Ultrapotent Inhibitors of Wild-type and Multi-drug Resistant HIV

野生型和多重耐药艾滋病毒的超强抑制剂

• 批准号: 9605989
• 负责人: Stefan G Sarafianos
• 金额: $ 27.04万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-11-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9605989
• 关键词: Ultrapotent; Inhibitors; Wild; type; Multi

DESCRIPTION: Nucleoside reverse transcriptase inhibitors (NRTIs) are key components of Highly Active Antiretroviral Therapies (HAART) for the treatment of HIV-infected patients. All FDA-approved anti-HIV NRTIs lack a 3'-OH, and therefore inhibit DNA polymerization by HIV RT through immediate chain termination. The absence of a 3'-OH also imparts detrimental properties to these NRTIs by reducing their binding affinity for RT compared to the natural dNTP substrates and reducing intracellular conversion to active NRTI triphosphates. We have reported during the first funding cycle that 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a nucleoside analog that retains the 3'-OH moiety and demonstrates exceptional antiviral properties (EC50 = 50 pM in PBMCs) and a remarkable selectivity index (>200,000). EFdA's potency and selectivity index is by orders of magnitude more favorable than all currently-approved anti-HIV drugs. Despite the presence of a 3'-OH, the incorporated EFdA-monophosphate acts primarily as an immediate chain terminator because RT has difficulty translocating on the primer possessing 3'-terminal EFdA-MP, which is a unique mechanism of action. Therefore, EFdA-TP is a Translocation-Defective RT inhibitor (TDRTI). Additionally, EFdA has also been shown to efficiently inhibit clinically-important NRTI-resistant HIV strains, and demonstrating hypersusceptibility to the tenofovir-resistant K65R HIV. Notably, in our study of SIV-infected macaques the animals that had suppressed viral loads upon treatment with EFdA carried the M184V mutation, suggesting that M184V can be effectively suppressed by EFdA. We have also shown that EFdA has a remarkably high barrier for HIV resistance, and many EFdA-resistant HIV strains have reduced replication capacity. More recently we have shown that the combination of EFdA with Rilpivirine shows a synergistic effect, which would be useful in the design of new therapeutic regimens. We will build on our work from the first funding cycle to understand the potency of EFdA at the RT and cellular levels, development of EFdA resistance, and EFdA combinations with currently-approved anti-HIV drugs. We will also use biochemical and structural approaches to characterize the inhibition mechanism of EFdA at the RT level, the activation of EFdA by deoxycytidine kinase (dCK) and deamination by adenosine deaminase (ADA). This study will provide information that will guide the design of novel NRTIs and EFdA combination therapies with other approved anti-HIV drugs that may lead to a breakthrough in the treatment of HIV infection.

描述：核苷逆转录酶抑制剂（NRTIS）是高度活性抗逆转录病毒疗法（HAART）的关键组成部分，用于治疗HIV感染的患者。所有由FDA批准的抗HIV NRTI都缺乏3'-OH，因此通过立即链终止抑制HIV RT通过HIV RT抑制DNA聚合。与天然DNTP底物相比，没有3'-OH的缺乏通过降低其对RT的结合亲和力，并减少了细胞内转化为活性NRTI三磷酸盐，从而赋予了这些NRTI的有害特性。 我们在第一个融资周期中报道说，4'-乙基-2-氟-2'-脱氧腺苷（EFDA）是一种核苷类似物，保留了3'-OH部分，并证明了出色的抗病毒特性（EC50 = 50 = 50 pm在PBMC中）和出色的选择性指数（> 200,000）（> 200,000）。 EFDA的效力和选择性指数的数量级比所有当前批准的抗HIV药物都要好。尽管存在3'-OH，但掺入的EFDA单磷酸盐主要起作用，主要是直接链终结子，因为RT在具有3'-末端EFDA-MP的引物上很难转移，这是一种独特的作用机制。因此，EFDA-TP是转运缺陷的RT抑制剂（TDRTI）。此外，EFDA还被证明可以有效抑制临床上最重要的NRTI抗HIV菌株，并证明对耐替诺福韦K65R HIV的超敏度。值得注意的是，在我们对SIV感染的猕猴的研究中，用EFDA治疗后抑制病毒载量的动物携带了M184V突变，这表明M184V可以被EFDA有效抑制。我们还表明，EFDA具有抗HIV耐药性的高障碍，许多耐EFDA的HIV菌株的复制能力降低。最近，我们表明，EFDA与rilpivirine的组合显示出协同作用，这对新的治疗方案的设计非常有用。 从第一个融资周期开始，我们将基于我们的工作，以了解EFDA在RT和细胞水平上的效力，EFDA耐药性的发展以及EFDA与当前批准的抗HIV药物的组合。我们还将使用生化和结构方法来表征EFDA在RT水平上的抑制机制，脱氧胞苷激酶（DCK）激活EFDA以及腺苷脱氨酶（ADA）的脱氨基。 这项研究将提供信息，这些信息将指导新型NRTI和EFDA组合疗法与其他认可的抗HIV药物的设计，这可能会导致HIV感染治疗的突破。