Enhanced Delivery of Adenovirus, Using Proteoliposomes Containing Wildtype or V156K Apolipoprotein A-I and Dimyristoylphosphatidylcholine

Abstract

The delivery of genes or viruses via liposomes is a common approach used to enhance delivery efficiency. In the current study, to enhance delivery efficiency, proteoliposomes (PLs) containing adenovirus (Ad) were synthesized with dimyristoylphosphatidylcholine (DMPC), cholesterol, and apolipoprotein A-I (apoA-I). Wildtype apoA-I (WT) or V156K-apoA-I (V156K) was then used as an apolipoprotein to compare the structural and functional differences of the PLs. The particle diameter of V156K-PL-Ad was slightly larger than that of WT-PL-Ad, based on native gel electrophoresis. V156K showed more rapid phospholipid bilayer formation than did the WT, based on DMPC clearance. In addition, V156K exhibited maximal fluorescence that was more blue than that of WT in the PL state. Moreover, isothermal denaturation in response to the addition of guanidine hydrochloride (Gnd-HCl) revealed that V156K was more resistant, with no denaturation until 3 M Gnd-HCl was added. In addition, electron microscopy revealed that the viral particles were well associated with PL particles, which had a discoidal structure and were shaped like rouleaux. In addition, treatment of Ad in the PL state showed enhanced green fluorescent protein (GFP) expression when compared with treatment with Ad alone or with DMPC-Ad in hepatoma and brain glioma cells. Cells treated with WT-PL-Ad and V156K-PL-Ad showed approximately 50% more GFP expression than cells treated with Ad alone or with DMPC-Ad after 24 hr of incubation at 37 degrees C, indicating that viral stability was highly increased in the PL state. Furthermore, V156K-PL-Ad showed the highest expression of GFP in adult zebrafish (9 weeks old) at 5 days postinjection (10.5- and 3.8-fold more GFP expressed than by Ad only and DMPC-Ad, respectively). In conclusion, the efficiency of viral delivery and the stability of the virus were significantly enhanced when PLs containing apoA-I were used in cellular and zebrafish models.