scholarly journals Phorbol ester enhances human immunodeficiency virus-promoted gene expression and acts on a repeated 10-base-pair functional enhancer element.

1987 ◽  
Vol 7 (10) ◽  
pp. 3759-3766 ◽  
Author(s):  
J D Kaufman ◽  
G Valandra ◽  
G Roderiquez ◽  
G Bushar ◽  
C Giri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Cell Lines ◽  
T Cell Activation ◽  
Potent Inducer ◽  
Enhancer Element ◽  
Immunodeficiency Virus ◽  
Cat Gene ◽  
Cat Expression

T-cell activation pathways are involved in the regulation of human immunodeficiency virus (HIV) expression. Phorbol 12-myristate 13-acetate (PMA) is a potent inducer of T-cell immune functions and has recently been demonstrated to increase viral replication in cell lines infected with HIV. To define sequences required for viral induction by PMA. T-cell lines were transiently transfected with viral long terminal repeat (LTR) sequences directing chloramphenicol acetyltransferase (CAT) gene expression. PMA added to transfected cell cultures 24 h before harvest reproducibly increased both CAT mRNA and enzyme expression 2- to 2-fold. Sequences necessary for basal and PMA-induced levels of CAT expression were determined by deletion and enhancer reconstitution constructs with fragments and oligonucleotides from the original LTR-CAT expression plasmid. PMA-inducible and basal activity required tandem repeats of a core enhancer element (GGGACTTTCC) located in the LTR between -105 and -82 relative to the RNA start site. The enhancerlike sequence could be inserted at a site distant to the CAT gene open reading frame and functioned in a position- and orientation-independent manner. The data thus define a transcriptionally active regulatory-enhancer element critical to the control of HIV gene expression.

Phorbol ester enhances human immunodeficiency virus-promoted gene expression and acts on a repeated 10-base-pair functional enhancer element

1987 ◽  
Vol 7 (10) ◽  
pp. 3759-3766
Author(s):  
J D Kaufman ◽  
G Valandra ◽  
G Roderiquez ◽  
G Bushar ◽  
C Giri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Cell Lines ◽  
T Cell Activation ◽  
Potent Inducer ◽  
Enhancer Element ◽  
Immunodeficiency Virus ◽  
Cat Gene ◽  
Cat Expression

T-cell activation pathways are involved in the regulation of human immunodeficiency virus (HIV) expression. Phorbol 12-myristate 13-acetate (PMA) is a potent inducer of T-cell immune functions and has recently been demonstrated to increase viral replication in cell lines infected with HIV. To define sequences required for viral induction by PMA. T-cell lines were transiently transfected with viral long terminal repeat (LTR) sequences directing chloramphenicol acetyltransferase (CAT) gene expression. PMA added to transfected cell cultures 24 h before harvest reproducibly increased both CAT mRNA and enzyme expression 2- to 2-fold. Sequences necessary for basal and PMA-induced levels of CAT expression were determined by deletion and enhancer reconstitution constructs with fragments and oligonucleotides from the original LTR-CAT expression plasmid. PMA-inducible and basal activity required tandem repeats of a core enhancer element (GGGACTTTCC) located in the LTR between -105 and -82 relative to the RNA start site. The enhancerlike sequence could be inserted at a site distant to the CAT gene open reading frame and functioned in a position- and orientation-independent manner. The data thus define a transcriptionally active regulatory-enhancer element critical to the control of HIV gene expression.

scholarly journals Cellular Gene Expression upon Human Immunodeficiency Virus Type 1 Infection of CD4+-T-Cell Lines

2003 ◽  
Vol 77 (2) ◽  
pp. 1392-1402 ◽  
Author(s):  
Angélique B. van 't Wout ◽  
Ginger K. Lehrman ◽  
Svetlana A. Mikheeva ◽  
Gemma C. O'Keeffe ◽  
Michael G. Katze ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Cell Lines ◽  
Human Immunodeficiency Virus Type ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
T Cell Lines ◽  
Hiv 1

ABSTRACT The expression levels of ∼4,600 cellular RNA transcripts were assessed in CD4+-T-cell lines at different times after infection with human immunodeficiency virus type 1 strain BRU (HIV-1BRU) using DNA microarrays. We found that several classes of genes were inhibited by HIV-1BRU infection, consistent with the G2 arrest of HIV-1-infected cells induced by Vpr. These included genes involved in cell division and transcription, a family of DEAD-box proteins (RNA helicases), and all genes involved in translation and splicing. However, the overall level of cell activation and signaling was increased in infected cells, consistent with strong virus production. These included a subgroup of transcription factors, including EGR1 and JUN, suggesting they play a specific role in the HIV-1 life cycle. Some regulatory changes were cell line specific; however, the majority, including enzymes involved in cholesterol biosynthesis, of changes were regulated in most infected cell lines. Compendium analysis comparing gene expression profiles of our HIV-1 infection experiments to those of cells exposed to heat shock, interferon, or influenza A virus indicated that HIV-1 infection largely induced specific changes rather than simply activating stress response or cytokine response pathways. Thus, microarray analysis confirmed several known HIV-1 host cell interactions and permitted identification of specific cellular pathways not previously implicated in HIV-1 infection. Continuing analyses are expected to suggest strategies for impacting HIV-1 replication in vivo by targeting these pathways.

scholarly journals Maintenance of Viral Suppression in Human Immunodeficiency Virus Controllers Despite Waning T-Cell Responses During Antiretroviral Therapy

2020 ◽  
Vol 222 (11) ◽  
pp. 1837-1842 ◽  
Author(s):  
Nikolaus Jilg ◽  
Pilar Garcia-Broncano ◽  
Michael Peluso ◽  
Florencia P Segal ◽  
Ronald J Bosch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Undetectable Viremia ◽  
Hiv Controllers

Abstract AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses. During ART, significant decreases were observed in a broad range of T-cell responses. Eight controllers in A5308 and the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort showed no viremia above the level of quantification in the first 12 weeks after ART discontinuation. ART significantly reduced HIV-specific T-cell responses in HIV controllers but did not adversely affect controller status after ART discontinuation.

Non-mitogenic T cell activation signals are sufficient for induction of human immunodeficiency virus transcription

1991 ◽  
Vol 21 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Rob A. Gruters ◽  
Sigrid A. Otto ◽  
Bert J. M. Al ◽  
Arthur J. Verhoeven ◽  
Cornelis L. Verweij ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Virus Transcription ◽  
Immunodeficiency Virus

scholarly journals Rational Design of Drugs That Induce Human Immunodeficiency Virus Replication

2003 ◽  
Vol 77 (19) ◽  
pp. 10227-10236 ◽  
Author(s):  
Dean H. Hamer ◽  
Sven Bocklandt ◽  
Louise McHugh ◽  
Tae-Wook Chun ◽  
Peter M. Blumberg ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
T Cell Activation ◽  
Rational Design ◽  
Latent Reservoir ◽  
Viral Gene ◽  
Human Immunodeficiency Virus Replication ◽  
Immunodeficiency Virus ◽  
Latently Infected ◽  
Hiv 1

ABSTRACT Drugs that induce human immunodeficiency virus type 1 (HIV-1) replication could be used in combination with highly active antiretroviral therapy (HAART) to reduce the size of the latent reservoir that is in part responsible for viral persistence. Protein kinase C (PKC) is a logical target for such drugs because it activates HIV-1 transcription through multiple mechanisms. Here we show that HIV-1 gene expression can be induced by potent synthetic analogues of the lipid second messenger diacylglycerol (DAG) synthesized on a five-member ring platform that reduces the entropy of binding relative to that of the more flexible DAG template. By varying the alkyl side chains of these synthetic DAG lactones, it was possible to maximize their potency and ability to render latently infected T cells sensitive to killing by an anti-HIV-1 immunotoxin while minimizing the side effects of CD4 and CXCR4 downregulation and tumor necrosis factor alpha upregulation. The two lead compounds, LMC03 and LMC07, regulated a series of PKC-sensitive genes involved in T-cell activation and induced viral gene expression in peripheral blood mononuclear cells from HIV-1-infected individuals. These studies demonstrate the potential for the rational design of agents that, in conjunction with HAART and HIV-specific toxins, can be used to decrease or eliminate the pool of latently infected reservoirs by forcing viral expression.

scholarly journals Multiple Blocks to Human Immunodeficiency Virus Type 1 Replication in Rodent Cells

2000 ◽  
Vol 74 (21) ◽  
pp. 9868-9877 ◽  
Author(s):  
Paul D. Bieniasz ◽  
Bryan R. Cullen
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
Cell Lines ◽  
Infectious Virus ◽  
Human Gene ◽  
Human Cells ◽  
Gene Products ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The recent identification of human gene products that are required for early steps in the human immunodeficiency virus type 1 (HIV-1) life cycle has raised the possibility that rodents might be engineered to support HIV-1 infection. Therefore, we have examined the ability of modified mouse, rat, and hamster cell lines to support productive HIV-1 replication. Rodent cells, engineered to support Tat function by stable expression of a permissive cyclin T1 protein, proved to be able to support reverse transcription, integration, and early gene expression at levels comparable to those observed in human cell lines. Surprisingly, however, levels of CD4- and coreceptor-dependent virus entry were reduced to a variable but significant extent in both mouse and rat fibroblast cell lines. Additional posttranscriptional defects were observed, including a reduced level of unspliced HIV-1 genomic RNA and reduced structural gene expression. Furthermore, the HIV-1 Gag precursor is generally inefficiently processed and is poorly secreted from mouse and rat cells in a largely noninfectious form. These posttranscriptional defects, together, resulted in a dramatically reduced yield of infectious virus (up to 10,000-fold) over a single cycle of HIV-1 replication, as compared to human cells. Interestingly, these defects were less pronounced in one hamster cell line, CHO, which not only was able to produce infectious HIV-1 particles at a level close to that observed in human cells, but also could support transient, low-level HIV-1 replication. Importantly, the blocks to infectious virus production in mouse and rat cells are recessive, since they can be substantially suppressed by fusion with uninfected human cells. These studies imply the existence of one or more human gene products, either lacking or nonfunctional in most rodent cells that are critical for infectious HIV-1 virion morphogenesis.

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