Trajcevski Stéphane, Solly Sounkary K, Frisén Charlotte, Trenado Aurélie, Cosset François-Loïc, Klatzmann David
Laboratoire de biologie et thérapeutiques des pathologies immunitaires, CNRS UMR7087, Université Pierre et Marie Curie, Groupe hospitalier Pitié-Salpêtrière, 83 boulevard de l'hôpital, 75651 Paris cedex 13, France.
J Gene Med. 2005 Mar;7(3):276-87. doi: 10.1002/jgm.663.
Recently, several cancer gene therapy studies have shown that replication-competent retroviral vectors represent a major improvement over replication-defective ones in terms of transgene propagation efficiency. However, this positive effect is somewhat spoiled by the increased risk of dissemination and oncogenesis that replication-competent retroviral vectors entail. To enhance both their integral safety and their transgene capacity, we developed a semi-replication-competent retroviral vector system.
The semi-replication-competent retroviral vector system is based on two transcomplementing replication-defective retroviral vectors termed gag-pol vector (GPv) and env vector (Ev). Vector propagation was monitored in vitro and in solid tumors in vivo, using different reporter transgenes for GPv and Ev. Systemic vector dissemination and leukemogenesis was assessed by direct intravenous vector injection and subsequent bone marrow transplantation, in MLV-sensitive mice.
In vitro and in vivo the semi-replication-competent retroviral vectors propagate transgenes almost as efficiently as replication-competent ones. The semi-replication-competent retroviral vector system does not lead to detectable dissemination or leukemogenesis as does the replication-competent vector or the parental virus. Additionally, the vector duo allows co-propagation of different transgenes as well as mobilization of a third replication-defective vector.
This study is an initial proof of principle for the use of complementary retroviral vectors to deliver and propagate transgenes in vitro and in solid tumors in vivo, but with reduced pathogenicity compared to its parental virus. In-between replication-defective and replication-competent retroviral vectors, this semi-replicative system offers good grounds for its application in in vitro studies and allows envisioning its further development for cancer gene therapy.
最近，多项癌症基因治疗研究表明，就转基因传播效率而言，具有复制能力的逆转录病毒载体比无复制能力的载体有了重大改进。然而，这种积极效果在一定程度上被具有复制能力的逆转录病毒载体所带来的传播和致癌风险增加所抵消。为了提高其整体安全性和转基因容量，我们开发了一种半复制能力的逆转录病毒载体系统。
半复制能力的逆转录病毒载体系统基于两种相互补充的无复制能力的逆转录病毒载体，即gag-pol载体（GPv）和env载体（Ev）。使用针对GPv和Ev的不同报告基因，在体外和体内实体瘤中监测载体的传播。通过直接静脉注射载体并随后进行骨髓移植，在对MLV敏感的小鼠中评估全身载体传播和白血病发生情况。
在体外和体内，半复制能力的逆转录病毒载体传播转基因的效率几乎与具有复制能力的载体相同。与具有复制能力的载体或亲本病毒不同，半复制能力的逆转录病毒载体系统不会导致可检测到的传播或白血病发生。此外，这种双载体组合允许不同转基因的共同传播以及第三种无复制能力载体的动员。
本研究是关于使用互补逆转录病毒载体在体外和体内实体瘤中递送和传播转基因的初步原理证明，但其致病性低于亲本病毒。在无复制能力和具有复制能力的逆转录病毒载体之间，这种半复制系统为其在体外研究中的应用提供了充分依据，并有望进一步发展用于癌症基因治疗。
