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: 7391001
• 负责人: MICHAEL MARCEL LEDERMAN
• 金额: $ 158.58万
• 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 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7391001
• 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）：艾滋病毒大流行的增长主要是通过性传播，迫切需要制定战略，以限制其爆炸性传播。显然，目前还没有一项战略能够实现这一目标。因此，必须继续在多个层次和学科进行研究，以制定可能有用的预防战略，减少艾滋病毒的传播。我们已经组建了一个优秀的团队，他们提出了三个相互关联的项目，这些项目将提供新的信息，这些信息对一般杀微生物剂战略的发展至关重要，针对CCR 5的战略，以及更好地了解人类和非人类灵长类动物的女性生殖道。我们一直在开发RANTES类似物，在亚纳摩尔浓度下阻断OCRS并抑制HIV复制。我们的第一个领导者，PSC-RANTES保护了所有10的10个恒河猴挑战与SHIV 162 P3，从而提供了最有效的保护，对SHIV的任何代理迄今报道。这种策略的局限性包括对不同RANTES类似物阻断HIV接近CCR 5的基本机制的不完全理解，它们可能导致炎症的潜在激动剂活性，有限的保护持久性，综合的代价，以及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，可能会限制对人类和恒河猴女性生殖道的研究结果的概括，应用在另一个。在这里，我们建议解决这些问题，有三个项目：项目1：定义新的CCRs靶向杀微生物剂候选物的抑制机制-因为我们已经开发了几类RANTES类似物，对CCR 5定位和信号传导有不同的影响，这些研究旨在探索这些类似物的活性背后的细胞和分子相互作用。项目二：人类和恒河猴的比较妇科研究-这将侧重于定义人类和非人类灵长类动物的宫颈阴道上皮之间的相似性和差异，以确定这些动物中的发现可以转移到人类活动预测的程度。因此，这项工作的结果将是至关重要的RANTES类似物的发展，以及所有其他策略的局部预防艾滋病毒传播。项目三：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，并将开发完全重组剂的大规模GMP合成方法，以允许该策略的经济适用性。一个经验丰富的行政核心为这些项目提供基础设施支助，并提供统计专门知识，以分析项目结果。 项目1：确定新型CCRS靶向杀微生物剂候选物的抑制机制。 项目1描述（由申请人提供）：项目1的目标是确定三种新的趋化因子类似物的作用机制，这些趋化因子类似物具有阻断HIV-1通过CCR 5进入的强效活性。这些完全重组的分子显示出三种不同的活性特征：（I组）CCR 5阻断而无信号传导活性或受体内化;（II组），CCR 5快速内化而有信号传导活性;和（III组），中度CCR 5内化和阻断而无信号传导活性。这些新分子在安全性和生产成本方面具有显著的潜在优势，优于目前的抑制剂如PSC-RANTES，但对这些候选杀微生物剂的进一步改进需要对其作用机制的更详细的了解。我们将定义II组分子的细胞内螯合途径，并与III组分子进行比较。我们将研究一些假设，以解释长期的抗病毒活性在细胞内受体螯合（组I）或中度内化（组III）的情况下，包括CCR 5二聚体形成的变化，改变受体定位在膜上，变构效应，和受体内化独立的G-蛋白连接的信号转导。我们还将研究CCR 5，CCL 5和CCL 3L 1基因多态性对CCR 5蛋白合成和周转率的影响。这些研究旨在研究正常人供体的原代靶细胞对每种新抑制剂敏感性的变异性。我们还将使用一组突变的CCR 5分子来检查活性的结构相关性。我们将利用这些关于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，我们将与本计划中的其他项目进行协调实验，将我们在基于细胞的模型中的发现与组织外植体和整个动物模型中的现有和新的CCR 5抑制剂的作用联系起来。这种方法将产生更好和更安全的CCR 5抑制剂，可以以适合于在受影响最严重的地区阻止艾滋病毒/艾滋病传播的规模生产。