Biology Reference
In-Depth Information
VSV has a non-segmented 11 kb genome of negative stranded
RNA which is transcribed in the cytoplasm and encodes five structural
proteins. As reason for many advantages, VSV has been used as a
model system for studying the replication and assembly of enveloped
RNA viruses. VSV is known to efficiently propagate in many animal
cells and readily form pseudotype virions with the envelope proteins
from many other different viruses. Reverse genetics systems to recover
rabies virus and VSV from cDNA clones have become available.
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Recombinant VSV in which native envelope protein G is replaced
with foreign viral envelope protein or other membrane protein could
contribute to the study of viruses that inefficiently replicate in exper-
imental systems. Additionally, such pseudotype viruses could lead to
the induction of cellular and humoral host immunity.
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In HCV study, we and others have been adapted to utilize the VSV
pseudotype systems,
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and the pseudotype viruses possessing mod-
ified or unmodified HCV envelope proteins are infectious to human
hapatoma cell lines. HCV pseudotype VSVs can be produced by the
infection of VSV
G* viruses possessing
reporter gene in place of envelope G gene complemented in trans with
VSVG protein (Fig. 3). HCV E1 and E2 proteins are normally retained
in the ER by C-terminal retention signals.
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In the VSV pseudotype
systems, foreign envelope proteins should be expressed on cell surface
because VSV normally bud from the plasma membrane. Pseudotype
VSVs possessing chimeric proteins comprised of the ectodomains of
HCV envelope proteins with the signal sequence, transmembrane and
cytoplasmic regions of VSV G envelope protein were constructed.
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The chimeric E1 and E2 proteins were translocated onto the cell sur-
face and incorporated into the released VSV particles. This pseudotype
VSVs possessing chimeric E1 and E2 proteins could infect to human
hepatoma cell lines HepG2 and Huh7, human kidney cell line 293T,
monkey kidney cell lines COS7 and CV-1, but neither mouse, rat nor
hamster cell lines. Furthermore, chimeric HCV envelope proteins
expressing CHO cell lines induced membrane fusion with HepG2 cells
in a pH-dependent manner,
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confirmed that chimeric E1 and E2 pro-
teins were functionally expressed on the cell surface.
Recently, a recombinant VSV encoding foreign gene instead of
VSVG gene has been developed.
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∆
G*-G which consists of
∆
Although lack of infectivity of
