FLP-102: Rationally Engineered Antiviral Protein

描述（由申请人提供）：美洲商陆抗病毒蛋白（PAP）是一种29 kda的天然抗病毒药物，可以从美洲商陆植物Phytolacca americana的叶子中分离出来。PAP具有独特的去纯化HIV-I RNA的能力。PAP对耐药的原发性临床HIV-1分离株表现出有效的抗病毒活性。zidovudine （ZDV）敏感和耐药的临床HIV- 1分离株对PAP的敏感性均比ZDV高4倍。我们已经克隆了PAP基因，并建立了大规模生产和纯化克隆重组商陆抗病毒蛋白的程序。我们已经在体外测试了重组PAP对多种病毒的抗性，并证明它对DNA和RNA病毒的活性与天然PAP一样。我们还能够在2.1A分辨率下确定美洲商陆抗病毒蛋白的x射线晶体结构。最近，我们使用PAP- hiv RNA相互作用的分子模型来合理设计具有有效抗hiv活性的PAP突变体。两种重组PAP蛋白，FLP- 102 （151AA 152）和FLP- 105 （191AA 192）已经被设计、生产并在体外和体内进行了测试。这些蛋白比核糖体RNA更能去嘌呤化HIV-1 RNA，是比天然PAP或重组野生型PAP更有效的抗hiv药物。我们的初步研究表明，合理设计的FLP-102在人类艾滋病的替代小鼠Hu-PBL-SCID模型中，对基因型和表型型nrti耐药的临床HIV-1分离株表现出强有力的体内抗hiv活性。我们推测，由于FLP-102在体内和体外具有强大的抗hiv活性，它可能为高耐药HIV-1患者提供有效的挽救治疗基础。本I期计划的目标是：(I)研究合理设计的重组PAP蛋白FLP-102的广谱抗hiv活性；（ii）研究FLP-102在小鼠体内的毒性及药代动力学和药效学特征。FLP-102的临床前数据对于进一步探索这种新型重组PAP突变体在II期的应用至关重要。

DESCRIPTION (provided by applicant): Pokeweed antiviral protein (PAP) is a 29-kDa naturally occurring antiviral agent that can be isolated from the leaves of the pokeweed plant, Phytolacca americana. PAP has a unique ability to depurinate HIV-I RNA. PAP exhibits potent antiviral activity against drug-resistant primary clinical HIV-1 isolates. Both zidovudine (ZDV)-sensitive and ZDV-resistant clinical HIV- 1 isolates were found to be > 4 log more sensitive to PAP than to ZDV. We have cloned the gene for PAP and established procedures for large-scale production and purification of the cloned recombinant pokeweed antiviral protein. We have tested recombinant PAP against a broad panel of viruses in vitro and documented that it is as active as native PAP against both DNA and RNA viruses. We were also able to determine the X-ray crystal structure of pokeweed antiviral protein at 2.1A resolution. More recently, we have used a molecular model of PAP-HIV RNA interactions for the rational design of PAP mutants with potent anti-HIV activity. Two such recombinant PAP proteins, FLP- 102 (151AA 152) and FLP- 105 (191AA 192) have been engineered, produced, and tested both in vitro as well as in vivo. These proteins depurinate HIV-1 RNA much better than ribosomal RNA and are more potent anti-HIV agents than native PAP or recombinant wild-type PAP. Our preliminary studies indicate that the rationally engineered FLP-102 exhibits potent in vivo anti-HIV activity against a genotypically and phenotypically NRTI-resistant clinical HIV-1 isolate in a surrogate Hu-PBL-SCID mouse model of human AIDS. We hypothesize that FLP-102, because of its potent in vitro and in vivo anti-HIV activity may provide the basis for effective salvage therapies for patients harboring highly drug-resistant strains of HIV-1. The goal of this Phase I proposal is: (i) to study the broad-spectrum anti-HIV activity of rationally designed recombinant PAP protein FLP-102; and (ii) to study the in vivo toxicity profile and pharmacokinetic and pharmacodynamic features of FLP-102 in mice. The preclinical data on FLP-102 will be essential to further explore the utility of this novel recombinant PAP mutant for Phase II.