ABSTRACT
One of the major obstacles in the use of baculovirus vectors for in vivo gene transfer is the virus inactivation by serum complement. In this study, we investigated the effect of decay-accelerating factor (DAF), factor H (FH)-like protein-1 (FHL-1), C4b-binding protein (C4BP), and membrane cofactor protein (MCP) on protection of baculovirus vectors from the complement-mediated inactivation. Complement regulatory proteins were displayed on baculovirus surface as fusions to membrane anchor of the vesicular stomatitis virus-G (VSV-G) protein. This strategy resulted in abundant expression of recombinant proteins on the viral envelope while viral titers comparable to control virus were reached. The surface-modified vectors exhibited complement resistance in vitro, DAF showing the highest level of protection. Intraportal delivery of DAF-displaying baculovirus resulted in increased survival and enhanced gene expression in immunocompetent mice. Mice receiving DAF-displaying baculovirus also exhibited lower level of liver inflammation as evidenced by aspartate aminotransferase (AST). In line with this, macrophages treated with DAF baculovirus produced lower levels of inflammatory cytokines IL-1beta, IL-6, and IL-12p40 compared to control virus. These results suggest that DAF-display can protect the vector against complement inactivation but also reduce complement-mediated inflammation injury. In conclusion, complement shielded baculovirus vectors represent attractive tools for effective in vivo gene delivery.
Subject(s)
Baculoviridae/metabolism , Genetic Therapy/methods , Genetic Vectors/metabolism , Animals , Baculoviridae/genetics , CD55 Antigens/genetics , CD55 Antigens/metabolism , Cell Line , Complement C4b-Binding Protein/genetics , Complement C4b-Binding Protein/metabolism , Complement Factor H/genetics , Complement Factor H/metabolism , Electrophoresis, Polyacrylamide Gel , Genetic Vectors/genetics , Hep G2 Cells , Humans , Immunoblotting , Membrane Cofactor Protein/genetics , Membrane Cofactor Protein/metabolism , Mice , Mice, Inbred C57BLABSTRACT
BACKGROUND: Baculovirus expression vector system (BEVS) has become a standard in recombinant protein production and virus-like particle preparation for numerous applications. FINDINGS: We describe here protocols which adapt baculovirus generation into 96-well format. CONCLUSION: The established methodology allows simple baculovirus generation, fast virus titering within 18 h and efficient recombinant protein production in a high-throughput format. Furthermore, the produced baculovirus vectors are compatible with gene expression in vertebrate cells in vitro and in vivo.
