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

Activation of the Human Immunodeficiency Virus-1 Long Terminal Repeat by Respiratory Burst Oxidants of Neutrophils

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 350-356
Author(s):  
Seymour J. Klebanoff ◽  
Catherine M. Headley
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Long Terminal Repeat ◽  
Respiratory Burst ◽  
Terminal Repeat ◽  
Luciferase Reporter ◽  
Human Neutrophils ◽  
Jurkat T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

The human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) introduced in association with the luciferase reporter gene into Jurkat T cells was strongly activated by a combination of human neutrophils and phorbol myristate acetate (PMA). Activation was not observed when normal neutrophils were replaced by neutrophils which lack a respiratory burst, ie, from a patient with chronic granulomatous disease (CGD), was strongly inhibited by catalase, was potentiated by vanadate, was stimulated by relatively low concentrations of azide, and was inhibited by selective inhibitors of protein kinase C (PKC). The PMA affected activation in three ways: (1) by directly activating the LTR in Jurkat LTRluc; (2) by inducing a respiratory burst in neutrophils with the formation of H2O2; and (3) by increasing the sensitivity of Jurkat LTRluc to the activating effect of H2O2. When PMA was replaced by opsonized zymosan as the neutrophil stimulus, activation of the LTR was low unless azide was added. Activation in the presence of azide was not seen when CGD neutrophils were used or when catalase was added, suggesting that azide acts by inhibiting the degradation of H2O2. These findings indicate that activation of the HIV-1 LTR in Jurkat T cells can be induced by H2O2 released by neutrophils, particularly when PKC is concomitantly activated.

Regulation of nuclear factor of activated T cells by phosphotyrosyl-specific phosphatase activity: a positive effect on HIV-1 long terminal repeat–driven transcription and a possible implication of SHP-1

Blood ◽  
2001 ◽  
Vol 97 (8) ◽  
pp. 2390-2400 ◽  
Author(s):  
Jean-François Fortin ◽  
Benoit Barbeau ◽  
Gilles A. Robichaud ◽  
Marie-Ève Paré ◽  
Anne-Marie Lemieux ◽  
...  
Keyword(s):  
T Cells ◽  
Long Terminal Repeat ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Dominant Negative ◽  
Terminal Repeat ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Nfat Activation ◽  
Hiv 1

Abstract Although protein tyrosine phosphatase (PTP) inhibitors used in combination with other stimuli can induce interleukin 2 (IL-2) production in T cells, a direct implication of nuclear factor of activated T cells (NFAT) has not yet been demonstrated. This study reports that exposure of leukemic T cells and human peripheral blood mononuclear cells to bis-peroxovanadium (bpV) PTP inhibitors markedly induce activation and nuclear translocation of NFAT. NFAT activation by bpV was inhibited by the immunosuppressive drugs FK506 and cyclosporin A, as well as by a specific peptide inhibitor of NFAT activation. Mobility shift assays showed specific induction of the NFAT1 member by bpV molecules. The bpV-mediated NFAT activation was observed to be important for the up-regulation of the human immunodeficiency virus 1 (HIV-1) long terminal repeat (LTR) and the IL-2 promoter; NFAT1 was demonstrated to be particularly important in bpV-dependent positive action on HIV-1 LTR transcription. The active participation of p56lck, ZAP-70, p21ras, and calcium in the bpV-mediated signaling cascade leading to NFAT activation was confirmed, using deficient cell lines and dominant-negative mutants. Finally, overexpression of wild-type SHP-1 resulted in a greatly diminished activation of NFAT by bpV, suggesting an involvement of SHP-1 in the regulation of NFAT activation. These data were confirmed by constitutive NFAT translocation observed in Jurkat cells stably expressing a dominant-negative version of SHP-1. The study proposes that PTP activity attenuates constitutive kinase activities that otherwise would lead to constant NFAT activation and that this activation is participating in HIV-1 LTR stimulation by PTP inhibition.

scholarly journals PIWIL4 Maintains HIV-1 Latency by Enforcing Epigenetically Suppressive Modifications on the 5′ Long Terminal Repeat

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Zhangping He ◽  
Shuliang Jing ◽  
Tao Yang ◽  
Jingliang Chen ◽  
Feng Huang ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
P Element ◽  
Latent Reservoir ◽  
Jurkat T Cells ◽  
Latently Infected ◽  
Novel Strategy ◽  
Hiv 1

ABSTRACT Although substantial progress has been made in depicting the molecular pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection, the comprehensive mechanism of HIV-1 latency and the most promising therapeutic strategies to effectively reactivate the HIV-1 latent reservoir to achieve a functional cure for AIDS remain to be systematically illuminated. Here, we demonstrated that piwi (P element-induced Wimpy)-like RNA-mediated gene silencing 4 (PIWIL4) played an important role in suppressing HIV-1 transcription and contributed to the latency state in HIV-1-infected cells through its recruitment of various suppressive factors, including heterochromatin protein 1α/β/γ, SETDB1, and HDAC4. The knockdown of PIWIL4 enhanced HIV-1 transcription and reversed HIV-1 latency in both HIV-1 latently infected Jurkat T cells and primary CD4+ T lymphocytes and resting CD4+ T lymphocytes from HIV-1-infected individuals on suppressive combined antiretroviral therapy (cART). Furthermore, in the absence of PIWIL4, HIV-1 latently infected Jurkat T cells were more sensitive to reactivation with vorinostat (suberoylanilide hydroxamic acid, or SAHA), JQ1, or prostratin. These findings indicated that PIWIL4 promotes HIV-1 latency by imposing repressive marks at the HIV-1 5′ long terminal repeat. Thus, the manipulation of PIWIL4 could be a novel strategy for developing promising latency-reversing agents (LRAs). IMPORTANCE HIV-1 latency is systematically modulated by host factors and viral proteins. During this process, the suppression of HIV-1 transcription plays an essential role in promoting HIV-1 latency. In this study, we found that PIWIL4 repressed HIV-1 promoter activity and maintained HIV-1 latency. In particular, we report that PIWIL4 can regulate gene expression through its association with the suppressive activity of HDAC4. Therefore, we have identified a new function for PIWIL4: it is not only a suppressor of endogenous retrotransposons but also plays an important role in inhibiting transcription and leading to latent infection of HIV-1, a well-known exogenous retrovirus. Our results also indicate a novel therapeutic target to reactivate the HIV-1 latent reservoir.

scholarly journals Apobec3A maintains HIV-1 latency through recruitment of epigenetic silencing machinery to the long terminal repeat

2019 ◽  
Vol 116 (6) ◽  
pp. 2282-2289 ◽  
Author(s):  
Manabu Taura ◽  
Eric Song ◽  
Ya-Chi Ho ◽  
Akiko Iwasaki
Keyword(s):  
T Cells ◽  
Long Terminal Repeat ◽  
Cd4 T Cells ◽  
Terminal Repeat ◽  
Target Cells ◽  
Mrna Editing ◽  
Latently Infected ◽  
Infected Cells ◽  
Editing Enzyme ◽  
Hiv 1

HIV-1 integrates into the genome of target cells and establishes latency indefinitely. Understanding the molecular mechanism of HIV-1 latency maintenance is needed for therapeutic strategies to combat existing infection. In this study, we found an unexpected role for Apobec3A (apolipoprotein B MRNA editing enzyme catalytic subunit 3A, abbreviated “A3A”) in maintaining the latency state within HIV-1–infected cells. Overexpression of A3A in latently infected cell lines led to lower reactivation, while knockdown or knockout of A3A led to increased spontaneous and inducible HIV-1 reactivation. A3A maintains HIV-1 latency by associating with proviral DNA at the 5′ long terminal repeat region, recruiting KAP1 and HP1, and imposing repressive histone marks. We show that knockdown of A3A in latently infected human primary CD4 T cells enhanced HIV-1 reactivation. Collectively, we provide evidence and a mechanism by which A3A reinforces HIV-1 latency in infected CD4 T cells.

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
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