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

摘要：这项研究项目建立在德雷克塞尔大学实验室已经发起的联合努力的基础上， 费城和中国科学院上海药物研究所， 开发新型HIV-1治疗性抑制剂靶向进入，并研究潜在的 假设HIV-1 Env和宿主细胞共受体的拮抗剂可以共价连接成双功能 提高抗病毒活性和降低功能易感性的协同组合- 损害病毒抵抗力。仍然迫切需要新的HIV-1干预剂，以减少全球艾滋病毒感染。 艾滋病的发生和传播。HIV-1对宿主细胞的感染是由Env蛋白的相互作用启动的 在病毒暴露的表面有两个细胞受体，CD4和一个辅助受体， 通常是CCR5或CXCR4。我们相信，联合抑制Env和辅助受体将是一种有效的方法。 有效的手段来抑制感染的进展，包括在接触的最早阶段， 病毒，并且另外具有使表达Env和共受体两者的感染细胞增殖的潜力 在病毒增殖过程中在其表面上的蛋白质。在我们的合作实验室里，我们一直在 研究新的肽三唑（PT）gp120拮抗剂以及CCR5和CXCR4共受体 对手。由R 01 AI 106633 - 01资助的中美项目于2013年启动，取得成果 共价结合联合收割机CCR5和gp120拮抗剂以形成双功能嵌合体的合成方案 LJC 240-连接体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的效力 并且结合了两种组分抑制剂的抗Env和抗CoR性质。奇美拉是 特异于CCR5表达细胞，具有最小的（如果有的话）一般细胞毒性， CD4阴性细胞的不必要的感染增强。我们在第一个R01阶段获得的结果 我认为，针对Env和辅助受体的协同作用抑制剂可以提高这些药物的潜在用途。 用于治疗干预的抑制剂类型。在我们这里提出的工作中，我们将扩展双功能 嵌合体的努力，以提高抗病毒效力，并包括新发现的和蛋白水解耐药 大环PT（cPT）以及不同类型的共受体抑制剂（CoRI），特别是对于大环PT（cPT）和共受体抑制剂（CoRI）， CXCR4和CCR5。此外，这些嵌合体也可以抑制细胞感染的机制 因为已经被感染的细胞需要更好地了解。在本项目的具体目标中，我们将[1]扩展 合成努力获得多样化和潜力优化PT-CoRI嵌合体，[2]了解它们如何发挥作用 机械地在细胞-病毒界面和感染的细胞，和[3]评估双功能的能力， 嵌合体比单独的抑制剂组分更好地避免病毒诱变逃逸。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病毒粒子和感染细胞的灭活剂，并将扩大我们的 了解Env-共受体结合机制。

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.