Baculovirus mediated transduction: analysis of vesicular stomatitis virus glycoprotein pseudotyping

The recombinant baculoviruses were constructed to investigate the necessity of VSV-G pseudotyping for mammalian cell transduction. The viruses were designed to express green fluorescent protein (GFP) gene under the control of cytomegalovirus promoter, with or without pseudotyping with VSV-G. VSV-G was placed under the control of polyhedrin promoter that is recognized by insect cells, allowing the formation of pseudotyped baculovirus. The study findings demonstrate that the pseudotyping of baculovirus significantly enhanced transduction efficiency compared to non-pseudotyped baculovirus, resulting in consequent distinction in the expression of GFP in mammalian cells. The results confirmed that pseudotyping is important for baculovirus mediated gene delivery. Further, when full-length VSV-G pseudotyping was compared with truncated VSV-G containing GED domain (G-stem of ectodomain in conjunction with the TM and CT domains of the glycoprotein), latter was relatively less efficient in transducing mammalian cells. This study demonstrated that pseudotyping with full-length VSV-G had better transduction efficiency in mammalian cells. However, at higher multiplicity of infection, both full-length and truncated VSV-G showed equivalent transduction. This study established the significance of pseudotyping of baculovirus with full-length VSV-G for efficient transduction of mammalian cells, utilizing the highly sensitive GFP marker system. These findings have significant implications in designing of baculovirus vector based antigen delivery for developing new generation vaccines.