Defining the Landscape of HLA Risk Alleles in Primary Nephrotic Syndrome and Post Kidney Transplant Recurrence

项目总结 肾病综合征(NS)是一种知之甚少的免疫介导的肾脏疾病。在儿童中，80%的病例 对类固醇敏感，被称为类固醇敏感型NS(SSNS)，而另外20%是类固醇 抗性(SRNS)。SRNS是终末期肾病的主要原因，需要透析和肾脏。 移植；不幸的是，60%的SRNS患者在移植后会出现疾病复发 最终导致肾移植失败。我们和其他人已经证明了人类白细胞中的变种 抗原(HLA)基因与NS相关，意味着获得性免疫缺陷，涉及调节失调 T和B淋巴细胞的表达，可能在NS的发病机制中起中心作用。而人类白细胞抗原与肾病综合征的相关性 之前的研究是使用全基因组关联芯片在小的单一种族队列中进行的 由于人类白细胞抗原基因的覆盖范围有限，已发现的变异只占NS风险的一小部分。因此， 与NS相关的确切的HLA等位基因/单倍型仍不清楚。为了增进我们对NS的理解， 我们和其他人招募了3700多名患有原发、继发和移植后NS的多民族患者 来自主要的多中心肾脏疾病研究。我们打算表演最先进的下一代 主要人类白细胞抗原I和II类基因编码区和非编码区的测序(NGS)以确定 这些基因变异与NS风险、治疗反应和疾病复发的关系 在肾移植后。我们的主要假设是某些人类白细胞抗原等位基因/单倍型 与NS相关可以预测原发NS患者的皮质类固醇反应模式和疾病风险 肾移植后复发。我们将检验我们的假设并评估潜在的分子 机制通过以下目的：1)使用高分辨率的人类白细胞抗原识别NS人类白细胞抗原的风险等位基因/单倍型 在多民族患者队列中检测NGS并确定基因分型与治疗的关系 回答，2)调查原发NS-HL A风险等位基因/单倍型与继发病因的关系 免疫介导的NS(IgA和膜性肾病)，3)确定共同的结构和功能 NS型人类白细胞抗原风险等位基因/单倍型和非风险等位基因中的基序 这些等位基因在NS患者B淋巴细胞和肾脏中的蛋白表达，以及4)决定能力 已知的和新的NS人类白细胞抗原风险单倍型预测肾移植后的疾病复发。 意义：本申请中提出的研究将使用主要人类白细胞抗原基因的前沿NGS来 确定与NS、治疗反应和疾病相关的精确的HLA等位基因/单倍型 肾移植后复发。理解人类白细胞抗原变异体的内在作用和适应性 肾病综合征的免疫功能障碍将导致发现在疾病中重要的新途径 发病机制和治疗不仅对NS，而且对其他常见的肾小球疾病也是如此。

PROJECT SUMMARY Nephrotic syndrome (NS) is a poorly understood immune-mediated kidney disease. In children, 80% of all cases are steroid responsive and are referred to as steroid sensitive NS (SSNS), while the other 20% are steroid resistant (SRNS). SRNS is a major cause of end-stage kidney disease requiring dialysis and kidney transplantation; unfortunately, 60% of patients with SRNS will develop disease recurrence following transplant and ultimately kidney allograft failure. We and others have demonstrated that variants in Human Leukocyte Antigen (HLA) genes are associated with NS, signifying that defects in adaptive immunity, involving dysregulation of both T and B lymphocytes, may be central to NS pathogenesis. While the association between HLA and NS is strong, previous studies were carried out in small mono-ethnic cohorts using genome wide association chips with limited coverage of the HLA genes, and variants uncovered account for a small fraction of NS risk. Therefore, the precise HLA alleles/haplotypes associated with NS remain unknown. To enhance our understanding of NS, we and others have enrolled over 3,700 multi-ethnic patients with primary, secondary, and post-transplant NS from major multicenter kidney disease studies. We propose to perform state of the art next generation sequencing (NGS) of the coding and non-coding regions of major HLA class I and II genes to determine the relationship between variants in these genes and risk of NS, response to therapy, and disease recurrence following kidney transplantation. Our overarching hypothesis is that certain HLA alleles/haplotypes associated with NS can predict pattern of corticosteroid response in primary NS and the risk of disease recurrence following kidney transplantation. We will test our hypothesis and evaluate potential molecular mechanisms through the following aims: 1) Identify NS HLA risk alleles/haplotypes using high resolution HLA NGS in a cohort of multi-ethnic patients and determine the relationship between genotypes and therapy response, 2) Investigate the association between primary NS HLA risk alleles/haplotypes and secondary causes of immune-mediated NS (IgA and membranous nephropathy), 3) Determine common structural and functional motifs within NS HLA risk alleles/haplotypes and non-risk alleles by in-silico modeling and compare gene and protein expression of these alleles in B lymphocytes and kidneys of patients with NS, and 4) Determine the ability of known and novel NS HLA risk haplotypes to predict disease recurrence following kidney transplantation. Significance: The studies proposed in this application will use cutting-edge NGS of major HLA genes to identify the precise HLA alleles/haplotypes that are associated with NS, therapy response, and disease recurrence following kidney transplantation. Understanding the intrinsic role of HLA variants and adaptive immunity dysfunction in NS will lead to identification of novel pathways that are important in disease pathogenesis and therapy not just for NS, but also for other common glomerular diseases.