Biology Reference
In-Depth Information
in a pH-dependent manner, and, furthermore, the expression of either
or all of the candidate receptor molecules, such as hCD81, LDLr, SR-
BI and DC-SIGN failed to confer permissivity to pseudotype infection,
suggesting that unknown additional molecule(s) are necessary for
pseudotype HIVs entry.
44
Since pseudotype VSVs and retroviruses exhibit a different cell
tropism for infection, each pseudotype virus might have different
characteristics for the envelope proteins and then utilize different cel-
lular receptors. One possibility is that chimeric E1 protein of the
pseudotype VSVs and authentic E1 protein of the pseudotype retro-
viruses are revealed to be modified into complex-type and high-
mannose-type carbohydrates, respectively, suggesting that carbohy-
drate modification of E1 protein confers cell tropisms of the pseudo-
type particles. Although a single chain antibody against E2 antibody
obtained from a chronic hepatitis C patient exhibited partial neutral-
ization of pseudotype VSVs,
15
neutralization of pseudotype VSVs by
mouse monoclonal antibodies against HCV E1 and E2 proteins or
patient sera was not observed.
66,101
This is clear contrast to a high
prevalence of neutralization antibody against pseudotype retrovirus
particles in patients of hepatitis C.
8
One of the characteristics of HCV
infection is an establishment of a persistent infection, therefore HCV
virions like pseudotype retroviruses might be easily eliminated by the
neutralization antibody present in most of hepatitis C patients.
Further study to determine the cell tropism of VSV and retrovirus
pseudotype particles and the neutralization activity of antibodies
raised against E1 and E2 proteins in HCV patients are needed.
1)
Glycosaminoglycans
Glycosaminoglycans (GAGs) are ubiquitously present on the cell sur-
face, acquiring a net negative charge through N and O sulfation.
13
A variety of viruses
69,91
and other microorganisms
110
have been shown to
interact with GAGs, especially heparin or heparan sulfate, in an early
step of binding or entry to the host cells. In case of
Flaviviridae
fam-
ily, flaviviruses such as dengue virus
18,37,43
and Japanese Encephalitis
virus
55,56
and pestiviruses such as classical swine fever virus
45
and
