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Kumari N, Ahmad A, Berto-Junior C, Ivanov A, Wen F, Lin X, Diaz S, Okpala I, Taylor JG, Jerebtsova M, Nekhai S. Antiviral response and HIV-1 inhibition in sickle cell disease. iScience 2024; 27:108813. [PMID: 38318349 PMCID: PMC10839265 DOI: 10.1016/j.isci.2024.108813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 11/03/2023] [Accepted: 01/02/2024] [Indexed: 02/07/2024] Open
Abstract
Sickle cell disease (SCD) is characterized by hemolysis, vaso-occlusion, and ischemia. HIV-1 infection was previously shown to be suppressed in SCD PBMCs. Here, we report that HIV-1 suppression is attributed to the increased expression of iron, hypoxia, and interferon-induced innate antiviral factors. Inhibition of upregulated antiviral genes, HMOX-1, CDKN1A, and CH25H, increased HIV-1 replication in SCD PBMCs, suggesting their critical role in HIV-1 suppression. Levels of IFN-β were elevated in SCD patients. Sickle cell hemoglobin (HbS) treatment of THP-1-derived and primary monocyte-derived macrophages induced production of IFN-β, upregulated antiviral gene expression, and suppressed HIV-1 infection. Infection with mouse-adapted EcoHIV was suppressed in the SCD mice that also exhibited elevated levels of antiviral restriction factors. Our findings suggest that hemolysis and release of HbS leads to the induction of IFN-β production, induction of cellular antiviral state by the expression of iron and IFN-driven factors, and suppression of HIV-1 infection.
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Affiliation(s)
- Namita Kumari
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
- Department of Medicine, Howard University, Washington, DC, USA
| | - Asrar Ahmad
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
| | - Clemilson Berto-Junior
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
- Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andrey Ivanov
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
| | - Fayuan Wen
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
| | - Xionghao Lin
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
| | - Sharmin Diaz
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
| | | | - James G. Taylor
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
- Department of Medicine, Howard University, Washington, DC, USA
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Canada
| | | | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA
- Department of Medicine, Howard University, Washington, DC, USA
- Department of Microbiology, Howard University, Washington, DC, USA
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2
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Sperber HS, Raymond KA, Bouzidi MS, Ma T, Valdebenito S, Eugenin EA, Roan NR, Deeks SG, Winning S, Fandrey J, Schwarzer R, Pillai SK. The hypoxia-regulated ectonucleotidase CD73 is a host determinant of HIV latency. Cell Rep 2023; 42:113285. [PMID: 37910505 PMCID: PMC10838153 DOI: 10.1016/j.celrep.2023.113285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 07/04/2023] [Accepted: 09/29/2023] [Indexed: 11/03/2023] Open
Abstract
Deciphering the mechanisms underlying viral persistence is critical to achieving a cure for human immunodeficiency virus (HIV) infection. Here, we implement a systems approach to discover molecular signatures of HIV latently infected CD4+ T cells, identifying the immunosuppressive, adenosine-producing ectonucleotidase CD73 as a key surface marker of latent cells. Hypoxic conditioning, reflecting the lymphoid tissue microenvironment, increases the frequency of CD73+ CD4+ T cells and promotes HIV latency. Transcriptomic profiles of CD73+ CD4+ T cells favor viral quiescence, immune evasion, and cell survival. CD73+ CD4+ T cells are capable of harboring a functional HIV reservoir and reinitiating productive infection ex vivo. CD73 or adenosine receptor blockade facilitates latent HIV reactivation in vitro, mechanistically linking adenosine signaling to viral quiescence. Finally, tissue imaging of lymph nodes from HIV-infected individuals on antiretroviral therapy reveals spatial association between CD73 expression and HIV persistence in vivo. Our findings warrant development of HIV-cure strategies targeting the hypoxia-CD73-adenosine axis.
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Affiliation(s)
- Hannah S Sperber
- Vitalant Research Institute, San Francisco, CA, USA; Free University of Berlin, Institute of Biochemistry, Berlin, Germany; University of California, San Francisco, San Francisco, CA, USA; University Hospital Essen, Institute for Translational HIV Research, Essen, Germany
| | - Kyle A Raymond
- Vitalant Research Institute, San Francisco, CA, USA; University of California, San Francisco, San Francisco, CA, USA
| | - Mohamed S Bouzidi
- Vitalant Research Institute, San Francisco, CA, USA; University of California, San Francisco, San Francisco, CA, USA
| | - Tongcui Ma
- University of California, San Francisco, San Francisco, CA, USA; Gladstone Institutes, San Francisco, CA, USA
| | | | | | - Nadia R Roan
- University of California, San Francisco, San Francisco, CA, USA; Gladstone Institutes, San Francisco, CA, USA
| | - Steven G Deeks
- University of California, San Francisco, San Francisco, CA, USA
| | - Sandra Winning
- University of Duisburg-Essen, Institute for Physiology, Essen, Germany
| | - Joachim Fandrey
- University of Duisburg-Essen, Institute for Physiology, Essen, Germany
| | - Roland Schwarzer
- University Hospital Essen, Institute for Translational HIV Research, Essen, Germany.
| | - Satish K Pillai
- Vitalant Research Institute, San Francisco, CA, USA; University of California, San Francisco, San Francisco, CA, USA.
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3
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Ogundiran AI, Chang TL, Ivanov A, Kumari N, Nekhai S, Chandran PL. Shear-reversible clusters of HIV-1 in solution: stabilized by antibodies, dispersed by mucin. J Virol 2023; 97:e0075223. [PMID: 37712704 PMCID: PMC10617397 DOI: 10.1128/jvi.00752-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/03/2023] [Indexed: 09/16/2023] Open
Abstract
IMPORTANCE The phenomenon of reversible clustering is expected to further nuance HIV immune stealth because virus surfaces can escape interaction with antibodies (Abs) by hiding temporarily within clusters. It is well known that mucin reduces HIV virulence, and the current perspective is that mucin aggregates HIV-1 to reduce infections. Our findings, however, suggest that mucin is dispersing HIV clusters. The study proposes a new paradigm for how HIV-1 may broadly evade Ab recognition with reversible clustering and why mucin effectively neutralizes HIV-1.
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Affiliation(s)
- Ayobami I. Ogundiran
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
| | - Tzu-Lan Chang
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
| | - Andrey Ivanov
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
- Department of Medicine, College of Medicine, Howard University, Washington, DC, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
- Department of Medicine, College of Medicine, Howard University, Washington, DC, USA
| | - Preethi L. Chandran
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
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4
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Akinsulie OC, Shahzad S, Ogunleye SC, Oladapo IP, Joshi M, Ugwu CE, Gbadegoye JO, Hassan FO, Adeleke R, Afolabi Akande Q, Adesola RO. Crosstalk between hypoxic cellular micro-environment and the immune system: a potential therapeutic target for infectious diseases. Front Immunol 2023; 14:1224102. [PMID: 37600803 PMCID: PMC10434535 DOI: 10.3389/fimmu.2023.1224102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/26/2023] [Indexed: 08/22/2023] Open
Abstract
There are overwhelming reports on the promotional effect of hypoxia on the malignant behavior of various forms of cancer cells. This has been proposed and tested exhaustively in the light of cancer immunotherapy. However, there could be more interesting functions of a hypoxic cellular micro-environment than malignancy. There is a highly intricate crosstalk between hypoxia inducible factor (HIF), a transcriptional factor produced during hypoxia, and nuclear factor kappa B (NF-κB) which has been well characterized in various immune cell types. This important crosstalk shares common activating and inhibitory stimuli, regulators, and molecular targets. Impaired hydroxylase activity contributes to the activation of HIFs. Inflammatory ligands activate NF-κB activity, which leads to the expression of inflammatory and anti-apoptotic genes. The eventual sequelae of the interaction between these two molecular players in immune cells, either bolstering or abrogating functions, is largely cell-type dependent. Importantly, this holds promise for interesting therapeutic interventions against several infectious diseases, as some HIF agonists have helped prevent immune-related diseases. Hypoxia and inflammation are common features of infectious diseases. Here, we highlighted the role of this crosstalk in the light of functional immunity against infection and inflammation, with special focus on various innate and adaptive immune cells. Particularly, we discussed the bidirectional effects of this crosstalk in the regulation of immune responses by monocytes/macrophages, dendritic cells, neutrophils, B cells, and T cells. We believe an advanced understanding of the interplay between HIFs and NF-kB could reveal novel therapeutic targets for various infectious diseases with limited treatment options.
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Affiliation(s)
- Olalekan Chris Akinsulie
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Sammuel Shahzad
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Seto Charles Ogunleye
- College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Ifeoluwa Peace Oladapo
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Melina Joshi
- Center for Molecular Dynamics Nepal, Kathmandu, Nepal
| | - Charles Egede Ugwu
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, United States
| | - Joy Olaoluwa Gbadegoye
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Fasilat Oluwakemi Hassan
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Richard Adeleke
- College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Qudus Afolabi Akande
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States
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5
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Yero A, Bouassa RSM, Ancuta P, Estaquier J, Jenabian MA. Immuno-metabolic control of the balance between Th17-polarized and regulatory T-cells during HIV infection. Cytokine Growth Factor Rev 2023; 69:1-13. [PMID: 36681548 DOI: 10.1016/j.cytogfr.2023.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
Th17-polarized CD4+ effector T-cells together with their immunosuppressive regulatory T-cell (Treg) counterparts, with transcriptional profiles governed by the lineage transcription factors RORγt/RORC2 and FOXP3, respectively, are important gatekeepers at mucosal interfaces. Alterations in the Th17/Treg ratios, due to the rapid depletion of Th17 cells and increased Treg frequencies, are a hallmark of both HIV and SIV infections and a marker of disease progression. The shift in Th17/Treg balance, in favor of increased Treg frequencies, contributes to gut mucosal permeability, immune dysfunction, and microbial translocation, subsequently leading to chronic immune activation/inflammation and disease progression. Of particular interest, Th17 cells and Tregs share developmental routes, with changes in the Th17 versus Treg fate decision influencing the pro-inflammatory versus anti-inflammatory responses. The differentiation and function of Th17 cells and Tregs rely on independent yet complementary metabolic pathways. Several pathways have been described in the literature to be involved in Th17 versus Treg polarization, including 1) the activity of ectonucleotidases CD39/CD73; 2) the increase in TGF-β1 production; 3) a hypoxic environment, and subsequent upregulation in hypoxia-inducible factor-1α (HIF-1α); 4) the increased mTOR activity and glycolysis induction; 5) the lipid metabolism, including fatty acid synthesis, fatty acids oxidation, cholesterol synthesis, and lipid storage, which are regulated by the AMPK, mevalonate and PPARγ pathways; and 6) the tryptophan catabolism. These metabolic pathways are understudied in the context of HIV-1 infection. The purpose of this review is to summarize the current knowledge on metabolic pathways that are dysregulated during HIV-1 infection and their impact on Th17/Treg balance.
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Affiliation(s)
- Alexis Yero
- Department of Biological Sciences and CERMO-FC Research Centre, Université du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Ralph-Sydney Mboumba Bouassa
- Department of Biological Sciences and CERMO-FC Research Centre, Université du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Petronela Ancuta
- Centre de recherche du centre hospitalier de l'Université de Montréal (CR-CHUM), Montréal, QC, Canada; Département de microbiologie, infectiologie et immunologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Jerome Estaquier
- Centre hospitalier universitaire (CHU) de Québec Research Center, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | - Mohammad-Ali Jenabian
- Department of Biological Sciences and CERMO-FC Research Centre, Université du Québec à Montréal (UQAM), Montréal, QC, Canada; Département de microbiologie, infectiologie et immunologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.
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6
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Nekhai S, Kumari N. HIV-1 infection in sickle cell disease and sickle cell trait: role of iron and innate response. Expert Rev Hematol 2022; 15:253-263. [PMID: 35322747 PMCID: PMC9041812 DOI: 10.1080/17474086.2022.2054799] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Sickle cell disease (SCD), an inherited hemoglobinopathy, affects primarily African Americans in the U.S.A. In addition, about 15% African Americans carry sickle cell trait (SCT). Despite the risk associated with blood transfusions, SCD patients have lower risk of acquiring HIV-1 infection. SCT individuals might also have some protection from HIV-1 infection. AREAS COVERED Here, we will review recent and previous studies with the focus on molecular mechanisms that might underlie and contribute to the protection of individuals with SCD and SCT from HIV-1 infection. As both of these conditions predispose to hemolysis, we will focus our discussion on the effects of systemic and intracellular iron on HIV-1 infection and progression. We will also review changes in iron metabolism and activation of innate antiviral responses in SCD and SCT and their effects on HIV-1 infection. EXPERT OPINION Previous studies, including ours, showed that SCD might protect from HIV-1 infection. This protection is likely due to the upregulation of complex protein network in response to hemolysis, hypoxia and interferon signaling. These findings are important not only for HIV-1 field but also for SCD cure efforts as antiviral state of SCD patients may adversely affect lentivirus-based gene therapy efforts.
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Affiliation(s)
- Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington DC, USA
- Department of Medicine, Howard University, Washington DC, USA
- Corresponding Author: Sergei Nekhai, , Center for Sickle Cell Disease, Howard University, HUIRB, Suite 321D, 2201 Georgia Avenue, NW, Washington DC 20059, USA, Phone: (202) 806-3378
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington DC, USA
- Department of Medicine, Howard University, Washington DC, USA
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7
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Zhou K, Zhuang S, Liu F, Chen Y, Li Y, Wang S, Li Y, Wen H, Lin X, Wang J, Huang Y, He C, Xu N, Li Z, Xu L, Zhang Z, Chen LF, Chen R, Liu M. Disrupting the Cdk9/Cyclin T1 heterodimer of 7SK snRNP for the Brd4 and AFF1/4 guided reconstitution of active P-TEFb. Nucleic Acids Res 2021; 50:750-762. [PMID: 34935961 PMCID: PMC8789079 DOI: 10.1093/nar/gkab1228] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/23/2021] [Accepted: 12/10/2021] [Indexed: 01/16/2023] Open
Abstract
P-TEFb modulates RNA polymerase II elongation through alternative interaction with negative and positive regulation factors. While inactive P-TEFbs are mainly sequestered in the 7SK snRNP complex in a chromatin-free state, most of its active forms are in complex with its recruitment factors, Brd4 and SEC, in a chromatin-associated state. Thus, switching from inactive 7SK snRNP to active P-TEFb (Brd4/P-TEFb or SEC/P-TEFb) is essential for global gene expression. Although it has been shown that cellular signaling stimulates the disruption of 7SK snRNP, releasing dephosphorylated and catalytically inactive P-TEFb, little is known about how the inactive released P-TEFb is reactivated. Here, we show that the Cdk9/CycT1 heterodimer released from 7SK snRNP is completely dissociated into monomers in response to stress. Brd4 or SEC then recruits monomerized Cdk9 and CycT1 to reassemble the core P-TEFb. Meanwhile, the binding of monomeric dephosphorylated Cdk9 to either Brd4 or SEC induces the autophosphorylation of T186 of Cdk9. Finally, the same mechanism is employed during nocodazole released entry into early G1 phase of cell cycle. Therefore, our studies demonstrate a novel mechanism by which Cdk9 and CycT1 monomers are reassembled on chromatin to form active P-TEFb by its interaction with Brd4 or SEC to regulate transcription.
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Affiliation(s)
- Kai Zhou
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Songkuan Zhuang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Fulong Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Yanheng Chen
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - You Li
- Biomolecular Interaction Centre, University of Canterbury, Christchurch 8140, New Zealand
| | - Shihui Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Yuxuan Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Huixin Wen
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Xiaohua Lin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Jie Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Yue Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Cailing He
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Nan Xu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Zongshu Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Lang Xu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Zixuan Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Lin-Feng Chen
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ruichuan Chen
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
| | - Min Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005, Fujian, China
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Impact of Hypoxia over Human Viral Infections and Key Cellular Processes. Int J Mol Sci 2021; 22:ijms22157954. [PMID: 34360716 PMCID: PMC8347150 DOI: 10.3390/ijms22157954] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/20/2021] [Indexed: 01/01/2023] Open
Abstract
Oxygen is essential for aerobic cells, and thus its sensing is critical for the optimal maintenance of vital cellular and tissue processes such as metabolism, pH homeostasis, and angiogenesis, among others. Hypoxia-inducible factors (HIFs) play central roles in oxygen sensing. Under hypoxic conditions, the α subunit of HIFs is stabilized and forms active heterodimers that translocate to the nucleus and regulate the expression of important sets of genes. This process, in turn, will induce several physiological changes intended to adapt to these new and adverse conditions. Over the last decades, numerous studies have reported a close relationship between viral infections and hypoxia. Interestingly, this relation is somewhat bidirectional, with some viruses inducing a hypoxic response to promote their replication, while others inhibit hypoxic cellular responses. Here, we review and discuss the cellular responses to hypoxia and discuss how HIFs can promote a wide range of physiological and transcriptional changes in the cell that modulate numerous human viral infections.
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Ogharandukun E, Tewolde W, Damtae E, Wang S, Ivanov A, Kumari N, Nekhai S, Chandran PL. Establishing Rules for Self-Adhesion and Aggregation of N-Glycan Sugars Using Virus Glycan Shields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13769-13783. [PMID: 33186493 PMCID: PMC7798417 DOI: 10.1021/acs.langmuir.0c01953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The surfaces of cells and pathogens are covered with short polymers of sugars known as glycans. Complex N-glycans have a core of three mannose sugars with distal repeats of N-acetylglucosamine and galactose sugars terminating with sialic acid (SA). Long-range tough and short-range brittle self-adhesions were observed between SA and mannose residues, respectively, in ill-defined artificial monolayers. We investigated if and how these adhesions translate when the residues are presented in N-glycan architecture with SA at the surface and mannose at the core and with other glycan sugars. Two pseudotyped viruses with complex N-glycan shields were brought together in force spectroscopy (FS). At higher ramp rates, slime-like adhesions were observed between the shields, whereas Velcro-like adhesions were observed at lower rates. The higher approach rates compress the virus as a whole, and the self-adhesion between the surface SA is sampled. At the lower ramp rates, however, the complex glycan shield is penetrated and adhesion from the mannose core is accessed. The slime-like and Velcro-like adhesions were lost when SA and mannose were cleaved, respectively. While virus self-adhesion in forced contact was modulated by glycan penetrability, the self-aggregation of the freely diffusing virus was only determined by the surface sugar. Mannose-terminal viruses self-aggregated in solution, and SA-terminal ones required Ca2+ ions to self-aggregate. Viruses with galactose or N-acetylglucosamine surfaces did not self-aggregate, irrespective of whether or not a mannose core was present below the N-acetylglucosamine surface. Well-defined rules appear to govern the self-adhesion and -aggregation of N-glycosylated surfaces, regardless of whether the sugars are presented in an ill-defined monolayer, or N-glycan, or even polymer architecture.
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10
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Liu PJ, Balfe P, McKeating JA, Schilling M. Oxygen Sensing and Viral Replication: Implications for Tropism and Pathogenesis. Viruses 2020; 12:E1213. [PMID: 33113858 PMCID: PMC7693908 DOI: 10.3390/v12111213] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022] Open
Abstract
The ability to detect and respond to varying oxygen tension is an essential prerequisite to life. Several mechanisms regulate the cellular response to oxygen including the prolyl hydroxylase domain (PHD)/factor inhibiting HIF (FIH)-hypoxia inducible factor (HIF) pathway, cysteamine (2-aminoethanethiol) dioxygenase (ADO) system, and the lysine-specific demethylases (KDM) 5A and KDM6A. Using a systems-based approach we discuss the literature on oxygen sensing pathways in the context of virus replication in different tissues that experience variable oxygen tension. Current information supports a model where the PHD-HIF pathway enhances the replication of viruses infecting tissues under low oxygen, however, the reverse is true for viruses with a selective tropism for higher oxygen environments. Differences in oxygen tension and associated HIF signaling may play an important role in viral tropism and pathogenesis. Thus, pharmaceutical agents that modulate HIF activity could provide novel treatment options for viral infections and associated pathological conditions.
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11
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Zhuang X, Pedroza-Pacheco I, Nawroth I, Kliszczak AE, Magri A, Paes W, Rubio CO, Yang H, Ashcroft M, Mole D, Balfe P, Borrow P, McKeating JA. Hypoxic microenvironment shapes HIV-1 replication and latency. Commun Biol 2020; 3:376. [PMID: 32665623 PMCID: PMC7360605 DOI: 10.1038/s42003-020-1103-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 06/17/2020] [Indexed: 12/14/2022] Open
Abstract
Viral replication is defined by the cellular microenvironment and one key factor is local oxygen tension, where hypoxia inducible factors (HIFs) regulate the cellular response to oxygen. Human immunodeficiency virus (HIV) infected cells within secondary lymphoid tissues exist in a low-oxygen or hypoxic environment in vivo. However, the majority of studies on HIV replication and latency are performed under laboratory conditions where HIFs are inactive. We show a role for HIF-2α in restricting HIV transcription via direct binding to the viral promoter. Hypoxia reduced tumor necrosis factor or histone deacetylase inhibitor, Romidepsin, mediated reactivation of HIV and inhibiting HIF signaling-pathways reversed this phenotype. Our data support a model where the low-oxygen environment of the lymph node may suppress HIV replication and promote latency. We identify a mechanism that may contribute to the limited efficacy of latency reversing agents in reactivating HIV and suggest new strategies to control latent HIV-1.
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Affiliation(s)
- Xiaodong Zhuang
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | | | - Isabel Nawroth
- Institute of Immunity and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
| | - Anna E Kliszczak
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Andrea Magri
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Wayne Paes
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | | | - Hongbing Yang
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Margaret Ashcroft
- Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0AH, UK
| | - David Mole
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Peter Balfe
- Institute of Immunity and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
| | - Persephone Borrow
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Jane A McKeating
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7FZ, UK.
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Jerebtsova M, Ahmad A, Kumari N, Rutagarama O, Nekhai S. Macrophage HIV-1 Gene Expression and Delay Resolution of Inflammation in HIV-Tg Mice. Viruses 2020; 12:v12030277. [PMID: 32121564 PMCID: PMC7150751 DOI: 10.3390/v12030277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 02/06/2023] Open
Abstract
While antiretroviral therapy increases the longevity of people living with HIV (PLWH), about 30% of this population suffers from three or more concurrent comorbidities, whose mechanisms are not well understood. Chronic activation and dysfunction of the immune system could be one potential cause of these comorbidities. We recently demonstrated reduced macrophage infiltration and delayed resolution of inflammation in the lungs of HIV-transgenic mice. Additionally, trans-endothelial migration of HIV-positive macrophages was reduced in vitro. Here, we analyze macrophages’ response to LPS challenge in the kidney and peritoneum of HIV-Tg mice. In contrast to the lung infiltration, renal and peritoneal macrophage infiltrations were similar in WT and HIV-Tg mice. Higher levels of HIV-1 gene expression were detected in lung macrophages compared to peritoneal macrophages. In peritoneal macrophages, HIV-1 gene expression was increased when they were cultured at 21% O2 compared to 5% O2, inversely correlating with reduced trans-endothelial migration at higher oxygen levels in vitro. The resolution of macrophage infiltration was reduced in both the lung and the peritoneal cavity of HIV-Tg mice. Taken together, our study described the organ-specific alteration of macrophage dynamics in HIV-Tg mice. The delayed resolution of macrophage infiltration might constitute a risk factor for the development of multiple comorbidities in PLWH.
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Affiliation(s)
- Marina Jerebtsova
- Department of Microbiology, College of Medicine, Howard University, Washington, DC 20059, USA;
- Correspondence: (M.J.); (S.N.)
| | - Asrar Ahmad
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, USA; (A.A.); (N.K.)
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, USA; (A.A.); (N.K.)
| | - Ornela Rutagarama
- Department of Microbiology, College of Medicine, Howard University, Washington, DC 20059, USA;
| | - Sergei Nekhai
- Department of Microbiology, College of Medicine, Howard University, Washington, DC 20059, USA;
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC 20059, USA; (A.A.); (N.K.)
- Department of Medicine, College of Medicine, Howard University, Washington, DC 20059, USA
- Correspondence: (M.J.); (S.N.)
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13
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Bourgeois C, Gorwood J, Barrail-Tran A, Lagathu C, Capeau J, Desjardins D, Le Grand R, Damouche A, Béréziat V, Lambotte O. Specific Biological Features of Adipose Tissue, and Their Impact on HIV Persistence. Front Microbiol 2019; 10:2837. [PMID: 31921023 PMCID: PMC6927940 DOI: 10.3389/fmicb.2019.02837] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/22/2019] [Indexed: 12/19/2022] Open
Abstract
Although white AT can contribute to anti-infectious immune responses, it can also be targeted and perturbed by pathogens. The AT's immune involvement is primarily due to strong pro-inflammatory responses (with both local and paracrine effects), and the large number of fat-resident macrophages. Adipocytes also exert direct antimicrobial responses. In recent years, it has been found that memory T cells accumulate in AT, where they provide efficient secondary responses against viral pathogens. These observations have prompted researchers to re-evaluate the links between obesity and susceptibility to infections. In contrast, AT serves as a reservoir for several persistence pathogens, such as human adenovirus Ad-36, Trypanosoma gondii, Mycobacterium tuberculosis, influenza A virus, and cytomegalovirus (CMV). The presence and persistence of bacterial DNA in AT has led to the concept of a tissue-specific microbiota. The unexpected coexistence of immune cells and pathogens within the specific AT environment is intriguing, and its impact on anti-infectious immune responses requires further evaluation. AT has been recently identified as a site of HIV persistence. In the context of HIV infection, AT is targeted by both the virus and the antiretroviral drugs. AT's intrinsic metabolic features, large overall mass, and wide distribution make it a major tissue reservoir, and one that may contribute to the pathophysiology of chronic HIV infections. Here, we review the immune, metabolic, viral, and pharmacological aspects that contribute to HIV persistence in AT. We also evaluate the respective impacts of both intrinsic and HIV-induced factors on AT's involvement as a viral reservoir. Lastly, we examine the potential consequences of HIV persistence on the metabolic and immune activities of AT.
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Affiliation(s)
- Christine Bourgeois
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
| | - Jennifer Gorwood
- INSERM UMR_S 938, Centre de Recherche Saint-Antoine, Institut Hospitalo-Universitaire de Cardio-Métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Aurélie Barrail-Tran
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
- AP-HP, Service de Médecine Interne et Immunologie Clinique, Hôpital Bicêtre, Groupe Hospitalier Universitaire Paris Sud, Le Kremlin-Bicêtre, France
| | - Claire Lagathu
- INSERM UMR_S 938, Centre de Recherche Saint-Antoine, Institut Hospitalo-Universitaire de Cardio-Métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Jacqueline Capeau
- INSERM UMR_S 938, Centre de Recherche Saint-Antoine, Institut Hospitalo-Universitaire de Cardio-Métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Delphine Desjardins
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
| | - Roger Le Grand
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
| | - Abderaouf Damouche
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
| | - Véronique Béréziat
- INSERM UMR_S 938, Centre de Recherche Saint-Antoine, Institut Hospitalo-Universitaire de Cardio-Métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Olivier Lambotte
- Center for Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, IBFJ, CEA, Université Paris Sud, INSERM U1184, Fontenay-aux-Roses, France
- AP-HP, Service de Médecine Interne et Immunologie Clinique, Hôpital Bicêtre, Groupe Hospitalier Universitaire Paris Sud, Le Kremlin-Bicêtre, France
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14
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Abeyratne-Perera HK, Ogharandukun E, Chandran PL. Complex-type N-glycans on VSV-G pseudotyped HIV exhibit 'tough' sialic and 'brittle' mannose self-adhesions. SOFT MATTER 2019; 15:4525-4540. [PMID: 31099376 DOI: 10.1039/c9sm00579j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The complex-type glycan shields of eukaryotic cells have a core layer of mannose residues buried under tiers of sugars that end with sialic acid (SA) residues. We investigate if the self-latching of mannose residues, earlier reported in pure monolayer studies, also manifests in the setting of a complex-type glycan shield. Would distal SA residues impede access to the mannose core? The interactions of mannobiose-, SA-, and lactose-coated probes with the complex-type VSV-G glycan shield on an HIV pseudovirus were studied with force-spectroscopy and gold-nanoparticle solutions. In force spectroscopy, the sugar probes can be forced to sample the depths of the glycan shield, whereas with sugar-coated nanoparticles, only interactions permitted by freely-diffusive contact occur. Deep-indentation mechanics was performed to verify the inferred structure of the engineered virus and to isolate the glycan shield layer for subsequent interaction studies. The adhesion between the sugar-probes and complex-type glycan shield was deconvoluted by comparing against the cross- and self- adhesions between the sugars in pure monolayers. Results from complementing systems were consistent with mannobiose-coated probes latching to the mannose core in the glycan shield, unhindered by the SA and distal sugars, with a short-range 'brittle' release of adhesion resulting in tightly coated viruses. SA-Coated probes, however, adhere to the terminal SA layer of a glycan shield with long-range and mechanically 'tough' adhesions resulting in large-scale virus aggregation. Lactose-coated probes exhibit ill-defined adherence to sialic residues. The selection and positioning of sugars within a glycan shield can influence how carbohydrate surfaces of different composition adhere.
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Affiliation(s)
- Hashanthi K Abeyratne-Perera
- Biochemistry and Molecular Biology Department, College of Medicine, 1011 LK Downing Hall 2300 6th Street, NW, Howard University, Washington, DC 20059, USA.
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15
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Kulkarni A, Mateus M, Thinnes CC, McCullagh JS, Schofield CJ, Taylor GP, Bangham CRM. Glucose Metabolism and Oxygen Availability Govern Reactivation of the Latent Human Retrovirus HTLV-1. Cell Chem Biol 2017; 24:1377-1387.e3. [PMID: 28965728 PMCID: PMC5696563 DOI: 10.1016/j.chembiol.2017.08.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/24/2017] [Accepted: 08/17/2017] [Indexed: 12/30/2022]
Abstract
The human retrovirus HTLV-1 causes a hematological malignancy or neuroinflammatory disease in ∼10% of infected individuals. HTLV-1 primarily infects CD4+ T lymphocytes and persists as a provirus integrated in their genome. HTLV-1 appears transcriptionally latent in freshly isolated cells; however, the chronically active anti-HTLV-1 cytotoxic T cell response observed in infected individuals indicates frequent proviral expression in vivo. The kinetics and regulation of HTLV-1 proviral expression in vivo are poorly understood. By using hypoxia, small-molecule hypoxia mimics, and inhibitors of specific metabolic pathways, we show that physiologically relevant levels of hypoxia, as routinely encountered by circulating T cells in the lymphoid organs and bone marrow, significantly enhance HTLV-1 reactivation from latency. Furthermore, culturing naturally infected CD4+ T cells in glucose-free medium or chemical inhibition of glycolysis or the mitochondrial electron transport chain strongly suppresses HTLV-1 plus-strand transcription. We conclude that glucose metabolism and oxygen tension regulate HTLV-1 proviral latency and reactivation in vivo. Physiological (1%) hypoxia enhances HTLV-1 plus-strand transcription HTLV-1 transcription is hypoxia regulated but HIF independent Inhibition of glycolysis or the mitochondrial ETC suppresses HTLV-1 transcription Extracellular glucose concentration regulates HTLV-1 reactivation from latency
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Affiliation(s)
- Anurag Kulkarni
- Section of Virology, Department of Medicine, Imperial College, London W2 1PG, UK
| | - Manuel Mateus
- Section of Virology, Department of Medicine, Imperial College, London W2 1PG, UK
| | - Cyrille C Thinnes
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, UK
| | - James S McCullagh
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, UK
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, UK
| | - Graham P Taylor
- Section of Virology, Department of Medicine, Imperial College, London W2 1PG, UK
| | - Charles R M Bangham
- Section of Virology, Department of Medicine, Imperial College, London W2 1PG, UK.
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16
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Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease. Blood Adv 2016; 1:170-183. [PMID: 28203649 DOI: 10.1182/bloodadvances.2016000745] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The low incidence of HIV-1 infection in patients with sickle cell disease (SCD) and inhibition of HIV-1 replication in vitro under the conditions of low intracellular iron or heme treatment suggests a potential restriction of HIV-1 infection in SCD. We investigated HIV-1 ex vivo infection of SCD peripheral blood mononuclear cells (PBMCs) and found that HIV-1 replication was inhibited at the level of reverse transcription (RT) and transcription. We observed increased expression of heme and iron-regulated genes, previously shown to inhibit HIV-1, including ferroportin, IKBα, HO-1, p21, and SAM domain and HD domain-containing protein 1 (SAMHD1). HIV-1 inhibition was less pronounced in hepcidin-treated SCD PBMCs and more pronounced in the iron or iron chelators treated, suggesting a key role of iron metabolism. In SCD PBMCs, labile iron levels were reduced and protein levels of ferroportin, HIF-1α, IKBα, and HO-1 were increased. Hemin treatment induced ferroportin expression and inhibited HIV-1 in THP-1 cells, mimicking the HIV-1 inhibition in SCD PBMCs, especially as hepcidin similarly prevented HIV-1 inhibition. In THP-1 cells with knocked down ferroportin, IKBα, or HO-1 genes but not HIF-1α or p21, HIV-1 was not inhibited by hemin. Activity of SAMHD1-regulatory CDK2 was decreased, and SAMHD1 phosphorylation was reduced in SCD PBMCs and hemin-treated THP-1 cells, suggesting SAMHD1-mediated HIV-1 restriction in SCD. Our findings point to ferroportin as a trigger of HIV-1 restriction in SCD settings, linking reduced intracellular iron levels to the inhibition of CDK2 activity, reduction of SAMHD1 phosphorylation, increased IKBα expression, and inhibition of HIV-1 RT and transcription.
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17
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Vassilaki N, Frakolaki E. Virus-host interactions under hypoxia. Microbes Infect 2016; 19:193-203. [PMID: 27771294 DOI: 10.1016/j.micinf.2016.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 10/10/2016] [Accepted: 10/12/2016] [Indexed: 12/14/2022]
Abstract
Oxygen tension can exert a significant effect on viral propagation in vitro and possibly in vivo. In general, hypoxia restricts the replication of viruses that naturally infect tissues exposed to ambient oxygen and induces the growth of viruses that naturally target tissues exposed to low oxygen. Some viruses can reprogram cell bioenergetics towards lowering cellular respiration and therefore oxygen consumption in order to support their replication. Aim of this review is to summarize findings on the interplay between viral infection and oxygen levels, highlighting the implicated oxygen tension-sensitive elements and metabolic determinants and concluding with possible therapeutic approaches targeting these mediators.
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Affiliation(s)
- Niki Vassilaki
- Molecular Virology Laboratory, Hellenic Pasteur Institute, 127 Vas. Sofias Av., 11521, Athens, Greece.
| | - Efseveia Frakolaki
- Molecular Virology Laboratory, Hellenic Pasteur Institute, 127 Vas. Sofias Av., 11521, Athens, Greece
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18
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Phenyl-1-Pyridin-2yl-ethanone-based iron chelators increase IκB-α expression, modulate CDK2 and CDK9 activities, and inhibit HIV-1 transcription. Antimicrob Agents Chemother 2014; 58:6558-71. [PMID: 25155598 DOI: 10.1128/aac.02918-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
HIV-1 transcription is activated by the Tat protein, which recruits CDK9/cyclin T1 to the HIV-1 promoter. CDK9 is phosphorylated by CDK2, which facilitates formation of the high-molecular-weight positive transcription elongation factor b (P-TEFb) complex. We previously showed that chelation of intracellular iron inhibits CDK2 and CDK9 activities and suppresses HIV-1 transcription, but the mechanism of the inhibition was not understood. In the present study, we tested a set of novel iron chelators for the ability to inhibit HIV-1 transcription and elucidated their mechanism of action. Novel phenyl-1-pyridin-2yl-ethanone (PPY)-based iron chelators were synthesized and examined for their effects on cellular iron, HIV-1 inhibition, and cytotoxicity. Activities of CDK2 and CDK9, expression of CDK9-dependent and CDK2-inhibitory mRNAs, NF-κB expression, and HIV-1- and NF-κB-dependent transcription were determined. PPY-based iron chelators significantly inhibited HIV-1, with minimal cytotoxicity, in cultured and primary cells chronically or acutely infected with HIV-1 subtype B, but they had less of an effect on HIV-1 subtype C. Iron chelators upregulated the expression of IκB-α, with increased accumulation of cytoplasmic NF-κB. The iron chelators inhibited CDK2 activity and reduced the amount of CDK9/cyclin T1 in the large P-TEFb complex. Iron chelators reduced HIV-1 Gag and Env mRNA synthesis but had no effect on HIV-1 reverse transcription. In addition, iron chelators moderately inhibited basal HIV-1 transcription, equally affecting HIV-1 and Sp1- or NF-κB-driven transcription. By virtue of their involvement in targeting several key steps in HIV-1 transcription, these novel iron chelators have the potential for the development of new therapeutics for the treatment of HIV-1 infection.
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19
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Safronova OS, Nakahama KI, Morita I. Acute hypoxia affects P-TEFb through HDAC3 and HEXIM1-dependent mechanism to promote gene-specific transcriptional repression. Nucleic Acids Res 2014; 42:8954-69. [PMID: 25056306 PMCID: PMC4132729 DOI: 10.1093/nar/gku611] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hypoxia is associated with a variety of physiological and pathological conditions and elicits specific transcriptional responses. The elongation competence of RNA Polymerase II is regulated by the positive transcription elongation factor b (P-TEFb)-dependent phosphorylation of Ser2 residues on its C-terminal domain. Here, we report that hypoxia inhibits transcription at the level of elongation. The mechanism involves enhanced formation of inactive complex of P-TEFb with its inhibitor HEXIM1 in an HDAC3-dependent manner. Microarray transcriptome profiling of hypoxia primary response genes identified ∼79% of these genes being HEXIM1-dependent. Hypoxic repression of P-TEFb was associated with reduced acetylation of its Cdk9 and Cyclin T1 subunits. Hypoxia caused nuclear translocation and co-localization of the Cdk9 and HDAC3/N-CoR repressor complex. We demonstrated that the described mechanism is involved in hypoxic repression of the monocyte chemoattractant protein-1 (MCP-1) gene. Thus, HEXIM1 and HDAC-dependent deacetylation of Cdk9 and Cyclin T1 in response to hypoxia signalling alters the P-TEFb functional equilibrium, resulting in repression of transcription.
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Affiliation(s)
- Olga S Safronova
- Department of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan Global Center of Excellence Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Ken-Ichi Nakahama
- Department of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Ikuo Morita
- Department of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan Global Center of Excellence Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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20
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Nekhai S, Kumari N, Dhawan S. Role of cellular iron and oxygen in the regulation of HIV-1 infection. Future Virol 2013; 8:301-311. [PMID: 23678366 DOI: 10.2217/fvl.13.6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Despite efficient antiretroviral therapy, eradication of HIV-1 infection is challenging and requires novel biological insights and therapeutic strategies. Among other physiological and environmental factors, intracellular iron greatly affects HIV-1 replication. Higher iron stores were shown to be associated with faster progression of HIV-1 infection and to inversely correlate with the survival of HIV-1 infected patients. Iron is required for several steps in the HIV-1 life cycle, including reverse transcription, HIV-1 gene expression and capsid assembly. Here, the authors present a comprehensive review of the molecular mechanisms involved in iron- and oxygen-mediated regulation of HIV-1 replication. We also propose key intracellular pathways that may be involved in regulating HIV-1 replication, via protein kinase complexes, CDK9/cyclin T1 and CDK 2/cyclin E, protein phosphatase-1 and other host factors.
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Affiliation(s)
- Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, 520 W Street, NW, Washington DC 20059, USA
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21
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Nouraie M, Nekhai S, Gordeuk VR. Sickle cell disease is associated with decreased HIV but higher HBV and HCV comorbidities in U.S. hospital discharge records: a cross-sectional study. Sex Transm Infect 2012; 88:528-33. [PMID: 22628662 DOI: 10.1136/sextrans-2011-050459] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Some studies suggest that HIV infection progresses slowly in patients with sickle cell disease (SCD). The authors aimed to determine the relationships between SCD and HIV infection. METHODS National Hospital Discharge Survey data from adult African-Americans in the period of 1997-2009 were analysed. The comorbidities of SCD with HIV infections in hospital discharges were analysed. Multiple logistic regression was used to test the association between SCD and HIV. For comparative purposes, the relationships of SCD with hepatitis B virus (HBV) and hepatitis C virus (HCV) were also assessed. RESULTS 423,431 records were divided into two time periods 1997-2003 (53% of records) and 2004-2009 (47% of records). The frequency of HIV diagnosis was lower in patients with SCD (1.5% vs 3.3% in patients without SCD). In logistic regression, SCD diagnosis was associated with an OR of 0.24 (95% CI 0.18 to 0.32) for HIV diagnosis in the first period and with an OR of 0.31 (95% CI 0.22 to 0.42) in the second period. In contrast, SCD was associated with higher risk of HCV (OR=2.01, 95% CI 1.56 to 2.59 in the first period and OR=2.12, 95% CI 1.71 to 2.63 in the second period). SCD was also associated with a higher risk of HBV (OR=1.15, 95% CI 0.72 to 1.83 in the first period and OR=1.82, 95% CI 1.24 to 2.68 in the second period). CONCLUSIONS The lower risk of HIV comorbidity, but not HCV and HBV, with SCD is consistent with the possibility that SCD has a unique effect in altering the risk of HIV infection or progression. Investigation of how the haemolytic and immunological changes of SCD influence HIV might lead to new therapeutic or preventive approaches.
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Affiliation(s)
- Mehdi Nouraie
- Center for Sickle Cell Disease, Howard University, Washington, DC, USA.
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22
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Hypoxia induces the gene expression and extracellular transmission of persistent lymphocytic choriomeningitis virus. J Virol 2011; 85:13069-76. [PMID: 21957293 DOI: 10.1128/jvi.00829-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The physiological context of virus-infected cells can markedly affect multiplication and spread of the virus progeny. During persistent infection, the virus exploits the host cell without disturbing its vital functions. However, microenvironmental hypoxia can uncouple this intimate relationship and escalate virus pathogenesis. Accumulating evidence suggests that hypoxia-inducible factor (HIF) modulates gene expression of the viruses that pass through a DNA stage, contain hypoxia-responsive promoter elements, and replicate in the nucleus. Here we show that hypoxia can influence the gene expression and transmission of the cytoplasmic RNA virus lymphocytic choriomeningitis virus (LCMV), which is a neglected human pathogen and teratogen. The MX strain of LCMV, which we used as a model, replicates in a persistent mode in human HeLa cells, fails to produce mature envelope glycoproteins, and spreads through cell-cell contacts in the absence of extracellular infectious virions. Both exposure of MX-infected HeLa cells to chronic hypoxia and gene transfer approaches led to increased virus RNA transcription and higher levels of the viral proteins via a HIF-dependent mechanism. Moreover, hypoxia enhanced the formation of infectious virions capable of transmitting LCMV by cell-free medium. This LCMV "reactivation" might have health-compromising consequences in hypoxia-associated situations, such as fetal development and ischemia-related pathologies.
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23
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Lahat N, Bitterman H, Engelmayer-Goren M, Rosenzweig D, Weiss-Cerem L, Rahat MA. Reduced TIMP-2 in hypoxia enhances angiogenesis. Am J Physiol Cell Physiol 2010; 300:C557-66. [PMID: 21148412 DOI: 10.1152/ajpcell.00177.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia, which characterizes ischemia, trauma, inflammation, and solid tumors, recruits monocytes, immobilizes them, and alters their function, leading to an anti-inflammatory and proangiogenic phenotype. Monocyte extravasation from the circulation and their migration in tissues are partially mediated by the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). The mechanisms evoked by hypoxia that regulate monocyte migration and activation are not entirely clear. Specifically, the effect of hypoxia on TIMPs in these cells has hardly been investigated. We show that hypoxia reduces TIMP-2 secretion from human primary monocytes and from the monocyte-like cell lines U937 and THP-1 by three- to fourfold (P < 0.01), by inhibiting TIMP-2 transcription through mechanisms that involve the transcription factor SP-1. Hypoxia also lowers TIMP-2 protein secretion from human endothelial cells (by 2-fold, P < 0.05). TIMP-2 levels do not influence the reduced migration of THP-1 cells in hypoxia; however, low TIMP-2 levels enhance endothelial cell migration/proliferation, their ability to form tubelike structures in vitro, and the appearance of mature blood vessels in a Matrigel plug assay in vivo. Thus we conclude that reduced TIMP-2 levels secreted from both hypoxic monocytes and endothelial cells are proangiogenic.
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Affiliation(s)
- Nitza Lahat
- Immunology Research Unit, Carmel Medical Ctr., 7 Michal St., Haifa 34362, Israel.
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24
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Washington AT, Singh G, Aiyar A. Diametrically opposed effects of hypoxia and oxidative stress on two viral transactivators. Virol J 2010; 7:93. [PMID: 20459757 PMCID: PMC2874542 DOI: 10.1186/1743-422x-7-93] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 05/10/2010] [Indexed: 11/21/2022] Open
Abstract
Background Many pathogens exist in multiple physiological niches within the host. Differences between aerobic and anaerobic conditions are known to alter the expression of bacterial virulence factors, typically through the conditional activity of transactivators that modulate their expression. More recently, changes in physiological niches have been shown to affect the expression of viral genes. For many viruses, differences in oxygen tension between hypoxia and normoxia alter gene expression or function. Oxygen tension also affects many mammalian transactivators including AP-1, NFkB, and p53 by affecting the reduced state of critical cysteines in these proteins. We have recently determined that an essential cys-x-x-cys motif in the EBNA1 transactivator of Epstein-Barr virus is redox-regulated, such that transactivation is favoured under reducing conditions. The crucial Tat transactivator of human immunodeficiency virus (HIV) has an essential cysteine-rich region, and is also regulated by redox. Contrary to EBNA1, it is reported that Tat's activity is increased by oxidative stress. Here we have compared the effects of hypoxia, oxidative stress, and cellular redox modulators on EBNA1 and Tat. Results Our results indicate that unlike EBNA1, Tat is less active during hypoxia. Agents that generate hydroxyl and superoxide radicals reduce EBNA1's activity but increase transactivation by Tat. The cellular redox modulator, APE1/Ref-1, increases EBNA1's activity, without any effect on Tat. Conversely, thioredoxin reductase 1 (TRR1) reduces Tat's function without any effect on EBNA1. Conclusions We conclude that oxygen partial pressure and oxidative stress affects the functions of EBNA1 and Tat in a dramatically opposed fashion. Tat is more active during oxidative stress, whereas EBNA1's activity is compromised under these conditions. The two proteins respond to differing cellular redox modulators, suggesting that the oxidized cysteine adduct is a disulfide bond(s) in Tat, but sulfenic acid in EBNA1. The effect of oxygen partial pressure on transactivator function suggests that changes in redox may underlie differences in virus-infected cells dependent upon the physiological niches they traffic to.
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Affiliation(s)
- Amber T Washington
- Department of Microbiology, Immunology and Parasitology, LSU Health Sciences Center, New Orleans, LA 70112, USA
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