Natural Product-Inspired Method for Enhancing HIV Protease Inhibitors

增强 HIV 蛋白酶抑制剂的天然产物方法

• 批准号: 8259867
• 负责人: Jason E Gestwicki
• 金额: $ 19.44万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8259867
• 关键词: AIDS/HIV problem; Acquired Immunodeficiency Syndrome; Address; Affinity; Albumins; Amprenavir; Anti-Retroviral Agents; Area; Area Under Curve; Behavior; Binding; Bioavailable; Biodistribution; Biological; Biological Factors; Blood Cells; CD4 Positive T Lymphocytes; Cells; Chemical Structure; Collection; Complex; Coupling; Cytochrome P450; Deposition; Disease; Dose; Drug resistance; Enzymes; Erythrocytes; Exposure to; FK506; Goals; HIV; HIV Infections; HIV Protease; HIV Protease Inhibitors; HIV-2 protease; Half-Life; Highly Active Antiretroviral Therapy; Human; Human immunodeficiency virus test; In Vitro; Inhibitory Concentration 50; Leukocytes; Life; Measures; Membrane; Metabolic; Metabolism; Methods; Modeling; Molecular; Mus; Penetration; Peptide Hydrolases; Pharmaceutical Preparations; Pharmacology; Property; Protein Binding; Relative (related person); Ritonavir; Role; Safety; Solutions; Source; Structure-Activity Relationship; System; Tacrolimus Binding Proteins; Technology; Testing; Therapeutic; Tissues; Vial device; Whole Blood; Work; analog; base; compliance behavior; design; effective therapy; improved; inhibitor/antagonist; innovation; insight; interest; nephrotoxicity; protein expression

DESCRIPTION (provided by applicant): Highly active anti-retroviral therapy (HAART) has been remarkably effective for managing HIV infection / AIDS. However, patient compliance with HAART is often variable due to treatment- related complications. This is a serious problem that facilitates the emergence of drug resistance. One issue that contributes to HAART-associated complications is the poor metabolic stability and low cellular penetration of the HIV protease inhibitors. Our group has been exploring a new method for addressing these limitations. This strategy is directly inspired by the pharmacological properties of the natural product, FK506, which has a surprisingly long halftime in humans (t1/2 ~ 40 hrs) despite being an excellent substrate for P450 enzymes in vitro. We recently wondered whether this apparent contradiction might arise from this compound's high affinity for the FK506-binding protein (FKBP). Blood cells, including both erythrocytes and leukocytes, express unusually high levels of FKBP but they are virtually devoid of P450 enzymes. Therefore, we hypothesized that affinity-driven accumulation within this protected cellular niche might limit exposure to key metabolic enzymes and, thereby, extend drug lifetime. Moreover, FK506 is rapidly absorbed (~1 hr), highly penetrant to biological membranes and naturally targeted to leukocytes via its FKBP-binding moiety. Together, these properties appear to align with the major problems facing HIV protease inhibitors. Based on these observations, we tethered an FKBP-binding group to an amprenavir analog, creating a bifunctional molecule that can bind both FKBP and HIV protease. We found that the resulting compound retained anti-protease activity (IC50 ~ 20 nM). Moreover, it was now sequestered into blood cells (by at least 8-fold) and its half-life was increased by ~ 20-fold in mice. The lifetime of this compound was superior to that of ritonavir-boosted amprenavir and, moreover, its metabolic stability was now independent of ritonavir co-administration. Based on these promising initial findings, we now propose to carefully explore the molecular mechanisms governing this behavior. Specifically, we reason that cellular partitioning and lifetime are dictated, in part, by the affinity of the compound for FKBP. To explore this central hypothesis, we propose the following specific aims: (1) synthesize a collection of FKBP-binding amprenavir derivatives and measure their relative affinities for albumin, FKBP and HIV protease and (2) explore how cellular partitioning correlates with binding affinities and relative protein expression levels. From these observations, we expect to understand the key structure-activity relationships in the context of the ternary complex (i.e. FKBP-drug-HIV protease). The immediate goal of this study is to create potent, safe and long-lived HIV protease inhibitors that selectively target FKBP-expressing, HIV-infected cells. This study is significant because it addresses an important problem in the treatment of AIDS. The proposed work is innovative because it will explore a fundamentally new, "natural product-inspired" strategy. PUBLIC HEALTH RELEVANCE: HIV protease inhibitors are an important component of modern anti-retroviral strategies. However, these compounds have poor metabolic stability and low cellular penetration. Current solutions to these problems are effective, but they are also associated with significant complications, including nephrotoxicity. The goal of this project is to explore how a "natural product-inspired" strategy might directly improve the safety of HIV protease inhibitors and the treatment of AIDS.

描述（由申请人提供）：高度活跃的抗逆转录病毒疗法（HAART）对管理HIV感染 /艾滋病非常有效。但是，由于与治疗相关并发症，患者对HAART的遵守通常是可变的。这是一个促进耐药性出现的严重问题。导致HAART相关并发症的一个问题是代谢稳定性差和HIV蛋白酶抑制剂的细胞渗透率低。我们的小组一直在探索一种解决这些限制的新方法。该策略直接受到天然产物FK506的药理特性的启发，该策略在人类中的半场时间（T1/2〜40小时）出人意料地长，尽管在体外是P450酶的出色底物。我们最近想知道，这种明显的矛盾是否可能是由于该化合物对FK506结合蛋白（FKBP）的高亲和力。血细胞，包括红细胞和白细胞，表现出异常高的FKBP，但实际上没有P450酶。因此，我们假设在该受保护的细胞生态位中亲和力驱动的积累可能会限制暴露于关键代谢酶，从而延长药物寿命。此外，FK506被迅速吸收（约1小时），高度渗透到生物膜上，并通过其FKBP结合部分自然地靶向白细胞。总之，这些特性似乎与HIV蛋白酶抑制剂面临的主要问题保持一致。基于这些观察结果，我们将FKBP结合组束缚在一个杂草类似物上，从而产生了可以粘合FKBP和HIV蛋白酶的双功能分子。我们发现所得化合物保留了抗蛋白酶活性（IC50〜20 nm）。此外，它现在被隔离为血细胞（至少8倍），其半衰期在小鼠中增加了约20倍。该化合物的寿命优于利托纳维尔（Ritonavir）增强的Amprenavir，此外，它的代谢稳定性现在独立于Ritonavir共同管理。基于这些有希望的初始发现，我们现在建议仔细探索有关这种行为的分子机制。具体而言，我们认为细胞分配和寿命部分是由化合物对FKBP的亲和力决定的。为了探讨这一中心假设，我们提出了以下特定目的：（1）合成FKBP结合的Amprenavir衍生物的集合，并测量其对白蛋白，FKBP和HIV蛋白酶的相对亲和力，以及（2）探索细胞分配如何与结合亲密蛋白质和相对蛋白表达水平相关。从这些观察结果中，我们期望在三元复合物（即FKBP-Prug-HIV蛋白酶）的背景下理解关键的结构活性关系。这项研究的直接目标是创建有效，安全和长寿的HIV蛋白酶抑制剂，以选择性地靶向表达FKBP的HIV感染细胞。这项研究很重要，因为它解决了艾滋病治疗的重要问题。拟议的工作具有创新性，因为它将探索一种从根本上新的，“自然产品启发”的策略。 公共卫生相关性：HIV蛋白酶抑制剂是现代抗逆转录病毒策略的重要组成部分。但是，这些化合物的代谢稳定性差和细胞渗透率低。当前解决这些问题的解决方案是有效的，但它们也与包括肾毒性在内的重大并发症有关。该项目的目的是探索“自然产品启发的”策略如何直接改善HIV蛋白酶抑制剂的安全性和艾滋病治疗。