title: Complement regulatory proteins are incorporated into lentiviral vectors and protect particles against complement inactivation.
abstract: Lentiviral vectors pseudotyped with G glycoprotein from vesicular stomatitis virus (VSV-G) and baculovirus gp64 are inactivated by human complement. The extent of vector inactivation in serum from individual donors was examined and results showed wide donor-dependent variation in complement sensitivity for VSV-G-pseudotyped lentivectors. Amphotropic envelope (Ampho)-pseudotyped vectors were generally resistant to serum from all donors, while gp64-pseudotyped vectors were inactivated but showed less donor-to-donor variation than VSV-G. In animal sera, the vectors were mostly resistant to inactivation by rodent complement, whereas canine complement caused a moderate reduction in titer. In a novel advance for the lentiviral vector system, human complement-resistant-pseudotyped lentivector particles were produced through incorporation of complement regulatory proteins (CRPs). Decay accelerating factor (DAF)/CD55 provided the most effective protection using this method, while membrane cofactor protein (MCP)/CD46 showed donor-dependent protection and CD59 provided little or no protection against complement inactivation. Unlike previous approaches using CRPs to produce complement-resistant viral vectors, CRP-containing lentivectors particles were generated for this study without engineering the CRP molecules. Thus, through overexpression of native DAF/CD55 in the viral producer cell, an easy method was developed for generation of lentiviral vectors that are almost completely resistant to inactivation by human complement. Production of complement-resistant lentiviral particles is a critical step toward use of these vectors for in vivo gene therapy applications.
authors.affiliation: Cell Genesys Inc., South San Francisco, CA 94080, USA.
authors.forename: C
authors.initials: C
authors.lastname: Schauber-Plewa
authors.forename: A
authors.initials: A
authors.lastname: Simmons
authors.forename: M J
authors.initials: MJ
authors.lastname: Tuerk
authors.forename: C D
authors.initials: CD
authors.lastname: Pacheco
authors.forename: G
authors.initials: G
authors.lastname: Veres
mesh_terms: D000818:Animals; D003169:Complement Inactivator Proteins / Q000235:genetics*; D004285:Dogs; D005818:Genetic Engineering; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D047468:Immunoprecipitation; D051379:Mice; D008810:Mice, Inbred C57BL; D051381:Rats; D011919:Rats, Inbred Strains; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics*
chemical_list: D003169:Complement Inactivator Proteins