Stevenson M, Boos E, Herbert C, Hale A, Green N, Lyons M, Chandler L, Ulbrich K, van Rooijen N, Mautner V, Fisher K, Seymour L
Department of Clinical Pharmacology, University of Oxford, Oxford, UK.
Gene Ther. 2006 Feb;13(4):356-68. doi: 10.1038/sj.gt.3302655.
Non-human adenovirus vectors have attractive immunological properties for gene therapy but are frequently restricted by inefficient transduction of human target cells. Using chicken embryo lethal orphan (CELO) virus, we employed a nongenetic mechanism of polymer coating and retargeting with basic fibroblast growth factor (bFGF-pc-CELOluc), a strategy that permits efficient tropism modification of human adenovirus. bFGF-pc-CELOluc showed efficient uptake and transgene expression in chick embryo fibroblasts (CEF), and increased levels of binding and internalization in a variety of human cell lines. Transgene expression was also greater than unmodified CELOluc in PC-3 human prostate cells, although the specific activity (RLU per internalized viral genome) was decreased. In CEF, the specific activity of bFGF-pc-CELOluc was considerably higher than in the human prostate cell line PC-3. Retargeted virus was fully resistant to inhibition by human serum with known adenovirus-neutralizing activity in vitro, while in mice CELOluc was cleared less rapidly from the blood than Adluc following i.v. administration in the presence of adenovirus neutralizing serum. Polymer coating and retargeting with bFGF further reduced rates of clearance for both viruses, suggesting protection against both neutralizing and opsonizing factors. The data indicate that CELO virus may be retargeted to infect human cells via alternative, potentially disease-specific, receptors and resist the effects of pre-existing humoral immunity.
非人类腺病毒载体在基因治疗中具有吸引人的免疫学特性，但常常受到人类靶细胞转导效率低下的限制。我们利用鸡胚致死孤儿（CELO）病毒，采用了一种聚合物包被和用碱性成纤维细胞生长因子重靶向的非遗传机制（bFGF-pc-CELOluc），这是一种能够有效改变人类腺病毒嗜性的策略。bFGF-pc-CELOluc在鸡胚成纤维细胞（CEF）中显示出高效摄取和转基因表达，并在多种人类细胞系中提高了结合和内化水平。在PC-3人前列腺细胞中，转基因表达也高于未修饰的CELOluc，尽管比活性（每个内化病毒基因组的相对光单位）有所降低。在CEF中，bFGF-pc-CELOluc的比活性明显高于人前列腺细胞系PC-3。重靶向病毒在体外对具有已知腺病毒中和活性的人血清抑制作用完全耐药，而在小鼠中，静脉注射腺病毒中和血清后，CELOluc从血液中清除的速度比Adluc慢。用bFGF进行聚合物包被和重靶向进一步降低了两种病毒的清除率，表明其对中和因子和调理素均有保护作用。数据表明，CELO病毒可能通过替代的、潜在疾病特异性的受体重靶向感染人类细胞，并抵抗预先存在的体液免疫的影响。
