Development of Antiviral Therapy of HIV-1 Infection

HIV-1感染的抗病毒治疗的进展

• 批准号: 7292023
• 负责人: Hiroaki Mitsuya
• 金额: --
• 依托单位: DIVISION OF CLINICAL SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7292023
• 关键词: Development; Antiviral; Therapy; HIV; Infection

In this report period, we carried on our long-standing research line, development of anti human immunodeficiency virus (HIV) drugs. We pursued three major lines of research: Project 1 - Identification and development of new antiviral agents active against HIV-1; Project 2 - Study of CC-chemokine/CCR5 interactions and development of CCR5 inhibitors as potential therapeutics for therapy of AIDS; and Project 3 - Study of the mechanisms of emergence of drug-resistant HIV-1 variants. Project 1: We have identified novel protease inhibitors containing 3(R),3a(S),6a(R)-bis tetrahydrofuranyl urethane (bis-THF) in collaboration with Professor Arun Ghosh of University of Illinois at Chicago. It is of note that UIC-00317/TMC114, one of the bis-THF congeners, has proceeded to Phase IIb Clinical trials in european countries. Continuing further collaboration with Dr. Ghosh and his group, we are developing more effective and resistant HIV-"repellant" protease inhibitors containing unique active components.Project 2: Considering that certain CXCR4/CCR5 inhibitors, if successfully developed, would "resist" to the emergence of resistant virus because the target for CXCR4/CCR5 inhibitors is indeed a cellular apparatus, therefore, HIV-1 cannot use the same strategy to acquire resistance to RTIs and PIs: "to change itself". We thus redirected our attentions from the NRTI- and PI related research lines and started our efforts to identify such entry inhibitors. In collaboration with scientists of Ono Pharmaceutical Co., Ltd., which is based in Osaka, Japan, we identified a new class of CCR5 inhibitors, spirodiketopiperazine (SDP) derivatives. SDP derivatives bind to CCR5, block CC-chemokine(CC)/CCR5 interactions, and inhibit HIV-1 infection of CCR5+ cells (Maeda & Mitsuya, J. Biol. Chem. 276:35194, 2001). One such CCR5 inhibitor aplaviroc (AVC: AK602/ONO4128/GW873140), exerts potent activity against a wide spectrum of laboratory and primary R5-HIV-1 isolates including multi-drug resistant HIVMDR (IC50 values of 0.2-0.6 nM), which is associated with its high CCR5-binding affinity (KD values of 2 nM) and potent inhibition of CCR5-gp120 binding. AVC is now under multiple phase III clinical trials in the United States. Previously reported CCR5 inhibitors tested (e.g., Sch-C, TAK779) fully blocked HIV infection as well as CC/CCR5 binding, while AVC, despite its much greater anti-HIV activity, partially suppressed the interactions at high concentrations (Maeda & Mitsuya, J. Virol. 78:8654, 2004). We also characterized the binding profile of AVC by using CHO cells expressing various mutant CCR5 species whose amino acid(s) was substituted in the extracellular loops (ECL) and transmembrane (TM) domain of CCR5. The data suggest that AVC's binding site is located in a hydrophobic pocket in the proximity of the interface between the second ECL (ECL-2B) and the upper TM domain. Several mutations in the pocket turned out to decrease the binding of HIV gp120 and all CC chemokines examined to CCR5, suggesting that the hydrophobic pocket is critical for CCR5's ligand-specific conformational changes induced by CC-chemokines and gp120. AVC, once bound to CCR5+ human cells, remained on the cell surface for >9 hr after thorough washing, and blocked R5-HIV infection upon delayed HIV-1 exposure. When intraperitoneally administered twice daily to R5-HIV-1JRFL-infected hu-PBM-NOD-SCID mice, AK602 successfully suppressed HIV-1 replication and blocked CD4+ T-cell decrease (Nakata & Mitsuya, J. Virol. 79: 2087, 2005). Phase I clinical trial in healthy individuals showed that AK602 was safe and well tolerated with no QTc prolongation. Receptor occupancy studies demonstrate prolonged receptor binding to CCR5 and suggest QD or BID dosing. In an early phase II-10 day monotherapy study enrolling HIV-1 viremia in patients with AIDS, AVC demonstrated potent antiviral activity (mean 1.66 log decrease in viral load at nadir, Lalezari et al., ICAAC 2004) .

本报告期，我们延续了长期的研究路线，开发抗人类免疫缺陷病毒（HIV）药物。我们进行了三个主要研究方向： 项目 1 - 鉴定和开发有效对抗 HIV-1 的新型抗病毒药物；项目2 - 研究CC趋化因子/CCR5相互作用并开发CCR5抑制剂作为治疗艾滋病的潜在疗法；项目3——研究耐药性HIV-1变异体的出现机制。项目1：我们与伊利诺伊大学芝加哥分校的Arun Ghosh教授合作，发现了含有3(R),3a(S),6a(R)-双四氢呋喃基氨基甲酸酯(bis-THF)的新型蛋白酶抑制剂。值得注意的是，bis-THF同系物之一的UIC-00317/TMC114已在欧洲国家进入IIb期临床试验。继续与 Ghosh 博士及其团队进一步合作，我们正在开发更有效、更耐药的 HIV“排斥”蛋白酶抑制剂，其中含有独特的活性成分。项目 2：考虑到某些 CXCR4/CCR5 抑制剂如果成功开发，将“抵抗”HIV耐药病毒的出现是因为CXCR4/CCR5抑制剂的靶标确实是细胞器，因此，HIV-1不能使用相同的策略来获得对RTI和PI的耐药性： “改变自己”。因此，我们将注意力从 NRTI 和 PI 相关研究领域转移，并开始努力识别此类进入抑制剂。我们与总部位于日本大阪的小野制药有限公司的科学家合作，发现了一类新型 CCR5 抑制剂：螺二酮哌嗪 (SDP) 衍生物。 SDP衍生物结合CCR5，阻断CC-趋化因子(CC)/CCR5相互作用，并抑制CCR5+细胞的HIV-1感染(Maeda & Mitsuya, J. Biol. Chem. 276:35194, 2001)。其中一种 CCR5 抑制剂阿普拉韦洛克（AVC：AK602/ONO4128/GW873140）对多种实验室和原发性 R5-HIV-1 分离株发挥有效活性，包括多重耐药 HIVMDR（IC50 值为 0.2-0.6 nM），与其高 CCR5 结合亲和力（KD 值为 2 nM）和有效抑制CCR5-gp120 结合。 AVC 目前正在美国进行多项 III 期临床试验。先前报道的测试的 CCR5 抑制剂（例如 Sch-C、TAK779）完全阻断了 HIV 感染以及 CC/CCR5 结合，而 AVC 尽管其抗 HIV 活性更强，但在高浓度下部分抑制了相互作用（Maeda & Mitsuya， J.维罗尔，78：8654，2004）。我们还通过使用表达各种突变型 CCR5 物种的 CHO 细胞来表征 AVC 的结合谱，这些突变型 CCR5 物种的氨基酸在 CCR5 的胞外环 (ECL) 和跨膜 (TM) 结构域中被取代。数据表明，AVC 的结合位点位于第二个 ECL (ECL-2B) 和上部 TM 结构域之间界面附近的疏水口袋中。口袋中的几个突变结果降低了 HIV gp120 和所有检测到的 CC 趋化因子与 CCR5 的结合，表明疏水口袋对于 CC 趋化因子和 gp120 诱导的 CCR5 配体特异性构象变化至关重要。 AVC 一旦与 CCR5+ 人类细胞结合，在彻底清洗后会在细胞表面保留超过 9 小时，并在延迟暴露于 HIV-1 后阻断 R5-HIV 感染。当每日两次腹膜内给予 R5-HIV-1JRFL 感染的 hu-PBM-NOD-SCID 小鼠时，AK602 成功抑制 HIV-1 复制并阻止 CD4+ T 细胞减少 (Nakata & Mitsuya, J. Virol. 79: 2087, 2005 ）。在健康个体中进行的 I 期临床试验表明 AK602 安全且耐受性良好，且无 QTc 延长。受体占用研究表明受体与 CCR5 的结合时间延长，建议 QD 或 BID 给药。在一项招募 HIV-1 病毒血症患者的早期 II-10 天单药治疗研究中，AVC 表现出强大的抗病毒活性（最低点时病毒载量平均减少 1.66 个对数，Lalezari 等人，ICAAC 2004）。