Podocyte-specific human PLA2R transgenic mouse model of membranous nephropathy

足细胞特异性人PLA2R转基因小鼠膜性肾病模型

• 批准号: 8103239
• 负责人: DAVID J SALANT
• 金额: $ 20.91万
• 依托单位: BOSTON MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-02 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8103239
• 关键词: Animal Testing; Antibodies; Antigen Targeting; Antigens; Autoantibodies; Binding; Biopsy; Cavia; Cell Aging; Chinchilla (genus); Clinical; Complement; Deposition; Development; Disease; Eicosanoid Production; Epitopes; Future; Goals; Human; Idiopathic Membranous Nephropathy; IgG1; IgG4; Immune; Immunoglobulin G; Injury; Kidney; Laboratory Animals; Ligand Binding; Location; Mediating; Membranous Glomerulonephritis; Modeling; Mus; Oryctolagus cuniculus; Pathogenicity; Patients; Phospholipase; Play; Positioning Attribute; Proteinuria; Rattus; Role; Serum; Specificity; System; Techniques; Testing; Transgenic Mice; Transgenic Organisms; complement pathway; in vivo; model development; mouse model; nephrin; podocyte; promoter; public health relevance; receptor; tool

DESCRIPTION (provided by applicant): The primary goal of this exploratory proposal is to develop a tool to determine if circulating autoantibodies directed at the M-type phospholipase receptor (PLA2R) from patients with idiopathic membranous nephropathy (MN) are pathogenic. We have established that about 75% of patients with idiopathic MN have circulating anti-PLA2R autoantibodies whereas none of the disease or normal controls has tested positive, thus indicating a high degree of specificity. The anti-PLA2R antibodies are IgG4, the subclass that predominates in idiopathic but not secondary MN, the antigen PLA2R is expressed on podocytes and colocalizes with IgG4 in the glomerular immune deposits of patients with MN, and the antibodies can be eluted from the glomerular immune deposits of MN renal biopsies. Moreover, the presence of circulating anti-PLA2R antibodies correlates with disease activity in MN. Although these findings strongly suggest that anti-PLA2R antibodies are responsible for, or at least contribute to disease development, proof of pathogenicity has yet to be established. Whereas simple transfer of the disease to laboratory animals with human anti-PLA2R would readily answer this question, human anti-PLA2R does not recognize PLA2R in the glomeruli of any small laboratory animal tested to date. Therefore, we plan to take advantage of both the lack of immunoreactive PLA2R in mouse glomeruli and the refinement of podocyte- specific transgenic techniques to develop a mouse model in which the human PLA2R is expressed in podocytes. To that end we propose the following specific aims: Specific Aim 1: Produce a transgenic mouse utilizing the NPHS1 (nephrin) promoter to drive expression of human PLA2R exclusively in mouse podocytes. Specific Aim 2: Verify that human PLA2R is expressed on mouse podocytes in vivo. Specific Aim 3: a) Determine if injected human anti-PLA2R autoantibodies bind to human PLA2R and form immune deposits typical of MN in the transgenic mouse glomeruli. b) Establish if injected human anti-PLA2R antibodies are able to cause proteinuria in the human PLA2R transgenic mouse. Specific Aim 4: Determine if the human PLA2R transgenic mice develop anti-PLA2R antibodies and MN when actively immunized with human PLA2R. Successful development of this model will pave the way for studies to both establish the pathogenic role of human anti-PLA2R autoantibodies and define the mechanisms of injury. PUBLIC HEALTH RELEVANCE: Having demonstrated that the M-type phospholipase receptor (PLA2R) is a specific target antigen of circulating autoantibodies in a high proportion of patients with idiopathic membranous nephropathy, we propose to develop a mouse model to determine if the antibodies are responsible for the clinical (proteinuria) and pathological manifestations of the disease. To that end, we will produce transgenic mice in which the human PLA2R is expressed on mouse podocytes, the location of the antigen in human kidneys.

描述（由申请人提供）：该探索性建议的主要目标是开发一种工具来确定针对特发性膜性膜肾病（MN）患者的针对M型磷脂酶受体（PLA2R）的循环自身抗体是否是致病性的。我们已经确定，大约75％的特发性MN患者具有循环抗PLA2R自身抗体，而疾病或正常对照组均未测试阳性，因此表明具有高度的特异性。抗PLA2R抗体是IgG4，是特发性（但不是继发MN）的亚类，抗原PLA2R在足细胞上表达，并与IgG4一起在患者的肾小球免疫沉积物中与IgG4共定位，抗体可以从MN和抗体中产生抗体，并且可以从抗体中受到肾小球的plosies ry nune nune glomulune mornulun glomulune mornulun numeull glomulune nune andunemular mornulun normulune andune andune andune。此外，循环抗Pla2R抗体的存在与MN中的疾病活性相关。尽管这些发现强烈表明抗Pla2R抗体是为疾病发展的原因或至少有助于疾病的原因，但尚未确定致病性证据。尽管将这种疾病的简单转移到具有人类抗Pla2r的实验动物的情况下，很容易回答这个问题，但人类抗Pla2r尚未识别迄今已测试的任何小型实验室动物的肾小球中的PLA2R。因此，我们计划利用小鼠肾小球中缺乏免疫反应性PLA2R以及足细胞 - 特异性转基因技术的细化来开发小鼠模型，其中人PLA2R在足细胞中表达。为此，我们提出了以下特定目的：特定目标1：利用NPHS1（Nephrin）启动子产生转基因小鼠，仅在小鼠足细胞中驱动人PLA2R的表达。 具体目标2：验证人PLA2R是否在体内小鼠足细胞上表达。 特定目标3：a）确定注射的人类抗Pla2r自身抗体是否与人PLA2R结合，并形成转基因小鼠肾小球中MN典型的免疫沉积物。 b）确定注射的人类抗Pla2r抗体是否能够在人PLA2R转基因小鼠中引起蛋白尿。 具体目标4：确定人PLA2R转基因小鼠在用人PLA2R主动免疫时是否会产生抗Pla2r抗体和MN。该模型的成功开发将为研究建立人类抗Pla2r自身抗体的致病作用并定义损伤机制铺平道路。 公共卫生相关性：证明M型磷脂酶受体（PLA2R）是在很大比例的特发性膜性肾病患者中循环自身抗体的特定靶抗原，我们建议我们开发一种小鼠模型来确定抗体是否负责抗体（proteineinuria）和病理学的疾病）。为此，我们将产生转基因小鼠，其中人PLA2R在小鼠足细胞上表达，抗原在人肾脏中的位置。