Innate B cell immunity and antibody-mediated rejection of human kidney allografts

项目摘要 移植目前是一些终末期肾脏疾病的首选治疗方法。相当可观 在过去的几十年里，在预防肾移植早期排斥反应方面取得了进展。然而，长期的生存 发生率仍然很低，可能是由于抗体介导的排斥反应(ABMR)。尽管有特异性的抗体 供体人类白细胞抗原分子(DSA)无可争议地对ABMR、其他类型的抗体、 特别是自身抗体，也被牵连进来。我们实验室以前的研究与自然 用ABMR反应凋亡细胞的抗体(NAB)。此外，我们还发现，高水平的免疫球蛋白抗体在 移植前血清与长期移植物丢失相关，与抗人类白细胞抗原抗体无关。在此基础上 数据，我们假设NAB在ABMR的发展和随后的移植物中是重要的元素 损失。在这里，我们建议通过将我们的分析扩展到更大的接受治疗的患者组来继续这些研究 在其他中心。我们还将调查NABS的来源，并表征这些病毒的致病潜力 体内的抗体。我们的实验将在三个目标下进行： AIM-1。目的：确定血清免疫球蛋白抗体是否与ABMR和远期移植肾丢失相关。我们 将开展移植前后血清中免疫球蛋白抗体的多中心盲法大规模评估 样本来自肾移植受者的广泛队列。将对血清免疫球蛋白抗体进行检测 与供者特异性抗体、其他非人类白细胞抗原抗体以及一系列全面的 临床参数包括不同类型的排斥反应和移植物丢失的原因。然后，预测性模型将 评估NABS水平作为预测排斥和移植的重要因素的临床相关性 失败了。还将评估NABS、DSA和其他类型抗体之间的协同作用。 目的2.确定ABMR期间NABS的来源。使用Elispot分析，我们将评估 肾移植受者血和移植物组织中IgM和IgG型NABS产生细胞的频率 确定这一频率是否与血清NABS水平和ABMR相关。我们还将尝试 研究产生NABS的先天B细胞的表型。 目的3.验证NABS在体内的致病性。在这个目的中，我们将使用小鼠主动脉移植 模型研究免疫球蛋白抗体在体内的致病性。通过NABS和DSA的被动转移 移植小鼠后，我们还将研究两种抗体的协同作用。最后，我们将使用 一系列突变小鼠研究NABS介导的分子、免疫细胞和途径 血管排斥反应。

Project Summary Transplantation is currently the treatment of choice for a number of end stage kidney diseases. Considerable progress has been made in the past decades to prevent early rejection of kidney grafts. Yet, long-term survival rates remain poor, due presumably to antibody-mediated rejection (ABMR). Although antibodies specific to donor HLA molecules (DSA) indisputably contribute to mechanisms of ABMR, other types of antibodies, especially autoantibodies, have also been implicated. Previous studies from our lab associated natural antibodies (Nabs) reactive to apoptotic cells with ABMR. Moreover, we found that high level of IgG Nabs in pre-transplant serum correlated with long-term graft loss independently of anti-HLA antibodies. Based on this data, we hypothesize that Nabs are important elements in the development of ABMR and subsequently graft loss. Here, we propose to continue these studies by extending our analysis to a larger group of patients treated at other centers. We will also investigate the source of Nabs and characterize the pathogenic potential of these antibodies in vivo. Our experiments will be carried out in 3 aims: Aim-1. To determine whether serum IgG Nabs correlate with ABMR and long-term kidney graft loss. We will carry out a blinded multi-center large-scale assessment of IgG Nabs in pre- and post-transplant serum samples from an extensive cohort of kidney transplant recipients. Serum IgG Nabs measurements will be correlated with donor specific antibodies, other non-HLA antibodies as well as a comprehensive series of clinical parameters including different types of rejection and causes of graft loss. A predictive model will then be built to evaluate the clinical relevance of Nabs levels as a significant factor predicting rejection and graft failure. The synergistic effect between Nabs, DSA and other types of antibodies will also be evaluated. Aim 2. To determine the source of Nabs during ABMR. Using ELISPOT assays we will assess the frequency of IgM and IgG Nabs-producing cells in the blood and graft tissue of kidney transplant recipients and determine whether this frequency correlates with serum Nabs levels and ABMR. We will also attempt to characterize the phenotype of Nabs-producing innate B cells. Aim 3. To verify the pathogenicity of Nabs in vivo. In this aim we will use a mouse aortic transplantation model to study the pathogenicity of IgG Nabs in vivo. Through passive transfer of Nabs and DSA in transplanted mice, we will also investigate the synergistic effect of both types of antibodies. Lastly, we will use a series of mutant mice to investigate the molecules, immune cells and pathways involved in Nabs-mediated vascular rejection.