Establishing and characterizing BAFF RFP reporter and BAFF knockin mice

描述（由申请人提供）：BAFF （B细胞活化因子，BLyS, TNFSF13B）是一种tnf家族细胞因子，由许多细胞类型产生，如树突状细胞（dc）、单核细胞、中性粒细胞、T细胞和B细胞以及基质细胞。BAFF对于成熟B细胞的发育和对抗原（Ags）的反应至关重要。BAFF表达的失调与许多免疫性疾病的发展有关，最明显的是自身免疫性疾病，如系统性红斑狼疮（SLE）。正在开发和测试治疗与BAFF失调相关疾病的新药。然而，对于BAFF在体内何时、何地以及如何产生，以及哪些产生BAFF的细胞参与B细胞反应和B细胞相关疾病，我们所知相对较少。我们将开发两种工具来监测BAFF的组织和细胞特异性表达，并评估哪些产生BAFF的细胞有助于免疫反应和免疫病理。我们有两个目标：目标1。BAFF- rfp报告基因和BAFF/BLyS敲入（KI）小鼠的产生。使用双重组酶载体，我们将首先在Baff （Tnfsf13b）位点的一个等位基因上产生一个表达明亮、高度稳定的红色荧光蛋白（RFP）单体形式TagRFP-T的转基因（Tg）系。我们还将创建BAFF KI系（BAFFfl/+小鼠），并将这些小鼠与适当的B6-Cre系杂交，以创建在dc或B细胞中缺乏BAFF表达的敲除（KO）小鼠。目标2。确定来自dc或B细胞的BAFF在B细胞发育和体液免疫应答中的作用。我们将比较WT小鼠、BAFF DC KO小鼠和BAFF B细胞KO小鼠分别接种T细胞依赖性Ag和T细胞非依赖性Ag后的抗体反应。我们还将利用BAFF- rfp报告小鼠在免疫后一段时间内监测BAFF在不同细胞类型中的表达。由于BAFF- rfp报告细胞和BAFFfl/fl KI小鼠将极大地加强基础B细胞生物学研究，并使临床前研究得以开展，以确定功能重要的BAFF来源以及治疗对BAFF产生和功能的影响，因此所提出的研究具有高度意义和潜在的高影响。

DESCRIPTION (provided by applicant): BAFF (B cell activating factor, BLyS, TNFSF13B) is a TNF-family cytokine produced by a number of cell types such as dendritic cells (DCs), monocytes, neutrophils, T and B cells and stromal cells. BAFF is essential for mature B cells to develop and to respond to antigens (Ags). Dysregulation of BAFF expression has been implicated in the development of a number of immunologic diseases, most notably autoimmune diseases like systemic lupus erythematosus (SLE). New drugs are being developed and tested for treating diseases associated with BAFF dysregulation. However, relatively little is known about when, where and how BAFF is produced in vivo and about which BAFF-producing cells contribute to B cell responses and B cell associated diseases. We will develop two tools for monitoring tissue and cell specific expression of BAFF and for assessing which BAFF-producing cells contribute to immune responses and immunopathology. We have two Aims: Aim 1. Generation of BAFF-RFP reporter and BAFF/BLyS knockin (KI) mice. Using a dual recombinase vector we will first generate a transgenic (Tg) line expressing a bright, highly stable monomeric form of red fluorescent protein (RFP) designated TagRFP-T on one allele of the Baff (Tnfsf13b) locus. We will also create a BAFF KI line (BAFFfl/+ mice) and cross these mice with appropriate B6-Cre lines to create knockout (KO) mice lacking BAFF expression in either DCs or B cells. Aim 2. Determining the role of BAFF derived from DCs or B cells in B cell development and humoral immune responses. We will compare the antibody responses of WT mice, BAFF DC KO mice and BAFF B cell KO mice immunized with either a T cell-dependent Ag or a T cell-independent Ag. We will also monitor the expression of BAFF in different cell types over time after immunization using BAFF-RFP reporter mice. The proposed studies are highly significant and have the potential to have high impact since the BAFF-RFP reporter and BAFFfl/fl KI mice will greatly enhance basic B cell biology research and enable pre-clinical studies to be carried out to identify functionally important sources of BAFF and the effect of therapies on BAFF production and function.