Bifunctional Chimeras Targeting Both HIV-1 Env and Host Cell Co-receptors

摘要：该研究项目建立在德雷克塞尔大学实验室已于#年启动的联合工作基础上。 费城和中国科学院上海药学研究所共同致力于 靶向进入的新型HIV-1治疗抑制剂的开发及其潜在的研究 HIV-1Env和宿主细胞共受体拮抗剂可以共价连接成双功能假说 提高抗病毒活性和降低对功能的敏感性的协同组合- 对病毒的抵抗力下降。仍然迫切需要新的HIV-1干预试剂来减少全球 艾滋病的发生和传播。HIV-1对宿主细胞的感染是由Env蛋白相互作用引起的 在病毒暴露的表面上有两个细胞受体的复合体，CD4和大多数 通常是CCR5或CXCR4。我们认为，联合抑制Env和辅助受体将是一种 抑制感染进展的有效手段，包括在接触病毒的最初阶段 病毒，此外还有可能灭活同时表达Env和辅受体的受感染细胞 在病毒增殖过程中它们表面的蛋白质。在我们合作的实验室里，我们一直在 新型多肽三氮唑gp120拮抗剂及CCR5和CXCR4受体的研究 对抗者。2013年由R01AI106633-01资助的美国-中国项目取得的成果建立 CCR5和gp120拮抗剂共价结合形成双功能嵌合体的合成方案 LJC240-接头4-UM15。重要的是，嵌合体在抑制病毒细胞感染方面具有亚纳摩尔效力。 并且结合了这两种组分抑制剂的抗环境和抗血管活性。嵌合体是 对表达CCR5的细胞具有特异性，即使有任何一般的细胞毒性，也是最小的，并且没有检测到 不想要的感染增强了CD4阴性细胞。我们在第一个R01期间取得的结果 认为针对Env和辅受体的协同作用抑制剂可以改善这些药物的潜在用途 用于治疗干预的抑制剂的类型。在我们这里提出的工作中，我们将扩展双功能 嵌合体努力提高抗病毒效力并包括新发现的和具有蛋白分解抗性的嵌合体 大环PT‘s(CPT’s)以及不同类型的共受体抑制剂(CORI‘s)，特别是对两者 CXCR4和CCR5。此外，这些嵌合体还可以抑制细胞感染的机制 因为已经感染的细胞需要更好地了解。在这个项目的具体目标上，我们将[1]扩展 获得多样化和效力优化的PT-Cori嵌合体的合成努力，[2]了解它们是如何作用的 在细胞-病毒界面和感染细胞的机械上，以及[3]评估双功能的能力 嵌合体比单独的抑制物组分更好地避免病毒突变逃逸。总体而言，该项目将 导致有效的HIV-1细胞进入抑制剂和HIV-1病毒粒子和受感染细胞的灭活剂，并将扩大我们的 环境共同受体参与机制的知识。

SUMMARY: This research project builds on an already-initiated joint effort by laboratories at Drexel University in Philadelphia and the Shanghai Institute of Materia Medica, Chinese Academy of Sciences, to pursue the development of new classes of HIV-1 therapeutic inhibitors targeting entry and to investigate the underlying hypothesis that antagonists of HIV-1 Env and host cell co-receptors can be covalently joined into bifunctional synergistic combinations that improve antiviral activity and decrease the susceptibility to function- compromising viral resistance. New agents for HIV-1 intervention remain urgently needed to reduce the global occurrence and spread of AIDS. HIV-1 infection of host cells is initiated by the interaction of the Env protein complex on the exposed surface of the virus with two cell receptors, CD4 and a co-receptor that is most commonly either CCR5 or CXCR4. We believe that combined inhibition of Env and co-receptors would be an effective means to suppress the progression of infection, including at the earliest stages of exposure to the virus, and in addition have the potential to inactivate infected cells expressing both Env and co-receptor proteins on their surface during virus proliferation. In our collaborating laboratories, we have been investigating novel peptide triazole (PT) gp120 antagonists and both CCR5 and CXCR4 co-receptor antagonists. Results obtained in a US-China project, initiated in 2013 funded by R01 AI106633-01, established the synthetic protocol to covalently combine CCR5 and gp120 antagonists to form the bifunctional chimera LJC240-linker4-UM15. Importantly, the chimera has a sub-nanomolar potency in inhibiting virus cell infection and combines both the antiEnv and antiCoR properties of the two component inhibitors. The chimera is specific for CCR5-expressing cells, has minimal if any general cellular toxicity and exhibits no detectable unwanted infection enhancement of CD4-negative cells. The results we have obtained in this first R01 period argue that coordinately acting inhibitors targeting Env and co-receptor can improve the potential use of these types of inhibitors for therapeutic intervention. In the work we propose here, we will expand the bifunctional chimera effort to improve antiviral potency and to include newly discovered and proteolytically-resistant macrocyclic PT's (cPT's) as well as different types of co-receptor inhibitors (CoRI's), in particular for both CXCR4 and CCR5. In addition, the mechanisms by which these chimeras can suppress cell infection as well as already-infected cells need to be better understood. In the Specific Aims of this project, we will [1] expand the synthetic effort to obtain diverse and potency-optimized PT-CoRI chimeras, [2] learn how they act mechanistically at the cell-virus interface and with infected cells, and [3] evaluate the ability of the bifunctional chimeras to better avoid virus mutagenic escape than individual inhibitor components. Overall, this project will lead to potent HIV-1 cell entry inhibitors and inactivators of HIV-1 virions and infected cells, and will expand our knowledge of Env-co-receptor engagement mechanisms.