Objective: The herpes simplex virus-thymidine kinase suicide gene (HSV-TK) was delivered to the human retinal pigment epithelial cell (RPE) by a new vesicular stomatitis virus G protein (VSV-G) retroviral vector. The growth inhibitory effects of ganciclovir on VSV-G/HSV-TK transfected RPE were studied.
Methods: A VSV-G retrovirus-packaging cell line 293GPG was transferred with retroviral vector plasmas bearing HSV-TK (G1NaCTK) or galactosidase (LacZ gene, G1BgSvNa) to produce a 293GPG/TK cell line or a 293GPG/LacZ cell line, respectively. LacZ activity was assessed following transduction of CRL2302 cells. HSV-TK transfected RPE and NIH3T3 cells (at different titer levels) were treated with ganciclovir. The growth inhibitory effects of ganciclovir on various cell lines were studied.
Results: The titer of VSV-G/HSV-TK concentration was 1.2 x 10(8) cfu/ml. At a high titer (MOI = 200), the efficiency of LacZ gene transfer in CRL2302 cells was 58%. Ganciclovir inhibited the growth of cells transfected by HSV-TK. The maximum inhibitory rate (45%) was obtained at cells with a high titer (MOI = 200).
Conclusion: Our results suggested that VSV-G/LacZ and VSV-G/HSV-TK retroviral vectors are highly efficient for in vitro delivery and stable expression of genes in NIH3T3 cells and human RPE cells. The cells modified by HSV-TK gene are very sensitive to ganciclovir and the cell growth can be inhibited by ganciclovir.