Coxsackievirus B3 used as a gene therapy vector to express functional FGF2.

Current gene therapies are predominantly based on a handful of viral vectors. The limited choice of delivery vectors has been one of the stumbling blocks to the advancement of gene therapy. Therefore, the development of novel recombinant vectors should facilitate the application of gene therapies. In this study, we examined coxsackievirus B3 (CVB3) as a novel recombinant vector for the delivery and expression of a foreign gene in vitro and in vivo. A recombinant CVB3 complementary DNA was constructed by inserting a gene encoding human fibroblast growth factor 2 (FGF2). The recombinant virus (CVB3-FGF2) efficiently expressed FGF2 in HeLa cells and human cardiomyocytes in vitro and in mouse hindlimbs in vivo. The injection of the recombinant virus into mice with ischemic hindlimbs protected the hindlimbs from ischemic necrosis. CVB3-FGF2 injection significantly improved the blood flow in the ischemic limbs for over 3 weeks compared with that in the phosphate-buffered saline- or CVB3-injected controls, suggesting that FGF2 expressed from CVB3-FGF2 is functional and therapeutically effective. The virulence of CVB3 was also drastically attenuated in the recombinant virus. Thus, CVB3 can be modified to express a functional foreign protein, supporting its use as a novel viral vector for gene therapy.