Restriction of human immunodeficiency virus type 1 production in a human astrocytoma cell line is associated with a cellular block in Rev function.
Chronically human immunodeficiency virus type 1 (HIV-1) strain IIIB-infected human TH4-7-5 astrocytoma cells show low-level virus production. Cocultivation of TH4-7-5 cells with myelomonocytic cells led to active virus production in these target cells after a lag period, indicating cell-determined restriction of virus replication in the glial cells. HIV-1 transcript patterns of TH4-7-5 cells contained only a small proportion of Rev-dependent mRNA species, mimicking a Rev-negative phenotype despite the presence of rev mRNAs and protein. Sequencing of the single provirus integrated in TH4-7-5 cells demonstrated that the rev gene and the Rev-responsive element are intact. These results suggested inhibited function of the Rev-regulatory unit in these astrocytoma cells. Transfection of TH4-7-5 cells with a Rev expression plasmid resulted in weak or no induction of proviral p24gag antigen levels compared with the dramatic increase observed in Rev-permissive HeLa cells. Immunofluorescence analysis of TH4-7-5 cells transfected with a rev-expressing plasmid revealed prominent cytoplasmic and nuclear-nucleolar localization of Rev, in contrast to the predominant nuclear-nucleolar localization pattern of Rev in HeLa cells. We conclude that restriction of virus production in TH4-7-5 cells is at least partially due to a block in Rev-dependent posttranscriptional regulation of HIV expression.
Neumann
M
M
GSF-Institute of Molecular Virology, Oberschleissheim, Germany.
Felber
B K
BK
Kleinschmidt
A
A
Froese
B
B
Erfle
V
V
Pavlakis
G N
GN
Brack-Werner
R
R
D000595:Amino Acid Sequence; D001253:Astrocytes / Q000821:virology*; D001254:Astrocytoma; D001483:Base Sequence; D017931:DNA Primers; D015694:Gene Products, rev / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D011533:Proviruses / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014779:Virus Replication; D054321:rev Gene Products, Human Immunodeficiency Virus
D017931:DNA Primers; D015694:Gene Products, rev; D054321:rev Gene Products, Human Immunodeficiency Virus