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. Gene Therapy (2005) 12, 238-245.

Acquisition of Complement Resistance through Incorporation of CD55/Decay-Accelerating Factor into Viral Particles Bearing Baculovirus GP64

“…Furthermore, among the pseudotyped lentiviruses produced through an incorporation of each CRP, DAF-containing lentiviruses generated in the viral producer cells overexpressing a native form of DAF exhibited potent resistance to inactivation by human complement (33). However, our data indicated that pseudotype and recombinant VSVs bearing the GP64 produced in naive mammalian cells actively incorporate sufficiently large amounts of human DAF into viral particles to confer the particles with resistance to serum inactivation.…”

Altering the Tropism of Lentiviral Vectors through Pseudotyping

“…Lentiviral vectors pseudotyped with the baculovirus GP64 were found to be inactivated by human complement [Schauber, 2004]. In animal sera, the vectors were mostly resistant to inactivation by rodent complement, whereas canine complement caused a moderate reduction in titer [Schauber-Plewa, 2005]. Human complement-resistant pseudotyped HIV-1 vector particles were subsequently produced through incorporation of complement regulatory proteins.…”

Virion-Associated Complement Regulator CD55 Is More Potent than CD46 in Mediating Resistance of Mumps Virus and Vesicular Stomatitis Virus to Neutralization

“…The ability of viruses to activate complement as well as counteract complement pathways can play important roles in viral pathogenesis (e.g., see references 10, 29, and 41). In addition, it is increasingly clear that a greater understanding of complement interactions with viruses will be needed for the design of more effective viral vaccines and therapeutic vectors (31,39). The overall goal of the work described here was to understand the mechanisms by which the negative-strand RNA viruses mumps virus (MuV) and vesicular stomatitis virus (VSV) limit complement-mediated neutralization.…”