Project 2: Limiting anti-drug antibodies

项目摘要(项目2--限制针对AAV提供的bNAbs的抗药抗体) 鉴于收集到的大量具有强大中和活性的人类单抗 随着广泛的HIV-1分离株(BNAbs)的出现，人们已经可以预见长期的 将这些抗体结合起来，作为实现严格的、长期的病毒学控制的手段 没有持续的抗病毒药物治疗。在初步数据和最近发表在 免疫方面，我们发现AAV介导的两个bNAbs 10-1074和3BNC117的持续表达， 在未经治疗的SHV-AD8感染导致强劲的长期抑制后86周引入 病毒复制超过三年。这只猴子被称为“迈阿密猴子”。我们也 尽管如此，使用AAV持续递送的bNAbs已经受到抗药性的严重阻碍 大多数猕猴对bNAb的抗体(ADA)反应。尽管广泛的抗体样蛋白 免疫粘附素eCD4-Ig的免疫原性较低，它还会增加ADA，这可能会限制其疗效或 它在人体内的安全性。因此，该项目致力于寻找能够有效和 用免疫原性bNAb 3BCN117作为我们的抗体，实际上抑制了ADA对抗体的反应 主要测试用例。在这个项目中，我们将评估三种这样做的方法：(1)消除CpG 转基因中的基序，(2)口服耐受性，以及(3)与协调的双特异性抗体的耐受性 BNab与红细胞结合。此外，我们将协助评估来自不同国家的反兴奋剂机构的反应 衣壳和启动子(项目1)，以及来自AAV转基因的表达已被 推迟四个月(项目4)。然后，我们将使用这些方法和AAV的最佳组合- 表达的bNAbs用于建立和表征ART治疗和未治疗的恒河猴的功能性治疗 猕猴。因此，该项目将解决使用AAV表达的bNAbs用于 HIV-1的预防和治疗。

PROJECT SUMMARY (Project 2 – Limiting anti-drug antibodies against AAV-delivered bNAbs) Given the remarkable collection of human monoclonal antibodies with potent neutralizing activity against a broad range of HIV-1 isolates (bNAbs), it has become possible to envision long-term delivery of a combination of such antibodies as a means for achieving stringent, long-term virological control in the absence of continuing antiviral drug therapy. In preliminary data and recently published paper in Immunity, we shown that sustained AAV-mediated expression of two bNAbs, 10-1074 and 3BNC117, introduced 86 weeks after an untreated SHIV-AD8 infection resulted in robust long-term suppression of viral replication for over three years. This monkey has been referred to as “the Miami monkey”. We also nonetheless show that consistent delivery of bNAbs using AAV has been severely hampered by anti-drug antibody (ADA) responses to the bNAb in the majority of macaques. Although the broad antibody-like immunoadhesin eCD4-Ig is less immunogenic, it also raises ADA that could potentially limit its efficacy or its safety in humans. This project is therefore committed to finding approaches that can effectively and practically suppress ADA responses to an antibody, using the immunogenic bNAb 3BCN117 as our primary test case. In this project we will evaluate three approaches for doing so: (1) elimination of CpG motifs in the transgene, (2) oral tolerization, and (3) tolerization with a bispecific antibody that coordinates bNAb binding to erythrocytes. In addition, we will assist in evaluating the ADA responses from different capsids and promoters (Project 1), and those from an AAV transgene whose expression has been delayed by four months (Project 4). We will then use the best combination of these approaches and AAV- expressed bNAbs to establish and characterize functional cures in ART-treated and untreated rhesus macaques. This project will therefore address a central challenge to the use AAV-expressed bNAbs for HIV-1 prophylaxis and therapy.