scholarly journals Attenuated and Wild-Type HIV-1 Infections and Long Terminal Repeat-Mediated Gene Expression from Plasmids Delivered by Gene Gun to Human Skin ex Vivo and Macaques in Vivo

Virology ◽  
2001 ◽  
Vol 287 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Stephen J. Kent ◽  
Paul U. Cameron ◽  
Jeanette C. Reece ◽  
Phillip R. Thompson ◽  
Damian F.J. Purcell
Keyword(s):  
Gene Expression ◽  
Long Terminal Repeat ◽  
Human Skin ◽  
Ex Vivo ◽  
Terminal Repeat ◽  
Gene Gun ◽  
Wild Type ◽  
Hiv 1

scholarly journals FoxP3 Enhances HIV-1 Gene Expression by Modulating NFκB Occupancy at the Long Terminal Repeat in Human T Cells

2007 ◽  
Vol 282 (22) ◽  
pp. 15973-15980 ◽  
Author(s):  
Derek Holmes ◽  
Geoffry Knudsen ◽  
Stephanie Mackey-Cushman ◽  
Lishan Su
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
Human T Cells ◽  
Hiv 1

Assessment of PD-1 expression in human resting and activated natural killer cells and murine tumor models.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 36-36
Author(s):  
Sean J. Judge ◽  
Cordelia Dunai ◽  
Ian R. Sturgill ◽  
Kevin M. Stoffel ◽  
William J. Murphy ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Ex Vivo ◽  
Fold Increase ◽  
Wild Type ◽  
Immunodeficient Mice

36 Background: Blockade of the PD-1/PD-L1/2 axis has revolutionized cancer therapy. Although reinvigorated PD-1+ T cells are the main effectors in the response to checkpoint blockade, the contribution of Natural Killer (NK) cells to PD-1/PD-L1 inhibition is under debate. While PD-1 has been identified on NK cells, this appears to be restricted to small populations under limited conditions. We sought to evaluate the extent of PD-1 expression in mouse and human resting and activated NK cells. Methods: Human NK cells were isolated from healthy donor PBMCs and cancer patients. Ex vivo activation and proliferation techniques included recombinant human cytokine and feeder line co-culture. Murine NK cells were isolated from splenocytes, and PBMCs from wild type and immunodeficient mice. We assessed NK cell surface markers and intracellular cytokine by flow cytometry, and gene expression by quantitative RT-PCR. Results: Over 21-days of ex vivo expansion, expression of PD-1 or PD-L1 on human NK cells was < 1% at all time points, while TIGIT+ expression increased to > 85%. Conversely, ConA stimulation of T cells increased PD-1 expression with no change in TIGIT expression. QRT-PCR demonstrated absent PD-1 expression in purified NK cells compared to a 5-fold increase in PD-1 gene expression in ConA stimulated PBMCs. PD-1/PD-L1 was also < 1% in the NK92 cell line and < 2.5% in peripheral CD56+CD3- NK cells from patients with soft tissue sarcoma (STS). NK cells from digested freshly resected STS show variable PD-1 ( < 10%) and minimal PD-L1 ( < 1%) expression with a small, but measurable population of intra-tumoral NK cells (1% of immune cells). In vivo mouse studies showed < 5% PD-1+ NK cells in spleen and tumor of CT26 tumor-bearing mice, while PD-L1+ NK cells increased in frequency from spleen (5-35%) to tumor (40-95%) in both wild type BALB/C and SCID mice. Conclusions: In contrast to prior studies, we did not observe a substantial PD-1+ population on human or murine NK cells after multiple activation strategies compared to T cells. Contrary to its application in T cells, our data suggest that PD-1 is not a useful marker for NK cell exhaustion/dysfunction. PD-L1 on NK cells may represent an important link between NK and T cell immunotherapy.

scholarly journals Toll-Interacting Protein Suppresses HIV-1 Long-Terminal-Repeat-Driven Gene Expression and Silences the Post-Integrational Transcription of Viral Proviral DNA

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0125563 ◽  
Author(s):  
Fu-Chun Yang ◽  
Wen-Dong Kuang ◽  
Chuan Li ◽  
Wei-Wei Sun ◽  
Di Qu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
Interacting Protein ◽  
Proviral Dna ◽  
Hiv 1

scholarly journals Both the Exact Target Site Sequence and a Long Poly(A) Tail Are Required for Precise Insertion of the 18S Ribosomal DNA-Specific Non-Long Terminal Repeat Retrotransposon R7Ag

2016 ◽  
Vol 36 (10) ◽  
pp. 1494-1508 ◽  
Author(s):  
Narisu Nichuguti ◽  
Mayumi Hayase ◽  
Haruhiko Fujiwara
Keyword(s):  
Long Terminal Repeat ◽  
Ribosomal Dna ◽  
18S Rdna ◽  
Ex Vivo ◽  
Nuclear Periphery ◽  
Recombinant Baculovirus ◽  
Target Site ◽  
Terminal Repeat ◽  
Dependent Manner

Ribosomal elements (R elements) are site-specific non-long terminal repeat (LTR) retrotransposons that target ribosomal DNA (rDNA). To elucidate how R elements specifically access their target sites, we isolated and characterized the 18S rDNA-specific R element R7Ag fromAnopheles gambiae. Using anin vivoandex vivorecombinant baculovirus retrotransposition system, we found that the exact host 18S rDNA sequence at the target site is essential for the precise insertion of R7Ag. In addition, a long poly(A) tail is necessary for the accurate initiation of R7Ag reverse transcription, a novel mechanism found in non-LTR elements. We further compared the subcellular localizations of proteins in R7Ag as well as R1Bm, another R element that targets 28S rDNA. Although the open reading frame 1 proteins (ORF1ps) of both R7Ag and R1Bm localized predominantly in the cytoplasm, ORF2 proteins (ORF2ps) colocalized in the nucleus with the nucleolar marker fibrillarin. The ORF1ps and ORF2ps of both R elements colocalized largely in the nuclear periphery and to a lesser extent within the nucleus. These results suggest that R7Ag and R1Bm proteins may access nucleolar rDNA targets in an ORF2p-dependent manner.

Inhibition oftat-Activated, HIV-1 Long Terminal Repeat-Mediated Gene Expression by Glucocorticoids

1993 ◽  
Vol 9 (11) ◽  
pp. 1055-1056 ◽  
Author(s):  
Debashis Mitra ◽  
Santosh Sikder ◽  
Jeffrey Laurence
Keyword(s):  
Gene Expression ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
Hiv 1

scholarly journals Collaboration of a detrimental HLA-B*35:01 allele with HLA-A*24:02 in co-evolution of HIV-1 with T-cells leading to poorer clinical outcomes

2021 ◽  
Author(s):  
Nozomi Kuse ◽  
Hayato Murakoshi ◽  
Tomohiro Akahoshi ◽  
Takayuki Chikata ◽  
Katherine L James ◽  
...  
Keyword(s):  
T Cells ◽  
Clinical Outcomes ◽  
Ex Vivo ◽  
Mutant Virus ◽  
Target Cells ◽  
Wild Type ◽  
Infected Cells ◽  
Hiv 1

Although mutant-specific T-cells are elicited in some individuals infected with HIV-1 mutant viruses, the detailed characteristics of these T-cells remain unknown. A recent study showed that the accumulation of strains expressing Nef135F, which were selected by HLA-A*24:02-restricted T-cells, was associated with poor outcomes in individuals with the detrimental HLA-B*35:01 allele, and that HLA-B*35:01-restricted NefYF9(Nef135-143)-specific T-cells failed to recognize target cells infected with Nef135F mutant viruses. Here we investigated HLA-B*35:01-restricted T-cells specific for the NefFF9 epitope incorporating the Nef135F mutation. Longitudinal TCR clonotype analysis demonstrated that 3 types of HLA-B*35:01-restricted T-cells (wild type-specific, mutant-specific, and cross-reactive) with different T-cell repertoires were elicited during the clinical course. HLA-B*35:01 + individuals possessing wild type-specific T-cells had a significantly lower pVL than those with mutant-specific and/or cross-reactive T-cells, even though the latter T-cells effectively recognized the mutant virus-infected cells. These results suggest that mutant-specific and cross-reactive T-cells could only partially suppress HIV-1 replication in vivo. Ex vivo analysis of the T-cells showed higher expression of PD-1 on cross-reactive T-cells and lower expression of CD160/2B4 on the mutant-specific T cells than other T-cells, implying that these inhibitory and stimulatory molecules are key to the reduced function of these T-cells. In the present study, we demonstrate that mutant-specific and cross-reactive T-cells do not contribute to suppression of HIV-1 replication in HIV-1-infected individuals, even though they have the capacity to recognize mutant virus-infected cells. Thus, the collaboration of HLA-A*24:02 with the detrimental allele HLA-B*35:01 resulted in the co-evolution of HIV-1 alongside virus-specific T-cells, leading to poorer clinical outcomes. Importance HIV-1 escape mutations are selected under pressure from HIV-1-specific CD8 + T-cells. Accumulation of these mutations in circulating viruses impairs control of HIV-1 by HIV-1-specific T-cells. Although it is known that HIV-1-specific T-cells recognizing mutant virus were elicited in some individuals infected with mutant virus, the role of these T-cells remains unclear. Accumulation of Phenylalanine at HIV-1 Nef135 (Nef135F), which is selected by HLA-A*24:02-restricted T-cells, led to poor clinical outcome in individuals carrying the detrimental HLA-B*35:01 allele. In the present study, we found that HLA-B*35:01-restricted mutant-specific and cross-reactive T-cells were elicited in HLA-B*35:01 + individuals infected with Nef135F mutant virus. These T-cells could not effectively suppress HIV-1 replication in vivo even though they could recognize mutant virus-infected cells in vitro . Mutant-specific and cross-reactive T-cells expressed lower levels of stimulatory molecules and higher levels of inhibitory molecules, respectively, suggesting a potential mechanism whereby these T-cells fail to suppress HIV-1 replication in HIV-1-infected individuals.

scholarly journals Two-long terminal repeat (LTR) DNA circles are a substrate for HIV-1 integrase

2019 ◽  
Vol 294 (20) ◽  
pp. 8286-8295 ◽  
Author(s):  
Clémence Richetta ◽  
Sylvain Thierry ◽  
Eloise Thierry ◽  
Paul Lesbats ◽  
Delphine Lapaillerie ◽  
...  
Keyword(s):  
Viral Replication ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
Host Genome ◽  
End Joining ◽  
Viral Dna ◽  
Retroviral Integrase ◽  
Hiv 1

Integration of the HIV-1 DNA into the host genome is essential for viral replication and is catalyzed by the retroviral integrase. To date, the only substrate described to be involved in this critical reaction is the linear viral DNA produced in reverse transcription. However, during HIV-1 infection, two-long terminal repeat DNA circles (2-LTRcs) are also generated through the ligation of the viral DNA ends by the host cell's nonhomologous DNA end-joining pathway. These DNAs contain all the genetic information required for viral replication, but their role in HIV-1's life cycle remains unknown. We previously showed that both linear and circular DNA fragments containing the 2-LTR palindrome junction can be efficiently cleaved in vitro by recombinant integrases, leading to the formation of linear 3′-processed–like DNA. In this report, using in vitro experiments with purified proteins and DNAs along with DNA endonuclease and in vivo integration assays, we show that this circularized genome can also be efficiently used as a substrate in HIV-1 integrase-mediated integration both in vitro and in eukaryotic cells. Notably, we demonstrate that the palindrome cleavage occurs via a two-step mechanism leading to a blunt-ended DNA product, followed by a classical 3′-processing reaction; this cleavage leads to integrase-dependent integration, highlighted by a 5-bp duplication of the host genome. Our results suggest that 2-LTRc may constitute a reserve supply of HIV-1 genomes for proviral integration.

scholarly journals Sequence-specific recognition of the HIV-1 long terminal repeat by distamycin: a DNAase I footprinting study

1994 ◽  
Vol 299 (2) ◽  
pp. 451-458 ◽  
Author(s):  
G Feriotto ◽  
C Mischiati ◽  
R Gambari
Keyword(s):  
Long Terminal Repeat ◽  
Dna Sequences ◽  
Molecular Mechanisms ◽  
Terminal Repeat ◽  
Experimental Therapy ◽  
Mobility Shift ◽  
Target Dna ◽  
Hiv 1

Pharmacological modulation of the interaction between transcription factors and target DNA sequences of cellular and viral genes could have important effects in the experimental therapy of a large variety of human pathologies. For instance, alteration of the DNA/protein interaction might be among the molecular mechanisms of action of DNA-binding drugs, leading to an inhibition of the expression of genes involved in the control of in vitro and in vivo growth of neoplastic cells and virus DNA replication. Natural oligopeptides, such as distamycin, are powerful inhibitors of the interaction between nuclear factors and target DNA sequences and, therefore, have been proposed as compounds retaining antibiotic, antineoplastic and antiviral properties. In this study we performed DNAase I footprinting analysis using a PCR product mimicking a region of the long terminal repeat (LTR) of the human immunodeficiency type 1 (HIV-1) retrovirus. The data obtained suggest that distamycin binds to different regions of the HIV-1 LTR depending on the DNA sequence. Electrophoretic mobility shift assays using both crude nuclear extracts from the Jurkat T-lymphoid cell line and the recombinant proteins transcription factor IID and Sp1 suggest that distamycin differentially inhibits the interaction of these two proteins with their specific DNA target sequences, in good agreement with the results obtained by DNAase I footprinting analysis.

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