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Casper C, Corey L, Cohen JI, Damania B, Gershon AA, Kaslow DC, Krug LT, Martin J, Mbulaiteye SM, Mocarski ES, Moore PS, Ogembo JG, Phipps W, Whitby D, Wood C. KSHV (HHV8) vaccine: promises and potential pitfalls for a new anti-cancer vaccine. NPJ Vaccines 2022; 7:108. [PMID: 36127367 PMCID: PMC9488886 DOI: 10.1038/s41541-022-00535-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 09/02/2022] [Indexed: 01/25/2023] Open
Abstract
Seven viruses cause at least 15% of the total cancer burden. Viral cancers have been described as the "low-hanging fruit" that can be potentially prevented or treated by new vaccines that would alter the course of global human cancer. Kaposi sarcoma herpesvirus (KSHV or HHV8) is the sole cause of Kaposi sarcoma, which primarily afflicts resource-poor and socially marginalized populations. This review summarizes a recent NIH-sponsored workshop's findings on the epidemiology and biology of KSHV as an overlooked but potentially vaccine-preventable infection. The unique epidemiology of this virus provides opportunities to prevent its cancers if an effective, inexpensive, and well-tolerated vaccine can be developed and delivered.
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Affiliation(s)
- Corey Casper
- Infectious Disease Research Institute, 1616 Eastlake Ave. East, Suite 400, Seattle, WA, 98102, USA
| | - Lawrence Corey
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA, 98109, USA
| | - Jeffrey I Cohen
- Laboratory of Infectious Diseases, National Institutes of Health, Bldg. 50, Room 6134, 50 South Drive, MSC8007, Bethesda, MD, 20892-8007, USA
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center & Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, US
| | - Anne A Gershon
- Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, 630 West 168th Street, New York, NY10032, US
| | - David C Kaslow
- PATH Essential Medicines, PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, USA
| | - Laurie T Krug
- HIV and AIDS Malignancy Branch, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Jeffrey Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, NIH, HHS, 9609 Medical Center Dr, Rm. 6E118 MSC 3330, Bethesda, MD, 20892, USA
| | | | - Patrick S Moore
- Cancer Virology Program, Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
| | - Javier Gordon Ogembo
- Department of Immuno-Oncology, Beckman Research Institute of City of Hope, Duarte, CA, 91010, USA
| | - Warren Phipps
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center; Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Denise Whitby
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Charles Wood
- Department of Interdisciplinary Oncology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA
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Davis-Poynter N, Farrell HE. Constitutive Signaling by the Human Cytomegalovirus G Protein Coupled Receptor Homologs US28 and UL33 Enables Trophoblast Migration In Vitro. Viruses 2022; 14:v14020391. [PMID: 35215985 PMCID: PMC8879092 DOI: 10.3390/v14020391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/06/2022] [Accepted: 02/08/2022] [Indexed: 12/26/2022] Open
Abstract
Human cytomegalovirus (HCMV) encodes four homologs of G protein coupled receptors (vGPCRs), of which two, designated UL33 and US28, signal constitutively. UL33 and US28 are also conserved with chemokine receptors: US28 binds numerous chemokine classes, including the membrane bound chemokine, fractalkine; whereas UL33 remains an orphan receptor. There is emerging data that UL33 and US28 each contribute to HCMV associated disease, although no studies to date have reported their potential contribution to aberrant placental physiology that has been detected with HCMV congenital infection. We investigated the signaling repertoire of UL33 and US28 and their potential to enable trophoblast mobilization in vitro. Results demonstrate the constitutive activation of CREB by each vGPCR in ACIM-88 and HTR-8SVneo trophoblasts; constitutive NF-kB activation was detected for US28 only. Constitutive signaling by each vGPCR enabled trophoblast migration. For US28, fractalkine exhibited inverse agonist activity and dampened trophoblast migration. UL33 stimulated expression of both p38 mitogen activated (MAP) and Jun N-terminal (JNK) kinases; while p38 MAP kinase stimulated CREB, JNK was inhibitory, suggesting that UL33 dependent CREB activation was regulated by p38/JNK crosstalk. Given that chemokines and their receptors are important for placental development, these data point to the potential of HCMV UL33 and US28 to interfere with trophoblast responses which are important for normal placental development.
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Affiliation(s)
- Nicholas Davis-Poynter
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia 4072, Australia;
- Centre for Child Health Research, The University of Queensland, Brisbane 4000, Australia
| | - Helen E. Farrell
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia 4072, Australia;
- Centre for Child Health Research, The University of Queensland, Brisbane 4000, Australia
- Correspondence:
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Abstract
Herpesviruses infect virtually all humans and establish lifelong latency and reactivate to infect other humans. Latency requires multiple functions: maintaining the herpesvirus genome in the nuclei of cells; partitioning the viral genome to daughter cells in dividing cells; avoiding recognition by the immune system by limiting protein expression; producing noncoding viral RNAs (including microRNAs) to suppress lytic gene expression or regulate cellular protein expression that could otherwise eliminate virus-infected cells; modulating the epigenetic state of the viral genome to regulate viral gene expression; and reactivating to infect other hosts. Licensed antivirals inhibit virus replication, but do not affect latency. Understanding of the mechanisms of latency is leading to novel approaches to destroy latently infected cells or inhibit reactivation from latency.
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Fröhlich J, Grundhoff A. Epigenetic control in Kaposi sarcoma-associated herpesvirus infection and associated disease. Semin Immunopathol 2020; 42:143-157. [PMID: 32219477 PMCID: PMC7174275 DOI: 10.1007/s00281-020-00787-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/20/2020] [Indexed: 12/15/2022]
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) is the etiologic agent of several malignancies of endothelial and B-cell origin. The fact that latently infected tumor cells in these malignancies do not express classical viral oncogenes suggests that pathogenesis of KSHV-associated disease results from multistep processes that, in addition to constitutive viral gene expression, may require accumulation of cellular alterations. Heritable changes of the epigenome have emerged as an important co-factor that contributes to the pathogenesis of many non-viral cancers. Since KSHV encodes a number of factors that directly or indirectly manipulate host cell chromatin, it is an intriguing possibility that epigenetic reprogramming also contributes to the pathogenesis of KSHV-associated tumors. The fact that heritable histone modifications have also been shown to regulate viral gene expression programs in KSHV-infected tumor cells underlines the importance of epigenetic control during latency and tumorigenesis. We here review what is presently known about the role of epigenetic regulation of viral and host chromatin in KSHV infection and discuss how viral manipulation of these processes may contribute to the development of KSHV-associated disease.
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Affiliation(s)
- Jacqueline Fröhlich
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Adam Grundhoff
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany.
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He M, Cheng F, da Silva SR, Tan B, Sorel O, Gruffaz M, Li T, Gao SJ. Molecular Biology of KSHV in Relation to HIV/AIDS-Associated Oncogenesis. Cancer Treat Res 2019; 177:23-62. [PMID: 30523620 DOI: 10.1007/978-3-030-03502-0_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Discovered in 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) has been associated with four human malignancies including Kaposi's sarcoma, primary effusion lymphoma, a subset of multicentric Castleman's disease, and KSHV inflammatory cytokine syndrome. These malignancies mostly occur in immunocompromised patients including patients with acquired immunodeficiency syndrome and often cause significant mortality because of the lack of effective therapies. Significant progresses have been made to understand the molecular basis of KSHV infection and KSHV-induced oncogenesis in the last two decades. This chapter provides an update on the recent advancements focusing on the molecular events of KSHV primary infection, the mechanisms regulating KSHV life cycle, innate and adaptive immunity, mechanism of KSHV-induced tumorigenesis and inflammation, and metabolic reprogramming in KSHV infection and KSHV-transformed cells.
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Affiliation(s)
- Meilan He
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Fan Cheng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Suzane Ramos da Silva
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Brandon Tan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Océane Sorel
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Marion Gruffaz
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Tingting Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Shou-Jiang Gao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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Purushothaman P, Uppal T, Sarkar R, Verma SC. KSHV-Mediated Angiogenesis in Tumor Progression. Viruses 2016; 8:E198. [PMID: 27447661 PMCID: PMC4974533 DOI: 10.3390/v8070198] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/18/2016] [Accepted: 07/07/2016] [Indexed: 12/14/2022] Open
Abstract
Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), is a malignant human oncovirus belonging to the gamma herpesvirus family. HHV-8 is closely linked to the pathogenesis of Kaposi's sarcoma (KS) and two other B-cell lymphoproliferative diseases: primary effusion lymphoma (PEL) and a plasmablastic variant of multicentric Castleman's disease (MCD). KS is an invasive tumor of endothelial cells most commonly found in untreated HIV-AIDS or immuno-compromised individuals. KS tumors are highly vascularized and have abnormal, excessive neo-angiogenesis, inflammation, and proliferation of infected endothelial cells. KSHV directly induces angiogenesis in an autocrine and paracrine fashion through a complex interplay of various viral and cellular pro-angiogenic and inflammatory factors. KS is believed to originate due to a combination of KSHV's efficient strategies for evading host immune systems and several pro-angiogenic and pro-inflammatory stimuli. In addition, KSHV infection of endothelial cells produces a wide array of viral oncoproteins with transforming capabilities that regulate multiple host-signaling pathways involved in the activation of angiogenesis. It is likely that the cellular-signaling pathways of angiogenesis and lymph-angiogenesis modulate the rate of tumorigenesis induction by KSHV. This review summarizes the current knowledge on regulating KSHV-mediated angiogenesis by integrating the findings reported thus far on the roles of host and viral genes in oncogenesis, recent developments in cell-culture/animal-model systems, and various anti-angiogenic therapies for treating KSHV-related lymphoproliferative disorders.
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Affiliation(s)
- Pravinkumar Purushothaman
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Timsy Uppal
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Roni Sarkar
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Subhash C Verma
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
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Characterization of G protein coupling mediated by the conserved D134(3.49) of DRY motif, M241(6.34), and F251(6.44) residues on human CXCR1. FEBS Open Bio 2015; 5:182-90. [PMID: 25834784 PMCID: PMC4372616 DOI: 10.1016/j.fob.2015.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 01/01/2023] Open
Abstract
Mutations in the DRY motif of CXCR1 abolish ligand binding and receptor activation. Point mutations between TM6 and i3 loop result in constitutive activity of CXCR1. Constitutive activity of mutant CXCR1 occurs via Gα15 signaling activation. The highly conserved DRY motifs have distinct roles in CXCR1 and CXCR2.
CXCR1, a receptor for interleukin-8 (IL-8), plays an important role in defending against pathogen invasion during neutrophil-mediated innate immune response. Human CXCR1 is a G protein-coupled receptor (GPCR) with its characteristic seven transmembrane domains (TMs). Functional and structural analyses of several GPCRs have revealed that conserved residues on TM3 (including the highly conserved Asp-Arg-Tyr (DRY) motif) and TM6 near intracellular loops contain domains critical for G protein coupling as well as GPCR activation. The objective of this study was to elucidate the role of critical amino acid residues on TM3 near intracellular loop 2 (i2) and TM6 near intracellular loop 3 (i3), including S1323.47 (Baldwin location), D1343.49, M2416.34, and F2516.44, in G protein coupling and CXCR1 activation. The results demonstrate that mutations of D1343.49 at DRY motif of CXCR1 (D134N and D134V) completely abolished the ligand binding and functional response of the receptor. Additionally, point mutations at positions 241 and 251 between TM6 and i3 loop generated mutant receptors with modest constitutive activity via Gα15 signaling activation. Our results show that D1343.49 on the highly conserved DRY motif has a distinct role for CXCR1 compared to its homologues (CXCR2 and KSHV-GPCR) in G protein coupling and receptor activation. In addition, M2416.34 and F2516.44 along with our previously identified V2476.40 on TM6 are spatially located in a “hot spot” likely essential for CXCR1 activation. Identification of these amino acid residues may be useful for elucidating mechanism of CXCR1 activation and designing specific antagonists for the treatment of CXCR1-mediated diseases.
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Key Words
- CXCR1
- CXCR1, CXC receptor 1
- Chemokine receptor
- Constitutive activity
- DRY motif, Asp-Arg-Tyr motif
- G protein coupled receptor
- GPCR, G protein-coupled receptor
- Gα15
- Gαi
- IL-8, interleukin 8
- IP, inositol phosphate
- Kd, affinity constants
- PLC, phospholipase C
- PTX, pertussis toxin
- TMs, transmembrane domain
- WT, wild type
- i2, intracellular loop 2
- i3, intracellular loop 3
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8
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Cousins E, Nicholas J. Molecular biology of human herpesvirus 8: novel functions and virus-host interactions implicated in viral pathogenesis and replication. Recent Results Cancer Res 2014; 193:227-68. [PMID: 24008302 PMCID: PMC4124616 DOI: 10.1007/978-3-642-38965-8_13] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), is the second identified human gammaherpesvirus. Like its relative Epstein-Barr virus, HHV-8 is linked to B-cell tumors, specifically primary effusion lymphoma and multicentric Castleman's disease, in addition to endothelial-derived KS. HHV-8 is unusual in its possession of a plethora of "accessory" genes and encoded proteins in addition to the core, conserved herpesvirus and gammaherpesvirus genes that are necessary for basic biological functions of these viruses. The HHV-8 accessory proteins specify not only activities deducible from their cellular protein homologies but also novel, unsuspected activities that have revealed new mechanisms of virus-host interaction that serve virus replication or latency and may contribute to the development and progression of virus-associated neoplasia. These proteins include viral interleukin-6 (vIL-6), viral chemokines (vCCLs), viral G protein-coupled receptor (vGPCR), viral interferon regulatory factors (vIRFs), and viral antiapoptotic proteins homologous to FLICE (FADD-like IL-1β converting enzyme)-inhibitory protein (FLIP) and survivin. Other HHV-8 proteins, such as signaling membrane receptors encoded by open reading frames K1 and K15, also interact with host mechanisms in unique ways and have been implicated in viral pathogenesis. Additionally, a set of micro-RNAs encoded by HHV-8 appear to modulate expression of multiple host proteins to provide conditions conducive to virus persistence within the host and could also contribute to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus-host interactions and their potential roles in both virus biology and virus-associated disease.
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Affiliation(s)
- Emily Cousins
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 1650 Orleans Street, Baltimore, MD, 21287, USA,
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9
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Estep RD, Wong SW. Rhesus macaque rhadinovirus-associated disease. Curr Opin Virol 2013; 3:245-50. [PMID: 23747119 DOI: 10.1016/j.coviro.2013.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/01/2013] [Accepted: 05/14/2013] [Indexed: 11/18/2022]
Abstract
Rhesus macaque rhadinovirus (RRV) is a gamma-2 herpesvirus that naturally infects rhesus macaque (RM) monkeys and is closely related to human herpesvirus-8 (HHV-8)/Kaposi's sarcoma-associated herpesvirus (KSHV). Infection of immunodeficient RM induces disease in infected RM that resembles KSHV-associated pathologies. Importantly, RRV possesses homologues of KSHV ORFs that are postulated to play a role in disease development. As such, RRV has emerged as a prominent in vivo model system for examining mechanisms of infection and disease of these pathogenic herpesviruses, and has provided unique insight into how these viruses cause disease.
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Affiliation(s)
- Ryan D Estep
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006, United States
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10
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Dai L, Bai L, Lu Y, Xu Z, Reiss K, Del Valle L, Kaleeba J, Toole BP, Parsons C, Qin Z. Emmprin and KSHV: new partners in viral cancer pathogenesis. Cancer Lett 2013; 337:161-6. [PMID: 23743354 PMCID: PMC3728473 DOI: 10.1016/j.canlet.2013.05.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/24/2013] [Accepted: 05/27/2013] [Indexed: 01/15/2023]
Abstract
Emmprin regulates pathogenic elements relevant to virus-associated cancer, including drug resistance and cell migration. Kaposi's sarcoma-associated herpesvirus (KSHV) regulates emmprin expression and downstream function. Targeting emmprin or its interacting proteins at the cell surface suppresses KSHV-induced pathogenesis in vitro.
Emmprin (CD147; basigin) is a multifunctional glycoprotein expressed at higher levels by cancer cells and stromal cells in the tumor microenvironment. Through direct effects within tumor cells and promotion of tumor–stroma interactions, emmprin participates in induction of tumor cell invasiveness, angiogenesis, metastasis and chemoresistance. Although its contribution to cancer progression has been widely studied, the role of emmprin in viral oncogenesis still remains largely unclear, and only a small body of available literature implicates emmprin-associated mechanisms in viral pathogenesis and tumorigenesis. We summarize these data in this review, focusing on the role of emmprin in pathogenesis associated with the Kaposi sarcoma-associated herpesvirus (KSHV), a common etiology for cancers arising in the setting of immune suppression. We also discuss future directions for mechanistic studies exploring roles for emmprin in viral cancer pathogenesis.
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Affiliation(s)
- Lu Dai
- Research Center for Translational Medicine, East Hospital, Tongji University School of Medicine, Shanghai 200120, China
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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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12
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Lee HR, Brulois K, Wong L, Jung JU. Modulation of Immune System by Kaposi's Sarcoma-Associated Herpesvirus: Lessons from Viral Evasion Strategies. Front Microbiol 2012; 3:44. [PMID: 22403573 PMCID: PMC3293256 DOI: 10.3389/fmicb.2012.00044] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 01/27/2012] [Indexed: 12/14/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), a member of the herpesvirus family, has evolved to establish a long-term, latent infection of cells such that while they carry the viral genome gene expression is highly restricted. Latency is a state of cryptic viral infection associated with genomic persistence in their host and this hallmark of KSHV infection leads to several clinical-epidemiological diseases such as KS, a plasmablastic variant of multicentric Castleman's disease, and primary effusion lymphoma upon immune suppression of infected hosts. In order to sustain efficient life-long persistency as well as their life cycle, KSHV dedicates a large portion of its genome to encode immunomodulatory proteins that antagonize its host's immune system. In this review, we will describe our current knowledge of the immune evasion strategies employed by KSHV at distinct stages of its viral life cycle to control the host's immune system.
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Affiliation(s)
- Hye-Ra Lee
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California Los Angeles, CA, USA
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Abstract
G protein-coupled receptors (GPCRs) play important roles in inflammation. Inflammatory cells such as polymorphonuclear leukocytes (PMN), monocytes and macrophages express a large number of GPCRs for classic chemoattractants and chemokines. These receptors are critical to the migration of phagocytes and their accumulation at sites of inflammation, where these cells can exacerbate inflammation but also contribute to its resolution. Besides chemoattractant GPCRs, protease activated receptors (PARs) such as PAR1 are involved in the regulation of vascular endothelial permeability. Prostaglandin receptors play different roles in inflammatory cell activation, and can mediate both proinflammatory and anti-inflammatory functions. Many GPCRs present in inflammatory cells also mediate transcription factor activation, resulting in the synthesis and secretion of inflammatory factors and, in some cases, molecules that suppress inflammation. An understanding of the signaling paradigms of GPCRs in inflammatory cells is likely to facilitate translational research and development of improved anti-inflammatory therapies.
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Phosphorylation and polyubiquitination of transforming growth factor beta-activated kinase 1 are necessary for activation of NF-kappaB by the Kaposi's sarcoma-associated herpesvirus G protein-coupled receptor. J Virol 2010; 85:1980-93. [PMID: 21159881 DOI: 10.1128/jvi.01911-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) G protein-coupled receptor (vGPCR) protein has been shown to induce several signaling pathways leading to the modulation of host gene expression. The hijacking of these pathways facilitates the viral life cycle and leads to tumorigenesis. In the present work, we show that transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is an important player in NF-κB activation induced by vGPCR. We observed that the expression of an inactive TAK1 kinase mutant (TAK1M) reduces vGPCR-induced NF-κB nuclear translocation and transcriptional activity. Consequently, the expression of several NF-κB target genes normally induced by vGPCR was blocked by TAK1M expression, including interleukin 8 (IL-8), Gro1, IκBα, COX-2, cIAP2, and Bcl2 genes. Similar results were obtained after downregulation of TAK1 by small interfering RNA (siRNA) technology. The expression of vGPCR recruited TAK1 to the plasma membrane, and vGPCR interacts with TAK1. vGPCR expression also induced TAK1 phosphorylation and lysine 63-linked polyubiquitination, the two markers of the kinase's activation. Finally, inhibition of TAK1 by celastrol inhibited vGPCR-induced NF-κB activation, indicating this natural compound could be used as a potential therapeutic drug against KSHV malignancies involving vGPCR.
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15
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Histamine signalling in Schistosoma mansoni: Immunolocalisation and characterisation of a new histamine-responsive receptor (SmGPR-2). Int J Parasitol 2010; 40:1395-406. [DOI: 10.1016/j.ijpara.2010.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 04/01/2010] [Accepted: 04/05/2010] [Indexed: 11/24/2022]
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Van den Broeke C, Radu M, Chernoff J, Favoreel HW. An emerging role for p21-activated kinases (Paks) in viral infections. Trends Cell Biol 2010; 20:160-9. [PMID: 20071173 DOI: 10.1016/j.tcb.2009.12.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 12/14/2009] [Accepted: 12/14/2009] [Indexed: 01/28/2023]
Abstract
p21-activated protein kinases (Paks) are cytosolic serine/threonine protein kinases that act as effectors for small (p21) GTPases of the Cdc42 and Rac families. It has long been established that Paks play a major role in a host of vital cellular functions such as proliferation, survival and motility, and abnormal Pak function is associated with a number of human diseases. Here, we discuss emerging evidence that these enzymes also play a major role in the entry, replication and spread of many important pathogenic human viruses, including HIV. Careful assessment of the potential role of Paks in antiviral immunity will be pivotal to evaluate thoroughly the potential of agents that inhibit Pak as a new class of anti-viral therapeutics.
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Affiliation(s)
- Celine Van den Broeke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Emuss V, Lagos D, Pizzey A, Gratrix F, Henderson SR, Boshoff C. KSHV manipulates Notch signaling by DLL4 and JAG1 to alter cell cycle genes in lymphatic endothelia. PLoS Pathog 2009; 5:e1000616. [PMID: 19816565 PMCID: PMC2751827 DOI: 10.1371/journal.ppat.1000616] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 09/11/2009] [Indexed: 12/14/2022] Open
Abstract
Increased expression of Notch signaling pathway components is observed in Kaposi sarcoma (KS) but the mechanism underlying the manipulation of the canonical Notch pathway by the causative agent of KS, Kaposi sarcoma herpesvirus (KSHV), has not been fully elucidated. Here, we describe the mechanism through which KSHV directly modulates the expression of the Notch ligands JAG1 and DLL4 in lymphatic endothelial cells. Expression of KSHV-encoded vFLIP induces JAG1 through an NFkappaB-dependent mechanism, while vGPCR upregulates DLL4 through a mechanism dependent on ERK. Both vFLIP and vGPCR instigate functional Notch signalling through NOTCH4. Gene expression profiling showed that JAG1- or DLL4-stimulated signaling results in the suppression of genes associated with the cell cycle in adjacent lymphatic endothelial cells, indicating a role for Notch signaling in inducing cellular quiescence in these cells. Upregulation of JAG1 and DLL4 by KSHV could therefore alter the expression of cell cycle components in neighbouring uninfected cells during latent and lytic phases of viral infection, influencing cellular quiescence and plasticity. In addition, differences in signaling potency between these ligands suggest a possible complementary role for JAG1 and DLL4 in the context of KS.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Calcium-Binding Proteins/physiology
- Cell Cycle/genetics
- Cell Cycle/physiology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/physiology
- Endothelium, Vascular/virology
- Gene Expression Regulation, Viral
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/physiology
- Humans
- Intercellular Signaling Peptides and Proteins/physiology
- Jagged-1 Protein
- Lymphatic System/cytology
- Lymphatic System/physiology
- Lymphatic System/virology
- Membrane Proteins/physiology
- Oligonucleotide Array Sequence Analysis
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/physiology
- RNA, Messenger/genetics
- Receptor, Notch4
- Receptors, Notch/genetics
- Receptors, Notch/physiology
- Sarcoma, Kaposi/genetics
- Sarcoma, Kaposi/virology
- Serrate-Jagged Proteins
- Signal Transduction
- Up-Regulation
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Affiliation(s)
- Victoria Emuss
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, University College London, London, United Kingdom
| | - Dimitrios Lagos
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, University College London, London, United Kingdom
| | - Arnold Pizzey
- Research Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
| | - Fiona Gratrix
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, University College London, London, United Kingdom
| | - Stephen R. Henderson
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, University College London, London, United Kingdom
| | - Chris Boshoff
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, University College London, London, United Kingdom
- * E-mail:
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18
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Kaposi sarcoma-associated herpes virus (KSHV) G protein-coupled receptor (vGPCR) activates the ORF50 lytic switch promoter: a potential positive feedback loop for sustained ORF50 gene expression. Virology 2009; 392:34-51. [PMID: 19640558 DOI: 10.1016/j.virol.2009.07.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/15/2009] [Accepted: 07/03/2009] [Indexed: 11/23/2022]
Abstract
KSHV vGPCR, a lytic cycle associated protein, induces several signaling pathways leading to the activation of various transcription factors and consequently the expression of cellular and viral genes. Though the role of vGPCR in KSHV tumorigenicity has been well studied, its function related to the viral life cycle is poorly understood. Reduction in vGPCR by RNA interference also resulted in the reduction in KSHV lytic switch ORF50 gene and protein expression. Induction of vGPCR by doxycycline in BC3.14 cells also resulted in more KSHV production. When this was explored, induction of the ORF50 promoter by vGPCR expression was observed. Further examination of the molecular mechanisms by which vGPCR regulates the ORF50 promoter, using various ORF50 promoter constructs, revealed that induction of ORF50 promoter by vGPCR did not involve AP1 but was dependent on Sp1 and Sp3 transcription factors. vGPCR signaling led to an increase in Sp1 and Sp3 DNA binding activity and a decrease in histone deacetylase (HDAC) activity. These activities were pertussis toxin independent, did not involve Rho and Rac-GTPases and involved the heterotrimeric G protein subunits Galpha12 and Galphaq. Studies using pharmacologic inhibitors and dominant-negative proteins identified phospholipase C, the novel protein kinase C (novel PKC) family and protein kinase D (PKD) as part of the signaling initiated by vGPCR leading to ORF50 promoter activation. Taken together, this study suggests a role for vGPCR in the sustained expression of ORF50 which could lead to a continued activation of lytic cycle genes and ultimately to successful viral progeny formation.
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Lagos D, Vart RJ, Gratrix F, Westrop SJ, Emuss V, Wong PP, Robey R, Imami N, Bower M, Gotch F, Boshoff C. Toll-like receptor 4 mediates innate immunity to Kaposi sarcoma herpesvirus. Cell Host Microbe 2008; 4:470-83. [PMID: 18996347 PMCID: PMC2698447 DOI: 10.1016/j.chom.2008.09.012] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 07/28/2008] [Accepted: 09/16/2008] [Indexed: 02/06/2023]
Abstract
The involvement of Toll-like receptor 4 (TLR4) in immunity against human herpesviruses has not been previously demonstrated. We show that infection of endothelial cells with Kaposi sarcoma herpesvirus (KSHV), a human oncogenic virus, leads to rapid suppression of TLR4 expression. This is a mechanism of immune escape as TLR4 mediates innate immunity against KSHV. In vitro, cells lacking TLR4 are more susceptible to KSHV infection, whereas activation of TLR4 protects cells from infection. In vivo, HIV-1-infected individuals carrying a mutant TLR4 allele appear more likely to have multicentric Castleman's disease, a lymphoproliferation associated with enhanced KSHV replication. ERK activation by KSHV structural proteins and the KSHV-encoded vGPCR plays a key role in the TLR4 downregulation, whereas the KSHV vIRF1 also contributes to this effect. Our findings reveal a role for TLR4 in innate immunity against herpesviruses and suggest the potential use of TLR4 agonists for the treatment of KSHV-related neoplasms.
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Affiliation(s)
- Dimitrios Lagos
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
- Correspondence: (D.L.), (C.B.)
| | - Richard James Vart
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
| | - Fiona Gratrix
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
| | - Samantha Jane Westrop
- Department of Immunology Chelsea and Westminster Hospital, Imperial College London, London SW10 9NH, UK
| | - Victoria Emuss
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
| | - Ping-Pui Wong
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
| | - Rebecca Robey
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
- Department of Immunology Chelsea and Westminster Hospital, Imperial College London, London SW10 9NH, UK
| | - Nesrina Imami
- Department of Immunology Chelsea and Westminster Hospital, Imperial College London, London SW10 9NH, UK
| | - Mark Bower
- Imperial College School of Medicine Chelsea and Westminster Hospital, Imperial College London, London SW10 9NH, UK
| | - Frances Gotch
- Department of Immunology Chelsea and Westminster Hospital, Imperial College London, London SW10 9NH, UK
| | - Chris Boshoff
- Cancer Research UK Viral Oncology Group, UCL Cancer Institute, Paul O'Gorman Building, Huntley Street, University College London, London WC1E 6BT, UK
- Correspondence: (D.L.), (C.B.)
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