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Miller WE, O'Connor CM. CMV-encoded GPCRs in infection, disease, and pathogenesis. Adv Virus Res 2024; 118:1-75. [PMID: 38461029 DOI: 10.1016/bs.aivir.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
G protein coupled receptors (GPCRs) are seven-transmembrane domain proteins that modulate cellular processes in response to external stimuli. These receptors represent the largest family of membrane proteins, and in mammals, their signaling regulates important physiological functions, such as vision, taste, and olfaction. Many organisms, including yeast, slime molds, and viruses encode GPCRs. Cytomegaloviruses (CMVs) are large, betaherpesviruses, that encode viral GPCRs (vGPCRs). Human CMV (HCMV) encodes four vGPCRs, including UL33, UL78, US27, and US28. Each of these vGPCRs, as well as their rodent and primate orthologues, have been investigated for their contributions to viral infection and disease. Herein, we discuss how the CMV vGPCRs function during lytic and latent infection, as well as our understanding of how they impact viral pathogenesis.
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Affiliation(s)
- William E Miller
- Department of Molecular and Cellular Bioscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christine M O'Connor
- Infection Biology, Sheikha Fatima bint Mubarak Global Center for Pathogen and Human Health Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States; Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH, United States; Case Comprehensive Cancer Center, Cleveland, OH, United States.
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2
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Bonavita CM, White TM, Francis J, Farrell HE, Davis-Poynter NJ, Cardin RD. The Viral G-Protein-Coupled Receptor Homologs M33 and US28 Promote Cardiac Dysfunction during Murine Cytomegalovirus Infection. Viruses 2023; 15:711. [PMID: 36992420 PMCID: PMC10054303 DOI: 10.3390/v15030711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world population and causes lifelong latent infection. HCMV has been shown to exacerbate cardiovascular diseases, including myocarditis, vascular sclerosis, and transplant vasculopathy. Recently, we have shown that murine CMV (MCMV) recapitulates the cardiovascular dysfunction observed in patients with HCMV-induced myocarditis. To understand the viral mechanisms involved in CMV-induced heart dysfunction, we further characterized cardiac function in response to MCMV and examined virally encoded G-protein-coupled receptor homologs (vGPCRs) US28 and M33 as potential factors that promote infection in the heart. We hypothesized that the CMV-encoded vGPCRs could exacerbate cardiovascular damage and dysfunction. Three viruses were used to evaluate the role of vGPCRs in cardiac dysfunction: wild-type MCMV, a M33-deficient virus (∆M33), and a virus with the M33 open reading frame (ORF) replaced with US28, an HCMV vGPCR (i.e., US28+). Our in vivo studies revealed that M33 plays a role in promoting cardiac dysfunction by increasing viral load and heart rate during acute infection. During latency, ΔM33-infected mice demonstrated reduced calcification, altered cellular gene expression, and less cardiac hypertrophy compared with wild-type MCMV-infected mice. Ex vivo viral reactivation from hearts was less efficient in ΔM33-infected animals. HCMV protein US28 expression restored the ability of the M33-deficient virus to reactivate from the heart. US28+ MCMV infection caused damage to the heart comparable with wild-type MCMV infection, suggesting that the US28 protein is sufficient to complement the function of M33 in the heart. Altogether, these data suggest a role for vGPCRs in viral pathogenesis in the heart and thus suggest that vGPCRs promote long-term cardiac damage and dysfunction.
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Affiliation(s)
- Cassandra M. Bonavita
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Timothy M. White
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Joseph Francis
- Department of Comparative Biological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Helen E. Farrell
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane 4072, Australia
| | | | - Rhonda D. Cardin
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, 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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The mouse cytomegalovirus G protein-coupled receptor homolog, M33, coordinates key features of in vivo infection via distinct components of its signalling repertoire. J Virol 2021; 96:e0186721. [PMID: 34878888 DOI: 10.1128/jvi.01867-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Common to all cytomegalovirus (CMV) genomes analysed to date is the presence of G protein-coupled receptors (GPCR). Animal models of CMV provide insights into their role in viral fitness. The mouse cytomegalovirus (MCMV) GPCR, M33, facilitates dendritic cell (DC)-dependent viremia, the extravasation of blood-borne infected DC to the salivary gland and the frequency of reactivation events from latently-infected tissue explants. Constitutive G protein-coupled M33 signalling is required for these phenotypes, although the contribution of distinct biochemical pathways activated by M33 is unknown. M33 engages Gq/11 to constitutively activate phospholipase C β (PLCβ) and downstream cyclic AMP response-element binding protein (CREB) in vitro. Identification of a MCMV M33 mutant (M33ΔC38) for which CREB signalling was disabled, but PLCβ activation was preserved, provided the opportunity to investigate their relevance in vivo. Following intranasal infection with MCMV M33ΔC38, the absence of M33 CREB Gq/11-dependent signalling correlated with reduced mobilisation of lytically-infected DC to draining lymph node high endothelial venules (HEVs) and reduced viremia compared with wild type MCMV. In contrast, M33ΔC38-infected DC within the vascular compartment extravasated to the salivary glands via a pertussis toxin-sensitive, Gi/o-dependent and CREB-independent mechanism. In the context of MCMV latency, spleen explants from M33ΔC38-infected mice were markedly attenuated for reactivation. Taken together, these data demonstrate that key features of the MCMV lifecycle are coordinated in diverse tissues by distinct pathways of the M33 signalling repertoire. IMPORTANCE G protein-coupled receptors (GPCRs) act as cell surface molecular "switches" which regulate the cellular response to environmental stimuli. All cytomegalovirus (CMV) genomes analysed to date possess GPCR homologs with phylogenetic evidence for independent gene capture events, signifying important in vivo roles. The mouse CMV (MCMV) GPCR homolog, designated M33, is important for cell-associated virus spread and for the establishment and/or reactivation of latent MCMV infection. The signalling repertoire of M33 is distinct from cellular GPCRs and little is known of the relevance of component signalling pathways for in vivo M33 function. In this report, we show temporal and tissue-specific M33 signalling is required facilitating in vivo infection. Understanding the relevance of the viral GPCR signalling profiles for in vivo function will provide opportunities for future targeted interventions.
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Characterization of murine cytomegalovirus infection and induction of calcification in Murine Aortic Vascular Smooth Muscle Cells (MOVAS). J Virol Methods 2021; 297:114270. [PMID: 34461152 DOI: 10.1016/j.jviromet.2021.114270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 02/06/2023]
Abstract
Human cytomegalovirus (HCMV) is a widespread pathogen that causes lifelong latent infection in the majority of the world population. HCMV is associated with increased incidence and severity of many cardiovascular diseases including myocarditis, atherosclerosis, and transplant vasculopathy. Due to the species-restricted nature of cytomegalovirus infection, murine cytomegalovirus (MCMV) is a useful model that recapitulates many of the features of HCMV infection of the cardiovascular system. While in vivo MCMV studies are able to answer many questions regarding pathogenesis of infection, in vitro experiments using cell lines are useful tools to further understand the potential underlying mechanisms. In this study, we characterize MCMV infection of the murine aortic smooth muscle cell line (MOVAS). Our findings demonstrate that MOVAS cells are permissive for MCMV infection, form plaques under carboxymethyl cellulose overlay, and produce progeny virus similar to NIH 3T3 murine embryonic fibroblasts. In addition, MCMV infection induces calcification in MOVAS cells similar to that seen in the epicardium of MCMV-infected hearts. We conclude that MOVAS cells are a useful in vitro tool for studying CMV-mediated cardiac calcification.
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Fritz NM, Stamminger T, Ramsperger-Gleixner M, Kuckhahn AV, Müller R, Weyand M, Heim C. Cytomegalovirus chemokine receptor M33 knockout reduces chronic allograft rejection in a murine aortic transplant model. Transpl Immunol 2020; 64:101359. [PMID: 33301898 DOI: 10.1016/j.trim.2020.101359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 01/02/2023]
Abstract
BACKGROUND Numerous studies suggest that cytomegalovirus (CMV) infection may act as isolated risk factor in the development of cardiac allograft vasculopathy (CAV). Viral G protein-coupled receptors (GPCRs) are thought to contribute to the pathogenic changes associated with CMV infection. The aim of this study was to investigate the role of murine cytomegalovirus GPCR M33 in the development of CAV in a murine aortic allograft model. METHODS MHC I-mismatched aortas of C.B10 (H2b) mice were transplanted into BALB/c (H2d) recipients, which were either mock-infected, infected with wild type (WT) MCMV or MCMV with a deleted M33-receptor gene (delM33). Persistence of cytomegalovirus infection was confirmed by qPCR and by luciferase assay to ensure active viral replication. Grafts were harvested on days 21 and 37 for intragraft mRNA expression and histological analysis. RESULTS Active viral replication was demonstrated and MCMV presence was confirmed by PCR within spleen, liver, salivary glands, lung and the aortic transplant. Infection with delM33 resulted in significantly less intimal proliferation compared to WT-MCMV but more pronounced proliferation than in mock-infected allografts (32.19% [delM33] vs. 41.71% [WT-MCMV] vs. 24.33% [MCMV-]). Intragraft expression of most analyzed genes was significantly increased in infected mice. VCAM-1, ICAM-1, PDGFβ, CXCR3 and Granzyme B were distinctly less expressed in grafts of delM33 infected compared to WT infected mice. Cellular infiltration revealed reduced dendritic cells and T cells in grafts infected with delM33 compared to WT MCMV. CONCLUSIONS These data suggest that the MCMV encoded receptor M33 plays an important role as a viral effector mechanism contributing to the development of CAV in a murine aortic transplant model.
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Affiliation(s)
- Niklas M Fritz
- Department of Cardiac Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Krankenhausstraße 12, 91054 Erlangen, Germany
| | - Thomas Stamminger
- Institute for Virology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Martina Ramsperger-Gleixner
- Department of Cardiac Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Krankenhausstraße 12, 91054 Erlangen, Germany
| | - Annika V Kuckhahn
- Department of Cardiac Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Krankenhausstraße 12, 91054 Erlangen, Germany
| | - Regina Müller
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University Erlangen-Nürnberg, Schlossgarten 4, 91054 Erlangen, Germany
| | - Michael Weyand
- Department of Cardiac Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Krankenhausstraße 12, 91054 Erlangen, Germany
| | - Christian Heim
- Department of Cardiac Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Krankenhausstraße 12, 91054 Erlangen, Germany.
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Jones IKA, Haese NN, Gatault P, Streblow ZJ, Andoh TF, Denton M, Streblow CE, Bonin K, Kreklywich CN, Burg JM, Orloff SL, Streblow DN. Rat Cytomegalovirus Virion-Associated Proteins R131 and R129 Are Necessary for Infection of Macrophages and Dendritic Cells. Pathogens 2020; 9:E963. [PMID: 33228102 PMCID: PMC7699341 DOI: 10.3390/pathogens9110963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/05/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
Cytomegalovirus (CMV) establishes persistent, latent infection in hosts, causing diseases in immunocompromised patients, transplant recipients, and neonates. CMV infection modifies the host chemokine axis by modulating chemokine and chemokine receptor expression and by encoding putative chemokine and chemokine receptor homologues. The viral proteins have roles in cellular signaling, migration, and transformation, as well as viral dissemination, tropism, latency and reactivation. Herein, we review the contribution of CMV-encoded chemokines and chemokine receptors to these processes, and further elucidate the viral tropism role of rat CMV (RCMV) R129 and R131. These homologues of the human CMV (HCMV)-encoded chemokines UL128 and UL130 are of particular interest because of their dual role as chemokines and members of the pentameric entry complex, which is required for entry into cell types that are essential for viral transmission and dissemination. The contributions of UL128 and UL130 to acceleration of solid organ transplant chronic rejection are poorly understood, and are in need of an effective in vivo model system to elucidate the phenomenon. We demonstrated similar molecular entry requirements for R129 and R131 in the rat cells, as observed for HCMV, and provided evidence that R129 and R131 are part of the viral entry complex required for entry into macrophages, dendritic cells, and bone marrow cells.
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Affiliation(s)
- Iris K. A. Jones
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Nicole N. Haese
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Philippe Gatault
- Renal Transplant Unit, 10 Boulevard Tonnellé, University Hospital of Tours, 37032 Tours, France;
| | - Zachary J. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Takeshi F. Andoh
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
| | - Michael Denton
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Cassilyn E. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Kiley Bonin
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Craig N. Kreklywich
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
| | - Jennifer M. Burg
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
| | - Susan L. Orloff
- Department of Surgery, Oregon Health & Science University, Portland, OR 97239, USA; (J.M.B.); (S.L.O.)
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Daniel N. Streblow
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA; (I.K.A.J.); (N.N.H.); (Z.J.S.); (T.F.A.); (M.D.); (C.E.S.); (K.B.); (C.N.K.)
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Roles of GP33, a guinea pig cytomegalovirus-encoded G protein-coupled receptor homolog, in cellular signaling, viral growth and inflammation in vitro and in vivo. PLoS Pathog 2018; 14:e1007487. [PMID: 30571759 PMCID: PMC6319746 DOI: 10.1371/journal.ppat.1007487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 01/04/2019] [Accepted: 11/27/2018] [Indexed: 11/23/2022] Open
Abstract
Cytomegaloviruses (CMVs) encode cellular homologs to evade host immune functions. In this study, we analyzed the roles of GP33, a guinea pig CMV (GPCMV)-encoded G protein-coupled receptor (GPCR) homolog, in cellular signaling, viral growth and pathogenesis. The cDNA structure of GP33 was determined by RACE. The effects of GP33 on some signaling pathways were analyzed in transient transfection assays. The redET two-step recombination system for a BAC containing the GPCMV genome was used to construct a mutant GPCMV containing an early stop codon in the GP33 gene (Δ33) and a rescued GPCMV (r33). We found the following: 1) GP33 activated the CRE- and NFAT-, but not the NFκB-mediated signaling pathway. 2) GP33 was dispensable for infection in tissue cultures and in normal animals. 3) In pregnant animals, viral loads of r33 in the livers, lungs, spleens, and placentas at 6 days post-infection were higher than those of Δ33, although the viruses were cleared by 3 weeks post-infection. 4) The presence of GP33 was associated with frequent lesions, including alveolar hemorrhage in the lungs, and inflammation in the lungs, livers, and spleens of the dams. Our findings suggest that GP33 has critical roles in the pathogenesis of GPCMV during pregnancy. We hypothesize that GP33-mediated signaling activates cytokine secretion from the infected cells, which results in inflammation in some of the maternal organs and the placentas. Alternatively, GP33 may facilitate transient inflammation that is induced by the chemokine network specific to the pregnancy. Cytomegalovirus (CMV) is a major pathogen that causes congenital diseases, including birth defects and developmental abnormalities in newborns. Better understanding of the immune evasion mechanisms may open the way to the development of new types of live attenuated vaccines for congenital CMV infection. In contrast to murine and rat CMVs, guinea pig CMV (GPCMV) causes infection in utero, which makes GPCMV animal models a useful tool for understanding the pathogenesis of congenital infection and evaluation of vaccine strategies. By constructing a GPCMV mutant lacking GP33, a viral G protein-coupled receptor homolog, this study found that GP33 was involved in the induction of significant inflammatory responses in pregnant but not in normal animals. As GP33 activated the NFAT- and CRE-, but not the NFκB-signal pathway, it is plausible that GP33 enhanced cytokine expression, which results in pathogenic outcomes in the maternal organs and placentas.
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Current Perspectives on Cytomegalovirus in Heart Transplantation. CURRENT TRANSPLANTATION REPORTS 2016. [DOI: 10.1007/s40472-016-0121-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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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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The M33 G protein-coupled receptor encoded by murine cytomegalovirus is dispensable for hematogenous dissemination but is required for growth within the salivary gland. J Virol 2014; 88:11811-24. [PMID: 25100846 DOI: 10.1128/jvi.01006-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a pathogen found worldwide and is a serious threat to immunocompromised individuals and developing fetuses. Due to the species specificity of cytomegaloviruses, murine cytomegalovirus (MCMV) has been used as a model for in vivo studies of HCMV pathogenesis. The MCMV genome, like the genomes of other beta- and gammaherpesviruses, encodes G protein-coupled receptors (GPCRs) that modulate host signaling pathways presumably to facilitate viral replication and dissemination. Among these viral receptors, the M33 GPCR carried by MCMV is an activator of CREB, NF-κB, and phospholipase C-β signaling pathways and has been implicated in aspects of pathogenesis in vivo, including persistence in the salivary glands of BALB/c mice. In this study, we used immunocompetent nonobese diabetic (NOD) and immunocompromised NOD-scid-gamma (NSG) mice to further investigate the salivary gland defect exhibited by M33 deficiency. Interestingly, we demonstrate that virus with an M33 deletion (ΔM33) can replicate in the salivary gland of immunocompromised animals, albeit with a 400-fold growth defect compared with the growth of wild-type virus. Moreover, we determined that M33 does not have a role in cell-associated hematogenous dissemination but is required for viral amplification once the virus reaches the salivary gland. We conclude that the reduced replicative capacity of the ΔM33 virus is due to a specific defect occurring within the localized environment of the salivary gland. Importantly, since the salivary gland represents a site essential for persistence and horizontal transmission, an understanding of the mechanisms of viral replication within this site could lead to the generation of novel therapeutics useful for the prevention of HCMV spread. Importance: Human cytomegalovirus infects the majority of the American people and can reside silently in infected individuals for the duration of their lives. Under a number of circumstances, the virus can reactivate, leading to a variety of diseases in both adults and developing babies, and therefore, identifying the function of viral proteins is essential to understand how the virus spreads and causes disease. We aim to utilize animal models to study the function of an important class of viral proteins termed G protein-coupled receptors with the ultimate goal of developing inhibitors to these proteins that could one day be used to prevent viral spread.
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Vischer HF, Siderius M, Leurs R, Smit MJ. Herpesvirus-encoded GPCRs: neglected players in inflammatory and proliferative diseases? Nat Rev Drug Discov 2014; 13:123-39. [DOI: 10.1038/nrd4189] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Abstract
Although human cytomegalovirus (HCMV) primary infection is generally asymptomatic, in immune-compromised patients HCMV increases morbidity and mortality. As a member of the betaherpesvirus family, in vivo studies of HCMV are limited due to its species specificity. CMVs from other species are often used as surrogates to express HCMV genes/proteins or used as models for inferring HCMV protein function in humans. Using innovative experiments, these animal models have answered important questions about CMV's life cycle, dissemination, pathogenesis, immune evasion, and host immune response. This chapter provides CMV biologists with an overview of the insights gained using these animal models. Subsequent chapters will provide details of the specifics of the experimental methods developed for each of the animal models discussed here.
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Affiliation(s)
- Pranay Dogra
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
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14
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Shimamura M. The contribution of cytomegalovirus to atherosclerotic events after kidney transplantation. J Infect Dis 2013; 207:1487-90. [PMID: 23417660 DOI: 10.1093/infdis/jit065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Engel P, Angulo A. Viral Immunomodulatory Proteins: Usurping Host Genes as a Survival Strategy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 738:256-76. [DOI: 10.1007/978-1-4614-1680-7_15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
Nearly all human beings, by the time they reach adolescence, are infected with multiple herpesviruses. At any given time, this family of viruses accounts for 35-40 billion human infections worldwide, making herpesviruses among the most prevalent pathogens known to exist. Compared to most other viruses, herpesviruses are also unique in that infection lasts the life of the host. Remarkably, despite their prevalence and persistence, little is known about how these viruses interact with their hosts, especially during the clinically asymptomatic phase of infection referred to as latency. This review explores data in human and animal systems that reveal the ability of latent herpesviruses to modulate the immune response to self and environmental antigens. From the perspective of the host, there are both potentially detrimental and surprisingly beneficial effects of this lifelong interaction. The realization that latent herpesvirus infection modulates immune responses in asymptomatic hosts forces us to reconsider what constitutes a 'normal' immune system in a healthy individual.
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Affiliation(s)
- Douglas W. White
- Division of Rheumatology, Gundersen Lutheran Medical Center, La Crosse, WI, USA
| | - R. Suzanne Beard
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Department of Microbiology & Immunology, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Erik S. Barton
- Department of Microbiology & Immunology, Wake Forest University School of Medicine, Winston-Salem NC, USA
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Gombos RB, Hemmings DG. Differential effects on nitric oxide-mediated vasodilation in mesenteric and uterine arteries from cytomegalovirus-infected mice. Am J Physiol Heart Circ Physiol 2010; 299:H1124-34. [DOI: 10.1152/ajpheart.01113.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chronic cytomegalovirus (CMV) infections are implicated in vascular diseases. Recently, we showed that an active mouse CMV (mCMV) infection in nonpregnant mice increased endothelial-dependent vasodilation in isolated mesenteric and uterine arteries. In late pregnancy, while increased vasodilation was found in mesenteric arteries from infected mice, there was a dramatic decrease in uterine arteries. Understanding the mechanisms for these vascular changes during CMV infections is important for pregnancy outcomes and long-term consequences of this chronic infection. Increased nitric oxide (NO) is implicated in CMV-associated atherosclerosis, and CMV replication is dependent on prostaglandin H synthase (PGHS) activity. Alternatively, CMV infections decrease NO under inflammatory conditions. We therefore hypothesized that changes in the contribution by NO or PGHS-induced vasodilators would explain the increased or decreased endothelial-dependent vasodilation in arteries from nonpregnant and late pregnant mice, respectively. We found that the contribution by NO to methacholine-induced vasodilation was significantly increased in mesenteric, but not uterine, arteries isolated from nonpregnant and pregnant mCMV-infected mice. Prostaglandin inhibition did not affect endothelial-dependent vasodilation in any group. Vasodilation responses to sodium nitroprusside, an NO donor, were increased in mesenteric and uterine arteries isolated only from mCMV-infected nonpregnant mice. These results explain the increased vasodilation responses observed in mesenteric arteries from mCMV-infected mice; however, the decreased vasodilation in uterine arteries from pregnant mice could not be explained by these mechanisms. Thus CMV infection affects the contribution of NO differently in endothelial-dependent vasodilation in pregnant compared with nonpregnant mice and also in the mesenteric compared with the uterine vascular bed.
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Affiliation(s)
| | - Denise G. Hemmings
- Obstetrics and Gynecology, and
- Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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18
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Maussang D, Vischer HF, Leurs R, Smit MJ. Herpesvirus-encoded G protein-coupled receptors as modulators of cellular function. Mol Pharmacol 2009; 76:692-701. [PMID: 19570946 DOI: 10.1124/mol.109.057091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Human herpesviruses (HHVs) are widespread pathogens involved in proliferative diseases, inflammatory conditions, and cardiovascular diseases. During evolution, homologs of human chemokine receptors were integrated into the HHV genomes. In addition to binding endogenous chemokines, these viral G protein-coupled receptors (vGPCRs) have acquired the ability to signal in a constitutive manner. Ligand-induced and ligand-independent and autocrine and paracrine signaling properties of vGPCRs modify the functions of the expressing cells and lead to transformation and escape from immune surveillance. Furthermore, cross-talk or heterodimerization with endogenous chemokine receptors represent other ways for vGPCRs to modify intracellular signaling and cellular functions. As such, these viral receptors seem to play a prominent role during viral pathogenesis and life cycle and thus represent innovative antiviral therapies.
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Affiliation(s)
- David Maussang
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
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19
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The M33 chemokine receptor homolog of murine cytomegalovirus exhibits a differential tissue-specific role during in vivo replication and latency. J Virol 2009; 83:7590-601. [PMID: 19439478 DOI: 10.1128/jvi.00386-09] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
M33, encoded by murine cytomegalovirus (MCMV), is a member of the UL33 homolog G-protein-coupled receptor (GPCR) family and is conserved across all the betaherpesviruses. Infection of mice with recombinant viruses lacking M33 or containing specific signaling domain mutations in M33 results in significantly diminished MCMV infection of the salivary glands. To determine the role of M33 in viral dissemination and/or infection in other tissues, viral infection with wild-type K181 virus and an M33 mutant virus, DeltaM33B(T2), was characterized using two different routes of inoculation. Following both intraperitoneal (i.p.) and intranasal (i.n.) inoculation, M33 was attenuated for infection of the spleen and pancreas as early as 7 days after infection. Following i.p. inoculation, DeltaM33B(T2) exhibited a severe defect in latency as measured by a diminished capacity to reactivate from spleens and lungs in reactivation assays (P < 0.001). Subsequent PCR analysis revealed markedly reduced DeltaM33B(T2) viral DNA levels in the latently infected spleens, lungs, and bone marrow. Following i.n. inoculation, latent DeltaM33B(T2) viral DNA was significantly reduced in the spleen and, in agreement with results from i.p. inoculation, did not reactivate from the spleen (P < 0.001). Furthermore, in vivo complementation of DeltaM33B(T2) virus replication and/or dissemination to the salivary glands and pancreas was achieved by coinfection with wild-type virus. Overall, our data suggest a critical tissue-specific role for M33 during infection in the salivary glands, spleen, and pancreas but not the lungs. Our data suggest that M33 contributes to the efficient establishment or maintenance of long-term latent MCMV infection.
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20
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Miller-Kittrell M, Sparer TE. Feeling manipulated: cytomegalovirus immune manipulation. Virol J 2009; 6:4. [PMID: 19134204 PMCID: PMC2636769 DOI: 10.1186/1743-422x-6-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 01/09/2009] [Indexed: 02/03/2023] Open
Abstract
No one likes to feel like they have been manipulated, but in the case of cytomegalovirus (CMV) immune manipulation, we do not really have much choice. Whether you call it CMV immune modulation, manipulation, or evasion, the bottom line is that CMV alters the immune response in such a way to allow the establishment of latency with lifelong shedding. With millions of years of coevolution within their hosts, CMVs, like other herpesviruses, encode numerous proteins that can broadly influence the magnitude and quality of both innate and adaptive immune responses. These viral proteins include both homologues of host proteins, such as MHC class I or chemokine homologues, and proteins with little similarity to any other known proteins, such as the chemokine binding protein. Although a strong immune response is launched against CMV, these virally encoded proteins can interfere with the host's ability to efficiently recognize and clear virus, while others induce or alter specific immune responses to benefit viral replication or spread within the host. Modulation of host immunity allows survival of both the virus and the host. One way of describing it would be a kind of "mutually assured survival" (as opposed to MAD, Mutually Assured Destruction). Evaluation of this relationship provides important insights into the life cycle of CMV as well as a greater understanding of the complexity of the immune response to pathogens in general.
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Affiliation(s)
- Mindy Miller-Kittrell
- Department of Microbiology, University of Tennessee, 1414 Cumberland Ave, Knoxville, TN, USA.
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21
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Britt W. Manifestations of human cytomegalovirus infection: proposed mechanisms of acute and chronic disease. Curr Top Microbiol Immunol 2008; 325:417-70. [PMID: 18637519 DOI: 10.1007/978-3-540-77349-8_23] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Infections with human cytomegalovirus (HCMV) are a major cause of morbidity and mortality in humans with acquired or developmental deficits in innate and adaptive immunity. In the normal immunocompetent host, symptoms rarely accompany acute infections, although prolonged virus shedding is frequent. Virus persistence is established in all infected individuals and appears to be maintained by both a chronic productive infections as well as latency with restricted viral gene expression. The contributions of the each of these mechanisms to the persistence of this virus in the individual is unknown but frequent virus shedding into the saliva and genitourinary tract likely accounts for the near universal incidence of infection in most populations in the world. The pathogenesis of disease associated with acute HCMV infection is most readily attributable to lytic virus replication and end organ damage either secondary to virus replication and cell death or from host immunological responses that target virus-infected cells. Antiviral agents limit the severity of disease associated with acute HCMV infections, suggesting a requirement for virus replication in clinical syndromes associated with acute infection. End organ disease secondary to unchecked virus replication can be observed in infants infected in utero, allograft recipients receiving potent immunosuppressive agents, and patients with HIV infections that exhibit a loss of adaptive immune function. In contrast, diseases associated with chronic or persistent infections appear in normal individuals and in the allografts of the transplant recipient. The manifestations of these infections appear related to chronic inflammation, but it is unclear if poorly controlled virus replication is necessary for the different phenotypic expressions of disease that are reported in these patients. Although the relationship between HCMV infection and chronic allograft rejection is well known, the mechanisms that account for the role of this virus in graft loss are not well understood. However, the capacity of this virus to persist in the midst of intense inflammation suggests that its persistence could serve as a trigger for the induction of host-vs-graft responses or alternatively host responses to HCMV could contribute to the inflammatory milieu characteristic of chronic allograft rejection.
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Affiliation(s)
- W Britt
- Department of Pediatrics, University of Alabama School of Medicine, Childrens Hospital, Harbor Bldg. 104, 1600 7th Ave. South Birmingham, AL 35233, USA.
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22
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Constitutive serum response factor activation by the viral chemokine receptor homologue pUS28 is differentially regulated by Galpha(q/11) and Galpha(16). Cell Signal 2008; 20:1528-37. [PMID: 18534820 DOI: 10.1016/j.cellsig.2008.04.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Accepted: 04/11/2008] [Indexed: 01/30/2023]
Abstract
Expression of the human cytomegalovirus (HCMV)-encoded chemokine receptor homologue pUS28 in mammalian cells results in ligand-dependent and -independent changes in the activity of multiple cellular signal transduction pathways. The ligand-dependent signalling activity of pUS28 has been shown to be predominantly mediated by heterotrimeric G proteins of the G(i/o) and G(12/13) subfamilies. Ligand-independent constitutive activity of pUS28 causing stimulation of inositol phosphate formation has been correlated with the coupling of pUS28 to G proteins of the G(q) family. It is well known that activation of G(q) proteins by cell surface receptors is coupled to activation of the Rho GTPase RhoA. Activated RhoA regulates numerous cellular functions, including the activity of the transcription factor serum response factor (SRF). The marked activation of G(q) proteins by pUS28 in transfected and HCMV-infected cells prompted us to investigate its effect on SRF activity. The results presented herein demonstrate that expression of pUS28 in COS-7 cells caused a vigorous induction of SRF activity. This effect was observed in the absence of chemokines known to interact with pUS28, and was specifically mediated by endogenous G(q) and/or G(11) as well as RhoA and/or a closely related Rho GTPase. The stimulatory effect of pUS28 and Galpha(q/11) was independent of phospholipase C-beta (PLCbeta) activation and was markedly sensitive to inhibition by wild-type, but not by constitutively active Galpha(16), thus identifying Galpha(16) as a modulator of Galpha(q/11) function likely to act by competing with Galpha(q/11) for and thus uncoupling Galpha(q/11) from activation by pUS28.
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23
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Case R, Sharp E, Benned-Jensen T, Rosenkilde MM, Davis-Poynter N, Farrell HE. Functional analysis of the murine cytomegalovirus chemokine receptor homologue M33: ablation of constitutive signaling is associated with an attenuated phenotype in vivo. J Virol 2008; 82:1884-98. [PMID: 18057236 PMCID: PMC2258698 DOI: 10.1128/jvi.02550-06] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 11/20/2007] [Indexed: 01/28/2023] Open
Abstract
The murine cytomegalovirus (MCMV) M33 gene is conserved among all betaherpesviruses and encodes a homologue of seven-transmembrane receptors (7TMR) with the capacity for constitutive signaling. Previous studies have demonstrated that M33 is important for MCMV dissemination to or replication within the salivary glands. In this study, we probed N- and C-terminal regions of M33 as well as known 7TMR signature motifs in transmembrane (TM) II and TM III to determine the impact on cell surface expression, constitutive signaling, and in vivo phenotype. The region between amino acids R(340) and A(353) of the C terminus was found to be important for CREB- and NFAT-mediated signaling, although not essential for phosphatidylinositol turnover. Tagging or truncation of the N terminus of M33 resulted in loss of cell surface expression. Within TM II, an F79D mutation abolished constitutive signaling, demonstrating a role, as in other cellular and viral 7TMR, of TM II in receptor activation. In TM III, the arginine (but not the asparagine) residue of the NRY motif (the counterpart of the common DRY motif in cellular 7TMR) was found to be essential for constitutive signaling. Selected mutations incorporated into recombinant MCMV showed that disruption of constitutive signaling for a viral 7TMR homologue resulted in a reduced capacity to disseminate to or replicate in the salivary glands. In addition, HCMV UL33 was found to partially compensate for the lack of M33 in vivo, suggesting conserved biological roles of the UL33 gene family.
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Affiliation(s)
- Ruth Case
- Clinical Medical Virology Centre, University of Queensland, Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Herston 4029, Queensland, Australia
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24
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Structure, function and physiological consequences of virally encoded chemokine seven transmembrane receptors. Br J Pharmacol 2008; 153 Suppl 1:S154-66. [PMID: 18204488 DOI: 10.1038/sj.bjp.0707660] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A number of human and animal herpes viruses encode G-protein coupled receptors with seven transmembrane (7TM) segments-most of which are clearly related to human chemokine receptors. It appears, that these receptors are used by the virus for immune evasion, cellular transformation, tissue targeting, and possibly for cell entry. In addition, many virally-encoded chemokine 7TM receptors have been suggested to be causally involved in pathogenic phenotypes like Kaposi sarcoma, atherosclerosis, HIV-infection and tumour development. The role of these receptors during the viral life cycle and in viral pathogenesis is still poorly understood. Here we focus on the current knowledge of structure, function and trafficking patterns of virally encoded chemokine receptors and further address the putative roles of these receptors in virus survival and host -cell and/or -immune system modulation. Finally, we highlight the emerging impact of these receptor on virus-mediated diseases.
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25
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Beisser PS, Lavreysen H, Bruggeman CA, Vink C. Chemokines and chemokine receptors encoded by cytomegaloviruses. Curr Top Microbiol Immunol 2008; 325:221-42. [PMID: 18637509 DOI: 10.1007/978-3-540-77349-8_13] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CMVs carry several genes that are homologous to genes of the host organism. These include genes homologous to those encoding chemokines (CKs) and G protein-coupled receptors (GPCRs). It is generally assumed that these CMV genes were hijacked from the host genome during the long co-evolution of virus and host. In light of the important function of the CK and GPCR families in the normal physiology of the host, it has previously been hypothesized that the CMV homologs of these proteins, CMV vCKs and vGPCRs, may also have a significant impact on this physiology, such that lifelong maintenance and/or replication of the virus within the infected host is guaranteed. In addition, several of these homologs were reported to have a major impact in the pathogenesis of infection. In this review, the current state of knowledge on the CMV vCKs and vGPCRs will be discussed.
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Affiliation(s)
- P S Beisser
- Department of Medical Microbiology, Cardiovascular Research Institute Maastricht, University Hospital Maastricht, PO Box 5800, AZ, Maastricht, The Netherlands
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26
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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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27
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Krebs P, Scandella E, Bolinger B, Engeler D, Miller S, Ludewig B. Chronic Immune Reactivity Against Persisting Microbial Antigen in the Vasculature Exacerbates Atherosclerotic Lesion Formation. Arterioscler Thromb Vasc Biol 2007; 27:2206-13. [PMID: 17656668 DOI: 10.1161/atvbaha.107.141846] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Objective—
The purpose of this study was to examine the relative contribution of different immunopathological mechanisms during murine cytomegalovirus (MCMV)-mediated acceleration of atheroma formation in apolipoprotein E–deficient (apoE
−/−
) mice.
Methods and Results—
To distinguish between the effects of systemic activation and cognate immune reactivity against a pathogen-derived persisting antigen in the vasculature, we used hypercholesterolemic transgenic mice constitutively expressing the β-galactosidase (β-gal) transgene in the cardiovascular system (apoE
−/−
×SM-LacZ). After infection with β-gal–recombinant MCMV-LacZ, apoE
−/−
, and apoE
−/−
×SM-LacZ mice mounted comparable cellular immune responses against the virus. β-gal–specific CD8
+
T cells expanded rapidly and remained detectable for at least 100 days in both mouse strains. However, compared with apoE
−/−
mice, apoE
−/−
×SM-LacZ mice developed drastically accelerated atherosclerosis. Moreover, atherosclerotic lesions in MCMV-LacZ–infected apoE
−/−
×SM-LacZ but not apoE
−/−
mice were associated with pronounced inflammatory infiltrates.
Conclusions—
Taken together, our data indicate that chronic immune reactivity against pathogen-derived antigens persisting in the vasculature significantly exacerbates atherogenesis.
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Affiliation(s)
- Philippe Krebs
- Research Department, Kantonsspital St Gallen, Rorschacherstrasse 95, CH-9007 St Gallen, Switzerland
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28
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Streblow DN, Orloff SL, Nelson JA. Acceleration of allograft failure by cytomegalovirus. Curr Opin Immunol 2007; 19:577-82. [PMID: 17716883 PMCID: PMC3509935 DOI: 10.1016/j.coi.2007.07.012] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 07/08/2007] [Indexed: 10/22/2022]
Abstract
A number of human herpesviruses are important opportunistic pathogens that have been associated with increased morbidity and mortality in transplant recipients including human cytomegalovirus (HCMV), HHV6, HHV7, HHV8 as well as HSV-1, VZV. However, HCMV has been linked both epidemiologically and through the use of animal models to the acceleration of acute and chronic allograft rejection. This review will cover the pathophysiology, epidemiology, and mechanisms of CMV-associated disease in the setting of transplantation.
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Affiliation(s)
| | - Susan L. Orloff
- Veterans Affairs, Portland VAMC, Portland, OR
- MMI, OHSU, Portland, OR
| | - Jay A. Nelson
- MMI, OHSU, Portland, OR
- Department of Surgery, OHSU, Portland, OR
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29
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Dagna L, Lusso P. Virus-encoded chemokines, chemokine receptors and chemokine-binding proteins: new paradigms for future therapy. Future Virol 2007. [DOI: 10.2217/17460794.2.4.353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over millions of years of coevolution with their hosts, viruses have learned the finest artifices of the immune system defense mechanisms and developed a variety of strategies for evading them. The chemokine system has been a primary target of these viral efforts because of the critical role it plays in the development of effective immune responses. Not only do chemokines control cellular recruitment at the site of infection, they also regulate the magnitude and character of the immune responses. Several viruses, and large DNA viruses in particular, have exploited the chemokine system by hijacking and reprogramming chemokine or chemokine-receptor genes, and/or secreting chemokine-binding proteins. In the past few years there has been intense investigation in this area, driven not only by the prospect of gaining a better understanding of viral-immune evasion mechanisms, but also by the possibility of targeting these molecules as part of future antiviral therapeutic approaches, as well as exploiting viral strategies of chemokine interference as novel therapies for inflammatory or neoplastic diseases.
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Affiliation(s)
- Lorenzo Dagna
- Vita-Salute San Raffaele University, Milan, Italy, and, San Raffaele Scientific Institute, Unit of Human Virology, Department of Biological & Technological Research (DIBIT), 20132 Milan, Italy
| | - Paolo Lusso
- San Raffaele Scientific Institute, Unit of Human Virology, Department of Biological & Technological Research (DIBIT), 20132 Milan, Italy
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30
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Tadagaki K, Yamanishi K, Mori Y. Reciprocal roles of cellular chemokine receptors and human herpesvirus 7-encoded chemokine receptors, U12 and U51. J Gen Virol 2007; 88:1423-1428. [PMID: 17412969 DOI: 10.1099/vir.0.82665-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human herpesvirus 7 (HHV-7) is a member of the subfamilyBetaherpesvirinaethat exhibits a restricted cell tropism, preferentially infecting CD4+T cellsin vitro. HHV-7 encodes two functional chemokine receptors, U12 and U51. The human chemokines that act as ligands for these receptors have been identified as CCL22 (the natural ligand for CCR4) and CCL19 (the natural ligand for CCR7). It was found that murine L1.2 cells co-expressing CCR4 or CCR7 and U12 responded to both CCL22 and CCL19 in calcium-mobilization assays, but migrated in response only to the appropriate ligand for the expressed cellular receptor. Similar results were obtained with L1.2 cells co-expressing CCR4 or CCR7 with U51. These results suggest that the HHV-7 U12 and U51 receptors can function in concert with CCR4 and CCR7 in host-cell signalling pathways.
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Affiliation(s)
- Kenjiro Tadagaki
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan
| | - Koichi Yamanishi
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan
| | - Yasuko Mori
- Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan
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31
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Vischer HF, Hulshof JW, de Esch IJP, Smit MJ, Leurs R. Virus-encoded G-protein-coupled receptors: constitutively active (dys)regulators of cell function and their potential as drug target. ERNST SCHERING FOUNDATION SYMPOSIUM PROCEEDINGS 2007:187-209. [PMID: 17703583 DOI: 10.1007/2789_2006_009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
G-protein-coupled receptors encoded by herpesviruses such as EBV, HCMV and KSHV are very interesting illustrations of the (patho)physiological importance of constitutive GPCR activity. These viral proteins are expressed on the cell surface of infected cells and often constitutively activate a variety of G-proteins. For some virus-encoded GPCRs, the constitutive activity has been shown to occur in vivo, i.e., in infected cells. In this paper, we will review the occurrence of virus-encoded GPCRs and describe their known signaling properties. Moreover, we will also review the efforts, directed towards the discovery of small molecule antagonist, that so far have been mainly focused on the HCMV-encoded GPCR US28. This virus-encoded receptor might be involved in cardiovascular diseases and cancer and seems an interesting target for drug intervention.
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Affiliation(s)
- H F Vischer
- Leiden/Amsterdam Center for Drug Research (LACDR), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
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32
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Sherrill JD, Miller WE. G protein-coupled receptor (GPCR) kinase 2 regulates agonist-independent Gq/11 signaling from the mouse cytomegalovirus GPCR M33. J Biol Chem 2006; 281:39796-805. [PMID: 17088245 PMCID: PMC2767100 DOI: 10.1074/jbc.m610026200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The mouse cytomegalovirus M33 protein is highly homologous to mammalian G protein-coupled receptors (GPCRs) yet functions in an agonist-independent manner to activate a number of classical GPCR signal transduction pathways. M33 is functionally similar to the human cytomegalovirus-encoded US28 GPCR in its ability to induce inositol phosphate accumulation, activate NF-kappaB, and promote smooth muscle cell migration. This ability to promote cellular migration suggests a role for viral GPCRs like M33 in viral dissemination in vivo, and accordingly, M33 is required for efficient murine cytomegalovirus replication in the mouse. Although previous studies have identified several M33-induced signaling pathways, little is known regarding the membrane-proximal events involved in signaling and regulation of this receptor. In this study, we used recombinant retroviruses to express M33 in wild-type and Galpha(q/11)(-/-) mouse embryonic fibroblasts and show that M33 couples directly to the G(q/11) signaling pathway to induce high levels of total inositol phosphates in an agonist-independent manner. Our data also show that GRK2 is a potent regulator of M33-induced G(q/11) signaling through its ability to phosphorylate M33 and sequester Galpha(q/11) proteins. Taken together, the results from this study provide the first genetic evidence of a viral GPCR coupling to a specific G protein signaling pathway as well as identify the first viral GPCR to be regulated specifically by both the catalytic activity of the GRK2 kinase domain and the Galpha(q/11) binding activity of the GRK2 RH domain.
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Affiliation(s)
| | - William E. Miller
- To whom correspondence should be addressed: Dept. of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0524. Tel.: 513-558-0866; Fax: 513-558-8474;
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33
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Pinto AK, Munks MW, Koszinowski UH, Hill AB. Coordinated function of murine cytomegalovirus genes completely inhibits CTL lysis. THE JOURNAL OF IMMUNOLOGY 2006; 177:3225-34. [PMID: 16920962 DOI: 10.4049/jimmunol.177.5.3225] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Murine CMV (MCMV) encodes three viral genes that interfere with Ag presentation (VIPRs) to CD8 T cells, m04, m06, and m152. Because the functional impact of these genes during normal infection of C57BL/6 mice is surprisingly modest, we wanted to determine whether the VIPRs are equally effective against the entire spectrum of H-2(b)-restricted CD8 T cell epitopes. We also wanted to understand how the VIPRs interact at a functional level. To address these questions, we used a panel of MCMV mutants lacking each VIPR in all possible combinations, and CTL specific for 15 H-2(b)-restricted MCMV epitopes. Only expression of all three MCMV VIPRs completely inhibited killing by CTL specific for all 15 epitopes, but removal of any one VIPR enabled lysis by at least some CTL. The dominant interaction between the VIPRs was cooperation: m06 increased the inhibition of lysis achieved by either m152 or m04. However, for 1 of 15 epitopes m04 functionally antagonized m152. There was little differential impact of any of the VIPRs on K(b) vs D(b), but a surprising degree of differential impact of the three VIPRs for different epitopes. These epitope-specific differences did not correlate with functional avidity, or with timing of VIPR expression in relation to Ag expression in the virus replication cycle. Although questions remain about the molecular mechanism and in vivo role of these genes, we conclude that the coordinated function of MCMV's three VIPRs results in a powerful inhibition of lysis of infected cells by CD8 T cells.
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Affiliation(s)
- Amelia K Pinto
- Oregon Health and Science University, Molecular Microbiology and Immunology, Portland, OR 97239, USA
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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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Smith LM, Shellam GR, Redwood AJ. Genes of murine cytomegalovirus exist as a number of distinct genotypes. Virology 2006; 352:450-65. [PMID: 16781754 DOI: 10.1016/j.virol.2006.04.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 04/18/2006] [Accepted: 04/26/2006] [Indexed: 11/21/2022]
Abstract
Murine cytomegaloviruses encode a number of genes which modulate polymorphic host immune responses. We suggest that these viral genes should themselves therefore exhibit sequence polymorphism. Additionally, clinical isolates of human cytomegalovirus (HCMV) have been shown to vary extensively from the common laboratory strains. Almost all research conducted on murine cytomegalovirus (MCMV) has used the laboratory strains Smith and K181, which have been extensively passaged in vitro and in vivo since isolation. Using the heteroduplex mobility assay (HMA) to determine levels of sequence variation 11 MCMV genes were examined from 26 isolates of MCMV from wild mice, as well as both laboratory strains. Both the HMA and sequencing of selected genes demonstrated that whilst certain genes (M33, mck-2, m147.5, m152) were highly conserved, others (m04, m06, M44, m138, m144, m145 and m155) contained significant sequence variation. Several of these genes (m06, m144 and m155) exist in wild MCMV strains as one of several distinct genotypes.
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Affiliation(s)
- Lee M Smith
- Discipline of Microbiology and Immunology, M502, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
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Vischer HF, Leurs R, Smit MJ. HCMV-encoded G-protein-coupled receptors as constitutively active modulators of cellular signaling networks. Trends Pharmacol Sci 2005; 27:56-63. [PMID: 16352349 DOI: 10.1016/j.tips.2005.11.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Revised: 10/05/2005] [Accepted: 11/21/2005] [Indexed: 11/19/2022]
Abstract
Several herpesviruses encode G-protein-coupled receptor (vGPCR) proteins that are homologous to human chemokine receptors. In contrast to chemokine receptors, many vGPCRs signal in a ligand-independent (constitutive) manner. Such constitutive signaling is of major significance because various pathologies are associated with activating GPCR mutations. Constitutive activity of the human herpesvirus 8-encoded GPCR (ORF74), for example, is essential for its oncogenic potential to cause angioproliferative Kaposi's sarcoma-like lesions. The human cytomegalovirus (HCMV) encodes four GPCRs, of which US28 and UL33 display constitutive activity in transfected, but also HCMV-infected, cells. In addition, US28 is activated by a broad spectrum of chemokines. Furthermore, both US28 and UL33 show promiscuous G-protein coupling, whereas chemokine receptors activate primarily G(i/o) proteins. Thus, these vGPCRs are versatile signaling devices, reprogramming cellular signaling networks to modulate cellular function after infection. By these means, these HCMV-encoded receptors might contribute to HCMV-related pathologies.
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Affiliation(s)
- Henry F Vischer
- Leiden/Amsterdam Center for Drug Research (LACDR), Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
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