Multi-component Polymeric System for Tumour Cell-Specific Gene Delivery Using a Universal Bungarotoxin Linker
作者:Ralph A. Willemsen、Michal Pechar、Robert C. Carlisle、Erik Schooten、Robert Pola、Amber J. Thompson、Leonard W. Seymour、Karel Ulbrich
DOI:10.1007/s11095-010-0088-8
日期:2010.11
A new universal tool for specific, non-covalent and non-destructive attachment of a recombinant antibody fragment to a polymer-modified adenovirus has been utilised to regulate the tropism of adenoviral gene delivery vector. We have prepared a multivalent reactive N-(2-hydroxypropyl)methacrylamide-based copolymer (PHPMA) bearing an α-bungarotoxin-binding peptide (BTXbp). The copolymer was used for covalent surface modification of adenoviral vectors (Ad). The α-bungarotoxin protein (BTX) has a nanomolar binding affinity for BTXbp, allowing non-covalent linkage of BTX fusion proteins. A single chain variable fragment of anti-PSMA antibody bearing BTX (scFv-BTX) binding to the prostate-specific membrane antigen (PSMA) was conjugated with the copolymer-coated adenovirus to enable specific infection of prostate cancer cells via PSMA receptors. As shown by ELISA, the copolymer-coated virus exhibited much reduced binding to anti-Ad antibodies. Infection of PC-3 and LNCaP prostate cancer cells was ∼100-fold less efficient with copolymer-coated Ad than with un-modified Ad. Conjugation of scFv-BTX with Ad-PHPMA-BTXbp led to 5–10-fold restoration of infection in PSMA-positive LNCaP cells. In PSMA-negative PC-3 cells, the conjugation of scFv-BTX with Ad-PHPMA-BTXbp gave no enhancement of infection. We have shown that the presented Ad-PHPMA-BTXbp/scFv-BTX system can be used as a universal tool for a receptor-specific virotherapy.
使用了一种新的通用工具,通过特定的、非共价的和非破坏性的附着方式,将重组抗体片段连接到聚合物修饰的腺病毒上,以调控腺病毒基因传递载体的趋向性。我们制备了一种多价反应性N-(2-羟丙基)甲基丙烯酰胺基共聚物(PHPMA),该共聚物带有α-金环蛇毒素结合肽(BTXbp)。该共聚物被用于腺病毒载体(Ad)的共价表面修饰。α-金环蛇毒素蛋白(BTX)对BTXbp具有纳摩尔级别的结合亲和力,从而可以实现BTX融合蛋白的非共价连接。携带BTX的抗PSMA抗体单链可变片段(scFv-BTX)与前列腺特异性膜抗原(PSMA)结合,并通过共聚物包被的腺病毒与之偶联,使得腺病毒能够通过PSMA受体特异性地感染前列腺癌细胞。如ELISA所示,经共聚物包被的病毒与抗Ad抗体的结合能力显著降低。与未经修饰的Ad相比,共聚物包被的Ad对PC-3和LNCaP前列腺癌细胞的感染效率降低了约100倍。在PSMA阳性LNCaP细胞中,scFv-BTX与Ad-PHPMA-BTXbp的偶联使得感染效率恢复至5-10倍。在PSMA阴性的PC-3细胞中,scFv-BTX与Ad-PHPMA-BTXbp的偶联对感染效率没有提升。我们已经证明,所提出的Ad-PHPMA-BTXbp/scFv-BTX系统可以作为一种用于受体特异性病毒治疗的通用工具。