Targeting complement inhibitors to the human proximal tubule

描述（由申请人提供）：几乎所有肾小球疾病都伴有与结局密切相关的肾小管间质（TI）病理。这种T1损伤可能发生，因为异常肾小球超滤液含有潜在的有害蛋白，包括自发活性补体系统的蛋白。虽然大多数宿主细胞携带补体调节蛋白（CRP），但这些蛋白在近端肾小管上皮细胞（PTEC）中表达不佳。有强有力的数据支持有害的C5 b-9活化发生在蛋白尿条件下的PTEC上。我们已经使用外源性CRP来限制细胞上和组织中的补体激活，包括在肾病模型中，并且最近使用重组单克隆抗体（mAb）和C3结合补体受体（CR2）来选择性地将CRP靶向经历补体攻击的相关细胞，包括蛋白尿诱导的T1损伤中的大鼠PTEC。本文提出的研究将应用这种方法将特异性C5 b-9抑制剂CD 59靶向人类PTEC。第一个目标将是研究保留天然特征的人PTEC培养物，包括可靶向的抗原的表达、CRP的库和对C5 b-9的功能应答。将在这些细胞上模拟暴露于最近过滤的血浆蛋白后可能发生的补体激活，并确定表型反应，包括与进展性肾病中随时间发生的反应相似的反应。然后，我们将评估可用于靶向治疗的PTEC抗原。将研究候选抗原，包括来自我们最近在大鼠中的研究的具有人类同源物的那些，以及在人类PTEC损伤中上调的那些。此外，将评价使用CR2靶向PTEC上补体激活位点的潜力。一旦我们创建了模型系统并确定了递送CRP的可行靶标，我们将创建mAb/CR2-CD 59嵌合体以靶向人PTEC。本文提出的工作应用来自蛋白尿诱导的Tl损伤的实验模型的基本原理和研究来开发用于类似人类疾病的疗法。肾脏疾病已经达到流行病的程度，花费我们的生命和金钱。这里提出的工作使用现代技术来设计治疗这些疾病。虽然这些被认为是试点和高风险的研究，成功完成可以给我们的治疗立即用于临床研究。

DESCRIPTION (provided by applicant): Nearly all glomerular diseases are accompanied by tubulointerstitial (Tl) pathology that is inextricably linked to outcome. Such Tl injury may occur because the abnormal glomerular ultrafiltrate contains potentially injurious proteins, including those of the spontaneously active complement system. Although most host cells bear complement regulatory proteins (CRPs), these are not well expressed by proximal tubular epithelial cells (PTECs). There are strong data supporting that deleterious C5b-9 activation occurs on PTECs in proteinuric conditions. We have used exogenous CRPs to limit complement activation on cells and in tissues, including in renal disease models, and have recently used recombinant monoclonal antibodies (mAbs) and C3-binding complement receptors (CR2) to selectively target CRPs to relevant cells undergoing complement attack, including the rat PTEC in proteinuria-induced Tl injury. The research proposed here will apply this approach to target the specific C5b-9 inhibitor, CD59, to the human PTEC. The first aim will be to study a human PTEC culture that retains native characteristics, including expression of antigens that can be targeted, the repertoire of CRPs, and the functional response to C5b-9. Complement activation as is likely to occur upon exposure to recently filtered plasma proteins will be modeled on these cells, and the phenotypic response determined, including parallels to what occurs over time in progressive renal disease. We will then evaluate PTEC antigens that can be used for targeted therapy. Candidate antigens will be studied, including those with human homologues from our recent studies in the rat, and those upregulated in human PTEC injury. In addition, the potential of using CR2 to target sites of complement activation on the PTEC will be evaluated. Once we have created a model system and identified viable targets to deliver CRPs, we will create mAb/CR2-CD59 chimers to target human PTECs. The work proposed here applies fundamental principles and research derived from experimental models of proteinuria-induced Tl injury to develop therapy for the analogous human diseases. Kidney disease has reached epidemic proportions, costing us in lives and money. The work proposed here uses modern technology to design treatment for these disorders. Although these are considered pilot and high-risk studies, successful completion could give us treatments for immediate use in clinical studies.