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Human Gammaherpesvirus 8 Oncogenes Associated with Kaposi’s Sarcoma. Int J Mol Sci 2022; 23:ijms23137203. [PMID: 35806208 PMCID: PMC9266852 DOI: 10.3390/ijms23137203] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 01/01/2023] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV), also known as human gammaherpesvirus 8 (HHV-8), contains oncogenes and proteins that modulate various cellular functions, including proliferation, differentiation, survival, and apoptosis, and is integral to KSHV infection and oncogenicity. In this review, we describe the most important KSHV genes [ORF 73 (LANA), ORF 72 (vCyclin), ORF 71 or ORFK13 (vFLIP), ORF 74 (vGPCR), ORF 16 (vBcl-2), ORF K2 (vIL-6), ORF K9 (vIRF 1)/ORF K10.5, ORF K10.6 (vIRF 3), ORF K1 (K1), ORF K15 (K15), and ORF 36 (vPK)] that have the potential to induce malignant phenotypic characteristics of Kaposi’s sarcoma. These oncogenes can be explored in prospective studies as future therapeutic targets of Kaposi’s sarcoma.
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Rosenkilde MM, Tsutsumi N, Knerr JM, Kildedal DF, Garcia KC. Viral G Protein-Coupled Receptors Encoded by β- and γ-Herpesviruses. Annu Rev Virol 2022; 9:329-351. [PMID: 35671566 PMCID: PMC9584139 DOI: 10.1146/annurev-virology-100220-113942] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Herpesviruses are ancient large DNA viruses that have exploited gene capture as part of their strategy to escape immune surveillance, promote virus spreading, or reprogram host cells to benefit their survival. Most acquired genes are transmembrane proteins and cytokines, such as viral G protein-coupled receptors (vGPCRs), chemokines, and chemokine-binding proteins. This review focuses on the vGPCRs encoded by the human β- and γ-herpesviruses. These include receptors from human cytomegalovirus, which encodes four vGPCRs: US27, US28, UL33, and UL78; human herpesvirus 6 and 7 with two receptors: U12 and U51; Epstein-Barr virus with one: BILF1; and Kaposi's sarcoma-associated herpesvirus with one: open reading frame 74. We discuss ligand binding, signaling, and structures of the vGPCRs in light of robust differences from endogenous receptors. Finally, we briefly discuss the therapeutic targeting of vGPCRs as future treatment of acute and chronic herpesvirus infections. Expected final online publication date for the Annual Review of Virology, Volume 9 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mette M Rosenkilde
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark;
| | - Naotaka Tsutsumi
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Julius M Knerr
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark;
| | | | - K Christopher Garcia
- Departments of Molecular and Cellular Physiology, and Structural Biology, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, USA;
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3
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Knerr JM, Kledal TN, Rosenkilde MM. Molecular Properties and Therapeutic Targeting of the EBV-Encoded Receptor BILF1. Cancers (Basel) 2021; 13:4079. [PMID: 34439235 PMCID: PMC8392491 DOI: 10.3390/cancers13164079] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 12/12/2022] Open
Abstract
The γ-herpesvirus Epstein-Barr Virus (EBV) establishes lifelong infections in approximately 90% of adults worldwide. Up to 1,000,000 people yearly are estimated to suffer from health conditions attributed to the infection with this virus, such as nasopharyngeal and gastric carcinomas as well as several forms of B, T and NK cell lymphoma. To date, no EBV-specific therapeutic option has reached the market, greatly reducing the survival prognoses of affected patients. Similar to other herpesviruses, EBV encodes for a G protein-coupled receptor (GPCR), BILF1, affecting a multitude of cellular signaling pathways. BILF1 has been identified to promote immune evasion and tumorigenesis, effectively ensuring a life-long persistence of EBV in, and driving detrimental health conditions to its host. This review summarizes the epidemiology of EBV-associated malignancies, their current standard-of-care, EBV-specific therapeutics in development, GPCRs and their druggability, and most importantly consolidates the findings of over 15 years of research on BILF1 in the context of EBV-specific drug development. Taken together, BILF1 constitutes a promising target for the development of novel EBV-specific therapeutics.
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Affiliation(s)
- Julius Maximilian Knerr
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, 2200 København, Denmark;
| | | | - Mette Marie Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, 2200 København, Denmark;
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4
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Targeting GRK5 for Treating Chronic Degenerative Diseases. Int J Mol Sci 2021; 22:ijms22041920. [PMID: 33671974 PMCID: PMC7919044 DOI: 10.3390/ijms22041920] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/27/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell-surface receptors and they are responsible for the transduction of extracellular signals, regulating almost all aspects of mammalian physiology. These receptors are specifically regulated by a family of serine/threonine kinases, called GPCR kinases (GRKs). Given the biological role of GPCRs, it is not surprising that GRKs are also involved in several pathophysiological processes. Particular importance is emerging for GRK5, which is a multifunctional protein, expressed in different cell types, and it has been found located in single or multiple subcellular compartments. For instance, when anchored to the plasma membrane, GRK5 exerts its canonical function, regulating GPCRs. However, under certain conditions (e.g., pro-hypertrophic stimuli), GRK5 translocates to the nucleus of cells where it can interact with non-GPCR-related proteins as well as DNA itself to promote “non-canonical” signaling, including gene transcription. Importantly, due to these actions, several studies have demonstrated that GRK5 has a pivotal role in the pathogenesis of chronic-degenerative disorders. This is true in the cardiac cells, tumor cells, and neurons. For this reason, in this review article, we will inform the readers of the most recent evidence that supports the importance of targeting GRK5 to prevent the development or progression of cancer, cardiovascular, and neurological diseases.
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Guo Q, Gao J, Cheng L, Yang X, Li F, Jiang G. The Epstein-Barr virus-encoded G protein-coupled receptor BILF1 upregulates ICAM-1 through a mechanism involving the NF-қB pathway. Biosci Biotechnol Biochem 2020; 84:1810-1819. [PMID: 32567483 DOI: 10.1080/09168451.2020.1777525] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Abstract
Although the Epstein-Barr virus (EBV) infection is usually asymptomatic, a primary encounter with the virus can cause mononucleosis. EBV infection is also strongly associated with lymphoma and epithelial cancers. The structure and infection mechanism of EBV have been well studied, but the EBV-encoded G protein-coupled receptor, BILF1, is not fully understood. Here, it was found that the EBV BILF1 was expressed early in the viral lytic cycle and its ectopic expression strikingly upregulated the ICAM-1 expression in Raji cells. The positive effect of BILF1 on the ICAM-1 promoter was observed and the BILF1 deficiency attenuated ICAM-1 promoter activity. Moreover, NF-κB binding sites were important for the regulation of ICAM-1 promoter by BILF1. Furthermore, BILF1 reduced the constitutive level of the IқB-a protein and increased the amount of nuclear NF-қB in Raji cells. In conclusion, this study determined that BILF1 upregulated ICAM-1 in a mechanism involving NF-қB.
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Affiliation(s)
- Qingwei Guo
- Department of Hematology, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Jie Gao
- Department of Central Lab, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Lu Cheng
- Department of Respiratory, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Xiaomei Yang
- Department of Hematology, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Fu Li
- Department of Hematology, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Guosheng Jiang
- Department of Immunology, Binzhou Medical University, Yantai, China
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6
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The role of G protein-coupled receptor kinases in the pathology of malignant tumors. Acta Pharmacol Sin 2018; 39:1699-1705. [PMID: 29921886 DOI: 10.1038/s41401-018-0049-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/20/2018] [Indexed: 12/28/2022] Open
Abstract
G protein-coupled receptor kinases (GRKs) constitute seven subtypes of serine/threonine protein kinases that specifically recognize and phosphorylate agonist-activated G protein-coupled receptors (GPCRs), thereby terminating the GPCRs-mediated signal transduction pathway. Recent research shows that GRKs also interact with non-GPCRs and participate in signal transduction in non-phosphorylated manner. Besides, GRKs activity can be regulated by multiple factors. Changes in GRKs expression have featured prominently in various tumor pathologies, and they are associated with angiogenesis, proliferation, migration, and invasion of malignant tumors. As a result, GRKs have been intensively studied as potential therapeutic targets. Herein, we review evolving understanding of the function of GRKs, the regulation of GRKs activity and the role of GRKs in human malignant tumor pathophysiology.
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7
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Waldschmidt HV, Bouley R, Kirchhoff PD, Lee P, Tesmer JJG, Larsen SD. Utilizing a structure-based docking approach to develop potent G protein-coupled receptor kinase (GRK) 2 and 5 inhibitors. Bioorg Med Chem Lett 2018; 28:1507-1515. [PMID: 29627263 DOI: 10.1016/j.bmcl.2018.03.082] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/07/2018] [Accepted: 03/28/2018] [Indexed: 01/06/2023]
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) regulate the desensitization and internalization of GPCRs. Two of these, GRK2 and GRK5, are upregulated in heart failure and are promising targets for heart failure treatment. Although there have been several reports of potent and selective inhibitors of GRK2 there are few for GRK5. Herein, we describe a ligand docking approach utilizing the crystal structures of the GRK2-Gβγ·GSK180736A and GRK5·CCG215022 complexes to search for amide substituents predicted to confer GRK2 and/or GRK5 potency and selectivity. From this campaign, we successfully generated two new potent GRK5 inhibitors, although neither exhibited selectivity over GRK2.
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Affiliation(s)
- Helen V Waldschmidt
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States; Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States
| | - Renee Bouley
- Department of Pharmacology and the Life Sciences Institute, University of Michigan, Ann Arbor, MI, United States
| | - Paul D Kirchhoff
- Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States
| | - Pil Lee
- Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States
| | - John J G Tesmer
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States; Department of Pharmacology and the Life Sciences Institute, University of Michigan, Ann Arbor, MI, United States; Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
| | - Scott D Larsen
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States; Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, MI, United States.
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8
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Gambardella J, Franco A, Giudice CD, Fiordelisi A, Cipolletta E, Ciccarelli M, Trimarco B, Iaccarino G, Sorriento D. Dual role of GRK5 in cancer development and progression. Transl Med UniSa 2016; 14:28-37. [PMID: 27326393 PMCID: PMC4912336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
GRK5 is a multifunctional protein that is able to move within the cell in response to various stimuli to regulate key intracellular signaling from receptor activation, on plasmamembrane, to gene transcription, in the nucleus. Thus, GRK5 is involved in the development and progression of several pathological conditions including cancer. Several reports underline the involvement of GRK5 in the regulation of tumor growth even if they appear controversial. Indeed, depending on its subcellular localization and on the type of cancer, GRK5 is able to both inhibit cancer progression, through the desensitization of GPCR and non GPCR-receptors (TSH, PGE2R, PDGFR), and induce tumor growth, acting on non-receptor substrates (p53, AUKA and NPM1). All these findings suggest that targeting GRK5 could be an useful anti-cancer strategy, for specific tumor types. In this review, we will discuss the different effects of this kinase in the induction and progression of tumorigenesis, the molecular mechanisms by which GRK5 exerts its effects, and the potential therapeutic strategies to modulate them.
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Affiliation(s)
- J Gambardella
- Department of Medicine and Surgery -University of Salerno, Italy
| | - A Franco
- Department of Advanced Biomedical Science -“Federico II” University of Naples, Italy
| | - C Del Giudice
- Department of Advanced Biomedical Science -“Federico II” University of Naples, Italy
| | - A Fiordelisi
- Department of Advanced Biomedical Science -“Federico II” University of Naples, Italy
| | - E Cipolletta
- Department of Medicine and Surgery -University of Salerno, Italy
| | - M Ciccarelli
- Department of Medicine and Surgery -University of Salerno, Italy
| | - B Trimarco
- Department of Advanced Biomedical Science -“Federico II” University of Naples, Italy
| | - G Iaccarino
- Department of Medicine and Surgery -University of Salerno, Italy
| | - D Sorriento
- Institute of Biostructure and Bioimaging - CNR, Naples, Italy.,Address for correspondence: Daniela Sorriento PhD, Institute of Biostructure and Bioimaging-CNR, Via T. De Amicis 95 Naples, Italy. Tel. +390817462220; FAX +390817462256;
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de Munnik SM, Kooistra AJ, van Offenbeek J, Nijmeijer S, de Graaf C, Smit MJ, Leurs R, Vischer HF. The Viral G Protein-Coupled Receptor ORF74 Hijacks β-Arrestins for Endocytic Trafficking in Response to Human Chemokines. PLoS One 2015; 10:e0124486. [PMID: 25894435 PMCID: PMC4403821 DOI: 10.1371/journal.pone.0124486] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/03/2015] [Indexed: 12/21/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus-infected cells express the virally encoded G protein-coupled receptor ORF74. Although ORF74 is constitutively active, it binds human CXC chemokines that modulate this basal activity. ORF74-induced signaling has been demonstrated to underlie the development of the angioproliferative tumor Kaposi’s sarcoma. Whereas G protein-dependent signaling of ORF74 has been the subject of several studies, the interaction of this viral GPCR with β-arrestins has hitherto not been investigated. Bioluminescence resonance energy transfer experiments demonstrate that ORF74 recruits β-arrestins and subsequently internalizes in response to human CXCL1 and CXCL8, but not CXCL10. Internalized ORF74 traffics via early endosomes to recycling and late endosomes. Site-directed mutagenesis and homology modeling identified four serine and threonine residues at the distal end of the intracellular carboxyl-terminal of ORF74 that are required for β-arrestin recruitment and subsequent endocytic trafficking. Hijacking of the human endocytic trafficking machinery is a previously unrecognized action of ORF74.
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Affiliation(s)
- Sabrina M. de Munnik
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Albert J. Kooistra
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Jody van Offenbeek
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Saskia Nijmeijer
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Chris de Graaf
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Martine J. Smit
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Rob Leurs
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
| | - Henry F. Vischer
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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10
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de Munnik SM, Smit MJ, Leurs R, Vischer HF. Modulation of cellular signaling by herpesvirus-encoded G protein-coupled receptors. Front Pharmacol 2015; 6:40. [PMID: 25805993 PMCID: PMC4353375 DOI: 10.3389/fphar.2015.00040] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/12/2015] [Indexed: 12/22/2022] Open
Abstract
Human herpesviruses (HHVs) are widespread infectious pathogens that have been associated with proliferative and inflammatory diseases. During viral evolution, HHVs have pirated genes encoding viral G protein-coupled receptors (vGPCRs), which are expressed on infected host cells. These vGPCRs show highest homology to human chemokine receptors, which play a key role in the immune system. Importantly, vGPCRs have acquired unique properties such as constitutive activity and the ability to bind a broad range of human chemokines. This allows vGPCRs to hijack human proteins and modulate cellular signaling for the benefit of the virus, ultimately resulting in immune evasion and viral dissemination to establish a widespread and lifelong infection. Knowledge on the mechanisms by which herpesviruses reprogram cellular signaling might provide insight in the contribution of vGPCRs to viral survival and herpesvirus-associated pathologies.
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Affiliation(s)
- Sabrina M de Munnik
- Amsterdam Institute for Molecules Medicines and Systems - Division of Medicinal Chemistry, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, Amsterdam Netherlands
| | - Martine J Smit
- Amsterdam Institute for Molecules Medicines and Systems - Division of Medicinal Chemistry, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, Amsterdam Netherlands
| | - Rob Leurs
- Amsterdam Institute for Molecules Medicines and Systems - Division of Medicinal Chemistry, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, Amsterdam Netherlands
| | - Henry F Vischer
- Amsterdam Institute for Molecules Medicines and Systems - Division of Medicinal Chemistry, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, Amsterdam Netherlands
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11
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Mølleskov-Jensen AS, Oliveira MT, Farrell HE, Davis-Poynter N. Virus-Encoded 7 Transmembrane Receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 129:353-93. [DOI: 10.1016/bs.pmbts.2014.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Maor Y, Yu J, Kuzontkoski PM, Dezube BJ, Zhang X, Groopman JE. Cannabidiol inhibits growth and induces programmed cell death in kaposi sarcoma-associated herpesvirus-infected endothelium. Genes Cancer 2012; 3:512-20. [PMID: 23264851 DOI: 10.1177/1947601912466556] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 10/11/2012] [Indexed: 12/13/2022] Open
Abstract
Kaposi sarcoma is the most common neoplasm caused by Kaposi sarcoma-associated herpesvirus (KSHV). It is prevalent among the elderly in the Mediterranean, inhabitants of sub-Saharan Africa, and immunocompromised individuals such as organ transplant recipients and AIDS patients. Current treatments for Kaposi sarcoma can inhibit tumor growth but are not able to eliminate KSHV from the host. When the host's immune system weakens, KSHV begins to replicate again, and active tumor growth ensues. New therapeutic approaches are needed. Cannabidiol (CBD), a plant-derived cannabinoid, exhibits promising antitumor effects without inducing psychoactive side effects. CBD is emerging as a novel therapeutic for various disorders, including cancer. In this study, we investigated the effects of CBD both on the infection of endothelial cells (ECs) by KSHV and on the growth and apoptosis of KSHV-infected ECs, an in vitro model for the transformation of normal endothelium to Kaposi sarcoma. While CBD did not affect the efficiency with which KSHV infected ECs, it reduced proliferation and induced apoptosis in those infected by the virus. CBD inhibited the expression of KSHV viral G protein-coupled receptor (vGPCR), its agonist, the chemokine growth-regulated protein α (GRO-α), vascular endothelial growth factor receptor 3 (VEGFR-3), and the VEGFR-3 ligand, vascular endothelial growth factor C (VEGF-C). This suggests a potential mechanism by which CBD exerts its effects on KSHV-infected endothelium and supports the further examination of CBD as a novel targeted agent for the treatment of Kaposi sarcoma.
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Affiliation(s)
- Yehoshua Maor
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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13
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Aguilar B, Choi I, Choi D, Chung HK, Lee S, Yoo J, Lee YS, Maeng YS, Lee HN, Park E, Kim KE, Kim NY, Baik JM, Jung JU, Koh CJ, Hong YK. Lymphatic reprogramming by Kaposi sarcoma herpes virus promotes the oncogenic activity of the virus-encoded G-protein-coupled receptor. Cancer Res 2012; 72:5833-42. [PMID: 22942256 PMCID: PMC3500425 DOI: 10.1158/0008-5472.can-12-1229] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Kaposi sarcoma, the most common cancer in HIV-positive individuals, is caused by endothelial transformation mediated by the Kaposi sarcoma herpes virus (KSHV)-encoded G-protein-coupled receptor (vGPCR). Infection of blood vascular endothelial cells (BEC) by KSHV reactivates an otherwise silenced embryonic program of lymphatic differentiation. Thus, Kaposi sarcoma tumors express numerous lymphatic endothelial cell (LEC) signature genes. A key unanswered question is how lymphatic reprogramming by the virus promotes tumorigenesis leading to Kaposi sarcoma formation. In this study, we present evidence that this process creates an environment needed to license the oncogenic activity of vGPCR. We found that the G-protein regulator RGS4 is an inhibitor of vGPCR that is expressed in BECs, but not in LECs. RGS4 was downregulated by the master regulator of LEC differentiation PROX1, which is upregulated by KSHV and directs KSHV-induced lymphatic reprogramming. Moreover, we found that KSHV upregulates the nuclear receptor LRH1, which physically interacts with PROX1 and synergizes with it to mediate repression of RGS4 expression. Mechanistic investigations revealed that RGS4 reduced vGPCR-enhanced cell proliferation, migration, VEGF expression, and Akt activation and suppressed tumor formation induced by vGPCR. Our findings resolve long-standing questions about the pathologic impact of KSHV-induced reprogramming of host cell identity, and they offer biologic and mechanistic insights supporting the hypothesis that a lymphatic microenvironment is more favorable for Kaposi sarcoma tumorigenesis.
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MESH Headings
- Animals
- Cell Differentiation/physiology
- Cell Transformation, Viral
- Down-Regulation
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelial Cells/virology
- Female
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/metabolism
- Herpesvirus 8, Human/physiology
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Nude
- Mice, SCID
- Oncogene Protein v-akt/metabolism
- Promoter Regions, Genetic
- RGS Proteins/antagonists & inhibitors
- RGS Proteins/biosynthesis
- RGS Proteins/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
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Affiliation(s)
- Berenice Aguilar
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Inho Choi
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Dongwon Choi
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Hee Kyoung Chung
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Sunju Lee
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Jaehyuk Yoo
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Yong Suk Lee
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Yong Sun Maeng
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Ha Neul Lee
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Eunkyung Park
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Kyu Eui Kim
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Nam Yoon Kim
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Jae Myung Baik
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Jae U. Jung
- Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Chester J. Koh
- Division of Pediatric Urology and Developmental Biology, Regenerative Medicine, and Surgery Program, Children’s Hospital Los Angeles and University of Southern California Keck School of Medicine, Los Angeles, California 90027
| | - Young-Kwon Hong
- Department of Surgery and Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
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15
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Abstract
Kaposi sarcoma (KS) occurs as a result of Kaposi sarcoma-associated herpesvirus (KSHV) infection, typically in the context of one of several immunodeficient states. In the US, patients with KS may either be co-infected with HIV or receiving immunosuppressant therapy following solid-organ transplantation. Systemic treatment of KS has traditionally involved one of several chemotherapeutic agents administered either in combination or as single agents, which typically provide reasonable response rates and short-term control. However, recurrence of KS is common, and progression-free intervals are under 1 year. For these reasons, new therapies have been sought and with the elucidation of novel pathogenic mechanisms of KS infection, rational therapeutic targets have been identified. These include KSHV replication, restoration of immune competence, and signal transduction pathways utilized by KSHV in the propagation of KS. This review focuses on these emerging targets in the treatment of patients with KS and also highlights important clinicopathologic characteristics.
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Affiliation(s)
- Ryan J Sullivan
- Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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16
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Kaposi's sarcoma-associated herpesvirus K7 induces viral G protein-coupled receptor degradation and reduces its tumorigenicity. PLoS Pathog 2008; 4:e1000157. [PMID: 18802460 PMCID: PMC2529400 DOI: 10.1371/journal.ppat.1000157] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 08/19/2008] [Indexed: 11/19/2022] Open
Abstract
The Kaposi's sarcoma-associated herpesvirus (KSHV) genome encodes a G protein-coupled receptor (vGPCR). vGPCR is a ligand-independent, constitutively active signaling molecule that promotes cell growth and proliferation; however, it is not clear how vGPCR is negatively regulated. We report here that the KSHV K7 small membrane protein interacts with vGPCR and induces its degradation, thereby dampening vGPCR signaling. K7 interaction with vGPCR is readily detected in transiently transfected human cells. Mutational analyses reveal that the K7 transmembrane domain is necessary and sufficient for this interaction. Biochemical and confocal microscopy studies indicate that K7 retains vGPCR in the endoplasmic reticulum (ER) and induces vGPCR proteasomeal degradation. Indeed, the knockdown of K7 by shRNA-mediated silencing increases vGPCR protein expression in BCBL-1 cells that are induced for KSHV lytic replication. Interestingly, K7 expression significantly reduces vGPCR tumorigenicity in nude mice. These findings define a viral factor that negatively regulates vGPCR protein expression and reveal a post-translational event that modulates GPCR-dependent transformation and tumorigenicity.
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17
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Sherrill JD, Miller WE. Desensitization of herpesvirus-encoded G protein-coupled receptors. Life Sci 2007; 82:125-34. [PMID: 18054964 DOI: 10.1016/j.lfs.2007.10.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Revised: 10/15/2007] [Accepted: 10/31/2007] [Indexed: 11/28/2022]
Abstract
Members of the herpesvirus family, including human cytomegalovirus (HCMV) and Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8), encode G protein-coupled receptor (GPCR) homologs, which strongly activate classical G protein signal transduction networks within the cell. In animal models of herpesvirus infection, the viral GPCRs appear to play physiologically important roles by enabling viral replication within tropic tissues and by promoting reactivation from latency. While a number of studies have defined intracellular signaling pathways activated by herpesviral GPCRs, it remains unclear if their physiological function is subjected to the process of desensitization as observed for cellular GPCRs. G protein-coupled receptor kinases (GRK) and arrestin proteins have been recently implicated in regulating viral GPCR signaling; however, the role that these desensitization proteins play in viral GPCR function in vivo remains unknown. Here, we review what is currently known regarding viral GPCR desensitization and discuss potential biological ramifications of viral GPCR regulation by the host cell desensitization machinery.
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Affiliation(s)
- Joseph D Sherrill
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA
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18
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Mehrad B, Keane MP, Strieter RM. Chemokines as mediators of angiogenesis. Thromb Haemost 2007; 97:755-62. [PMID: 17479186 PMCID: PMC3353527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Chemokines were originally described as cytokines that mediate leukocyte recruitment to sites of inflammation. Members of a subgroup of chemokines, the CXC family, also play a critical role in both physiologic and pathologic angiogenesis, including in the context of chronic inflammation, fibrosis, and malignancy. A unique feature of this family of cytokines is that, on the basis of their structure and receptor binding, individual ligands display either angiogenic or angiostatic biological activity in the regulation of angiogenesis. In this review, we summarize the key literature in this growing field.
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Affiliation(s)
- Borna Mehrad
- Division of Pulmonary and Critical Care Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Michael P. Keane
- Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Robert M. Strieter
- Division of Pulmonary and Critical Care Medicine, University of Virginia, Charlottesville, Virginia, USA
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19
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Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) is a gamma2-herpesvirus discovered in 1994 and is the agent responsible for Kaposi sarcoma (KS), an endothelial cell malignancy responsible for significant morbidity and mortality worldwide. Over time, KSHV has pirated many human genes whose products regulate angiogenesis, inflammation, and the cell cycle. One of these encodes for a mutated G protein-coupled receptor (GPCR) that is a homologue of the human IL-8 receptor. GPCRs are the largest family of signaling molecules and respond to a wide array of ligands. Unlike its normal counterpart, the mutations present in KSHV vGPCR result in constitutive, ligand-independent signaling activity. Signaling by the KSHV vGPCR results in the elaboration of many mitogenic and angiogenic cytokines that are vital to the biology of KS and other KSHV-driven malignancies. Several other herpesviruses also encode GPCRs, the functions of which are under ongoing investigation. In addition, several human diseases are associated with mutated mammalian GPCRs in germline or somatic cells.
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Affiliation(s)
- M Cannon
- Cancer Research UK Viral Oncology Group, Wolfson Institute for Biomedical Research University College London, The Cruciform Building, London WC1E 6BT, UK.
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20
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Margulies BJ, Gibson W. The chemokine receptor homologue encoded by US27 of human cytomegalovirus is heavily glycosylated and is present in infected human foreskin fibroblasts and enveloped virus particles. Virus Res 2006; 123:57-71. [PMID: 16963142 PMCID: PMC2676329 DOI: 10.1016/j.virusres.2006.08.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 08/07/2006] [Accepted: 08/07/2006] [Indexed: 11/26/2022]
Abstract
Human cytomegalovirus (HCMV), a member of the beta-herpesvirus family, encodes four homologues of cellular G protein-coupled receptors (GPCRs). One of these, the protein product of HCMV open reading frame (ORF) UL33, has been identified in HCMV-infected cells and virus particles and shown to be heat-aggregatable and N-glycosylated. Another, the product of ORF US28, has been functionally characterized as a beta-chemokine receptor. Here we report the use of RT-PCR, coupled in vitro transcription-translation, immunoprecipitation, and Western immunoassays to (i) show that RNA from the open reading frame US27 appears predominantly during the late phase of replication; (ii) identify the protein encoded by HCMV US27 in infected cells and enveloped virus particles; (iii) demonstrate that the US27-encoded protein is heterogeneously N-glycosylated and resolves as two species following treatment with peptide N-glycosidase F; and (iv) show that both the recombinant and deglycoylated infected cell US27 protein aggregate when heated in the presence of SDS prior to electrophoresis in polyacrylamide gels, a property which is abrogated with the addition of urea to sample buffer.
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Affiliation(s)
- Barry J Margulies
- Towson University Herpes Virus Lab, Department of Biological Sciences, Towson University, Towson, MD 21252, USA.
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21
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Couty JP, Gershengorn MC. G-protein-coupled receptors encoded by human herpesviruses. Trends Pharmacol Sci 2006; 26:405-11. [PMID: 15990176 DOI: 10.1016/j.tips.2005.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Revised: 05/13/2005] [Accepted: 06/16/2005] [Indexed: 11/16/2022]
Abstract
G-protein-coupled receptors (GPCRs) encoded by herpesviruses and poxviruses are homologous to mammalian chemokine receptors. GPCRs encoded by herpesvirus-6, herpesvirus-7, herpesvirus-8 and cytomegalovirus are among the best studied. Virally encoded GPCRs engage many different signal-transduction cascades, and have important roles in the life-cycles of the viruses and pathogenesis of human disease. Although signaling by these GPCRs might be modified by ligand binding, they often exhibit constitutive (basal) signaling activities that appear to provide selective advantages to the virus.
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Affiliation(s)
- Jean-Pierre Couty
- Department of Immunology, Institut Cochin, INSERM U567, UMR CNRS 8104, 27, rue du Faubourg Saint-Jacques 75014 Paris, France
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22
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Abstract
The defining characteristic of G protein-coupled receptor homologous desensitization is that the receptor must be occupied by an agonist or in an activated conformation that mimics an agonist-induced state. In most instances, the mechanistic basis for this characteristic is the high selectivity of G protein-coupled receptor kinases for the activated receptor. In this issue, Rankin et al. (p. 759) demonstrate that under some conditions, at least, the G protein-coupled receptor kinase GRK4 does not display a preference for the agonist-occupied D1 dopamine receptor. Coexpression of GRK4 and the D1 receptor in a heterologous system induces phosphorylation of the receptor in the absence of agonist, causing constitutive desensitization and internalization of the receptor. Lacking the normal rapid feedback mechanisms associated with homologous desensitization, a system incorporating constitutively active GRK4 will be prone to dysregulation, perhaps explaining the generally low expression of GRK4. Indeed, considerable evidence suggests that just such dysregulation resulting from mutationally activated GRK4 contributes to the heritable component of human essential hypertension (Physiol Genomics 19:223-246, 2004).
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Affiliation(s)
- Kim A Neve
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, USA.
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23
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Cannon M, Cesarman E, Boshoff C. KSHV G protein-coupled receptor inhibits lytic gene transcription in primary-effusion lymphoma cells via p21-mediated inhibition of Cdk2. Blood 2005; 107:277-84. [PMID: 16150942 PMCID: PMC1895347 DOI: 10.1182/blood-2005-06-2350] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Kaposi sarcoma (KS) remains the most common AIDS-associated malignancy worldwide. In sub-Saharan Africa especially, this aggressive endothelial-cell tumor is a cause of widespread morbidity and mortality. Infection with Kaposi sarcoma-associated herpesvirus (KSHV) is now known to be an etiologic force behind KS and primary-effusion lymphoma (PEL). Over time, KSHV has pirated many human genes whose products regulate angiogenesis, inflammation, and the cell cycle. One of these, the KSHV vGPCR, is a lytic product that is a constitutively active homolog of the IL-8 receptor. Although it is considered a viral oncogene and causes KS-like lesions in mice, vGPCR expression results in cell-cycle arrest of KSHV-infected PEL cells. In the present study, we show that this arrest is mediated by p21 in a p53-independent manner; the resulting Cdk2 inhibition decreases the efficiency of chemical induction of KSHV lytic transcripts ORF 50 and 26. Importantly, Cdk2 activity is also essential for replication in other human herpesviruses. The ability of vGPCR to delay or abort KSHV replication may explain how despite being a lytic product, this potent signaling molecule has a vital role in tumor formation via its induction of various KS-associated cytokines.
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Affiliation(s)
- Mark Cannon
- Division of International Medicine and Infectious Diseases, Department of Medicine, Weill Medical College of Cornell University, New York, NY, USA.
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24
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Neel NF, Schutyser E, Sai J, Fan GH, Richmond A. Chemokine receptor internalization and intracellular trafficking. Cytokine Growth Factor Rev 2005; 16:637-58. [PMID: 15998596 PMCID: PMC2668263 DOI: 10.1016/j.cytogfr.2005.05.008] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Accepted: 05/03/2005] [Indexed: 01/25/2023]
Abstract
The internalization and intracellular trafficking of chemokine receptors have important implications for the cellular responses elicited by chemokine receptors. The major pathway by which chemokine receptors internalize is the clathrin-mediated pathway, but some receptors may utilize lipid rafts/caveolae-dependent internalization routes. This review discusses the current knowledge and controversies regarding these two different routes of endocytosis. The functional consequences of internalization and the regulation of chemokine receptor recycling will also be addressed. Modifications of chemokine receptors, such as palmitoylation, ubiquitination, glycosylation, and sulfation, may also impact trafficking, chemotaxis and signaling. Finally, this review will cover the internalization and trafficking of viral and decoy chemokine receptors.
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Affiliation(s)
- Nicole F Neel
- Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, 432 PRB, 23rd Avenue South at Pierce, Nashville, TN 37232, USA.
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25
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Paulsen SJ, Rosenkilde MM, Eugen-Olsen J, Kledal TN. Epstein-Barr virus-encoded BILF1 is a constitutively active G protein-coupled receptor. J Virol 2005; 79:536-46. [PMID: 15596846 PMCID: PMC538743 DOI: 10.1128/jvi.79.1.536-546.2005] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Both beta- and gammaherpesviruses encode G protein-coupled receptors (GPCRs) with unique pharmacological phenotypes and important biological functions. An example is ORF74, the gamma2-herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded GPCR, which is highly constitutively active and considered the key oncogene in Kaposi's sarcoma pathogenesis. In contrast, the current annotation of the Epstein-Barr virus (EBV) genome does not reveal any GPCR homolog encoded by this human oncogenic gamma1-herpesvirus. However, by employing bioinformatics, we recognized that the previously established EBV open reading frame BILF1 indeed encodes a GPCR. Additionally, BILF1 is a member of a new family of related GPCRs exclusively encoded by gamma1-herpesviruses. Expression of hemagglutinin-tagged BILF1 in the HEK293 epithelial cell line revealed that BILF1 is expressed as an approximately 50-kDa glycosylated protein. Immunocytochemistry and confocal microscopy revealed that BILF1 localizes predominantly to the plasma membrane, similar to the localization of KSHV ORF74. Using chimeric G proteins, we found that human and rhesus EBV-encoded BILF1 are highly potent constitutively active receptors, activating Galphai. Furthermore, BILF1 is able to inhibit forskolin-triggered CREB activation via stimulation of endogenous G proteins in a pertussis toxin-sensitive manner, verifying that BILF1 signals constitutively through Galphai. We suggest that EBV may use BILF1 to regulate Galphai-activated pathways during viral lytic replication, thereby affecting disease progression.
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Affiliation(s)
- Sarah J Paulsen
- Clinical Research Unit, Copenhagen University Hospital, Hvidovre, Denmark
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26
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Strieter RM, Burdick MD, Sakkour A, Arnaiz NO, Belperio JA, Keane MP. CXC Chemokines in Cancer. CURRENT TOPICS IN MEMBRANES 2005. [DOI: 10.1016/s1063-5823(04)55010-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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27
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McLean KA, Holst PJ, Martini L, Schwartz TW, Rosenkilde MM. Similar activation of signal transduction pathways by the herpesvirus-encoded chemokine receptors US28 and ORF74. Virology 2004; 325:241-51. [PMID: 15246264 DOI: 10.1016/j.virol.2004.04.027] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Revised: 01/13/2004] [Accepted: 04/23/2004] [Indexed: 12/27/2022]
Abstract
The virally encoded chemokine receptors US28 from human cytomegalovirus and ORF74 from human herpesvirus 8 are both constitutively active. We show that both receptors constitutively activate the transcription factors nuclear factor of activated T cells (NFAT) and cAMP response element binding protein (CREB) and that both pathways are modulated by their respective endogenous receptor ligands. By addition of specific pathway modulators against the G protein subunit Galphai, phospholipase C, protein kinase C, calcineurin, p38 MAP kinase, and MEK1, we find that the constitutive and ligand-dependent inductions are mediated by multiple yet similar pathways in both receptors. The NFAT and CREB transcription factors and their upstream activators are known inducers of host and virally encoded genes. We propose that the activity of these virally encoded chemokine receptors coordinates host and potentially viral gene expression similarly. As ORF74 is a known inducer of neoplasia, these findings may have important implications for cytomegalovirus-associated pathogenicity.
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Affiliation(s)
- Katherine A McLean
- Laboratory for Molecular Pharmacology, Department of Pharmacology, The Panum Institute, University of Copenhagen, 2200 Copenhagen N, Denmark
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28
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Hecht I, Hershkoviz R, Shivtiel S, Lapidot T, Cohen IR, Lider O, Cahalon L. Heparin-disaccharide affects T cells: inhibition of NF-κB activation, cell migration, and modulation of intracellular signaling. J Leukoc Biol 2004; 75:1139-46. [PMID: 15020655 DOI: 10.1189/jlb.1203659] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We previously reported that disaccharides (DS), generated by enzymatic degradation of heparin or heparan sulfate, inhibit T cell-mediated immune reactions in rodents and regulate cytokine [tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-8, and IL-1beta] secretion by T cells, macrophages, or intestinal epithelial cells. Here, we investigated the effects of a trisulfated heparin DS (3S-DS) on two aspects of T cell function: secretion of proinflammatory cytokines and migration to an inflamed site. 3S-DS down-regulated nuclear factor-kappaB activity and reduced the secretion of TNF-alpha and interferon-gamma (IFN-gamma) by anti-CD3-activated T cells. In addition, 3S-DS inhibited CXC chemokine ligand 12 (CXCL12; stromal cell-derived factor-1alpha)-dependent migration in vitro and in vivo and decreased CXCL12-induced T cell adhesion to the extracellular matrix glycoprotein, fibronectin (FN). This inhibition was accompanied by attenuation of CXCL12-induced Pyk2 phosphorylation but did not involve internalization of the CXCL12 receptor, CXCR4, or phosphorylation of extracellular-regulated kinase. Despite inhibiting CXCL12-induced adhesion, 3S-DS, on its own, induced T cell adhesion to FN, which was accompanied by phosphorylation of Pyk2. A monosulfated DS showed no effect. Taken together, these data provide evidence that 3S-DS can regulate inflammation by inducing and modulating T cell-signaling events, desensitizing CXCR4, and modulating T cell receptor-induced responses.
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Affiliation(s)
- Iris Hecht
- Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel
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29
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Cannon ML, Cesarman E. The KSHV G protein-coupled receptor signals via multiple pathways to induce transcription factor activation in primary effusion lymphoma cells. Oncogene 2004; 23:514-23. [PMID: 14724579 DOI: 10.1038/sj.onc.1207021] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Kaposi's sarcoma-associated virus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). The KSHV G protein-couple receptor (vGPCR) is a homologue of the human IL-8 receptor that signals constitutively, activates mitogen- and stress-activated kinases, and induces transcription via multiple transcription factors including AP-1 and NFkappaB. Furthermore, vGPCR causes cellular transformation in vitro and leads to KS-like tumors in transgenic mouse models. vGPCR has therefore become an exciting potential therapeutic target for KSHV-mediated disease, but its signaling properties need to be better understood in the context of KSHV-infected hematopoietic cells. We recently described a PEL cell line that expresses vGPCR via an inducible promoter and have shown that vGPCR has broad capabilities of affecting cellular and viral transcription patterns in this highly relevant cell type. To elucidate the predominant signaling pathways used by vGPCR in PEL cells, we have used reporter gene assays to measure vGPCR activity in the presence of various pharmacologic enzyme inhibitors and plasmid constructs. We show that vGPCR-induced activation of AP-1 and CREB is mediated cooperatively by a Gq-ERK-1/2 and a Gi-PI3K-Src axis. Furthermore, unlike in other cell types, NFkappaB activation by vGPCR seems not to be substantially mediated by Gi or PI3K/Akt in PEL cells.
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Affiliation(s)
- Mark L Cannon
- Division of International Medicine and Infectious Disease, Department of Medicine, Weill Medical College of Cornell University, 1300 York Ave., Room A-421, New York, NY 10021, USA.
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30
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Strieter R, Belperio J, Keane M. CXC Chemokines in Angiogenesis Related to Pulmonary Fibrosis. LUNG BIOLOGY IN HEALTH AND DISEASE 2003. [DOI: 10.1201/b14211-13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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31
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Nicholas J. Human herpesvirus-8-encoded signalling ligands and receptors. J Biomed Sci 2003; 10:475-89. [PMID: 12928588 DOI: 10.1007/bf02256109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2003] [Accepted: 05/15/2003] [Indexed: 01/26/2023] Open
Abstract
Analysis of the genome of human herpesvirus 8 (HHV-8) led to the discovery of several novel genes, unique among the characterized gammaherpesviruses. These include cytokines (interleukin-6 and chemokine homologues), two putative signal-transducing transmembrane proteins encoded by genes K1 and K15 at the genome termini, and an OX-2 (CD200) receptor homologue that had not previously been identified in a gammaherpesvirus. HHV-8 also specifies a diverged version of the gammaherpesvirus-conserved G protein-coupled chemokine receptor (vGCR) and a latently expressed protein unique to HHV-8 specified by open reading frame (ORF) K12. These cytokine and receptor homologues mediate signal transduction or modulate the activities of other endogenous cytokines and receptors to enhance viral productive replication, regulate latent-lytic switching, evade host attack, or mediate cell survival. The viral signalling ligands and receptors are also potential contributors to virus-associated diseases, Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease, and so represent potentially important targets for therapeutic and antiviral drugs. Understanding these proteins' modes of action and functions in viral biology and disease is therefore of considerable importance, and the subject of this review.
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Affiliation(s)
- John Nicholas
- Molecular Virology Laboratories, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Md. 21231, USA.
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32
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Moorman NJ, Virgin HW, Speck SH. Disruption of the gene encoding the gammaHV68 v-GPCR leads to decreased efficiency of reactivation from latency. Virology 2003; 307:179-90. [PMID: 12667789 DOI: 10.1016/s0042-6822(02)00023-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Murine gammaherpesvirus 68 (gammaHV68; MHV68) infection of mice has been a useful model for characterizing the role of conserved herpesvirus genes in pathogenesis. One of the well conserved genes among gamma2-herpesvirus, gene 74, encodes a viral G-protein coupled receptor (v-GPCR). To examine the role of the gammaHV68 v-GPCR in pathogenesis we have generated a mutant virus in which 440 base pairs of the gene 74 open reading frame have been deleted (gammaHV68v-GPCRDelta440). This deletion did not affect the growth of the virus in single or multiple rounds of replication in vitro, nor acute replication in vivo as assessed by plaque assay of spleens and lungs on days 4, 7 and 9 post-infection (p.i.). The ability of the v-GPCR mutant virus to establish latency and to reactivate from latency was quantitated on days 16 and 42 p.i. While there was no detectable difference in the ability of the mutant virus to either establish latency or reactivate from latency on day 16 p.i., as compared to wild-type gammaHV68 and marker rescue virus, there was a significant decrease in the efficiency of virus reactivation by day 42 p.i. Notably, mice infected with the mutant virus lacking the v-GPCR contained a higher frequency of viral genome positive cells in the peritoneum by day 42 p.i. than mice infected with either wild type or marker rescue virus. However, analysis of virus reactivation demonstrated that approximately the same frequency of cells reactivated virus from mice infected with either the gammaHV68 v-GPCR mutant, wild-type virus, or marker rescue virus. From these experiments we conclude that the gammaHV68 v-GPCR is dispensable for acute virus replication in vivo, but does play a role in reactivation from latency.
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Affiliation(s)
- Nathaniel J Moorman
- Division of Microbiology & Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
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33
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Abstract
Human herpesvirus 8, also known as Kaposi sarcoma-associated herpesvirus, is etiologically associated with Kaposi sarcoma and other rare malignancies. Human herpesvirus 8 infection is common in certain areas of Africa and Italy, but occurs in only 0% to 15% of adult populations in North America and Europe. Reports of human herpesvirus 8 prevalence of 3% to over 50% among children in Central Africa, Brazil, and South Texas suggest that horizontal transmission of human herpesvirus 8 occurs among children. Primary human herpesvirus 8 infection in immunocompetent children is associated with a fever and maculopapular rash.
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Affiliation(s)
- Hal B Jenson
- Department of Pediatrics and Center for Pediatric Research, Eastern Virginia Medical School and Children's Hospital of the King's Daughters, Norfolk, 23507, USA.
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34
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Chiou CJ, Poole LJ, Kim PS, Ciufo DM, Cannon JS, ap Rhys CM, Alcendor DJ, Zong JC, Ambinder RF, Hayward GS. Patterns of gene expression and a transactivation function exhibited by the vGCR (ORF74) chemokine receptor protein of Kaposi's sarcoma-associated herpesvirus. J Virol 2002; 76:3421-39. [PMID: 11884567 PMCID: PMC136009 DOI: 10.1128/jvi.76.7.3421-3439.2002] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ORF74 or vGCR gene encoded by Kaposi's sarcoma-associated herpesvirus (KSHV; also called human herpesvirus 8) has properties of a ligand-independent membrane receptor signaling protein with angiogenic properties that is predicted to play a key role in the biology of the virus. We have examined the expression of vGCR mRNA and protein in primary effusion lymphoma (PEL) cell lines, PEL and multicentric Castleman's disease (MCD) tumors, Kaposi's sarcoma lesions and infected endothelial cell cultures. The vGCR gene proved to be expressed in PEL cell lines as a large spliced bicistronic mRNA of 3.2 kb that also encompasses the upstream vOX2 (K14) gene. This mRNA species was induced strongly by phorbol ester (TPA) and sodium butyrate treatment in the BCBL-1 cell line, but only weakly in the HBL6 cell line, and was classified as a relatively late and low-abundance delayed early class lytic cycle gene product. A complex bipartite upstream lytic cycle promoter for this mRNA was nestled within the intron of the 5'-overlapping but oppositely oriented latent-state transcription unit for LANA1/vCYC-D/vFLIP and responded strongly to both TPA induction and cotransfection with the KSHV RNA transactivator protein (RTA or ORF50) in transient reporter gene assays. A vGCR protein product of 45 kDa that readily dimerized was detected by Western blotting and in vitro translation and was localized in a cytoplasmic and membrane pattern in DNA-transfected Vero and 293T cells or adenovirus vGCR-transduced dermal microvascular endothelial cells (DMVEC) as detected by indirect immunofluorescence assay (IFA) and immunohistochemistry with a specific rabbit anti-vGCR antibody. Similarly, a subfraction of KSHV-positive cultured PEL cells and of KSHV (JSC-1) persistently infected DMVEC cells displayed cytoplasmic vGCR protein expression, but only after TPA or spontaneous lytic cycle induction, respectively. The vGCR protein was also detectable by immunohistochemical staining in a small fraction (0.5 to 3%) of the cells in PEL and MCD tumor and nodular Kaposi's sarcoma lesion specimens that were apparently undergoing lytic cycle expression. These properties are difficult to reconcile with the vGCR protein's playing a direct role in spindle cell proliferation, transformation, or latency, but could be compatible with proposed contributions to angiogenesis via downstream paracrine effects. The ability of vGCR to transactivate expression of both several KSHV promoter-driven luciferase (LUC) reporter genes and an NFkappaB motif containing the chloramphenicol acetyltransferase (CAT) reporter gene may also suggest an unexpected regulatory role in viral gene expression.
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MESH Headings
- Base Sequence
- Cell Line
- Cell Membrane/metabolism
- Cytoplasm/metabolism
- Gene Expression Regulation, Viral
- Herpesvirus 8, Human/metabolism
- Humans
- Immediate-Early Proteins/metabolism
- Molecular Sequence Data
- Promoter Regions, Genetic
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- RNA, Viral/analysis
- RNA, Viral/biosynthesis
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/genetics
- Receptors, Chemokine/metabolism
- Tetradecanoylphorbol Acetate/pharmacology
- Trans-Activators/metabolism
- Transcription, Genetic
- Viral Proteins/biosynthesis
- Viral Proteins/genetics
- Viral Proteins/metabolism
- Virus Latency
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Affiliation(s)
- Chuang-Jiun Chiou
- Molecular Virology Laboratories, Department of Oncology, Johns Hopkins School of Medicine, Baltimore, Maryland 21231, USA
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35
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Poole LJ, Yu Y, Kim PS, Zheng QZ, Pevsner J, Hayward GS. Altered patterns of cellular gene expression in dermal microvascular endothelial cells infected with Kaposi's sarcoma-associated herpesvirus. J Virol 2002; 76:3395-420. [PMID: 11884566 PMCID: PMC136008 DOI: 10.1128/jvi.76.7.3395-3420.2002] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV; also called human herpesvirus 8) is believed to be the etiologic agent of Kaposi's sarcoma, multicentric Castleman's disease, and AIDS-associated primary effusion lymphoma. KSHV infection of human dermal microvascular endothelial cells (DMVEC) in culture results in the conversion of cobblestone-shaped cells to spindle-shaped cells, a characteristic morphological feature of cells in KS lesions. All spindle-shaped cells in KSHV-infected DMVEC cultures express the latency-associated nuclear protein LANA1, and a subfraction of these cells undergo spontaneous lytic cycle induction that can be enhanced by tetradecanoyl phorbol acetate (TPA) treatment. To study the cellular response to infection by KSHV, we used two different gene array screening systems to examine the expression profile of either 2,350 or 9,180 human genes in infected compared to uninfected DMVEC cultures in both the presence and absence of TPA. In both cases, between 1.4 and 2.5% of the genes tested were found to be significantly upregulated or downregulated. Further analysis by both standard and real-time reverse transcription-PCR procedures directly confirmed these results for 14 of the most highly upregulated and 13 of the most highly downregulated genes out of a total of 37 that were selected for testing. These included strong upregulation of interferon-responsive genes such as interferon response factor 7 (IRF7) and myxovirus resistance protein R1, plus upregulation of exodus 2 beta-chemokine, RDC1 alpha-chemokine receptor, and transforming growth factor beta3, together with strong downregulation of cell adhesion factors alpha(4)-integrin and fibronectin plus downregulation of bone morphogenesis protein 4, matrix metalloproteinase 2, endothelial plasminogen activator inhibitor 1, connective tissue growth factor, and interleukin-8. Significant dysregulation of several other cytokine-related genes or receptors, as well as endothelial cell and macrophage markers, and various other genes associated with angiogenesis or transformation was also detected. Western immunoblot and immunohistochemical analyses confirmed that the cellular IRF7 protein levels were strongly upregulated during the early lytic cycle both in KSHV-infected DMVEC and in the body cavity-based lymphoma BCBL1 PEL cell line.
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MESH Headings
- Antigens, Viral/biosynthesis
- Blotting, Western
- Cells, Cultured
- DNA-Binding Proteins/biosynthesis
- DNA-Binding Proteins/genetics
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/virology
- Gene Expression Profiling
- Gene Expression Regulation, Viral
- Herpesvirus 8, Human/metabolism
- Humans
- Immunohistochemistry
- Interferon Regulatory Factor-7
- Nuclear Proteins/biosynthesis
- Oligonucleotide Array Sequence Analysis
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- Reverse Transcriptase Polymerase Chain Reaction
- Skin/blood supply
- Tetradecanoylphorbol Acetate/pharmacology
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Affiliation(s)
- Lynn J Poole
- Department of Pharmacology and Molecular Sciences, .Johns Hopkins University School of Medicine, Baltimore, Maryland 2120, USA
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36
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Holst PJ, Rosenkilde MM, Manfra D, Chen SC, Wiekowski MT, Holst B, Cifire F, Lipp M, Schwartz TW, Lira SA. Tumorigenesis induced by the HHV8-encoded chemokine receptor requires ligand modulation of high constitutive activity. J Clin Invest 2001; 108:1789-96. [PMID: 11748262 PMCID: PMC209468 DOI: 10.1172/jci13622] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ORF74 (or KSHV-vGPCR) is a highly constitutively active G protein-coupled receptor encoded by HHV8 that is regulated both positively and negatively by endogenous chemokines. When expressed in transgenic mice, this chemokine receptor induces an angioproliferative disease closely resembling Kaposi sarcoma (KS). Here we demonstrate that several lines of mice carrying mutated receptors deficient in either constitutive activity or chemokine regulation fail to develop KS-like disease. In addition, animals expressing a receptor that preserves chemokine binding and constitutive activity but that does not respond to agonist stimulation have a much lower incidence of angiogenic lesions and tumors. These results indicate that induction of the KS-like disease in transgenic mice by ORF74 requires not only high constitutive signaling activity but also modulation of this activity by endogenous chemokines.
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Affiliation(s)
- P J Holst
- Laboratory for Molecular Pharmacology, Department of Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
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37
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Shepard LW, Yang M, Xie P, Browning DD, Voyno-Yasenetskaya T, Kozasa T, Ye RD. Constitutive activation of NF-kappa B and secretion of interleukin-8 induced by the G protein-coupled receptor of Kaposi's sarcoma-associated herpesvirus involve G alpha(13) and RhoA. J Biol Chem 2001; 276:45979-87. [PMID: 11590141 DOI: 10.1074/jbc.m104783200] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The Kaposi's sarcoma herpesvirus (KSHV) open reading frame 74 encodes a G protein-coupled receptor (GPCR) for chemokines. Exogenous expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi's sarcoma. We show here that expression of KSHV-GPCR in transfected cells results in constitutive transactivation of nuclear factor kappa B (NF-kappa B) and secretion of interleukin-8, and this response involves activation of G alpha(13) and RhoA. The induced expression of a NF-kappa B luciferase reporter was partially reduced by pertussis toxin and the G beta gamma scavenger transducin, and enhanced by co-expression of G alpha(13) and to a lesser extent, G alpha(q). These results indicate coupling of KSHV-GPCR to multiple G proteins for NF-kappa B activation. Expression of KSHV-GPCR led to stress fiber formation in NIH 3T3 cells. To examine the involvement of the G alpha(13)-RhoA pathway in KSHV-GPCR-mediated NF-kappa B activation, HeLa cells were transfected with KSHV-GPCR alone and in combination with the regulator of G protein signaling (RGS) from p115RhoGEF or a dominant negative RhoA(T19N). Both constructs, as well as the C3 exoenzyme from Clostritium botulinum, partially reduced NF-kappa B activation by KSHV-GPCR, and by a constitutively active G alpha(13)(Q226L). KSHV-GPCR-induced NF-kappa B activation is accompanied by increased secretion of IL-8, a function mimicked by the activated G alpha(13) but not by an activated G alpha(q)(Q209L). These results suggest coupling of KSHV-GPCR to the G alpha(13)-RhoA pathway in addition to other G proteins.
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Affiliation(s)
- L W Shepard
- Department of Pharmacology, College of Medicine, University of Illinois, Chicago, Illinois 60612, USA
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38
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Couty JP, Geras-Raaka E, Weksler BB, Gershengorn MC. Kaposi's sarcoma-associated herpesvirus G protein-coupled receptor signals through multiple pathways in endothelial cells. J Biol Chem 2001; 276:33805-11. [PMID: 11448967 DOI: 10.1074/jbc.m104631200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV; human herpesvirus 8) encodes a chemokine-like G protein-coupled receptor (KSHV-GPCR) that is implicated in the pathogenesis of Kaposi's sarcoma (KS). Since endothelial cells appear to be targets for the virus, we developed an in vitro mouse lung endothelial cell model in which KSHV-GPCR is stably expressed and KSHV-GPCR signaling was studied. In mouse lung endothelial cells: 1) KSHV-GPCR does not exhibit basal signaling through the phosphoinositide-specific phospholipase C pathway but inositol phosphate production is stimulated by growth-related oncogene alpha (Gro-alpha) via a pertussis toxin (PTX)-insensitive pathway; 2) KSHV-GPCR signals basally through a PTX-sensitive pathway leading to a lowering of intracellular cAMP level that can be lowered further by Gro alpha and increased by interferon gamma-inducible protein 10; 3) KSHV-GPCR stimulates phosphatidylinositol 3-kinase via a PTX-insensitive mechanism; and 4) KSHV-GPCR activates nuclear factor-kappa B (NF-kappa B) by a PTX-sensitive G beta gamma subunit-mediated pathway. These data show that KSHV-GPCR couples to at least two G proteins and initiates signaling via at least three cascades in endothelial cells thereby increasing the complexity of regulation of endothelial cell function by KSHV-GPCR that may occur during viral infection.
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Affiliation(s)
- J P Couty
- Division of Molecular Medicine, Department of Medicine, Weill Medical College of Cornell University, New York, New York 10021, USA
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39
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Schwarz M, Murphy PM. Kaposi's sarcoma-associated herpesvirus G protein-coupled receptor constitutively activates NF-kappa B and induces proinflammatory cytokine and chemokine production via a C-terminal signaling determinant. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:505-13. [PMID: 11418689 DOI: 10.4049/jimmunol.167.1.505] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is believed to be the causative agent of Kaposi's sarcoma (KS), a multicentric growth factor-dependent tumor common in AIDS patients characterized histopathologically by spindle cell proliferation, angiogenesis, and leukocyte infiltration. Recently, open reading frame 74 of KSHV has been implicated as a major viral determinant of KS. Open reading frame 74 encodes KSHV G protein-coupled receptor (GPCR), a constitutively active chemokine receptor that directly transforms NIH 3T3 cells in vitro and induces multifocal KS-like lesions in KSHV-GPCR-transgenic mice. Interestingly, receptor-positive cells are very rare in lesions from these mice, implicating an indirect mechanism of tumorigenesis. In this regard, here we report that expression of KSHV-GPCR in transfected epithelial, monocytic, and T cell lines induced constitutive activation of the immunoregulatory transcription factors AP-1 and NF-kappaB. This was associated with constitutive induction of the proinflammatory NF-kappaB-dependent cytokines IL-1beta, IL-6, and TNF-alpha, and chemokines monocyte chemoattractant protein-1 and IL-8, as well as the AP-1-dependent basic fibroblast growth factor. In addition, IL-2 and IL-4 production was induced in transfected Jurkat T cells. Truncation of the final five amino acids in the cytoplasmic tail of KSHV-GPCR caused complete loss of its transforming and NF-kappaB-inducing activities, without affecting receptor expression or ligand binding. These data suggest that KS results in part from KSHV-GPCR induction of proinflammatory cytokine and growth factor gene expression, mediated by a signaling determinant within the last five amino acids of the C terminus, a domain that is also critical for direct cell transformation.
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Affiliation(s)
- M Schwarz
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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40
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Moore PS, Chang Y. Molecular virology of Kaposi's sarcoma-associated herpesvirus. Philos Trans R Soc Lond B Biol Sci 2001; 356:499-516. [PMID: 11313008 PMCID: PMC1088441 DOI: 10.1098/rstb.2000.0777] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), the most recently discovered human tumour virus, is the causative agent of Kaposi's sarcoma, primary effusion lymphoma and some forms of Castleman's disease. KSHV is a rhadinovirus, and like other rhadinoviruses, it has an extensive array of regulatory genes obtained from the host cell genome. These pirated KSHV proteins include homologues to cellular CD21, three different beta-chemokines, IL-6, BCL-2, several different interferon regulatory factor homologues, Fas-ligand ICE inhibitory protein (FLIP), cyclin D and a G-protein-coupled receptor, as well as DNA synthetic enzymes including thymidylate synthase, dihydrofolate reductase, DNA polymerase, thymidine kinase and ribonucleotide reductases. Despite marked differences between KSHV and Epstein-Barr virus, both viruses target many of the same cellular pathways, but use different strategies to achieve the same effects. KSHV proteins have been identified which inhibit cell-cycle regulation checkpoints, apoptosis control mechanisms and the immune response regulatory machinery. Inhibition of these cellular regulatory networks app ears to be a defensive means of allowing the virus to escape from innate antiviral immune responses. However, due to the overlapping nature of innate immune and tumour-suppressor pathways, inhibition of these regulatory networks can lead to unregulated cell proliferation and may contribute to virus-induced tumorigenesis.
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Affiliation(s)
- P S Moore
- School of Public Health and Department of Pathology, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, NY 10032, USA.
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41
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Lupu-Meiri M, Silver RB, Simons AH, Gershengorn MC, Oron Y. Constitutive signaling by Kaposi's sarcoma-associated herpesvirus G-protein-coupled receptor desensitizes calcium mobilization by other receptors. J Biol Chem 2001; 276:7122-8. [PMID: 11116138 DOI: 10.1074/jbc.m006359200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We coexpressed Kaposi's sarcoma-associated herpesvirus G protein-coupled receptors (KSHV-GPCRs) with thyrotropin-releasing hormone (TRH) receptors or m1-muscarinic-cholinergic receptors in Xenopus oocytes and in mammalian cells. In oocytes, KSHV-GPCR expression resulted in pronounced (81%) inhibition (heterologous desensitization) of Ca(2+)-activated chloride current responses to TRH and acetylcholine. Similar inhibitions of cytoplasmic free Ca(2+) responses to TRH were observed in human embryonic kidney HEK 293 EM cells and in mouse pituitary AtT20 cells. Further study of oocytes showed that this inhibition was partially reversed by interferon-gamma-inducible protein 10 (IP-10), an inverse agonist of KSHV-GPCR. The basal rate of (45)Ca(2+) efflux in oocytes expressing KSHV-GPCRs was 4.4 times greater than in control oocytes, and IP-10 rapidly inhibited increased (45)Ca(2+) efflux. In the absence of IP-10, growth-related oncogene alpha caused a further 2-fold increase in (45)Ca(2+) efflux. In KSHV-GPCR-expressing oocytes, responses to microinjected inositol 1,4,5-trisphosphate were inhibited by 74%, and this effect was partially reversed by interferon-gamma-inducible protein 10. Treatment with thapsigargin suggested that the pool of calcium available for mobilization by TRH was decreased in oocytes coexpressing KSHV-GPCRs. These results suggest that constitutive signaling by KSHV-GPCR causes heterologous desensitization of responses mediated by other receptors, which signal via the phosphoinositide/calcium pathway, which is caused by depletion of intracellular calcium pools.
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Affiliation(s)
- M Lupu-Meiri
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
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42
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Damania B, Jung JU. Comparative analysis of the transforming mechanisms of Epstein-Barr virus, Kaposi's sarcoma-associated herpesvirus, and Herpesvirus saimiri. Adv Cancer Res 2001; 80:51-82. [PMID: 11034540 DOI: 10.1016/s0065-230x(01)80012-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Members of the gamma herpesvirus family include the lymphocryptoviruses (gamma-1 herpesviruses) and the rhadinoviruses (gamma-2 herpesviruses). Gammaherpesvirinae uniformly establish long-term, latent, reactivatable infection of lymphocytes, and several members of the gamma herpesviruses are associated with lymphoproliferative diseases. Epstein-Barr virus is a lymphocryptovirus, whereas Kaposi sarcoma-associated herpesvirus and Herpesvirus saimiri are members of the rhadinovirus family. Genes encoded by these viruses are involved in a diverse array of cellular signaling pathways. This review attempts to cover our understanding of how viral proteins deregulate cellular signaling pathways that ultimately contribute to the conversion of normal cells to cancerous cells.
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Affiliation(s)
- B Damania
- Department of Microbiology and Molecular Genetics, New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772, USA
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43
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Khorana AA, Rosenblatt JD, Young FM. Immunopathogenesis of HIV and HTLV-1 infection: mechanisms for lymphomagenesis. Cancer Treat Res 2001; 104:19-74. [PMID: 11191127 DOI: 10.1007/978-1-4615-1601-9_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Affiliation(s)
- A A Khorana
- Cancer Center and Hematology-Oncology Unit, University of Rochester Medical Center, Rochester, New York, USA
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44
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Abstract
Here we present the first complete genomic sequence of Marek's disease virus serotype 3 (MDV3), also known as turkey herpesvirus (HVT). The 159,160-bp genome encodes an estimated 99 putative proteins and resembles alphaherpesviruses in genomic organization and gene content. HVT is very similar to MDV1 and MDV2 within the unique long (UL) and unique short (US) genomic regions, where homologous genes share a high degree of colinearity and their proteins share a high level of amino acid identity. Within the UL region, HVT contains 57 genes with homologues found in herpes simplex virus type 1 (HSV-1), six genes with homologues found only in MDV, and two genes (HVT068 and HVT070 genes) which are unique to HVT. The HVT US region is 2.2 kb shorter than that of MDV1 (Md5 strain) due to the absence of an MDV093 (SORF4) homologue and to differences at the UL/short repeat (RS) boundary. HVT lacks a homologue of MDV087, a protein encoded at the UL/RS boundary of MDV1 (Md5), and it contains two homologues of MDV096 (glycoprotein E) in the RS. HVT RS are 1,039 bp longer than those in MDV1, and with the exception of an ICP4 gene homologue, the gene content is different from that of MDV1. Six unique genes, including a homologue of the antiapoptotic gene Bcl-2, are found in the RS. This is the first reported Bcl-2 homologue in an alphaherpesvirus. HVT long repeats (RL) are 7,407 bp shorter than those in MDV1 and do not contain homologues of MDV1 genes with functions involving virulence, oncogenicity, and immune evasion. HVT lacks homologues of MDV1 oncoprotein MEQ, CxC chemokine, oncogenicity-associated phosphoprotein pp24, and conserved domains of phosphoprotein pp38. These significant genomic differences in and adjacent to RS and RL regions likely account for the differences in host range, virulence, and oncogenicity between nonpathogenic HVT and highly pathogenic MDV1.
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Affiliation(s)
- C L Afonso
- Plum Island Animal Disease Center, Agricultural Research Service, U. S. Department of Agriculture, Greenport, New York 11944, USA
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45
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Tulman ER, Afonso CL, Lu Z, Zsak L, Rock DL, Kutish GF. The genome of a very virulent Marek's disease virus. J Virol 2000; 74:7980-8. [PMID: 10933706 PMCID: PMC112329 DOI: 10.1128/jvi.74.17.7980-7988.2000] [Citation(s) in RCA: 207] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here we present the first complete genomic sequence, with analysis, of a very virulent strain of Marek's disease virus serotype 1 (MDV1), Md5. The genome is 177,874 bp and is predicted to encode 103 proteins. MDV1 is colinear with the prototypic alphaherpesvirus herpes simplex virus type 1 (HSV-1) within the unique long (UL) region, and it is most similar at the amino acid level to MDV2, herpesvirus of turkeys (HVT), and nonavian herpesviruses equine herpesviruses 1 and 4. MDV1 encodes 55 HSV-1 UL homologues together with 6 additional UL proteins that are absent in nonavian herpesviruses. The unique short (US) region is colinear with and has greater than 99% nucleotide identity to that of MDV1 strain GA; however, an extra nucleotide sequence at the Md5 US/short terminal repeat boundary results in a shorter US region and the presence of a second gene (encoding MDV097) similar to the SORF2 gene. MD5, like HVT, encodes an ICP4 homologue that contains a 900-amino-acid amino-terminal extension not found in other herpesviruses. Putative virulence and host range gene products include the oncoprotein MEQ, oncogenicity-associated phosphoproteins pp38 and pp24, a lipase homologue, a CxC chemokine, and unique proteins of unknown function MDV087 and MDV097 (SORF2 homologues) and MDV093 (SORF4). Consistent with its virulent phenotype, Md5 contains only two copies of the 132-bp repeat which has previously been associated with viral attenuation and loss of oncogenicity.
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Affiliation(s)
- E R Tulman
- Plum Island Animal Disease Center, Agricultural Research Service, U. S. Department of Agriculture, Greenport, New York 11944, USA
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46
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Hermouet S, Corre I, Lippert E. Interleukin-8 and other agonists of Gi2 proteins: autocrine paracrine growth factors for human hematopoietic progenitors acting in synergy with colony stimulating factors. Leuk Lymphoma 2000; 38:39-48. [PMID: 10811446 DOI: 10.3109/10428190009060317] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have reviewed the current knowledge on CXC chemokine interleukin-8 (IL-8) and human hematopoiesis, and more generally on agonists of heterotrimeric Gi2 proteins as regulators of human hematopoiesis. It appears that low doses of IL-8, a Gi2-agonist produced in an autocrine fashion by normal hematopoietic progenitors, mature blood cells and leukemic cells, promotes cell survival or/and proliferation in response to hematopoietic cytokines. More importantly, inactivation of the IL-8/Gi2 pathways inhibits CD34+ cell proliferation and colony formation. Similar positive effects on hematopoiesis of other, physiological or pathological, agonists of Gi2 proteins are discussed, as well as the molecular pathways involved and the consequences of activation of other G proteins (Gq, G16) by IL-8 and other Gi2-agonists.
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Affiliation(s)
- S Hermouet
- Laboratoire d'Hematologie and INSERM U463, Groupe Récepteurs et Cytokines, Institut de Biologie, Nantes, France.
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47
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Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is present in all epidemiologic forms of Kaposi's sarcoma (KS). The KSHV genome contains several open reading frames which are potentially implicated in the development of KS. Some are unique to KSHV; others are homologous to cellular genes. The putative role of these genes in the genesis of KS is discussed.
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Affiliation(s)
- H Gruffat
- Laboratoire de Virologie Humaine, U412 Inserm, ENS-Lyon, 46 allée d'Italie, 69364 cedex 07, Lyon, France
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48
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Rosenkilde MM, Schwartz TW. Potency of ligands correlates with affinity measured against agonist and inverse agonists but not against neutral ligand in constitutively active chemokine receptor. Mol Pharmacol 2000; 57:602-9. [PMID: 10692502 DOI: 10.1124/mol.57.3.602] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ORF-74, a 7TM receptor oncogene encoded by human herpes virus 8, shows 50% constitutive activity in stimulating phosphatidylinositol turnover and binds a large variety of CXC chemokines. These endogenous ligands cover a full spectrum of pharmacological properties with growth-related oncogene (GRO)-alpha and -gamma functioning as full agonists; GRObeta as a partial agonist; interleukin (IL)-8, neutrophil-activating peptide (NAP)-2, and epithelial cell-derived activating peptide (ENA)-78 as neutral ligands; granulocyte colony-stimulating factor (GCP)-2 as a partial inverse agonist; and interferon-gamma inducible protein (IP)-10 and stromal cell-derived factor (SDF)-1alpha as full inverse agonists. The affinity for the agonists was independent of whether it was determined in competition binding against the agonist (125)I-GROalpha, against the inverse agonist (125)I-IP-10, or against the neutral ligand (125)I-IL-8. Similarly, the affinities of the inverse agonists were within 1 order of magnitude independent of the choice of radioligand. In contrast, the neutral ligands IL-8, NAP-2, and ENA-78, which all displaced (125)I-IL-8 with single-digit nanomolar affinity showed up to 1000-fold lower affinity against both the radioactive agonist and against the radioactive inverse agonist. A close correlation was observed between the EC(50) values for the ligands and their IC(50) values measured against either radioactive agonist or radioactive inverse agonist, but a poor correlation was found to the IC(50) value measured against the neutral ligand. It is concluded that in ORF-74, ligands compete for binding more according to pharmacological property than to structural homology and that both agonists and inverse agonists, in contrast to neutral ligands, apparently bind with high affinity either to a common conformation of the receptor or to readily interconvertible states, not available for the neutral ligands.
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Affiliation(s)
- M M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Pharmacology, The Panum Institute, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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Yang TY, Chen SC, Leach MW, Manfra D, Homey B, Wiekowski M, Sullivan L, Jenh CH, Narula SK, Chensue SW, Lira SA. Transgenic expression of the chemokine receptor encoded by human herpesvirus 8 induces an angioproliferative disease resembling Kaposi's sarcoma. J Exp Med 2000; 191:445-54. [PMID: 10662790 PMCID: PMC2195818 DOI: 10.1084/jem.191.3.445] [Citation(s) in RCA: 333] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Human herpesvirus 8 (HHV8, also known as Kaposi's sarcoma [KS]-associated herpesvirus) has been implicated as an etiologic agent for KS, an angiogenic tumor composed of endothelial, inflammatory, and spindle cells. Here, we report that transgenic mice expressing the HHV8-encoded chemokine receptor (viral G protein-coupled receptor) within hematopoietic cells develop angioproliferative lesions in multiple organs that morphologically resemble KS lesions. These lesions are characterized by a spectrum of changes ranging from erythematous maculae to vascular tumors, by the presence of spindle and inflammatory cells, and by expression of vGPCR, CD34, and vascular endothelial growth factor. We conclude that vGPCR contributes to the development of the angioproliferative lesions observed in these mice and suggest that this chemokine receptor may play a role in the pathogenesis of KS in humans.
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MESH Headings
- Animals
- CD2 Antigens/genetics
- Cell Transformation, Neoplastic/genetics
- Cells, Cultured
- Disease Models, Animal
- Endothelial Growth Factors/metabolism
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Heart Neoplasms/pathology
- Hematopoietic Stem Cells/metabolism
- Herpesvirus 8, Human/genetics
- Lymphokines/metabolism
- Mice
- Mice, Transgenic
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/genetics
- Receptors, Growth Factor/metabolism
- Receptors, Vascular Endothelial Growth Factor
- Reverse Transcriptase Polymerase Chain Reaction
- Sarcoma, Kaposi/pathology
- Sarcoma, Kaposi/ultrastructure
- Sarcoma, Kaposi/virology
- Skin Neoplasms/pathology
- Tumor Virus Infections
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factors
- Viral Proteins/biosynthesis
- Viral Proteins/genetics
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Affiliation(s)
- Tong-Yuan Yang
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Shu-Cheng Chen
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Michael W. Leach
- From the Department of Drug Safety and Metabolism, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Denise Manfra
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Bernhard Homey
- Department of Immunology, DNAX Research Institute, Palo Alto, California 94304
| | - Maria Wiekowski
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Lee Sullivan
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Chung-Her Jenh
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Satwant K. Narula
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | - Stephen W. Chensue
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Sergio A. Lira
- From the Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey 07033
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50
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Camarda G, Spinetti G, Bernardini G, Mair C, Davis-Poynter N, Capogrossi MC, Napolitano M. The equine herpesvirus 2 E1 open reading frame encodes a functional chemokine receptor. J Virol 1999; 73:9843-8. [PMID: 10559296 PMCID: PMC113033 DOI: 10.1128/jvi.73.12.9843-9848.1999] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several herpesviruses contain open reading frames (ORFs) that encode potential homologs of eucaryotic genes. Equine herpesvirus 2 (EHV-2) is a gammaherpesvirus related to other lymphotropic herpesviruses such as herpesvirus saimiri and Epstein-Barr virus. The E1 ORF of EHV-2, a G protein-coupled receptor homolog, shows 31 to 47% amino acid identity with known CC chemokine receptors. To investigate whether E1 may encode a functional receptor, we cloned the E1 ORF and expressed it in stably transfected cell lines. We report here the identification of the CC chemokine eotaxin as a functional ligand for the EHV-2 E1 receptor. Chemokines are likely to play a role in the regulation of immune functions in equine hosts during EHV-2 infection and, via interaction with E1, may affect viral replication and/or escape from immune responses.
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Affiliation(s)
- G Camarda
- Laboratorio di Patologia Vascolare, Istituto Dermopatico dell'Immacolata-Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy
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