title: Screening of complement inhibitors: shielded baculoviruses increase the safety and efficacy of gene delivery.
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.
authors.affiliation: Department of Biotechnology and Molecular Medicine, AI Virtanen Institute, University of Eastern Finland, Kuopio, Finland.
authors.forename: Minna U
authors.initials: MU
authors.lastname: Kaikkonen
authors.forename: Antti I
authors.initials: AI
authors.lastname: Maatta
authors.forename: Seppo
authors.initials: S
authors.lastname: Ylä-Herttuala
authors.forename: Kari J
authors.initials: KJ
authors.lastname: Airenne
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism*; D018958:CD55 Antigens / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D050716:Complement C4b-Binding Protein / Q000235:genetics / Q000378:metabolism; D017242:Complement Factor H / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D015151:Immunoblotting; D051916:Membrane Cofactor Protein / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D018958:CD55 Antigens; D050716:Complement C4b-Binding Protein; D051916:Membrane Cofactor Protein; D017242:Complement Factor H