MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
J Virol. 2018 Sep 26;92(20). doi: 10.1128/JVI.01088-18. Print 2018 Oct 15.
T-20 (enfuvirtide) is the only membrane fusion inhibitor available for the treatment of viral infection; however, it has low anti-human immunodeficiency virus (anti-HIV) activity and a low genetic barrier for drug resistance. We recently reported that T-20 sequence-based lipopeptides possess extremely potent and efficacies (X. Ding, Z. Zhang, H. Chong, Y. Zhu, H. Wei, X. Wu, J. He, X. Wang, Y. He, 2017, J Virol 91:e00831-17, https://doi.org/10.1128/JVI.00831-17; H. Chong, J. Xue, Y. Zhu, Z. Cong, T. Chen, Y. Guo, Q. Wei, Y. Zhou, C. Qin, Y. He, 2018, J Virol 92:e00775-18, https://doi.org/10.1128/JVI.00775-18). Here, we focused on characterizing the structure-activity relationships of the T-20 derivatives. First, a novel lipopeptide termed LP-52 was generated with improved target-binding stability and anti-HIV activity. Second, a large panel of truncated lipopeptides was characterized, revealing a 21-amino-acid sequence core structure. Third, it was surprisingly found that the addition of the gp41 pocket-binding residues in the N terminus of the new inhibitors resulted in increased binding but decreased antiviral activities. Fourth, while LP-52 showed the most potent activity in inhibiting divergent HIV-1 subtypes, its truncated versions, such as LP-55 (25-mer) and LP-65 (24-mer), still maintained their potencies at very low picomolar concentrations; however, both the N- and C-terminal motifs of LP-52 played crucial roles in the inhibition of T-20-resistant HIV-1 mutants, HIV-2, and simian immunodeficiency virus (SIV) isolates. Fifth, we verified that LP-52 can bind to target cell membranes and human serum albumin and has low cytotoxicity and a high genetic barrier to inducing drug resistance. Development of novel membrane fusion inhibitors against HIV and other enveloped viruses is highly important in terms of the peptide drug T-20, which remains the only one for clinical use, even if it is limited by large dosages and resistance. Here, we report a novel T-20 sequence-based lipopeptide showing extremely potent and broad activities against HIV-1, HIV-2, SIV, and T-20-resistant mutants, as well as an extremely high therapeutic selectivity index and genetic resistance barrier. The structure-activity relationship (SAR) of the T-20 derivatives has been comprehensively characterized, revealing a critical sequence core structure and the target sites of viral vulnerability that do not include the gp41 pocket. The results also suggest that membrane-anchored inhibitors possess unique modes of action relative to unconjugated peptides. Combined, our series studies have not only provided drug candidates for clinical development but also offered important tools to elucidate the mechanisms of viral fusion and inhibition.
T-20（恩夫韦肽）是唯一可用于治疗病毒感染的膜融合抑制剂；然而，它对人类免疫缺陷病毒（抗 HIV）的活性较低，且耐药的遗传屏障较低。我们最近报道，T-20 序列基脂肽具有极其强大的效力和功效（X. Ding, Z. Zhang, H. Chong, Y. Zhu, H. Wei, X. Wu, J. He, X. Wang, Y. He, 2017, J Virol 91:e00831-17, https://doi.org/10.1128/JVI.00831-17; H. Chong, J. Xue, Y. Zhu, Z. Cong, T. Chen, Y. Guo, Q. Wei, Y. Zhou, C. Qin, Y. He, 2018, J Virol 92:e00775-18, https://doi.org/10.1128/JVI.00775-18）。在这里，我们专注于描述 T-20 衍生物的结构-活性关系。首先，生成了一种新型脂肽，称为 LP-52，其靶标结合稳定性和抗 HIV 活性得到改善。其次，对大量截短的脂肽进行了特征描述，揭示了一个由 21 个氨基酸组成的核心结构。第三，令人惊讶的是，在新抑制剂的 N 端添加 gp41 口袋结合残基会导致结合增加，但抗病毒活性降低。第四，尽管 LP-52 对多种不同的 HIV-1 亚型表现出最强的活性，但它的截短版本，如 LP-55（25 肽）和 LP-65（24 肽），仍在皮摩尔浓度非常低的情况下保持其效力；然而，LP-52 的 N 端和 C 端基序在抑制 T-20 耐药的 HIV-1 突变体、HIV-2 和猴免疫缺陷病毒（SIV）分离株方面都发挥着关键作用。第五，我们验证了 LP-52 可以与靶细胞膜和人血清白蛋白结合，并且具有低细胞毒性和高遗传耐药屏障。开发针对 HIV 和其他包膜病毒的新型膜融合抑制剂在肽类药物 T-20 方面非常重要，尽管 T-20 的用量大且存在耐药性限制，但它仍然是唯一一种临床应用的药物。在这里，我们报告了一种新型 T-20 序列基脂肽，对 HIV-1、HIV-2、SIV 和 T-20 耐药突变体具有极其强大和广泛的活性，以及极高的治疗选择性指数和遗传耐药屏障。T-20 衍生物的结构-活性关系（SAR）已得到全面描述，揭示了一个关键的序列核心结构和病毒脆弱性的靶位，不包括 gp41 口袋。结果还表明，膜锚定抑制剂与未缀合的肽相比具有独特的作用模式。综合来看，我们的系列研究不仅为临床开发提供了候选药物，还为阐明病毒融合和抑制的机制提供了重要工具。
