Polyomavirus Infection after Kidney Transplantation

描述（由申请人提供）：BK病毒感染的同种异体肾移植已成为相当关注的问题。我们在确定这些患者的临床病程方面发挥了主导作用。我们在这一领域的努力在过去的3年里得到了美国国立卫生研究院的RO-1资助。我们现在准备了一份竞争性的继续拨款申请，以继续研究这个重要的问题。具体目标# 1：表征BKV的序列多样性和系统发育进化，并确定其对临床实践中分子诊断分析的潜在影响。我们假设变异的BKV毒株损害了我们(a)确定病毒感染真实流行的能力，以及(b)准确定量从个体患者获得的临床样本中的病毒基因组载量的能力。我们的目标是澄清新的病毒株在自然界中发展的速度，并确定基于pcr的诊断分析是否也需要不断适应以弥补这种持续的进化。特异性目标2：描述影响肾脏PV复制的宿主和病毒因素。我们建议在细胞培养系统中直接测量突变型和野生型病毒的病毒复制率。此外，我们将确定发生BK病毒血症和病毒血症的风险是否取决于供体或宿主在能够调节宿主-病原体相互作用的基因中的多态性。具体目的3：研究阴燃BKV感染对慢性同种异体移植肾病发展的影响。我们假设无症状病毒尿，大约35%的患者出现，代表潜伏的BKV感染，有助于慢性同种异体移植肾病的发展。为了解决这个问题，我们将使用档案活检材料来评估病毒感染患者肾功能障碍的一系列进展。具体目标# 4：使用三维同源建模和虚拟筛选技术发现能够结合VP-1和t抗原分子功能域的抗bkv药物。鉴于肾移植受者BKV感染的重要性日益增加，迫切需要开发适合临床使用的抗BKV药物。我们假设，通过筛选能结合两种关键病毒蛋白（即病毒衣壳蛋白-1 （VP-1）和大T抗原）的化合物，可以发现抗bkv药物。

DESCRIPTION (provided by applicant): BK virus infection of the renal allograft has become a matter of considerable concern. We have played a leading role in defining the clinical course of these patients. Our effort in this area has been funded by an NIH sponsored RO-1 grant for the past 3 years. We have now prepared a competing continuation grant application to continue our study of this important problem. Specific Aim # 1: To characterize the sequence diversity and phylogenetic evolution of BKV, and determine its potential impact on molecular diagnostic assays in clinical practice. We hypothesize that variant BKV strains are compromising our ability to (a) determine the true prevalence of viral infection, and (b) accurately quantitate the viral genomic load in clinical samples obtained from individual patients. It will be our goal to clarify the rate at which new viral strains are developing in nature, and to determine whether PCR-based diagnostic assays will also need to be continuously adapted to compensate for this continuing evolution. Specific Aim # 2: To delineate host and viral factors that affect PV replication in the kidney. We propose to directly measure viral replication rates in mutant and wild type viruses in a cell culture system. In addition, we will determine if the risk of developing BK viruria and viremia is dependent on donor or host polymorphisms in genes capable of modulating host- pathogen interactions. Specific Aim #3: To examine the impact of smoldering BKV infections on the development of chronic allograft nephropathy. We hypothesize that asymptomatic viruria, which occurs in approximately 35% of our patients, represents a smoldering BKV infection that contributes to the development of chronic allograft nephropathy. To address this issue, we will use archival biopsy material to assess the serial progression of renal dysfunction in virus infected patients. Specific Aim # 4: To use 3- dimensional homology modeling and virtual screening technology to discover anti-BKV drugs capable of binding functional domains on the VP-1 and T-antigen molecules. Given the growing importance of BKV infection in renal transplant recipients, there is a pressing need to develop anti-BKV drugs suitable for clinical use. We hypothesize that anti-BKV drugs can be discovered by screening chemical libraries for compounds that can bind to two key viral proteins, namely, viral capsid protein-1 (VP-1) and large T antigen.