Cytotoxic immunoconjugates to deplete persistent HIV reservoirs

我们将开发细胞毒性抗艾滋病毒免疫缀合物，以消除持久的艾滋病毒水库。这些 这些分子旨在杀死产生传染性HIV的细胞。未结合的（裸）抗体可以通过以下途径杀死细胞： 补体和Fc受体介导的作用。我们假设细胞毒性免疫缀合物将 在杀死被感染的细胞方面比裸单克隆抗体更有效。它们可以用 如果在抗逆转录病毒治疗（ART）诱导的临床试验期间有足够的持续病毒复制， 延迟，或者在“激活和清除”协议中与延迟中断代理相结合。 存在不同形式的细胞毒性免疫缀合物，包括免疫毒素， 放射免疫缀合物和抗体-药物缀合物。每一个都有独特的优势， 艾滋病毒感染的治疗局限性。我们已经描述了抗HIV免疫毒素和抗体- 药物缀合物，确定了靶向它们的最佳mAb，并在小鼠中显示出抗病毒活性， 猕猴我们发现，虽然抗HIV免疫毒素在HIV感染者中可能有效， 在猕猴中，它们的效用受到免疫原性的限制。药物缀合物可能免疫原性较低，但 我们发现它们不如免疫毒素有效，并且它们可能仅在分裂细胞中具有细胞毒性。 我们将优化抗HIV免疫缀合物的设计，所有这些都基于针对HIV Env的相同mAb， 然后比较最佳免疫缀合物与未缀合的mAb和不相关的mAb的功效， 缀合物，使用相同的测定。为此，我们提出以下具体目标： 目标1.利用细胞毒性比较抗HIV免疫偶联物的疗效，优化设计。 我们将生产免疫原性更低的免疫毒素，更有效的抗体药物缀合物和211 At- 放射性免疫缀合物，并使用对Env表达细胞的细胞毒性比较它们。 目标二。使用原代细胞培养物比较偶联物和裸mAb。我们将测试 使用来自ART治疗患者的原代生长培养物的免疫缀合物的功效。 目标3。为了比较HIV感染、ART治疗的患者中的缀合物和未缀合mAb， 用人类造血组织重建的免疫缺陷小鼠。病毒血症和组织病毒载量 将进行定量和病毒整合分析。 这些研究旨在确定最有效的免疫缀合物形式，用于未来的测试， 在HIV感染ART治疗的猕猴中的临床候选者。这些研究也与 免疫偶联物在其它病症，特别是癌症中的用途。

We will develop cytotoxic anti-HIV immunoconjugates to eliminate persistent HIV reservoirs. These molecules aim to kill cells producing infectious HIV. Unconjugated (naked) antibodies can kill cells via complement and Fc-receptor mediated effects. We hypothesize that cytotoxic immunoconjugates will prove even more effective than naked mAbs in killing productively-infected cells. They may be used alone if there is sufficient ongoing virus replication during anti-retroviral therapy (ART)-induced clinical latency, or in conjunction with latency-disrupting agents in an “activate and purge” protocol. There are different forms of cytotoxic immunoconjugates, including immunotoxins, radioimmunoconjugates, and antibody-drug conjugates. Each may have unique advantages or limitations for the treatment of HIV infection. We have described anti-HIV immunotoxins and antibody- drug conjugates, identified the best mAbs for targeting them, and shown anti-viral activity in mice and macaques. We found that while anti-HIV immunotoxins were potentially effective in SHIV-infected macaques, their utility was limited by immunogenicity. Drug conjugates may be less immunogenic, but we found them less potent than immunotoxins, and they may only be cytotoxic in dividing cells. We will optimize the design of anti-HIV immunoconjugates, all based on the same mAbs to HIV Env, then compare the efficacy of the best immunoconjugates with unconjugated mAbs and irrelevant conjugates, using the same assays. To do so, we propose the following Specific Aims: Aim 1. To optimize design of anti-HIV immunoconjugates using cytotoxicity to compare efficacy. We will produce less-immunogenic immunotoxins, more potent antibody drug conjugates and 211At- radioimmunoconjugates and compare them using cytotoxicity on Env-expressing cells. Aim 2. To compare conjugates and naked mAbs using primary cell cultures. We will test the efficacy of immunoconjugates using primary outgrowth cultures from ART-treated patients. Aim 3. To compare conjugates and unconjugated mAbs in HIV-infected, ART-treated immunodeficient mice reconstituted with human hematopoietic tissue. Viremia and tissue virus loads will be quantified and viral integration analyses performed. These studies aim to identify the most effective form of immunoconjugate for future testing as a pre- clinical candidate in SHIV-infected ART treated macaques. These studies also have relevance for the use of immunoconjugates in other conditions, especially cancer.