Mäkelä Anna R, Enbäck Juulia, Laakkonen Johanna P, Vihinen-Ranta Maija, Laakkonen Pirjo, Oker-Blom Christian
NanoScience Center, Department of Biological and Environmental Science, University of Jyväskylä, Finland.
J Gene Med. 2008 Sep;10(9):1019-31. doi: 10.1002/jgm.1222.
Tumor-associated cells and vasculature express attractive molecular markers for site-specific vector targeting. To attain tumor-selective tropism, we recently developed a baculovirus vector displaying the lymphatic homing peptide LyP-1, originally identified by ex vivo/in vivo screening of phage display libraries, on the viral envelope by fusion to the transmembrane anchor of vesicular stomatitis virus G-protein.
In the present study, we explored the specificity and kinetics of viral binding and internalization as well as in vivo tumor homing of the LyP-1 displaying virus to elucidate the applicability of baculovirus for targeted therapies.
We demonstrated that the LyP-1 peptide contributes to saturable binding of baculovirus in human MDA-MB-435 and HepG2 carcinoma cells and escalates the kinetics of viral internalization leading to earlier nuclear accumulation and enhanced transgene expression. The LyP-1 displaying virus also showed stronger competitiveness against transduction with wild-type baculovirus, suggesting involvement of a specific receptor in cellular attachment and entry. Following intravenous injections, the modified virus accumulated within the human MDA-MB-435 and MDA-MB-231 carcinoma xenografts in mice with higher specificity and efficiency than the control virus. Targeting of the modified virus was more specific in the MDA-MB-435 than in the MDA-MB-231 xenografts as demonstrated by higher tumor accumulation and lower distribution in nontarget organs. No apparent cytotoxicity was associated with the surface modification.
This first demonstration of in vivo tumor targeting of a systemically administered, tropism-modified baculoviral vector highlights the potential of baculovirus-mediated targeted therapies.
肿瘤相关细胞和脉管系统表达出可用于位点特异性载体靶向的有吸引力的分子标志物。为实现肿瘤选择性嗜性，我们最近开发了一种杆状病毒载体，通过与水泡性口炎病毒G蛋白的跨膜锚定区融合，在病毒包膜上展示最初通过噬菌体展示文库的体外/体内筛选鉴定出的淋巴归巢肽LyP-1。
在本研究中，我们探究了展示LyP-1的病毒的病毒结合与内化的特异性和动力学以及体内肿瘤归巢情况，以阐明杆状病毒在靶向治疗中的适用性。
我们证明，LyP-1肽有助于杆状病毒在人MDA-MB-435和HepG2癌细胞中的饱和结合，并加快病毒内化动力学，导致更早的核积累和增强的转基因表达。展示LyP-1的病毒对野生型杆状病毒转导也表现出更强的竞争力，表明细胞附着和进入过程中有特定受体参与。静脉注射后，修饰病毒在小鼠的人MDA-MB-435和MDA-MB-231癌异种移植物中积累，其特异性和效率高于对照病毒。如在非靶器官中更高的肿瘤积累和更低的分布所示，修饰病毒在MDA-MB-435中的靶向比在MDA-MB-231异种移植物中更具特异性。表面修饰未伴随明显的细胞毒性。
这种系统给药的、嗜性修饰的杆状病毒载体在体内肿瘤靶向方面的首次证明突出了杆状病毒介导的靶向治疗的潜力。
