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M94A0251.TXT
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1994-10-08
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Document 0251
DOCN M94A0251
TI Persistent infection of MT-4 cells by human immunodeficiency virus type
1 becomes increasingly likely with in vitro serial passage of wild-type
but not nef mutant virus.
DT 9412
AU Nishino Y; Nakaya T; Fujinaga K; Kishi M; Azuma I; Ikuta K; Institute of
Immunological Science, Hokkaido University, Sapporo,; Japan.
SO J Gen Virol. 1994 Sep;75 ( Pt 9):2241-51. Unique Identifier : AIDSLINE
MED/94358722
AB Our previous studies have shown that human immunodeficiency virus type 1
(HIV-1), with mutations in accessory genes such as vif, vpr or vpu, can
generate persistent infection of MT-4 cells, whereas infection by
wild-type or nef mutant HIV-1 causes extensive cell death. The
possibility of generating a naturally attenuated form of HIV-1 with
reduced cytopathogenicity in MT-4 cells was examined by in vitro serial
passage of the wild-type and a nef mutant form of HIV-1, each derived
from the infectious molecular clone pNL432. The ability to cause
persistent infection was observed after four passages of wild-type HIV-1
with the frequency of persistence becoming progressively higher with
serial passage. In contrast, persistent infection was not observed even
after 50 passages of the nef mutant virus. Sequence analysis of the
accessory gene loci in genomes recovered from the persistent infections
caused by passaged virus revealed mutations in vif and vpr, but not in
vpu. The processing of the Env precursor to mature forms was not
modified in any of the passages of either wild-type or nef mutant HIV-1.
However, when compared with acute infections caused by similarly
passaged virus of both wild-type and nef mutant HIV-1, persistent
infections by passaged wild-type HIV-1 showed a significant decrease in
the cell surface expression and function of Env. Cell surface CD4 was
only partially down-regulated on cells acutely infected with the
passaged viruses, whereas on cells persistently infected with passaged
wild-type HIV-1 it was completely down-regulated. These results suggest
that, during serial passage of HIV-1, mutations accumulate at least in
the accessory genes vif and vpr in parallel with a lesser interaction
between cell surface Env and CD4 molecules, and lead to the generation
of less cytopathogenic viruses capable of persistent infection. Our
results also suggest an important role for the nef gene product in the
generation of HIV-1 strains that are less cytopathogenic.
DE Amino Acid Sequence Antigens, CD/BIOSYNTHESIS Antigens,
CD4/BIOSYNTHESIS Base Sequence Cell Membrane/METABOLISM/ULTRASTRUCTURE
Clone Cells Comparative Study DNA Primers Gene Products,
env/BIOSYNTHESIS *Genes, nef Genes, vif Genes, vpr Genes, vpu Giant
Cells Human HIV Envelope Protein gp120/BIOSYNTHESIS
HIV-1/GENETICS/*PHYSIOLOGY/PATHOGENICITY Kinetics Molecular Sequence
Data *Mutation Polymerase Chain Reaction Reverse
Transcriptase/METABOLISM Support, Non-U.S. Gov't T-Lymphocytes Time
Factors Viral Proteins/BIOSYNTHESIS/CHEMISTRY *Virus Replication
JOURNAL ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).