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Jie W, Rui-Fen Z, Zhong-Xiang H, Yan W, Wei-Na L, Yong-Ping M, Jing S, Jing-Yi C, Wan-Hong L, Xiao-Hua H, Zhi L, Yan S. Inhibition of cell proliferation by Tas of foamy viruses through cell cycle arrest or apoptosis underlines the different mechanisms of virus-host interactions. Virulence 2022; 13:342-354. [PMID: 35132916 PMCID: PMC8837258 DOI: 10.1080/21505594.2022.2029329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/22/2021] [Accepted: 01/11/2022] [Indexed: 11/22/2022] Open
Abstract
Foamy viruses belong to the Spumaretrovirinae subfamily member of the Retroviridae family and produce nonpathogenic infection to hosts in the natural conditions. However, infections of foamy viruses can dramatically cause severe cytopathic effects in vitro. To date, the exact molecular mechanism has remained unclear which implied the tremendous importance of virus-host cell immune reactions. In this study, we found that the transactivator Tas in two foamy viruses isolated from Old World Monkey (OWM) induced obvious inhibition of cell proliferation via the upregulation of Foxo3a expression. It was mediated by the generation of ROS and the initiation of ER stress, and ultimately, the mitochondrial apoptosis pathway was triggered. Notably, PFV Tas contributed to the accumulation of G0/G1 phase cycle arrest induced by the activation of the p53 signaling pathway and the nuclear transportation of HDAC4 via upregulating PPM1E expression. Together, these results demonstrated the different survival strategies by which foamy virus can hijack host cell cytokines and regulate virus-host cell interactions.
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Affiliation(s)
- Wei Jie
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Zhang Rui-Fen
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Hu Zhong-Xiang
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Wu Yan
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Liu Wei-Na
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Ma Yong-Ping
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Song Jing
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Chen Jing-Yi
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Liu Wan-Hong
- School of Medicine, Wuhan University, Wuhan, P. R. China
| | - He Xiao-Hua
- School of Medicine, Wuhan University, Wuhan, P. R. China
| | - Li Zhi
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
| | - Sun Yan
- College of Life Sciences, Shaanxi Normal University, Xi’an, P. R. China
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2
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Wang J, Li M, Zhang J, Gao Q, Ding Z, Sun J. Paliperidone alleviates MK-801-induced damage to prefrontal cortical neurons via the PP2A/PTEN pathway. J Affect Disord 2022; 317:265-277. [PMID: 36031001 DOI: 10.1016/j.jad.2022.08.071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 08/12/2022] [Accepted: 08/22/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND The putative mechanisms underlying the efficacy of the US Food and Drug Administration-approved antipsychotic drug paliperidone for the treatment of schizophrenia deserve additional investigation, which is the aim of the present animal study. METHODS The behavioral activities of mice were recorded in the open field test and light-dark box test. The effects of paliperidone on MK-801-induced neuronal damage in the prefrontal cortex were tested by flow cytometry, TUNEL staining assays, and ROS staining assays. The neuroprotective effects of paliperidone on neural dendrites and synapses were evaluated using Golgi staining and Sholl analysis. An adenovirus vector containing a Ca2+ indicator was used to monitor the calcium ion concentration in the prefrontal cortex. The expression levels of protein phosphatase 2A (PP2A) and phosphatase and tensin homolog (PTEN) were investigated using Western blotting. RESULTS The data showed that MK-801 caused stereotyped behavior in mice and induced synaptic damage and dendritic spine impairment compared with the control, whereas paliperidone ameliorated these changes. Moreover, paliperidone reversed MK-801-induced decreases in PP2A and PTEN levels in prefrontal cortical neurons. Furthermore, in primary cultured cortical neurons and HT-22 cells, paliperidone inhibited cell apoptosis caused by MK-801. In particular, pretreatment with the PP2A inhibitor LB-100 significantly restrained the protective effects of paliperidone on MK-801-treated neurons and on locomotor activity and stereotypical behavior of mice. LIMITATIONS Whether other proteins are involved in this pathway and how the pathway works have not been revealed. CONCLUSION Our data show that paliperidone alleviates neuronal damage induced by MK-801 via the PP2A/PTEN pathway.
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Affiliation(s)
- Jiaxu Wang
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Meng Li
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jing Zhang
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Qing Gao
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Zhaoxi Ding
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jinhao Sun
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong 250012, China.
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Mori L, Valente ST. Cure and Long-Term Remission Strategies. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2407:391-428. [PMID: 34985678 DOI: 10.1007/978-1-0716-1871-4_26] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The majority of virally suppressed individuals will experience rapid viral rebound upon antiretroviral therapy (ART) interruption, providing a strong rationale for the development of cure strategies. Moreover, despite ART virological control, HIV infection is still associated with chronic immune activation, inflammation, comorbidities, and accelerated aging. These effects are believed to be due, in part, to low-grade persistent transcription and trickling production of viral proteins from the pool of latent proviruses constituting the viral reservoir. In recent years there has been an increasing interest in developing what has been termed a functional cure for HIV. This approach entails the long-term, durable control of viral expression in the absence of therapy, preventing disease progression and transmission, despite the presence of detectable integrated proviruses. One such strategy, the block-and-lock approach for a functional cure, proposes the epigenetic silencing of proviral expression, locking the virus in a profound latent state, from which reactivation is very unlikely. The proof-of-concept for this approach was demonstrated with the use of a specific small molecule targeting HIV transcription. Here we review the principles behind the block-and-lock approach and some of the additional strategies proposed to silence HIV expression.
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Affiliation(s)
- Luisa Mori
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Susana T Valente
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA.
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4
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Cristinelli S, Angelino P, Janowczyk A, Delorenzi M, Ciuffi A. HIV Modifies the m6A and m5C Epitranscriptomic Landscape of the Host Cell. FRONTIERS IN VIROLOGY 2021. [DOI: 10.3389/fviro.2021.714475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The study of RNA modifications, today known as epitranscriptomics, is of growing interest. The N6-methyladenosine (m6A) and 5-methylcytosine (m5C) RNA modifications are abundantly present on mRNA molecules, and impact RNA interactions with other proteins or molecules, thereby affecting cellular processes, such as RNA splicing, export, stability, and translation. Recently m6A and m5C marks were found to be present on human immunodeficiency (HIV) transcripts as well and affect viral replication. Therefore, the discovery of RNA methylation provides a new layer of regulation of HIV expression and replication, and thus offers novel array of opportunities to inhibit replication. However, no study has been performed to date to investigate the impact of HIV replication on the transcript methylation level in the infected cell. We used a productive HIV infection model, consisting of the CD4+ SupT1 T cell line infected with a VSV-G pseudotyped HIVeGFP-based vector, to explore the temporal landscape of m6A and m5C epitranscriptomic marks upon HIV infection, and to compare it to mock-treated cells. Cells were collected at 12, 24, and 36 h post-infection for mRNA extraction and FACS analysis. M6A RNA modifications were investigated by methylated RNA immunoprecipitation followed by high-throughput sequencing (MeRIP-Seq). M5C RNA modifications were investigated using a bisulfite conversion approach followed by high-throughput sequencing (BS-Seq). Our data suggest that HIV infection impacted the methylation landscape of HIV-infected cells, inducing mostly increased methylation of cellular transcripts upon infection. Indeed, differential methylation (DM) analysis identified 59 m6A hypermethylated and only 2 hypomethylated transcripts and 14 m5C hypermethylated transcripts and 7 hypomethylated ones. All data and analyses are also freely accessible on an interactive web resource (http://sib-pc17.unil.ch/HIVmain.html). Furthermore, both m6A and m5C methylations were detected on viral transcripts and viral particle RNA genomes, as previously described, but additional patterns were identified. This work used differential epitranscriptomic analysis to identify novel players involved in HIV life cycle, thereby providing innovative opportunities for HIV regulation.
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Alves de Souza Rios L, Mapekula L, Mdletshe N, Chetty D, Mowla S. HIV-1 Transactivator of Transcription (Tat) Co-operates With AP-1 Factors to Enhance c-MYC Transcription. Front Cell Dev Biol 2021; 9:693706. [PMID: 34277639 PMCID: PMC8278106 DOI: 10.3389/fcell.2021.693706] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022] Open
Abstract
HIV-1 infection often leads to the development of co-morbidities including cancer. Burkitt lymphoma (BL) is one of the most over-represented non-Hodgkin lymphoma among HIV-infected individuals, and displays a highly aggressive phenotype in this population group, with comparatively poorer outcomes, despite these patients being on anti-retroviral therapy. Accumulating evidence indicates that the molecular pathogenesis of HIV-associated malignancies is unique, with components of the virus playing an active role in driving oncogenesis, and in order to improve patient prognosis and treatment, a better understanding of disease pathobiology and progression is needed. In this study, we found HIV-1 Tat to be localized within the tumor cells of BL patients, and enhanced expression of oncogenic c-MYC in these cells. Using luciferase reporter assays we show that HIV-1 Tat enhances the c-MYC gene promoter activity and that this is partially mediated via two AP-1 binding elements located at positions -1128 and -1375 bp, as revealed by mutagenesis experiments. We further demonstrate, using pull-down assays, that Tat can exist within a protein complex with the AP-1 factor JunB, and that this complex can bind these AP-1 sites within the c-MYC promoter, as shown by in vivo chromatin immunoprecipitation assays. Therefore, these findings show that in HIV-infected individuals, Tat infiltrates B-cells, where it can enhance the expression of oncogenic factors, which contributes toward the more aggressive disease phenotype observed in these patients.
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Affiliation(s)
| | - Lungile Mapekula
- Division of Haematology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Nontlantla Mdletshe
- Division of Haematology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Dharshnee Chetty
- Division of Anatomical Pathology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Shaheen Mowla
- Division of Haematology, Department of Pathology, University of Cape Town, Cape Town, South Africa
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6
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Hu ZG, Dong ZQ, Dong FF, Zhu Y, Chen P, Lu C, Pan MH. Identification of a PP2A gene in Bombyx mori with antiviral function against B. mori nucleopolyhedrovirus. INSECT SCIENCE 2020; 27:687-696. [PMID: 31070299 DOI: 10.1111/1744-7917.12678] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/11/2019] [Accepted: 04/28/2019] [Indexed: 06/09/2023]
Abstract
Ser/Thr protein phosphatase 2A (PP2A) is one of the type 2 protein phosphatases, which is required for many intracellular physiological processes and pathogen infection. However, the function of PP2A is unclear in silkworm, Bombyx mori. Here, we cloned and identified BmPP2A, a PP2A gene from B. mori, which has two HEAT domains and a high similarity to PP2A from other organisms. Our results showed that BmPP2A is localized in the cytoplasm and highly expressed in silkworm epidermis and midgut, and that Bombyx mori nucleopolyhedrovirus (BmNPV) infection induces down-regulation of BmPP2A expression. Furthermore, up-regulation of BmPP2A via overexpression significantly inhibited BmNPV multiplication. In contrast, down-regulation of BmPP2A via RNA interference and okadaic acid (a PP2A inhibitor) treatment allowed robust BmNPV replication. This is the first report of PP2A having an antiviral effect in silkworm and provides insights into the function of BmPP2A, a potential anti-BmNPV mechanism, and a possible target for the breeding of silkworm-resistant strains.
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Affiliation(s)
- Zhi-Gang Hu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Zhan-Qi Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Fei-Fan Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yan Zhu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Peng Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Min-Hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
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7
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Ayala-Suárez R, Díez-Fuertes F, Calonge E, De La Torre Tarazona HE, Gracia-Ruíz de Alda M, Capa L, Alcamí J. Insight in miRNome of Long-Term Non-Progressors and Elite Controllers Exposes Potential RNAi Role in Restraining HIV-1 Infection. J Clin Med 2020; 9:jcm9082452. [PMID: 32751854 PMCID: PMC7464121 DOI: 10.3390/jcm9082452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/17/2020] [Accepted: 07/29/2020] [Indexed: 12/14/2022] Open
Abstract
Long-term non-progressors (LTNP) and elite controllers (EC) represent spontaneous natural models of efficient HIV-1 response in the absence of treatment. The main purposes of this work are to describe the miRNome of HIV-1 infected patients with different extreme phenotypes and identify potentially altered pathways regulated by differentially expressed (DE) miRNAs. The miRNomes from peripheral blood mononuclear cells (PBMCs) of dual phenotype EC-LTNP or LTNP with detectable viremia and HIV-infected patients with typical progression before and after treatment, were obtained through miRNA-Seq and compared among them. The administration of treatment produces 18 DE miRNAs in typical progressors. LTNP condition shows 14 DE miRNA when compared to typical progressors, allowing LTNP phenotype differentiation. A set of four miRNAs: miR-144-3p, miR-18a-5p, miR-451a, and miR-324 is strongly downregulated in LTNP and related to protein regulation as AKT, mTOR, ERK or IKK, involved in immune response pathways. Deregulation of 28 miRNA is observed between EC-LTNP and viremic-LTNP, including previously described anti-HIV miRNAs: miR-29a, associated with LTNP phenotype, and miR-155, targeting different pre-integration complexes such as ADAM10 and TNPO3. A holistic perspective of the changes observed in the miRNome of patients with different phenotypes of HIV-control and non-progression is provided.
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Affiliation(s)
- Rubén Ayala-Suárez
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
| | - Francisco Díez-Fuertes
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
- HIV Unit, Hospital Clínic de Barcelona, 08036 Barcelona, Spain
- Correspondence: (F.D.-F.); (J.A.); Tel.: +34-91-822-3234 (F.D.-F.); +34-91-822-3943 (J.A.)
| | - Esther Calonge
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
| | - Humberto Erick De La Torre Tarazona
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
| | - María Gracia-Ruíz de Alda
- Sección de Enfermedades Infecciosas, Medicina Interna, Complejo Hospitalario de Navarra, 31008 Pamplona, Spain;
| | - Laura Capa
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
| | - José Alcamí
- AIDS Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, 28220 Madrid, Spain; (R.A.-S.); (E.C.); (H.E.D.L.T.T.); (L.C.)
- HIV Unit, Hospital Clínic de Barcelona, 08036 Barcelona, Spain
- Correspondence: (F.D.-F.); (J.A.); Tel.: +34-91-822-3234 (F.D.-F.); +34-91-822-3943 (J.A.)
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8
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Moses C, Hodgetts SI, Nugent F, Ben-Ary G, Park KK, Blancafort P, Harvey AR. Transcriptional repression of PTEN in neural cells using CRISPR/dCas9 epigenetic editing. Sci Rep 2020; 10:11393. [PMID: 32647121 PMCID: PMC7347541 DOI: 10.1038/s41598-020-68257-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022] Open
Abstract
After damage to the adult mammalian central nervous system (CNS), surviving neurons have limited capacity to regenerate and restore functional connectivity. Conditional genetic deletion of PTEN results in robust CNS axon regrowth, while PTEN repression with short hairpin RNA (shRNA) improves regeneration but to a lesser extent, likely due to suboptimal PTEN mRNA knockdown using this approach. Here we employed the CRISPR/dCas9 system to repress PTEN transcription in neural cells. We targeted the PTEN proximal promoter and 5' untranslated region with dCas9 fused to the repressor protein Krüppel-associated box (KRAB). dCas9-KRAB delivered in a lentiviral vector with one CRISPR guide RNA (gRNA) achieved potent and specific PTEN repression in human cell line models and neural cells derived from human iPSCs, and induced histone (H)3 methylation and deacetylation at the PTEN promoter. The dCas9-KRAB system outperformed a combination of four shRNAs targeting the PTEN transcript, a construct previously used in CNS injury models. The CRISPR system also worked more effectively than shRNAs for Pten repression in rat neural crest-derived PC-12 cells, and enhanced neurite outgrowth after nerve growth factor stimulation. PTEN silencing with CRISPR/dCas9 epigenetic editing may provide a new option for promoting axon regeneration and functional recovery after CNS trauma.
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Affiliation(s)
- C Moses
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia
| | - S I Hodgetts
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
- Perron Institute for Neurological and Translational Science, 8 Verdun Street, Nedlands, WA, 6009, Australia
| | - F Nugent
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - G Ben-Ary
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - K K Park
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - P Blancafort
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia.
- Greehey Children's Cancer Research Institute, UT Health San Antonio, 8403 Floyd Curl Drive, San Antonio, TX, 78229, USA.
| | - A R Harvey
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Perron Institute for Neurological and Translational Science, 8 Verdun Street, Nedlands, WA, 6009, Australia.
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Chaudhary O, Narayan V, Lelis F, Linz B, Watkins M, Veazey R, Aldovini A. Inhibition of p38 MAPK in combination with ART reduces SIV-induced immune activation and provides additional protection from immune system deterioration. PLoS Pathog 2018; 14:e1007268. [PMID: 30161247 PMCID: PMC6135519 DOI: 10.1371/journal.ppat.1007268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 09/12/2018] [Accepted: 08/08/2018] [Indexed: 12/12/2022] Open
Abstract
Differences in immune activation were identified as the most significant difference between AIDS-susceptible and resistant species. p38 MAPK, activated in HIV infection, is key to induction of interferon-stimulated genes and cytokine-mediated inflammation and is associated with some of the pathology produced by HIV or SIV infection in AIDS-susceptible primates. As small molecule p38 MAPK inhibitors are being tested in human trials for inflammatory diseases, we evaluated the effects of treating SIV-infected macaques with the p38 MAPK inhibitor PH-797804 in conjunction with ART. PH-797804 had no side effects, did not impact negatively the antiviral immune response and, used alone, had no significant effect on levels of immune activation and did not reduced the viremia. When administered with ART, it significantly reduced numerous immune activation markers compared to ART alone. CD38+/HLA-DR+ and Ki-67+ T-cell percentages in blood, lymph node and rectal CD4+ and CD8+ T cells, PD-1 expression in CD8+ T cells and plasma levels of IFNα, IFNγ, TNFα, IL-6, IP-10, sCD163 and C-reactive protein were all significantly reduced. Significant preservation of CD4+, CD4+ central memory, CD4+/IL-22+ and CD4+/IL-17+ T-cell percentages and improvement of Th17/Treg ratio in blood and rectal mucosa were also observed. Importantly, the addition of PH-797804 to ART initiated during chronic SIV infection reduced immune activation and restored immune system parameters to the levels observed when ART was initiated on week 1 after infection. After ART interruption, viremia rebounded in a similar fashion in all groups, regardless of when ART was initiated. We concluded that the inhibitor PH-797804 significantly reduced, even if did not normalized, the immune activation parameters evaluated during ART treatment, improved preservation of critical populations of the immune system targeted by SIV, and increased the efficacy of ART treatment initiated in chronic infection to levels similar to those observed when initiated in acute infection but did not affect positively or negatively viral reservoirs. The hallmark of Human Immunodeficiency Virus and Simian Immunodeficiency Virus infection in disease-susceptible species is the progressive decline of the CD4+ T cell population and heightened immune activation, which by itself can contribute to CD4+ T-cell death. The cellular pathway regulated by p38 MAPK, which is activated in HIV and SIV infection, can contribute significantly to immune activation. We tested in SIV-infected macaques a p38 MAPK inhibitor in combination with anti-retroviral therapy. This drug is already being evaluated in humans for treatment of immune activation associated with other diseases. We found that, when combined with antiretroviral therapy, the inhibitor PH-797804 significantly reduced a few parameters of SIV-induced immune activation and improved preservation of critical populations of the immune system targeted by SIV, but did not modulate viral reservoirs. Importantly, the addition of the inhibitor to anti-retroviral therapy during the chronic phase of the infection, which is the time when most HIV-infected individuals initiate treatment, permitted a more significant preservation of the immune system compared to antiretroviral therapy alone that was similar to that observed when anti-retroviral therapy was initiated in the acute phase of the infection, which rarely occurs in HIV infection.
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Affiliation(s)
- Omkar Chaudhary
- Boston Children’s Hospital, Department of Medicine, and Harvard Medical School, Department of Pediatrics, Boston MA, United States of America
| | - Vivek Narayan
- Boston Children’s Hospital, Department of Medicine, and Harvard Medical School, Department of Pediatrics, Boston MA, United States of America
| | - Felipe Lelis
- Boston Children’s Hospital, Department of Medicine, and Harvard Medical School, Department of Pediatrics, Boston MA, United States of America
| | - Brandon Linz
- Boston Children’s Hospital, Department of Medicine, and Harvard Medical School, Department of Pediatrics, Boston MA, United States of America
| | - Meagan Watkins
- Tulane National Primate Research Center, Division of Comparative Pathology, Covington LA, United States of America
| | - Ronald Veazey
- Tulane National Primate Research Center, Division of Comparative Pathology, Covington LA, United States of America
| | - Anna Aldovini
- Boston Children’s Hospital, Department of Medicine, and Harvard Medical School, Department of Pediatrics, Boston MA, United States of America
- * E-mail:
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10
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Abstract
Despite the success of antiretroviral therapy (ART), there is currently no HIV cure and treatment is life long. HIV persists during ART due to long-lived and proliferating latently infected CD4+ T cells. One strategy to eliminate latency is to activate virus production using latency reversing agents (LRAs) with the goal of triggering cell death through virus-induced cytolysis or immune-mediated clearance. However, multiple studies have demonstrated that activation of viral transcription alone is insufficient to induce cell death and some LRAs may counteract cell death by promoting cell survival. Here, we review new approaches to induce death of latently infected cells through apoptosis and inhibition of pathways critical for cell survival, which are often hijacked by HIV proteins. Given advances in the commercial development of compounds that induce apoptosis in cancer chemotherapy, these agents could move rapidly into clinical trials, either alone or in combination with LRAs, to eliminate latent HIV infection.
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11
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ER stress regulating protein phosphatase 2A-B56γ, targeted by hepatitis B virus X protein, induces cell cycle arrest and apoptosis of hepatocytes. Cell Death Dis 2018; 9:762. [PMID: 29988038 PMCID: PMC6037732 DOI: 10.1038/s41419-018-0787-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022]
Abstract
Hepatitis B virus X (HBx) protein contributes to the progression of hepatitis B virus (HBV)-related hepatic injury and diseases, but the exact mechanism remains unclear. Protein phosphatase 2 A (PP2A) is a major serine/threonine phosphatase involved in regulating many cellular phosphorylation signals that are important for regulation of cell cycle and apoptosis. Does HBx target to PP2A-B56γ and therefore affect HBx-induced hepatotoxicity? In the present study, the expression of B56γ positively correlated with the level of HBx in HBV-infected primary human hepatocytes in human-liver-chimeric mice, HBx-transgenic mice, HBV-infected cells, and HBx-expressing hepatic cells. B56γ promoted p53/p21-dependent cell cycle arrest and apoptosis. Mechanistically, B56γ was transactivated by AP-1, which was under the regulation of endoplasmic reticulum (ER) stress induced CREBH signaling in HBx-expressing hepatic cells. B56γ dephosphorylated p-Thr55-p53 to trigger p53/p21 pathway-dependent cell cycle G1 phase arrest, resulting in apoptosis of hepatic cells. In conclusion, this study provides a novel insight into a mechanism of B56γ mediating cell cycle arrest and apoptosis of HBx-expressing hepatic cells and a basis for B56γ being a potential therapeutic target for HBV-infected hepatic cells.
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12
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Spontaneous reactivation of latent HIV-1 promoters is linked to the cell cycle as revealed by a genetic-insulators-containing dual-fluorescence HIV-1-based vector. Sci Rep 2018; 8:10204. [PMID: 29977044 PMCID: PMC6033903 DOI: 10.1038/s41598-018-28161-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/05/2018] [Indexed: 12/31/2022] Open
Abstract
Long-lived latently HIV-1-infected cells represent a barrier to cure. We developed a dual-fluorescence HIV-1-based vector containing a pair of genetic insulators flanking a constitutive fluorescent reporter gene to study HIV-1 latency. The protective effects of these genetic insulators are demonstrated through long-term (up to 394 days) stable fluorescence profiles in transduced SUP-T1 cells. Analysis of 1,941 vector integration sites confirmed reproduction of HIV-1 integration patterns. We sorted monoclonal cells representing latent HIV-1 infections and found that both vector integration sites and integrity of the vector genomes influence the reactivation potentials of latent HIV-1 promoters. Interestingly, some latent monoclonal cells exhibited a small cell subpopulation with a spontaneously reactivated HIV-1 promoter. Higher expression levels of genes involved in cell cycle progression are observed in these cell subpopulations compared to their counterparts with HIV-1 promoters that remained latent. Consistently, larger fractions of spontaneously reactivated cells are in the S and G2 phases of the cell cycle. Furthermore, genistein and nocodazole treatments of these cell clones, which halted cells in the G2 phase, resulted in a 1.4–2.9-fold increase in spontaneous reactivation. Taken together, our HIV-1 latency model reveals that the spontaneous reactivation of latent HIV-1 promoters is linked to the cell cycle.
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13
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Faust TB, Li Y, Bacon CW, Jang GM, Weiss A, Jayaraman B, Newton BW, Krogan NJ, D'Orso I, Frankel AD. The HIV-1 Tat protein recruits a ubiquitin ligase to reorganize the 7SK snRNP for transcriptional activation. eLife 2018; 7:31879. [PMID: 29845934 PMCID: PMC5999396 DOI: 10.7554/elife.31879] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 05/26/2018] [Indexed: 12/12/2022] Open
Abstract
The HIV-1 Tat protein hijacks P-TEFb kinase to activate paused RNA polymerase II (RNAP II) at the viral promoter. Tat binds additional host factors, but it is unclear how they regulate RNAP II elongation. Here, we identify the cytoplasmic ubiquitin ligase UBE2O as critical for Tat transcriptional activity. Tat hijacks UBE2O to ubiquitinate the P-TEFb kinase inhibitor HEXIM1 of the 7SK snRNP, a fraction of which also resides in the cytoplasm bound to P-TEFb. HEXIM1 ubiquitination sequesters it in the cytoplasm and releases P-TEFb from the inhibitory 7SK complex. Free P-TEFb then becomes enriched in chromatin, a process that is also stimulated by treating cells with a CDK9 inhibitor. Finally, we demonstrate that UBE2O is critical for P-TEFb recruitment to the HIV-1 promoter. Together, the data support a unique model of elongation control where non-degradative ubiquitination of nuclear and cytoplasmic 7SK snRNP pools increases P-TEFb levels for transcriptional activation.
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Affiliation(s)
- Tyler B Faust
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Yang Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Curtis W Bacon
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Gwendolyn M Jang
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,J David Gladstone Institutes, San Francisco, United States
| | - Amit Weiss
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Bhargavi Jayaraman
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Billy W Newton
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,J David Gladstone Institutes, San Francisco, United States
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,J David Gladstone Institutes, San Francisco, United States
| | - Iván D'Orso
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Alan D Frankel
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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14
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Clark E, Nava B, Caputi M. Tat is a multifunctional viral protein that modulates cellular gene expression and functions. Oncotarget 2018; 8:27569-27581. [PMID: 28187438 PMCID: PMC5432358 DOI: 10.18632/oncotarget.15174] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/24/2017] [Indexed: 12/02/2022] Open
Abstract
The human immunodeficiency virus type I (HIV-1) has developed several strategies to condition the host environment to promote viral replication and spread. Viral proteins have evolved to perform multiple functions, aiding in the replication of the viral genome and modulating the cellular response to the infection. Tat is a small, versatile, viral protein that controls transcription of the HIV genome, regulates cellular gene expression and generates a permissive environment for viral replication by altering the immune response and facilitating viral spread to multiple tissues. Studies carried out utilizing biochemical, cellular, and genomic approaches show that the expression and activity of hundreds of genes and multiple molecular networks are modulated by Tat via multiple mechanisms.
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Affiliation(s)
- Evan Clark
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Brenda Nava
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Massimo Caputi
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
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15
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Faust TB, Binning JM, Gross JD, Frankel AD. Making Sense of Multifunctional Proteins: Human Immunodeficiency Virus Type 1 Accessory and Regulatory Proteins and Connections to Transcription. Annu Rev Virol 2017; 4:241-260. [PMID: 28961413 DOI: 10.1146/annurev-virology-101416-041654] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Viruses are completely dependent upon cellular machinery to support replication and have therefore developed strategies to co-opt cellular processes to optimize infection and counter host immune defenses. Many viruses, including human immunodeficiency virus type 1 (HIV-1), encode a relatively small number of genes. Viruses with limited genetic content often encode multifunctional proteins that function at multiple stages of the viral replication cycle. In this review, we discuss the functions of HIV-1 regulatory (Tat and Rev) and accessory (Vif, Vpr, Vpu, and Nef) proteins. Each of these proteins has a highly conserved primary activity; however, numerous additional activities have been attributed to these viral proteins. We explore the possibility that HIV-1 proteins leverage their multifunctional nature to alter host transcriptional networks to elicit a diverse set of cellular responses. Although these transcriptional effects appear to benefit the virus, it is not yet clear whether they are strongly selected for during viral evolution or are a ripple effect from the primary function. As our detailed knowledge of these viral proteins improves, we will undoubtedly uncover how the multifunctional nature of these HIV-1 regulatory and accessory proteins, and in particular their transcriptional functions, work to drive viral pathogenesis.
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Affiliation(s)
- Tyler B Faust
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158; ,
| | - Jennifer M Binning
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158; ,
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158; ,
| | - Alan D Frankel
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158; ,
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16
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Abstract
Despite the success of cART, greater than 50% of HIV infected people develop cognitive and motor deficits termed HIV-associated neurocognitive disorders (HAND). Macrophages are the major cell type infected in the CNS. Unlike for T cells, the virus does not kill macrophages and these long-lived cells may become HIV reservoirs in the brain. They produce cytokines/chemokines and viral proteins that promote inflammation and neuronal damage, playing a key role in HIV neuropathogenesis. HIV Tat is the transactivator of transcription that is essential for replication and transcriptional regulation of the virus and is the first protein to be produced after HIV infection. Even with successful cART, Tat is produced by infected cells. In this study we examined the role of the HIV Tat protein in the regulation of gene expression in human macrophages. Using THP-1 cells, a human monocyte/macrophage cell line, and their infection with lentivirus, we generated stable cell lines that express Tat-Flag. We performed ChIP-seq analysis of these cells and found 66 association sites of Tat in promoter or coding regions. Among these are C5, CRLF2/TSLPR, BDNF, and APBA1/Mint1, genes associated with inflammation/damage. We confirmed the association of Tat with these sequences by ChIP assay and expression of these genes in our THP-1 cell lines by qRT-PCR. We found that HIV Tat increased expression of C5, APBA1, and BDNF, and decreased CRLF2. The K50A Tat-mutation dysregulated expression of these genes without affecting the binding of the Tat complex to their gene sequences. Our data suggest that HIV Tat, produced by macrophage HIV reservoirs in the brain despite successful cART, contributes to neuropathogenesis in HIV-infected people.
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17
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Yoder AC, Guo K, Dillon SM, Phang T, Lee EJ, Harper MS, Helm K, Kappes JC, Ochsenbauer C, McCarter MD, Wilson CC, Santiago ML. The transcriptome of HIV-1 infected intestinal CD4+ T cells exposed to enteric bacteria. PLoS Pathog 2017; 13:e1006226. [PMID: 28241075 PMCID: PMC5344538 DOI: 10.1371/journal.ppat.1006226] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/09/2017] [Accepted: 02/08/2017] [Indexed: 01/01/2023] Open
Abstract
Global transcriptome studies can help pinpoint key cellular pathways exploited by viruses to replicate and cause pathogenesis. Previous data showed that laboratory-adapted HIV-1 triggers significant gene expression changes in CD4+ T cell lines and mitogen-activated CD4+ T cells from peripheral blood. However, HIV-1 primarily targets mucosal compartments during acute infection in vivo. Moreover, early HIV-1 infection causes extensive depletion of CD4+ T cells in the gastrointestinal tract that herald persistent inflammation due to the translocation of enteric microbes to the systemic circulation. Here, we profiled the transcriptome of primary intestinal CD4+ T cells infected ex vivo with transmitted/founder (TF) HIV-1. Infections were performed in the presence or absence of Prevotella stercorea, a gut microbe enriched in the mucosa of HIV-1-infected individuals that enhanced both TF HIV-1 replication and CD4+ T cell death ex vivo. In the absence of bacteria, HIV-1 triggered a cellular shutdown response involving the downregulation of HIV-1 reactome genes, while perturbing genes linked to OX40, PPAR and FOXO3 signaling. However, in the presence of bacteria, HIV-1 did not perturb these gene sets or pathways. Instead, HIV-1 enhanced granzyme expression and Th17 cell function, inhibited G1/S cell cycle checkpoint genes and triggered downstream cell death pathways in microbe-exposed gut CD4+ T cells. To gain insights on these differential effects, we profiled the gene expression landscape of HIV-1-uninfected gut CD4+ T cells exposed to bacteria. Microbial exposure upregulated genes involved in cellular proliferation, MAPK activation, Th17 cell differentiation and type I interferon signaling. Our findings reveal that microbial exposure influenced how HIV-1 altered the gut CD4+ T cell transcriptome, with potential consequences for HIV-1 susceptibility, cell survival and inflammation. The HIV-1- and microbe-altered pathways unraveled here may serve as a molecular blueprint to gain basic insights in mucosal HIV-1 pathogenesis.
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Affiliation(s)
- Alyson C. Yoder
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Kejun Guo
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Stephanie M. Dillon
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Tzu Phang
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
- The Cancer Center, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Eric J. Lee
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Michael S. Harper
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Karen Helm
- The Cancer Center, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Center for AIDS Research, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Center for AIDS Research, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Martin D. McCarter
- Department of Surgery, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Cara C. Wilson
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States of America
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States of America
- * E-mail: (MLS); (CCW)
| | - Mario L. Santiago
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States of America
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States of America
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States of America
- * E-mail: (MLS); (CCW)
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18
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Ensoli B, Nchabeleng M, Ensoli F, Tripiciano A, Bellino S, Picconi O, Sgadari C, Longo O, Tavoschi L, Joffe D, Cafaro A, Francavilla V, Moretti S, Pavone Cossut MR, Collacchi B, Arancio A, Paniccia G, Casabianca A, Magnani M, Buttò S, Levendal E, Ndimande JV, Asia B, Pillay Y, Garaci E, Monini P. HIV-Tat immunization induces cross-clade neutralizing antibodies and CD4(+) T cell increases in antiretroviral-treated South African volunteers: a randomized phase II clinical trial. Retrovirology 2016; 13:34. [PMID: 27277839 PMCID: PMC4899930 DOI: 10.1186/s12977-016-0261-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/14/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Although combined antiretroviral therapy (cART) has saved millions of lives, it is incapable of full immune reconstitution and virus eradication. The transactivator of transcription (Tat) protein is a key human immunodeficiency virus (HIV) virulence factor required for virus replication and transmission. Tat is expressed and released extracellularly by infected cells also under cART and in this form induces immune dysregulation, and promotes virus reactivation, entry and spreading. Of note, anti-Tat antibodies are rare in natural infection and, when present, correlate with asymptomatic state and reduced disease progression. This suggested that induction of anti-Tat antibodies represents a pathogenesis-driven intervention to block progression and to intensify cART. Indeed Tat-based vaccination was safe, immunogenic and capable of immune restoration in an open-label, randomized phase II clinical trial conducted in 168 cART-treated volunteers in Italy. To assess whether B-clade Tat immunization would be effective also in patients with different genetic background and infecting virus, a phase II trial was conducted in South Africa. METHODS The ISS T-003 was a 48-week randomised, double-blinded, placebo-controlled trial to evaluate immunogenicity (primary endpoint) and safety (secondary endpoint) of B-clade Tat (30 μg) given intradermally, three times at 4-week intervals, in 200 HIV-infected adults on effective cART (randomised 1:1) with CD4(+) T-cell counts ≥200 cells/µL. Study outcomes also included cross-clade anti-Tat antibodies, neutralization, CD4(+) T-cell counts and therapy compliance. RESULTS Immunization was safe and well-tolerated and induced durable, high titers anti-Tat B-clade antibodies in 97 % vaccinees. Anti-Tat antibodies were cross-clade (all vaccinees tested) and neutralized Tat-mediated entry of oligomeric B-clade and C-clade envelope in dendritic cells (24 participants tested). Anti-Tat antibody titers correlated positively with neutralization. Tat vaccination increased CD4(+) T-cell numbers (all participants tested), particularly when baseline levels were still low after years of therapy, and this had a positive correlation with HIV neutralization. Finally, in cART non-compliant patients (24 participants), vaccination contained viral load rebound and maintained CD4(+) T-cell numbers over study entry levels as compared to placebo. CONCLUSIONS The data indicate that Tat vaccination can restore the immune system and induces cross-clade neutralizing anti-Tat antibodies in patients with different genetic backgrounds and infecting viruses, supporting the conduct of phase III studies in South Africa. Trial registration ClinicalTrials.gov NCT01513135, 01/23/2012.
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Affiliation(s)
- Barbara Ensoli
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.
| | | | - Fabrizio Ensoli
- Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute, Istituti Fisioterapici Ospitalieri, Rome, Italy
| | - Antonella Tripiciano
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute, Istituti Fisioterapici Ospitalieri, Rome, Italy
| | - Stefania Bellino
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,National Center for Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy
| | - Orietta Picconi
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | - Cecilia Sgadari
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | - Olimpia Longo
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,Italian Medicines Agency, Rome, Italy
| | - Lara Tavoschi
- Head Office, National AIDS Center, Istituto Superiore di Sanità, Cape Town, South Africa.,European Center for Disease Prevention and Control, Stockholm, Sweden
| | - Daniel Joffe
- Head Office, National AIDS Center, Istituto Superiore di Sanità, Cape Town, South Africa
| | - Aurelio Cafaro
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | - Vittorio Francavilla
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute, Istituti Fisioterapici Ospitalieri, Rome, Italy
| | - Sonia Moretti
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | | | | | - Angela Arancio
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute, Istituti Fisioterapici Ospitalieri, Rome, Italy
| | - Giovanni Paniccia
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy.,Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute, Istituti Fisioterapici Ospitalieri, Rome, Italy
| | - Anna Casabianca
- Department of Biomolecular Science, University of Urbino, Urbino, Italy
| | - Mauro Magnani
- Department of Biomolecular Science, University of Urbino, Urbino, Italy
| | - Stefano Buttò
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | - Elise Levendal
- South African Medical Research Council, Cape Town, South Africa.,Health Systems Trust, Cape Town, South Africa
| | | | - Bennett Asia
- National Department of Health, Pretoria, South Africa
| | - Yogan Pillay
- National Department of Health, Pretoria, South Africa
| | - Enrico Garaci
- Istituto Superiore di Sanità, Rome, Italy.,University of Tor Vergata, Rome, Italy
| | - Paolo Monini
- Head Office, National AIDS Center, Istituto Superiore di Sanità, Cape Town, South Africa
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19
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Musinova YR, Sheval EV, Dib C, Germini D, Vassetzky YS. Functional roles of HIV-1 Tat protein in the nucleus. Cell Mol Life Sci 2016; 73:589-601. [PMID: 26507246 PMCID: PMC11108392 DOI: 10.1007/s00018-015-2077-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/01/2015] [Accepted: 10/16/2015] [Indexed: 02/06/2023]
Abstract
Human immunodeficiency virus-1 (HIV-1) Tat protein is one of the most important regulatory proteins for viral gene expression in the host cell and can modulate different cellular processes. In addition, Tat is secreted by the infected cell and can be internalized by neighboring cells; therefore, it affects both infected and uninfected cells. Tat can modulate cellular processes by interacting with different cellular structures and signaling pathways. In the nucleus, Tat might be localized either in the nucleoplasm or the nucleolus depending on its concentration. Here we review the distinct functions of Tat in the nucleoplasm and the nucleolus in connection with viral infection and HIV-induced oncogenesis.
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Affiliation(s)
- Yana R Musinova
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia
- LIA 1066 French-Russian Joint Cancer Research Laboratory, 94805, Villejuif, France
| | - Eugene V Sheval
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia
- LIA 1066 French-Russian Joint Cancer Research Laboratory, 94805, Villejuif, France
| | - Carla Dib
- LIA 1066 French-Russian Joint Cancer Research Laboratory, 94805, Villejuif, France
- UMR8126, Université Paris-Sud, CNRS, Institut de cancérologie Gustave Roussy, 94805, Villejuif, France
| | - Diego Germini
- LIA 1066 French-Russian Joint Cancer Research Laboratory, 94805, Villejuif, France
- UMR8126, Université Paris-Sud, CNRS, Institut de cancérologie Gustave Roussy, 94805, Villejuif, France
| | - Yegor S Vassetzky
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia.
- LIA 1066 French-Russian Joint Cancer Research Laboratory, 94805, Villejuif, France.
- UMR8126, Université Paris-Sud, CNRS, Institut de cancérologie Gustave Roussy, 94805, Villejuif, France.
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20
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Brief Report: Coordinated Modulation of Circulating miR-21 in HIV, HIV-Associated Pulmonary Arterial Hypertension, and HIV/Hepatitis C Virus Coinfection. J Acquir Immune Defic Syndr 2016; 70:236-41. [PMID: 26473639 DOI: 10.1097/qai.0000000000000741] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dysregulation of microRNA-21 (miR-21) is independently associated with HIV infection, pulmonary arterial hypertension (PAH), and hepatitis C virus (HCV) infection. To assess the expression of miR-21 in these overlapping comorbidities, we measured plasma miR-21 in HIV with and without PAH and then stratified by concomitant HCV infection. MiR-21 was increased in HIV and HIV-PAH versus uninfected subjects, but it did not differ between these groups. HIV/HCV coinfection correlated with even higher miR-21 levels within the HIV-infected population. These data reveal specific regulation of plasma miR-21 in HIV, HIV/HCV coinfection, and PAH and suggest that miR-21 may integrate complex disease-specific signaling in the setting of HIV infection.
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21
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Abstract
A virus protein called Tat plays a dual role in HIV infection by regulating the expression of genes belonging to the virus and genes belonging to the host cells.
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Affiliation(s)
- Matjaz Barboric
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Koh Fujinaga
- Department of Medicine, University of California, San Francisco, San Francisco, United States
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22
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Reeder JE, Kwak YT, McNamara RP, Forst CV, D'Orso I. HIV Tat controls RNA Polymerase II and the epigenetic landscape to transcriptionally reprogram target immune cells. eLife 2015; 4. [PMID: 26488441 PMCID: PMC4733046 DOI: 10.7554/elife.08955] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 10/20/2015] [Indexed: 12/22/2022] Open
Abstract
HIV encodes Tat, a small protein that facilitates viral transcription by binding an RNA structure (trans-activating RNA [TAR]) formed on nascent viral pre-messenger RNAs. Besides this well-characterized mechanism, Tat appears to modulate cellular transcription, but the target genes and molecular mechanisms remain poorly understood. We report here that Tat uses unexpected regulatory mechanisms to reprogram target immune cells to promote viral replication and rewire pathways beneficial for the virus. Tat functions through master transcriptional regulators bound at promoters and enhancers, rather than through cellular ‘TAR-like’ motifs, to both activate and repress gene sets sharing common functional annotations. Despite the complexity of transcriptional regulatory mechanisms in the cell, Tat precisely controls RNA polymerase II recruitment and pause release to fine-tune the initiation and elongation steps in target genes. We propose that a virus with a limited coding capacity has optimized its genome by evolving a small but ‘multitasking’ protein to simultaneously control viral and cellular transcription. DOI:http://dx.doi.org/10.7554/eLife.08955.001 The human immunodeficiency virus (HIV) reproduces and spreads throughout the body by hijacking human immune cells and causing them to copy the virus’s genetic information. As the virus multiplies, it also causes the death of the immune system cells that help the human body recognize and eliminate viruses. This allows the virus to multiply unchecked. Studies of the genetic material of HIV – which is in the form of single-stranded RNA molecules and contains only a handful of genes – have begun to reveal how the virus can wreak such havoc to the human immune system. A small protein encoded by the virus, called Tat, boosts the expression of HIV genes in infected immune cells by binding to a structure that forms on newly synthesized viral RNAs. Recent evidence suggests that HIV also changes the expression of human genes to make immune cells more hospitable to the virus. However, it was not known exactly which specific genes are targeted, or how the virus alters their expression. Now, Reeder, Kwak et al. reveal how the Tat protein alters the expression of more than 400 human genes. Rather than bind to the same structure seen in newly forming HIV RNAs, Tat turns on or off the expression of its human target genes by interacting with proteins that regulate human gene expression. In doing so, Tat is able to precisely control the activity of an enzyme called RNA Polymerase II that is necessary for the early steps of gene expression. Tat’s multitasking ability – boosting HIV gene expression at the same time as reprogramming human gene expression – helps explain how a virus with so little genetic material of its own can perform such a wide range of activities in infected cells. The work of Reeder, Kwak et al. suggests that Tat reshapes the human genome to position target genes in ways that allow them to be efficiently turned on or off. Future studies will further reveal how Tat accomplishes this genome remodeling during different stages of infection. In addition, further research is also necessary to look closely into the sets of genes targeted by Tat to find patterns of genes that work together to alter cell behavior, and investigate how these new behaviors allow HIV to thrive. DOI:http://dx.doi.org/10.7554/eLife.08955.002
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Affiliation(s)
- Jonathan E Reeder
- Department of Biological Sciences, University of Texas at Dallas, Richardson, United States.,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Youn-Tae Kwak
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ryan P McNamara
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Christian V Forst
- Department of Genetics and Genomic Sciences, Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Iván D'Orso
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
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Iordanskiy S, Van Duyne R, Sampey GC, Woodson CM, Fry K, Saifuddin M, Guo J, Wu Y, Romerio F, Kashanchi F. Therapeutic doses of irradiation activate viral transcription and induce apoptosis in HIV-1 infected cells. Virology 2015; 485:1-15. [PMID: 26184775 DOI: 10.1016/j.virol.2015.06.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/13/2015] [Accepted: 06/16/2015] [Indexed: 01/17/2023]
Abstract
The highly active antiretroviral therapy reduces HIV-1 RNA in plasma to undetectable levels. However, the virus continues to persist in the long-lived resting CD4(+) T cells, macrophages and astrocytes which form a viral reservoir in infected individuals. Reactivation of viral transcription is critical since the host immune response in combination with antiretroviral therapy may eradicate the virus. Using the chronically HIV-1 infected T lymphoblastoid and monocytic cell lines, primary quiescent CD4(+) T cells and humanized mice infected with dual-tropic HIV-1 89.6, we examined the effect of various X-ray irradiation (IR) doses (used for HIV-related lymphoma treatment and lower doses) on HIV-1 transcription and viability of infected cells. Treatment of both T cells and monocytes with IR, a well-defined stress signal, led to increase of HIV-1 transcription, as evidenced by the presence of RNA polymerase II and reduction of HDAC1 and methyl transferase SUV39H1 on the HIV-1 promoter. This correlated with the increased GFP signal and elevated level of intracellular HIV-1 RNA in the IR-treated quiescent CD4(+) T cells infected with GFP-encoding HIV-1. Exposition of latently HIV-1infected monocytes treated with PKC agonist bryostatin 1 to IR enhanced transcription activation effect of this latency-reversing agent. Increased HIV-1 replication after IR correlated with higher cell death: the level of phosphorylated Ser46 in p53, responsible for apoptosis induction, was markedly higher in the HIV-1 infected cells following IR treatment. Exposure of HIV-1 infected humanized mice with undetectable viral RNA level to IR resulted in a significant increase of HIV-1 RNA in plasma, lung and brain tissues. Collectively, these data point to the use of low to moderate dose of IR alone or in combination with HIV-1 transcription activators as a potential application for the "Shock and Kill" strategy for latently HIV-1 infected cells.
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Affiliation(s)
- Sergey Iordanskiy
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Rachel Van Duyne
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA; Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Gavin C Sampey
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Caitlin M Woodson
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Kelsi Fry
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Mohammed Saifuddin
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Jia Guo
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Yuntao Wu
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Fabio Romerio
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Fatah Kashanchi
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA.
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24
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Dhamija N, Choudhary D, Ladha JS, Pillai B, Mitra D. Tat predominantly associates with host promoter elements in HIV-1-infected T-cells - regulatory basis of transcriptional repression of c-Rel. FEBS J 2014; 282:595-610. [PMID: 25472883 DOI: 10.1111/febs.13168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/19/2014] [Accepted: 12/02/2014] [Indexed: 11/28/2022]
Abstract
HIV-1 Tat is a multifunctional regulatory protein that, in addition to its primary function of transactivating viral transcription, also tends to modulate cellular gene expression, for which the molecular mechanism remains to be clarified. We have reported earlier nuclear factor kappa B (NFκB) enhancer binding activity of Tat and proposed this DNA binding activity as a possible molecular basis for Tat-mediated regulation of cellular gene expression in infected cells. In the present study, we analyzed the genome-wide occupancy of Tat protein on host cell chromatin in HIV-1-infected T-cells to investigate a potential role of Tat on cellular gene expression. The results obtained identify a spectrum of binding sites of Tat protein on the chromatin and reveal that Tat is also recruited on a number of cellular gene promoters in HIV-1-infected T-cells, indicating its possible involvement in the regulation of gene expression of such cellular genes. Tat was identified as a repressor of one such validated gene, c-Rel, because it downregulates the expression of c-Rel in both Tat expressing and HIV-1-infected T-cells. The results also show that Tat downregulates c-Rel promoter activity by interacting with specific NFκB sites on the c-Rel promoter, thus providing a molecular basis of Tat-mediated regulation of cellular gene expression. Thus, in the present study, we have not only identified recruitment sites of Tat on the chromatin in HIV-1-infected T-cells, but also report for the first time that c-Rel is downregulated in HIV-1-infected cells specifically by interaction of Tat with NFκB binding sites on the promoter.
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25
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Olagnier D, Sze A, Bel Hadj S, Chiang C, Steel C, Han X, Routy JP, Lin R, Hiscott J, van Grevenynghe J. HTLV-1 Tax-mediated inhibition of FOXO3a activity is critical for the persistence of terminally differentiated CD4+ T cells. PLoS Pathog 2014; 10:e1004575. [PMID: 25521510 PMCID: PMC4270795 DOI: 10.1371/journal.ppat.1004575] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 11/13/2014] [Indexed: 11/18/2022] Open
Abstract
The mechanisms involved in the persistence of activated CD4+ T lymphocytes following primary human T leukemia/lymphoma virus type 1 (HTLV-1) infection remain unclear. Here, we demonstrate that the HTLV-1 Tax oncoprotein modulates phosphorylation and transcriptional activity of the FOXO3a transcription factor, via upstream activation of the AKT pathway. De novo HTLV-1 infection of CD4+ T cells or direct lentiviral-mediated introduction of Tax led to AKT activation and AKT-dependent inactivation of FOXO3a, via phosphorylation of residues Ser253 and Thr32. Inhibition of FOXO3a signalling led to the long-term survival of a population of highly activated, terminally differentiated CD4+Tax+CD27negCCR7neg T cells that maintained the capacity to disseminate infectious HTLV-1. CD4+ T cell persistence was reversed by chemical inhibition of AKT activity, lentiviral-mediated expression of a dominant-negative form of FOXO3a or by specific small interfering RNA (siRNA)-mediated silencing of FOXO3a. Overall this study provides new mechanistic insight into the strategies used by HTLV-1 to increase long-term maintenance of Tax+CD4+ T lymphocytes during the early stages of HTLV-1 pathogenesis.
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Affiliation(s)
- David Olagnier
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- VGTI Florida, Port St. Lucie, Florida, United States of America
| | - Alexandre Sze
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Samar Bel Hadj
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Cindy Chiang
- VGTI Florida, Port St. Lucie, Florida, United States of America
| | - Courtney Steel
- VGTI Florida, Port St. Lucie, Florida, United States of America
| | - Xiaoying Han
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Jean-Pierre Routy
- Immunodeficiency Service and Division of Haematology, Royal Victoria Hospital, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Rongtuan Lin
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - John Hiscott
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- VGTI Florida, Port St. Lucie, Florida, United States of America
| | - Julien van Grevenynghe
- Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- VGTI Florida, Port St. Lucie, Florida, United States of America
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26
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Hegedus A, Kavanagh Williamson M, Huthoff H. HIV-1 pathogenicity and virion production are dependent on the metabolic phenotype of activated CD4+ T cells. Retrovirology 2014; 11:98. [PMID: 25421745 PMCID: PMC4252996 DOI: 10.1186/s12977-014-0098-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 10/24/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND HIV-1, like all viruses, is entirely dependent on the host cell for providing the metabolic resources for completion of the viral replication cycle and the production of virions. It is well established that HIV-1 replicates efficiently in activated CD4+ T cells, whereas resting CD4+ T cells are refractory to infection with HIV-1. A hallmark of T cell activation is the upregulation of glycolysis to meet the biosynthetic and bioenergetic needs of cell proliferation and the execution of effector functions by the secretion of cytokines. To date, it has remained unknown if HIV-1 requires the high glycolytic activity of activated T cells to support its replication. RESULTS We report that in primary CD4+ T cells, the flux through the glycolytic pathway is increased upon infection with HIV-1. This increase in glycolytic activity does not occur in T cell lines when infected with HIV-1. By providing cells with galactose instead of glucose, the former being a poor substrate for glycolysis, we monitored the effect of preventing glycolysis in CD4+ T cells on virus replication cycle and cell fate. We observed that HIV-1 infected primary CD4+ T cells cultured in galactose have a survival advantage over those cultured in glucose and this coincides with reduced caspase 3 activation and apoptosis in cultures with galactose. T cell lines do not recapitulate this difference in cell death. Finally, we demonstrate that virion production is dependent on glycolysis as cultures containing galactose yield reduced amounts of HIV-1 virions compared with cultures containing glucose. CONCLUSIONS The replication of HIV-1 in primary CD4+ T cells causes an increase in glycolytic flux of the cell. Glycolysis is particularly required for virion production and additionally increases the sensitivity of the infected cell to virus-induced cell death.
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Affiliation(s)
- Andrea Hegedus
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
| | - Maia Kavanagh Williamson
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
| | - Hendrik Huthoff
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
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27
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Zhu XN, Chen LP, Bai Q, Ma L, Li DC, Zhang JM, Gao C, Lei ZN, Zhang ZB, Xing XM, Liu CX, He ZN, Li J, Xiao YM, Zhang AH, Zeng XW, Chen W. PP2A-AMPKα-HSF1 axis regulates the metal-inducible expression of HSPs and ROS clearance. Cell Signal 2014; 26:825-32. [PMID: 24412756 DOI: 10.1016/j.cellsig.2014.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 01/03/2014] [Indexed: 01/18/2023]
Abstract
Metals such as cadmium and arsenic are ubiquitous toxicants that cause a variety of adverse health effects. Heat shock proteins (HSPs) response to metal-induced stress and protect cells from further damage. However, the intracellular signalling pathways responsible for activation of HSPs expression are not fully understood. Here, we demonstrate that protein phosphatase 2A (PP2A) regulates expression of HSP70 and HSP27 via dephosphorylation of an AMP-activated protein kinase α subunit (AMPKα) at Thr172. Dephosphorylated AMPKα phosphorylates heat shock factor 1 (HSF1) at Ser303, leading to significant transcriptional suppression of HSP70 and HSP27 in CdCl2- or NaAsO2-treated cells. Suppression of PP2A regulatory B56δ subunit resulted in the sustained phosphorylation of AMPKα upon CdCl2 treatment, subsequent reduction in expression of HSP70 and HSP27, and thereby dramatic reduction of reactive oxygen species (ROS) clearance. We further revealed that PP2A B56δ physically interacted with AMPKα, providing evidence that PP2A B56δ-AMPKα-HSF1 signalling pathway participated in regulating the inducible expression of HSPs and ROS clearance. Taken together, we identified a novel PP2A-dependent signalling pathway involved in regulation of HSPs expression in response to metal stress.
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Affiliation(s)
- Xiao-nian Zhu
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Li-ping Chen
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Qing Bai
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Lu Ma
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Dao-chuan Li
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Jin-miao Zhang
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Chen Gao
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Zi-ning Lei
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Zheng-bao Zhang
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiu-mei Xing
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Cai-xia Liu
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Zhi-ni He
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Jie Li
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Yong-mei Xiao
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Ai-hua Zhang
- School of Public Health, Guiyang Medical University, Guiyang 550004, China
| | - Xiao-wen Zeng
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
| | - Wen Chen
- Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
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28
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Yoo SY, Le TKV, Jeong JJ, Kim DH. Poligapolide, a PI3K/Akt Inhibitor in Immunodeficiency Virus Type 1 TAT-Transduced CHME5 Cells, Isolated from the Rhizome of Polygala tenuifolia. Chem Pharm Bull (Tokyo) 2014; 62:467-71. [DOI: 10.1248/cpb.c13-00958] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Sul-Young Yoo
- Department of Life and Nanopharmaceutical Sciences and Department of Pharmacy, College of Pharmacy, Kyung Hee University
| | - Thi Kim Van Le
- Department of Life and Nanopharmaceutical Sciences and Department of Pharmacy, College of Pharmacy, Kyung Hee University
| | - Jin Ju Jeong
- Department of Life and Nanopharmaceutical Sciences and Department of Pharmacy, College of Pharmacy, Kyung Hee University
| | - Dong-Hyun Kim
- Department of Life and Nanopharmaceutical Sciences and Department of Pharmacy, College of Pharmacy, Kyung Hee University
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29
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Dahiya S, Irish BP, Nonnemacher MR, Wigdahl B. Genetic variation and HIV-associated neurologic disease. Adv Virus Res 2013; 87:183-240. [PMID: 23809924 DOI: 10.1016/b978-0-12-407698-3.00006-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
HIV-associated neurologic disease continues to be a significant complication in the era of highly active antiretroviral therapy. A substantial subset of the HIV-infected population shows impaired neuropsychological performance as a result of HIV-mediated neuroinflammation and eventual central nervous system (CNS) injury. CNS compartmentalization of HIV, coupled with the evolution of genetically isolated populations in the CNS, is responsible for poor prognosis in patients with AIDS, warranting further investigation and possible additions to the current therapeutic strategy. This chapter reviews key advances in the field of neuropathogenesis and studies that have highlighted how molecular diversity within the HIV genome may impact HIV-associated neurologic disease. We also discuss the possible functional implications of genetic variation within the viral promoter and possibly other regions of the viral genome, especially in the cells of monocyte-macrophage lineage, which are arguably key cellular players in HIV-associated CNS disease.
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Affiliation(s)
- Satinder Dahiya
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Bryan P Irish
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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30
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Jin H, Liu L, Deng W, Lu Y, Tian J, Li H, Liu J. HDAC inhibitor DWP0016 suppresses miR-22 to induce growth inhibition and apoptosis via p53-independent PTEN activation in neuroblastoma SH-SY5Y cells. Process Biochem 2013. [DOI: 10.1016/j.procbio.2013.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Abbas W, Herbein G. T-Cell Signaling in HIV-1 Infection. Open Virol J 2013; 7:57-71. [PMID: 23986795 PMCID: PMC3751038 DOI: 10.2174/1874357920130621001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 05/31/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022] Open
Abstract
HIV exploits the T-cell signaling network to gain access to downstream cellular components, which serves as effective tools to break the cellular barriers. Multiple host factors and their interaction with viral proteins contribute to the complexity of HIV-1 pathogenesis and disease progression. HIV-1 proteins gp120, Nef, Tat and Vpr alter the T-cell signaling pathways by activating multiple transcription factors including NF-ĸB, Sp1 and AP-1. HIV-1 evades the immune system by developing a multi-pronged strategy. Additionally, HIV-1 encoded proteins influence the apoptosis in the host cell favoring or blocking T-cell apoptosis. Thus, T-cell signaling hijacked by viral proteins accounts for both viral persistence and immune suppression during HIV-1 infection. Here, we summarize past and present studies on HIV-1 T-cell signaling with special focus on the possible role of T cells in facilitating viral infection and pathogenesis
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Affiliation(s)
- Wasim Abbas
- Department of Virology, Pathogens & Inflammation Laboratory, UPRES EA4266, SFR FED 4234, University of Franche-Comte, CHRU Besançon, F-25030 Besançon, France
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32
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Comandini A, Naro C, Adamo R, Akbar AN, Lanna A, Bonmassar E, Franzese O. Molecular mechanisms involved in HIV-1-Tat mediated inhibition of telomerase activity in human CD4+ T lymphocytes. Mol Immunol 2013; 54:181-92. [DOI: 10.1016/j.molimm.2012.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 12/16/2022]
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33
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Tat engagement of p38 MAP kinase and IRF7 pathways leads to activation of interferon-stimulated genes in antigen-presenting cells. Blood 2013; 121:4090-100. [PMID: 23535064 DOI: 10.1182/blood-2012-10-461566] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
As a result of its interaction with transcription factors, HIV type 1 (HIV-1) Tat can modulate the expression of both HIV and cellular genes. In antigen-presenting cells Tat induces the expression of a subset of interferon (IFN)-stimulated genes (ISGs) in the absence of IFNs. We investigated the genome-wide Tat association with promoters in immature dendritic cells and in monocyte-derived macrophages. Among others, Tat associated with the MAP2K6, MAP2K3, and IRF7 promoters that are functionally part of IL-1 and p38 mitogen-activated protein kinase (MAPK) signaling pathways. The association correlated with their increased gene expression, increased activation of p38 MAPK and of phosphorylated signal transducer and activator of transcription 1 (STAT1), and consequent induction of ISGs. Probing these pathways with RNA interference, pharmacological p38 MAPK inhibition, and in cell lines lacking STAT1s or the type I IFN receptor chain confirmed the role of MAPKKs and IRF7 in Tat-mediated modulation of ISGs and excluded the involvement of IFNs in this modulation. Tat interaction with the 2 MAPKK and IRF7 promoters in HIV-1-infected cells and the resulting persistent activation of ISGs, which include inflammatory cytokines and chemokines, can contribute to the increased immune activation that characterizes HIV infection.
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34
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Le TKV, Jeong JJ, Kim DH. Clionosterol and ethyl cholestan-22-enol isolated from the rhizome of Polygala tenuifolia inhibit phosphatidylinositol 3-kinase/Akt pathway. Biol Pharm Bull 2012; 35:1379-83. [PMID: 22863942 DOI: 10.1248/bpb.b12-00426] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphatidylinositol 3-kinase (PI3K)/Akt inhibitors were isolated from the rhizome of Polygala tenuifolia WILLD (PT, Polygalaceae), which has been used in traditional Chinese medicine for inflammation, dementia, amnesia, neurasthenia and cancer, by activity-guided fractionation. For the assay of PI3K/Akt pathway, cytoprotective Tat-transduced CHME5 cells, which are the cytoprotective phenotype against lypopolysaccharide (LPS)/cycloheximide (CHX), were used. We isolated 4 anti-cytoprotective compounds, clionasterol (1), ethyl cholestan-22-enol (2), 3-O-β-D-glucosyl ethyl cholestan-22-enol (3), and 3-O-β-D-glucopyranosyl clionasterol (4) from EtOAc fraction of PT against Tat-transduced CHME5 cells. Of them, (1) and (2) most potently abolished cytoprotective effect of Tat-transduced CHME5 cells. These constituents (1) and (2) inhibited the activation of 3-phosphoinositide-dependent kinase 1 (PDK1) and its downstream molecules, Akt/glycogen synthase kinase (GSK)3β, in PI3K/Akt cell survival signaling pathway, but did not suppress the activation of PI3K. Based on these finding, (1) and (2) may abolish the cytoprotective phenotype of Tat-transduced CHME5 cells by inhibiting PDK1 phosphorylation in PI3K/Akt pathway.
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Affiliation(s)
- Thi Kim Van Le
- Department of Life and Nanopharmaceutical Sciences and Department of Pharmacy, College of Pharmacy, Kyung Hee University, Seoul 130–701, Korea
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35
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Hedrick SM, Hess Michelini R, Doedens AL, Goldrath AW, Stone EL. FOXO transcription factors throughout T cell biology. Nat Rev Immunol 2012; 12:649-61. [PMID: 22918467 PMCID: PMC3875397 DOI: 10.1038/nri3278] [Citation(s) in RCA: 248] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The outcome of an infection with any given pathogen varies according to the dosage and route of infection, but, in addition, the physiological state of the host can determine the efficacy of clearance, the severity of infection and the extent of immunopathology. Here we propose that the forkhead box O (FOXO) transcription factor family--which is central to the integration of growth factor signalling, oxidative stress and inflammation--provides connections between physical well-being and the form and magnitude of an immune response. We present a case that FOXO transcription factors guide T cell differentiation and function in a context-driven manner, and might provide a link between metabolism and immunity.
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Affiliation(s)
- Stephen M Hedrick
- University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0377, USA.
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Jarboui MA, Bidoia C, Woods E, Roe B, Wynne K, Elia G, Hall WW, Gautier VW. Nucleolar protein trafficking in response to HIV-1 Tat: rewiring the nucleolus. PLoS One 2012; 7:e48702. [PMID: 23166591 PMCID: PMC3499507 DOI: 10.1371/journal.pone.0048702] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 10/03/2012] [Indexed: 12/20/2022] Open
Abstract
The trans-activator Tat protein is a viral regulatory protein essential for HIV-1 replication. Tat trafficks to the nucleoplasm and the nucleolus. The nucleolus, a highly dynamic and structured membrane-less sub-nuclear compartment, is the site of rRNA and ribosome biogenesis and is involved in numerous cellular functions including transcriptional regulation, cell cycle control and viral infection. Importantly, transient nucleolar trafficking of both Tat and HIV-1 viral transcripts are critical in HIV-1 replication, however, the role(s) of the nucleolus in HIV-1 replication remains unclear. To better understand how the interaction of Tat with the nucleolar machinery contributes to HIV-1 pathogenesis, we investigated the quantitative changes in the composition of the nucleolar proteome of Jurkat T-cells stably expressing HIV-1 Tat fused to a TAP tag. Using an organellar proteomic approach based on mass spectrometry, coupled with Stable Isotope Labelling in Cell culture (SILAC), we quantified 520 proteins, including 49 proteins showing significant changes in abundance in Jurkat T-cell nucleolus upon Tat expression. Numerous proteins exhibiting a fold change were well characterised Tat interactors and/or known to be critical for HIV-1 replication. This suggests that the spatial control and subcellular compartimentaliation of these cellular cofactors by Tat provide an additional layer of control for regulating cellular machinery involved in HIV-1 pathogenesis. Pathway analysis and network reconstruction revealed that Tat expression specifically resulted in the nucleolar enrichment of proteins collectively participating in ribosomal biogenesis, protein homeostasis, metabolic pathways including glycolytic, pentose phosphate, nucleotides and amino acids biosynthetic pathways, stress response, T-cell signaling pathways and genome integrity. We present here the first differential profiling of the nucleolar proteome of T-cells expressing HIV-1 Tat. We discuss how these proteins collectively participate in interconnected networks converging to adapt the nucleolus dynamic activities, which favor host biosynthetic activities and may contribute to create a cellular environment supporting robust HIV-1 production.
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Affiliation(s)
- Mohamed Ali Jarboui
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Carlo Bidoia
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Elena Woods
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Barbara Roe
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Kieran Wynne
- Mass Spectrometry Resource (MSR), Conway Institute for Biomolecular and Biomedical Research, University College Dublin (UCD), Dublin, Ireland
| | - Giuliano Elia
- Mass Spectrometry Resource (MSR), Conway Institute for Biomolecular and Biomedical Research, University College Dublin (UCD), Dublin, Ireland
| | - William W. Hall
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Virginie W. Gautier
- Centre for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
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Impact of Tat Genetic Variation on HIV-1 Disease. Adv Virol 2012; 2012:123605. [PMID: 22899925 PMCID: PMC3414192 DOI: 10.1155/2012/123605] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 05/14/2012] [Indexed: 01/08/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) promoter or long-terminal repeat (LTR) regulates viral gene expression by interacting with multiple viral and host factors. The viral transactivator protein Tat plays an important role in transcriptional activation of HIV-1 gene expression. Functional domains of Tat and its interaction with transactivation response element RNA and cellular transcription factors have been examined. Genetic variation within tat of different HIV-1 subtypes has been shown to affect the interaction of the viral transactivator with cellular and/or viral proteins, influencing the overall level of transcriptional activation as well as its action as a neurotoxic protein. Consequently, the genetic variability within tat may impact the molecular architecture of functional domains of the Tat protein that may impact HIV pathogenesis and disease. Tat as a therapeutic target for anti-HIV drugs has also been discussed.
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Abstract
Chronic HIV infection, which is primarily characterized by the progressive depletion of total CD4(+) T cells, also causes persistent inflammation and immune activation. This is followed by profound changes in cellular and tissue microenvironments that often lead to prolonged immune dysfunction. The global nature of this immune dysfunction suggests that factors that are involved in immune cell survival, proliferation, differentiation and maturation are all affected. Of particular interest is the transcriptional factor Foxo3a that regulates a number of genes that are critical in the development and the maintenance of T and B cells, dendritic cells (DCs) and macrophages. Alterations in the microenvironment mediated by HIV infection cause significant increase in the transcriptional activity of Foxo3a; this has major impact on T cell and B cell immunity. In fact, recent findings from HIV infected individuals highlight three important points: (1) the alteration of Foxo3a signaling during HIV infection deregulates innate and adaptive immune responses; (2) Foxo3a-mediated effects are reversible and could be restored by interfering with the Foxo3a pathway; and (3) down-regulation of Foxo3a transcriptional activity in elite controllers (ECs) represents a molecular signature, or a correlate of immunity, associated with natural protection and lack of disease progression. In this review, we will discuss how HIV-infection altered microenvironments could result in impaired immune responses via the Foxo3a signaling pathway. Defining precisely the molecular mechanisms of how persistent inflammation and immune activation are able to influence the Foxo3a pathway could ultimately help in the development of novel approaches to improve immune responses in HIV infected subjects.
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Dahiya S, Nonnemacher MR, Wigdahl B. Deployment of the human immunodeficiency virus type 1 protein arsenal: combating the host to enhance viral transcription and providing targets for therapeutic development. J Gen Virol 2012; 93:1151-1172. [PMID: 22422068 DOI: 10.1099/vir.0.041186-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Despite the success of highly active antiretroviral therapy in combating human immunodeficiency virus type 1 (HIV-1) infection, the virus still persists in viral reservoirs, often in a state of transcriptional silence. This review focuses on the HIV-1 protein and regulatory machinery and how expanding knowledge of the function of individual HIV-1-coded proteins has provided valuable insights into understanding HIV transcriptional regulation in selected susceptible cell types. Historically, Tat has been the most studied primary transactivator protein, but emerging knowledge of HIV-1 transcriptional regulation in cells of the monocyte-macrophage lineage has more recently established that a number of the HIV-1 accessory proteins like Vpr may directly or indirectly regulate the transcriptional process. The viral proteins Nef and matrix play important roles in modulating the cellular activation pathways to facilitate viral replication. These observations highlight the cross talk between the HIV-1 transcriptional machinery and cellular activation pathways. The review also discusses the proposed transcriptional regulation mechanisms that intersect with the pathways regulated by microRNAs and how development of the knowledge of chromatin biology has enhanced our understanding of key protein-protein and protein-DNA interactions that form the HIV-1 transcriptome. Finally, we discuss the potential pharmacological approaches to target viral persistence and enhance effective transcription to purge the virus in cellular reservoirs, especially within the central nervous system, and the novel therapeutics that are currently in various stages of development to achieve a much superior prognosis for the HIV-1-infected population.
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Affiliation(s)
- Satinder Dahiya
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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Marban C, Su T, Ferrari R, Li B, Vatakis D, Pellegrini M, Zack JA, Rohr O, Kurdistani SK. Genome-wide binding map of the HIV-1 Tat protein to the human genome. PLoS One 2011; 6:e26894. [PMID: 22073215 PMCID: PMC3208564 DOI: 10.1371/journal.pone.0026894] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 09/22/2011] [Indexed: 01/14/2023] Open
Abstract
The HIV-1 Trans-Activator of Transcription (Tat) protein binds to multiple host cellular factors and greatly enhances the level of transcription of the HIV genome. While Tat's control of viral transcription is well-studied, much less is known about the interaction of Tat with the human genome. Here, we report the genome-wide binding map of Tat to the human genome in Jurkat T cells using chromatin immunoprecipitation combined with next-generation sequencing. Surprisingly, we found that ~53% of the Tat target regions are within DNA repeat elements, greater than half of which are Alu sequences. The remaining target regions are located in introns and distal intergenic regions; only ~7% of Tat-bound regions are near transcription start sites (TSS) at gene promoters. Interestingly, Tat binds to promoters of genes that, in Jurkat cells, are bound by the ETS1 transcription factor, the CBP histone acetyltransferase and/or are enriched for histone H3 lysine 4 tri-methylation (H3K4me3) and H3K27me3. Tat binding is associated with genes enriched with functions in T cell biology and immune response. Our data reveal that Tat's interaction with the host genome is more extensive than previously thought, with potentially important implications for the viral life cycle.
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Affiliation(s)
- Céline Marban
- Institut de Virologie, Université de Strasbourg, Strasbourg, France
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Trent Su
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Division of Oral Biology and Medicine, School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Roberto Ferrari
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Bing Li
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Dimitrios Vatakis
- Division of Hematology and Oncology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Matteo Pellegrini
- Department of Molecular, Cellular, and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
- Eli and Edythe Broad Centre of Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jerome A. Zack
- Division of Hematology and Oncology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Eli and Edythe Broad Centre of Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, California, United States of America
| | - Olivier Rohr
- Institut de Virologie, Université de Strasbourg, Strasbourg, France
- Institut Universitaire de France (IUF), Paris, France
- * E-mail: (SKK); (OR)
| | - Siavash K. Kurdistani
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Eli and Edythe Broad Centre of Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (SKK); (OR)
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Guergnon J, Godet AN, Galioot A, Falanga PB, Colle JH, Cayla X, Garcia A. PP2A targeting by viral proteins: a widespread biological strategy from DNA/RNA tumor viruses to HIV-1. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1498-507. [PMID: 21856415 DOI: 10.1016/j.bbadis.2011.07.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 06/22/2011] [Accepted: 07/05/2011] [Indexed: 12/27/2022]
Abstract
Protein phosphatase 2A (PP2A) is a large family of holoenzymes that comprises 1% of total cellular proteins and accounts for the majority of Ser/Thr phosphatase activity in eukaryotic cells. Although initially viewed as constitutive housekeeping enzymes, it is now well established that PP2A proteins represent a family of highly and sophistically regulated phosphatases. The past decade, multiple complementary studies have improved our knowledge about structural and functional regulation of PP2A holoenzymes. In this regard, after summarizing major cellular regulation, this review will mainly focus on discussing a particulate biological strategy, used by various viruses, which is based on the targeting of PP2A enzymes by viral proteins in order to specifically deregulate, for their own benefit, cellular pathways of their hosts. The impact of such PP2A targeting for research in human diseases, and in further therapeutic developments, is also discussed.
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Affiliation(s)
- Julien Guergnon
- Laboratoire E3 Phosphatases-Unité Signalisation Moléculaire et Activation Cellulaire, Institut Pasteur 25, rue du Dr Roux, 75015 Paris, France
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Novel PI3K/Akt inhibitors screened by the cytoprotective function of human immunodeficiency virus type 1 Tat. PLoS One 2011; 6:e21781. [PMID: 21765914 PMCID: PMC3134463 DOI: 10.1371/journal.pone.0021781] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 06/08/2011] [Indexed: 02/07/2023] Open
Abstract
The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors.
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Février M, Dorgham K, Rebollo A. CD4+ T cell depletion in human immunodeficiency virus (HIV) infection: role of apoptosis. Viruses 2011; 3:586-612. [PMID: 21994747 PMCID: PMC3185763 DOI: 10.3390/v3050586] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/03/2011] [Accepted: 05/04/2011] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infection is principally a mucosal disease and the gastrointestinal (GI) tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT) might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis.
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Affiliation(s)
- Michèle Février
- Unité Génomique Virale et Vaccination, CNRS URA3015, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France.
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Maulik U, Bhattacharyya M, Mukhopadhyay A, Bandyopadhyay S. Identifying the immunodeficiency gateway proteins in humans and their involvement in microRNA regulation. MOLECULAR BIOSYSTEMS 2011; 7:1842-51. [PMID: 21437347 DOI: 10.1039/c1mb05026e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Very little is known to date about the regulation protocol between transcription factors (TFs), genes and microRNAs (miRNAs) associated with diseases in various organisms. In this paper, we focus on finding the activity of miRNAs through the HIV-1 regulatory pathway in humans at the systems level. For this, we integrate and study the characteristics of the interaction information between HIV-1 and human proteins obtained from literature and prediction analysis. This information, realized in the form of a bipartite network, is subsequently mined with an exhaustive graph search technique to identify the strong significant biclusters, which are effectively the bicliques. They are unified further to form the core bipartite subnetwork. Many of the known HIV-1 associated kinase proteins (including LCK) are found in this core module. From this, the secondary significant proteins are identified by mapping these gateway proteins to the human protein-protein interaction network. Finally, these proteins are mapped onto the TF-to-miRNA and miRNA-to-gene regulatory networks derived from a couple of current studies to obtain a global view of the HIV-1 mediated TF-gene-miRNA inter-regulatory network. Interestingly, a few miRNAs participating in this pathway at the secondary level are found to have oncogenic involvement.
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Affiliation(s)
- Ujjwal Maulik
- Department of Computer Science and Engineering, Jadavpur University, Kolkata-700032, India.
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