Project 2: Limiting anti-drug antibodies

项目摘要（项目 2 – 限制针对 AAV 传递的 bNAb 的抗药物抗体） 考虑到具有强大中和活性的人类单克隆抗体的显着收集 广泛的 HIV-1 分离株（bNAb），可以预见长期提供 此类抗体的组合作为实现严格、长期病毒学控制的手段 缺乏持续的抗病毒药物治疗。在初步数据和最近发表的论文中 免疫方面，我们证明了 AAV 介导的两种 bNAb 10-1074 和 3BNC117 的持续表达， 在未经治疗的 SHIV-AD8 感染 86 周后引入，导致对 病毒复制超过三年。这只猴子被称为“迈阿密猴”。我们也 尽管如此，表明使用 AAV 持续递送 bNAb 已受到抗药物的严重阻碍 大多数猕猴对 bNAb 产生抗体 (ADA) 反应。尽管广泛的抗体样 免疫粘附素 eCD4-Ig 的免疫原性较低，它还会提高 ADA，这可能会限制其功效或 它对人类的安全性。因此，该项目致力于寻找能够有效且有效的方法 使用免疫原性 bNAb 3BCN117 作为我们的研究，实际上抑制了对抗体的 ADA 反应 主要测试用例。在这个项目中，我们将评估三种方法：(1) 消除 CpG 转基因中的基序，(2) 口服耐受性，以及 (3) 协调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 ADA 回应 衣壳和启动子（项目 1），以及来自 AAV 转基因的衣壳和启动子，其表达已 推迟了四个月（项目 4）。然后我们将使用这些方法和 AAV 的最佳组合- 表达的 bNAb 用于建立和表征经 ART 治疗和未治疗的恒河猴的功能性治愈 猕猴。因此，该项目将解决使用 AAV 表达的 bNAb 的核心挑战 HIV-1 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.