Basic and Comparative Studies of CCR5 Inhibition to Prevent HIV Transmission

抑制 CCR5 预防 HIV 传播的基础和比较研究

• 批准号: 7879534
• 负责人: MICHAEL MARCEL LEDERMAN
• 金额: $ 157.97万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-06 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7879534
• 关键词: Basic; Comparative; Studies; CCR5; Inhibition

DESCRIPTION (provided by applicant): Growth of the HIV pandemic that is largely transmitted through sex, gives a compelling need to develop strategies to limit its explosive spread. It is clear that there is not yet a single strategy that will accomplish this. Thus it is vital to continue research at multiple levels and disciplines to develop potentially useful prevention strategies that may provide attenuation of HIV transmission. We have assembled an outstanding team who propose three interlocking projects that will provide new information critical to the development of microbicide strategies in general, to strategies targeting CCR5 and to developing a better understanding of the human and non-human primate female genital tract. We have been developing RANTES analogues that block OCRS and inhibit HIV replication at subnanomolar concentrations. Our first lead, PSC-RANTES has protected all 10 of 10 rhesus macaques challenged with SHIV 162P3 thus providing the most potent protection against SHIV of any agent reported to date. Limitations to this strategy include an incomplete understanding of the fundamental mechanisms whereby different RANTES analogues block HIV access to CCR5, their potential agonist activity that may result in inflammation, a limited durability of protection, the costs of synthesis and finally an incomplete understanding of the similarities and differences between the human and rhesus female genital tracts that may limit generalization of findings in the one to application in the other. Here, we propose to address each of these issues, with three projects: Project 1: Defining inhibitory Mechanisms of Novel CCRS-targeted Microbicide Candidates - As we have developed several classes of RANTES analogues with discreetly different effects on CCR5 localization and signaling, these studies are designed to explore the cellular and molecular interactions that underlie the activities of these analogues. Project 2: Comparative gynecologic studies in humans and rhesus macaques - This will focus on defining the similarities and differences between the cervicovaginal epithelium of humans and non-human primates to establish the degree to which findings in these animals can be transposed to projections of activity in humans. Thus, the results of this work will be critical both to the development of RANTES analogues as well as to all other strategies for topical prevention of HIV transmission. Project 3: Developing RANTES analogues as topical strategies to prevent HIV transmission: will explore agonist activities of different analogues to identify inhibitory pathways of potential inflammatory effects, will examine synergistic activities of HIV inhibitor combinations and novel hydrogel formulations to enhance the durability of protection and will develop methods for large scale GMP synthesis of fully recombinant agents that will permit affordable application of this strategy. An experienced Administrative Core provides infrastructural support for these projects as well as statistical expertise for analyses of their results. PROJECT 1: Defining Inhibitory Mechanisms of Novel CCRS-targeted Microbicide Candidates, Mosier, D. PROJECT 1 DESCRIPTION (provided by applicant): The goal of Project 1 is to define the mechanism of action of three new chemokine analogues with potent activity in blocking HIV-1 entry via CCR5. These fully recombinant molecules display three distinct activity profiles: (group I) CCR5 blockade without signaling activity or receptor internalization; (group II), CCR5 rapid internalization with signaling activity; and (group III), moderate CCR5 internalization and blockade without signaling activity. These new molecules have significant potential advantages in terms of safety and cost of production over current inhibitors such as PSC-RANTES, but further improvements on these candidate microbicides requires more detailed knowledge of their mechanisms of action. We will define the route to intracellular sequestration for group II molecules, and compare with that of the group III molecules. We will examine a number of hypotheses to explain prolonged antiviral activity in the absence of intracellular receptor sequestration (group I) or with moderate internalization (group III), including changes in CCR5 dimer formation, altered receptor localization in the membrane, allosteric effects, and receptor internalization independent of G-protein-linked signaling. We will also examine the impact of CCR5, CCL5, and CCL3L1 genetic polymorphisms on CCR5 protein synthesis and turnover rate. These studies are designed to investigate variability in the susceptibility of primary target cells from normal human donors to each of the new inhibitors. We will also use a panel of mutant CCR5 molecules to examine structural correlates of activity. We will use this information on mechanism and target cell variability to develop new molecules with even better activity profiles, and we will perform coordinated experiments with other projects in this Program to relate our findings in cell-based models to the effects of current and new CCR5 inhibitors in tissue explant and whole animal models. This approach will generate better and safer CCR5 inhibitors that can be produced on a scale suitable for stopping the spread of HIV/AIDS in the most-impacted areas.

描述（由申请人提供）：艾滋病毒大流行主要通过性传播，因此迫切需要制定限制其爆炸性传播的策略。显然，目前还没有一个单一的策略可以实现这一目标。因此，继续在多个层面和学科进行研究以制定可能有用的预防策略以减少艾滋病毒传播至关重要。我们组建了一支优秀的团队，提出了三个相互关联的项目，这些项目将为制定一般杀微生物剂策略、针对 CCR5 的策略以及更好地了解人类和非人类灵长类女性生殖道提供至关重要的新信息。我们一直在开发 RANTES 类似物，可以在亚纳摩尔浓度下阻断 OCRS 并抑制 HIV 复制。我们的第一个先导药物 PSC-RANTES 保护了受到 SHIV 162P3 挑战的 10 只恒河猴中的全部 10 只，从而提供了迄今为止报道的任何药物中最有效的针对 SHIV 的保护。这一策略的局限性包括对不同 RANTES 类似物阻止 HIV 接触 CCR5 的基本机制的不完全理解、可能导致炎症的潜在激动剂活性、有限的保护持久性、合成成本，以及最终对人类和恒河猴女性生殖道之间的相似性和差异的不完全理解，这可能限制将一个研究结果推广到另一个领域的应用。在这里，我们建议通过三个项目来解决这些问题： 项目 1：定义新型 CCRS 靶向杀菌剂候选物的抑制机制 - 由于我们已经开发了几类 RANTES 类似物，对 CCR5 定位和信号传导具有不同的影响，因此这些研究旨在探索这些类似物活性背后的细胞和分子相互作用。项目 2：人类和恒河猴的妇科比较研究 - 该项目将重点定义人类和非人类灵长类动物子宫颈阴道上皮之间的相似性和差异，以确定这些动物的发现可以在多大程度上转化为人类活动的预测。因此，这项工作的结果对于 RANTES 类似物的开发以及所有其他局部预防 HIV 传播的策略都至关重要。项目 3：开发 RANTES 类似物作为预防 HIV 传播的局部策略：将探索不同类似物的激动剂活性，以确定潜在炎症效应的抑制途径，将检查 HIV 抑制剂组合和新型水凝胶制剂的协同活性，以增强保护的持久性，并将开发完全重组药物的大规模 GMP 合成方法，从而允许该策略的经济应用。经验丰富的行政核心为这些项目提供基础设施支持，并为分析其结果提供统计专业知识。 项目 1：定义新型 CCRS 靶向杀菌剂候选物的抑制机制，Mosier, D. 项目 1 描述（由申请人提供）：项目 1 的目标是确定三种新型趋化因子类似物的作用机制，这些趋化因子类似物具有通过 CCR5 阻断 HIV-1 进入的有效活性。这些完全重组的分子显示出三种不同的活性特征：（I组）CCR5阻断，无信号传导活性或受体内化； (组II)，CCR5快速内化并具有信号活性； (组III)，中度CCR5内化和阻断，无信号传导活性。与 PSC-RANTES 等现有抑制剂相比，这些新分子在安全性和生产成本方面具有显着的潜在优势，但对这些候选杀菌剂的进一步改进需要更详细地了解其作用机制。我们将定义 II 族分子的细胞内隔离途径，并与 III 族分子进行比较。我们将研究一些假设来解释在没有细胞内受体隔离（第一组）或中度内化（第三组）的情况下延长的抗病毒活性，包括 CCR5 二聚体形成的变化、膜中受体定位的改变、变构效应和独立于 G 蛋白相关信号传导的受体内化。我们还将研究 CCR5、CCL5 和 CCL3L1 基因多态性对 CCR5 蛋白质合成和周转率的影响。这些研究旨在调查正常人类供体的主要靶细胞对每种新抑制剂的敏感性的变异性。我们还将使用一组突变型 CCR5 分子来检查活性的结构相关性。我们将利用有关机制和靶细胞变异性的信息来开发具有更好活性特征的新分子，并且我们将与本计划中的其他项目进行协调实验，将我们在细胞模型中的发现与当前和新型 CCR5 抑制剂在组​​织外植体和整个动物模型中的影响联系起来。这种方法将产生更好、更安全的 CCR5 抑制剂，其生产规模适合阻止艾滋病毒/艾滋病在受影响最严重的地区传播。