins that interface with Klf2, the molecular mechanisms that orchestrate B cell trafficking will be revealed. To achieve this goal, Aim 1 studies will initially use quantitative mass-spectrometry (MS) techniques to identify interactive proteins that facilitate Klf2 function. Parallel MS studies will define the protein complexes bound to the promoter regions of Klf2-regulated homing receptors. Together, these experiments will reveal a subset of Klf2-interactive proteins that directly shape B cell migration in a linage-specific manner. In Aim 2 studies, genes under Klf2 control that regulate B cell trafficking will be captured using a combination of DNA microarrays and chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-Seq) approaches. These results will define the genetic footprint of Klf2 and thus provide a cache of molecular targets involved in B cell homeostasis and self- tolerance. Access to primary B cell lineages that lack Klf2 provide the ideal control for the proposed biochemical and genetic experiments. Overall results emerging from the proposed project will provide the first insight into how mature B cell circulation patterns are maintained. In turn, these discoveries may promote the rationale design of new therapies to control B cell trafficking as a means of ameliorating disease.