Bonsted A, Engesaeter B Ø, Høgset A, Maelandsmo G M, Prasmickaite L, Kaalhus O, Berg K
Department of Biophysics, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, Norway.
Gene Ther. 2004 Jan;11(2):152-60. doi: 10.1038/sj.gt.3302166.
Poor efficiency of adenoviral gene transfer to target cells is a major limitation to adenoviral gene therapy. Inefficient gene transfer occurs in the absence of coxsackie- and adenovirus receptor (CAR) on the cell surface, and can be overcome by enhancing viral entry with cationic molecules. Recombinant adenovirus (Ad) noncovalently complexed with polycations imply a lack of transduction specificity. Therefore, we have investigated the potential of a novel light-specific treatment, named photochemical internalization (PCI), to enhance gene delivery of adenovirus serotype 5 (Ad5) complexed with the cationic agents poly-L-lysine (PLL) and SuperFect trade mark. Cell lines differing in their receptiveness to Ad5 were infected with amounts of virus transducing about 2% of the cells by conventional Ad infection. The combination of polycations and photochemical treatment enabled a substantial increase in reporter gene expression, resulting in up to 75% positive cells. The effect was most prominent in cell lines expressing moderate to low levels of CAR. Furthermore, we show that PCI enables proper gene delivery of fiberless Ad5 at viral concentrations and infection times where transduction of photochemically untreated cells was negligible, both in the absence and presence of PLL. Thus, we conclude that the photochemically induced transduction by adenoviral vectors complexed with polycations present an opportunity to obtain high cell-infectivity levels with low viral doses, also without the fiber-CAR interaction.
腺病毒基因向靶细胞的转移效率低下是腺病毒基因治疗的主要限制因素。在细胞表面缺乏柯萨奇病毒和腺病毒受体（CAR）时会发生低效的基因转移，而通过用阳离子分子增强病毒进入可以克服这一问题。与聚阳离子非共价复合的重组腺病毒（Ad）意味着缺乏转导特异性。因此，我们研究了一种名为光化学内化（PCI）的新型光特异性处理方法的潜力，以增强与阳离子试剂聚-L-赖氨酸（PLL）和超转染试剂（SuperFect商标）复合的5型腺病毒（Ad5）的基因递送。对Ad5接受性不同的细胞系，用传统Ad感染时能转导约2%细胞的病毒量进行感染。聚阳离子与光化学处理的结合使报告基因表达大幅增加，导致高达75%的阳性细胞。在表达中低水平CAR的细胞系中，这种效果最为显著。此外，我们表明，在不存在和存在PLL的情况下，在光化学未处理细胞的转导可忽略不计的病毒浓度和感染时间下，PCI能使无纤维Ad5实现适当的基因递送。因此，我们得出结论，与聚阳离子复合的腺病毒载体通过光化学诱导的转导提供了一个机会，即使用低病毒剂量也能获得高细胞感染率，而且无需纤维与CAR的相互作用。
