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Landázuri N, Gorwood J, Terelius Y, Öberg F, Yaiw KC, Rahbar A, Söderberg-Nauclér C. The Endothelin Receptor Antagonist Macitentan Inhibits Human Cytomegalovirus Infection. Cells 2021; 10:cells10113072. [PMID: 34831300 PMCID: PMC8619441 DOI: 10.3390/cells10113072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/15/2021] [Accepted: 10/23/2021] [Indexed: 12/27/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection is an important cause of morbidity and mortality in immunocompromised patients and a major etiological factor for congenital birth defects in newborns. Ganciclovir and its pro-drug valganciclovir are the preferred drugs in use today for prophylaxis and treatment of viremic patients. Due to long treatment times, patients are at risk for developing viral resistance to ganciclovir and to other drugs with a similar mechanism of action. We earlier found that the endothelin receptor B (ETBR) is upregulated during HCMV infection and that it plays an important role in the life cycle of this virus. Here, we tested the hypothesis that ETBR blockade could be used in the treatment of HCMV infection. As HCMV infection is specific to humans, we tested our hypothesis in human cell types that are relevant for HCMV pathogenesis; i.e., endothelial cells, epithelial cells and fibroblasts. We infected these cells with HCMV and treated them with the ETBR specific antagonist BQ788 or ETR antagonists that are approved by the FDA for treatment of pulmonary hypertension; macitentan, its metabolite ACT-132577, bosentan and ambrisentan, and as an anti-viral control, we used ganciclovir or letermovir. At concentrations expected to be relevant in vivo, macitentan, ACT-132577 and BQ788 effectively inhibited productive infection of HCMV. Of importance, macitentan also inhibited productive infection of a ganciclovir-resistant HCMV isolate. Our results suggest that binding or signaling through ETBR is crucial for viral replication, and that selected ETBR blockers inhibit HCMV infection.
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Affiliation(s)
- Natalia Landázuri
- Microbial Pathogenesis Unit, Department of Medicine Solna, Karolinska Institutet, SE-171 76 Stockholm, Sweden; (N.L.); (J.G.); (K.C.Y.); (A.R.)
- Division of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Jennifer Gorwood
- Microbial Pathogenesis Unit, Department of Medicine Solna, Karolinska Institutet, SE-171 76 Stockholm, Sweden; (N.L.); (J.G.); (K.C.Y.); (A.R.)
- Division of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Ylva Terelius
- Medivir AB, SE-141 22 Huddinge, Sweden; (Y.T.); (F.Ö.)
| | - Fredrik Öberg
- Medivir AB, SE-141 22 Huddinge, Sweden; (Y.T.); (F.Ö.)
| | - Koon Chu Yaiw
- Microbial Pathogenesis Unit, Department of Medicine Solna, Karolinska Institutet, SE-171 76 Stockholm, Sweden; (N.L.); (J.G.); (K.C.Y.); (A.R.)
- Division of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Afsar Rahbar
- Microbial Pathogenesis Unit, Department of Medicine Solna, Karolinska Institutet, SE-171 76 Stockholm, Sweden; (N.L.); (J.G.); (K.C.Y.); (A.R.)
- Division of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Cecilia Söderberg-Nauclér
- Microbial Pathogenesis Unit, Department of Medicine Solna, Karolinska Institutet, SE-171 76 Stockholm, Sweden; (N.L.); (J.G.); (K.C.Y.); (A.R.)
- Division of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
- Correspondence:
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Becker J, Kinast V, Döring M, Lipps C, Duran V, Spanier J, Tegtmeyer PK, Wirth D, Cicin-Sain L, Alcamí A, Kalinke U. Human monocyte-derived macrophages inhibit HCMV spread independent of classical antiviral cytokines. Virulence 2019; 9:1669-1684. [PMID: 30403913 PMCID: PMC7000197 DOI: 10.1080/21505594.2018.1535785] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Infection of healthy individuals with human cytomegalovirus (HCMV) is usually unnoticed and results in life-long latency, whereas HCMV reactivation as well as infection of newborns or immunocompromised patients can cause life-threatening disease. To better understand HCMV pathogenesis we studied mechanisms that restrict HCMV spread. We discovered that HCMV-infected cells can directly trigger plasmacytoid dendritic cells (pDC) to mount antiviral type I interferon (IFN-I) responses, even in the absence of cell-free virus. In contrast, monocyte-derived cells only expressed IFN-I when stimulated by cell-free HCMV, or upon encounter of HCMV-infected cells that already produced cell-free virus. Nevertheless, also in the absence of cell-free virus, i.e., upon co-culture of infected epithelial/endothelial cells and monocyte-derived macrophages (moMΦ) or dendritic cells (moDC), antiviral responses were induced that limited HCMV spread. The induction of this antiviral effect was dependent on cell-cell contact, whereas cell-free supernatants from co-culture experiments also inhibited virus spread, implying that soluble factors were critically needed. Interestingly, the antiviral effect was independent of IFN-γ, TNF-α, and IFN-I as indicated by cytokine inhibition experiments using neutralizing antibodies or the vaccinia virus-derived soluble IFN-I binding protein B18R, which traps human IFN-α and IFN-β. In conclusion, our results indicate that human macrophages and dendritic cells can limit HCMV spread by IFN-I dependent as well as independent mechanisms, whereas the latter ones might be particularly relevant for the restriction of HCMV transmission via cell-to-cell spread.
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Affiliation(s)
- Jennifer Becker
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Volker Kinast
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Marius Döring
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Christoph Lipps
- b Model Systems for Infection and Immunity , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Veronica Duran
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Julia Spanier
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Pia-Katharina Tegtmeyer
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
| | - Dagmar Wirth
- b Model Systems for Infection and Immunity , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Luka Cicin-Sain
- c Department of Vaccinology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,d German Center for Infection Research (DZIF) , Hannover-Braunschweig site , Germany.,e Institute for Virology , Hannover Medical School , Hannover , Germany
| | - Antonio Alcamí
- f Centro de Biología Molecular Severo Ochoa , Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid , Madrid , Spain
| | - Ulrich Kalinke
- a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School , Hannover , Germany
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Towler JC, Ebrahimi B, Lane B, Davison AJ, Dargan DJ. Human cytomegalovirus transcriptome activity differs during replication in human fibroblast, epithelial and astrocyte cell lines. J Gen Virol 2012; 93:1046-1058. [PMID: 22258857 PMCID: PMC3541802 DOI: 10.1099/vir.0.038083-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Broad cell tropism contributes to the pathogenesis of human cytomegalovirus (HCMV), but the extent to which cell type influences HCMV gene expression is unclear. A bespoke HCMV DNA microarray was used to monitor the transcriptome activity of the low passage Merlin strain of HCMV at 12, 24, 48 and 72 h post-infection, during a single round of replication in human fetal foreskin fibroblast cells (HFFF-2s), human retinal pigmented epithelial cells (RPE-1s) and human astrocytoma cells (U373MGs). In order to correlate transcriptome activity with concurrent biological responses, viral cytopathic effect, growth kinetics and genomic loads were examined in the three cell types. The temporal expression pattern of viral genes was broadly similar in HFFF-2s and RPE-1s, but dramatically different in U373MGs. Of the 165 known HCMV protein-coding genes, 41 and 48 were differentially regulated in RPE-1s and U373MGs, respectively, compared with HFFF-2s, and 22 of these were differentially regulated in both RPE-1s and U373MGs. In RPE-1s, all differentially regulated genes were downregulated, but, in U373MGs, some were down- and others upregulated. Differentially regulated genes were identified among the immediate-early, early, early late and true-late viral gene classes. Grouping of downregulated genes according to function at landmark stages of the replication cycle led to the identification of potential bottleneck stages (genome replication, virion assembly, and virion maturation and release) that may account for cell type-dependent viral growth kinetics. The possibility that cell type-specific differences in expressed cellular factors are responsible for modulation of viral gene expression is discussed.
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Affiliation(s)
- James C Towler
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK
| | - Bahram Ebrahimi
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Brian Lane
- Liverpool Microarray Facility, Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Andrew J Davison
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK
| | - Derrick J Dargan
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK
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Ebihara N, Chen L, Tokura T, Ushio H, Iwatsu M, Murakami A. Distinct Functions between Toll-Like Receptors 3 and 9 in Retinal Pigment Epithelial Cells. Ophthalmic Res 2007; 39:155-63. [PMID: 17534115 DOI: 10.1159/000103235] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 02/02/2007] [Indexed: 11/19/2022]
Abstract
Retinal pigment epithelial cells (RPE cells) are key players in the first-line defense against invading organisms such as viruses and bacteria. The interaction between RPE cells and viral or bacterial components is very important for clearance of these organisms. Toll-like receptors are a family of recognition receptors involved in innate immunity. Each TLR acts as a primary sensor of conserved microbial components and drives the induction of specific biological responses. TLR 3 is involved in the recognition of viral components, such as double-stranded RNA (dsRNA) and poly(I:C), while TLR 9 recognizes viral or bacterial DNA without methylation at CpG motifs. In the present study, we investigated the expression and function of TLR 3 and 9 in RPE cells. PCR analysis revealed expression of genes for TLR 3 and 9 in RPE cells. Expression of TLR 3 and 9 protein was detected in RPE cells by flow cytometry. TLR 3 and 9 showed strong intracellular expression. To detect angiogenetic factors produced by RPE cells, culture supernatant was examined with the Human Angiogenesis Antibody Array, which can simultaneously detect 20 different angiogenetic factors including cytokines, chemokines, soluble cytokine receptors, and growth factors. RPE cells showed high production of interleukin-8 (IL-8) and monocyte chemotactic protein-I (MCP-I). Furthermore, stimulation of RPE cells with the dsRNA analogue poly(I:C) enhanced the secretion of IL-8 and MCP-I, as well as enhancing the expression of junctional adhesion molecule-I (Jam-I) and intracellular adhesion molecule-I (ICAM-I), and promoted the adhesion of monocyte to these cells. In contrast, stimulation with the CpG-DNA motif only enhanced the secretion of IL-8. However, CpG-DNA motif enhanced phagocytosis in RPE cells. These results may indicate that TLR 3 and 9 play a distinct role in the inflammatory response that clears viruses from the retina.
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Affiliation(s)
- Nobuyuki Ebihara
- Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan.
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Dutt K, Ezeonu I. Human retinal and brain cell lines: A model of HCMV retinitis and encephalitis. DNA Cell Biol 2006; 25:581-96. [PMID: 17132089 DOI: 10.1089/dna.2006.25.581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although HIV is accepted as the etiologic agent in AIDS, other factors have been implicated in accelerating the disease. Human cytomegalovirus (HCMV) in particular has been implicated as a cofactor in the progression from AIDS-related complex (ARC) to AIDS. HCMV infection of the central nervous system (CNS) (brain, retina) has been reported in at least 50% of AIDS patients, and has been implicated in producing encephalitis and sight-threatening retinitis. HCMV exhibits strict species specificity and animal models for human HCMV are conspicuous by their absence. We have developed a human brain cell line (mixed glial/neuronal) and a multipotential human retinal precursor cell line (neuronal in nature). We have tested the suitability of these cell lines as models for the study of HCMV infectibility. In this study, we report that these cell lines are optimal for the study of HCMV infectibility and pathogenesis in tissues of neural origin and appropriate to study HIV-HCMV interaction. Immortalized human brain and retinal cell lines were infected with a laboratory strain of HCMV (AD 169, Towne) at a multiplicity of infection moi (1-5) and viral infectibility and cell specificity monitored by: (a) phenotypic analysis (multinucleate cells, syncytium formation, etc.), (b) antigen expression (IE, E, late) by immunohistochemistry, Western blot analysis, (c) presence of viral particles by TEM, and (d) expression of indicator plasmids (HIV-LTR-CAT). We report that both human retinal and brain cell lines are permissive for HCMV infectibility. Cell specificity was not seen; both cells expressing glial/neuronal cell markers were positive for the presence of HCMV early/late antigens. Formation of multinucleate giant cells with nuclear inclusion bodies and syncytia were seen. Productive viral infection was confirmed by the ability of cell-free supernatant from the third passage of infected cells to produce pathogenicity and express viral particles, when added to fresh cultures. Using indicator plasmids, HIV-LTR, and CAT, we have shown that HIV and HCMV interact at the cellular level. We have also shown that HIV production in retinal and brain cell lines transfected with cloned HIV was enhanced by HCMV-IE genes. We did not see any differences in HCMV. AD 169, Towne isolate, and data from both strains is presented in this paper. This model could prove extremely useful for the study of cell specificity/cellular and molecular interaction between HIV/HCMV and to test antiviral therapies.
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Affiliation(s)
- Kamla Dutt
- Department of Pathology, Morehouse School of Medicine, Atlanta, Georgia 30310, USA.
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Wang D, Shenk T. Human cytomegalovirus UL131 open reading frame is required for epithelial cell tropism. J Virol 2005; 79:10330-8. [PMID: 16051825 PMCID: PMC1182637 DOI: 10.1128/jvi.79.16.10330-10338.2005] [Citation(s) in RCA: 287] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epithelial cells are one of the prominent cell types infected by human cytomegalovirus (HCMV) within its host. However, many cultured epithelial cells, such as ARPE-19 retinal pigmented epithelial cells, are poorly infected by laboratory-adapted strains in cell culture, and little is known about the viral factors that determine HCMV epithelial cell tropism. In this report, we demonstrate that the UL131 open reading frame (ORF), and likely the entire UL131-128 locus, is required for efficient infection of epithelial cells. Repair of the mutated UL131 gene in the AD169 laboratory strain of HCMV restored its ability to infect both epithelial and endothelial cells while compromising its ability to replicate in fibroblasts. ARPE-19 epithelial cells support replication of the repaired AD169 virus as well as clinical isolates of HCMV. Productive infection of cultured epithelial cells, endothelial cells, and fibroblasts with the repaired AD169 virus leads to extensive membrane fusion and syncytium formation, suggesting that the virus may spread through cell-cell fusion.
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Affiliation(s)
- Dai Wang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA
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7
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Zhang M, Xin H, Atherton SS. Murine cytomegalovirus (MCMV) spreads to and replicates in the retina after endotoxin-induced disruption of the blood-retinal barrier of immunosuppressed BALB/c mice. J Neurovirol 2005; 11:365-75. [PMID: 16162479 DOI: 10.1080/13550280591002432] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The goal of this study was to determine whether disruption of the blood-retinal barrier (BRB) facilitates spread of MCMV to the retina in immunosuppressed (IS) BALB/c mice. IS mice were inoculated intravenously (i.v.) with murine cytomegalovirus (MCMV) or with macrophages infected with MCMV for 4 days in vitro. The BRB was disrupted by injection of sodium iodate (i.v.) or lipopolysaccharide (LPS, i.v. or anterior chamber). Frozen sections of ocular tissue were examined for MCMV antigens. The results showed that MCMV-infected cells were observed only in the choroid and ciliary body in IS mice with an intact BRB. After LPS injection, a few positive cells were observed in the retina of IS mice after i.v. injection of MCMV. In lipopolysaccharide (LPS)-treated IS mice, a few PKH-26-positive macrophages or MCMV-positive cells were observed in the retina at 1 or 2 days after injection of macrophages. No PKH-26-positive cells or virus-infected cells were noted in the retina of phosphate-buffered saline (PBS)-treated mice. Ten days after injection of virus-infected macrophages, MCMV-infected cells were observed in choroid and ciliary body of both LPS- and PBS-treated mice, but they were observed in the retina only in LPS-treated mice. The results support the idea that disruption of the BRB allows MCMV to spread to the retina of IS mice and that monocytes/macrophages disseminate MCMV to the retina in mice with a disrupted BRB. By extrapolation, damage to the BRB in immunosuppressed patients may facilitate spread of CMV-infected monocytes/macrophages to the retina.
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Affiliation(s)
- Ming Zhang
- Department of Cellular Biology and Anatomy, The Medical College of Georgia, Augusta, Georgia 30912, USA
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Udono-Fujimori R, Takahashi K, Takeda K, Furuyama K, Kaneko K, Takahashi S, Tamai M, Shibahara S. Expression of heme oxygenase-1 is repressed by interferon-gamma and induced by hypoxia in human retinal pigment epithelial cells. ACTA ACUST UNITED AC 2004; 271:3076-84. [PMID: 15233805 DOI: 10.1111/j.1432-1033.2004.04241.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The retinal pigment epithelium (RPE) is essential for maintenance of photoreceptors and normally functions under conditions enriched with reactive oxygen species. RPE therefore expresses various defense enzymes against oxidative stress, including heme oxygenase-1 (HO-1). HO-1 catalyzes heme breakdown to release iron, carbon monoxide, and biliverdin, which is reduced to bilirubin, a potent radical scavenger. HO-1 expression is induced by various environmental factors, which has been established as a defense mechanism. To explore the hypothesis that the expression level of HO-1 is reduced in those RPE cells under certain conditions, we analyzed the effects of interferon-gamma and hypoxia, each of which represses the expression of HO-1 mRNA in other types of human cells. Expression levels of HO-1 mRNA were reduced by interferon-gamma in two human RPE cell lines, D407 and ARPE-19, which was consistently associated with the induction of mRNA for Bach1, a transcriptional repressor for the HO-1 gene. On the other hand, HO-1 and Bach1 mRNAs were induced by hypoxia in D407 cells but remained unchanged in ARPE-19 cells, suggesting that Bach1 is not a sole regulator for HO-1 expression. The hypoxia-mediated induction of HO-1 mRNA in D407 cells depends on gene transcription and protein synthesis, as judged by the effects of their inhibitors. The half-life of HO-1 mRNA did not change during hypoxia. Thus, hypoxia may increase transcription of the HO-1 gene through a certain protein factor in RPE cells. These results indicate that RPE cells maintain retinal homeostasis by repressing or inducing the expression of HO-1, depending on the microenvironment.
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Affiliation(s)
- Reiko Udono-Fujimori
- Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai, Miyagi, Japan
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Snoeck R, Andrei G, Bodaghi B, Lagneaux L, Daelemans D, de Clercq E, Neyts J, Schols D, Naesens L, Michelson S, Bron D, Otto MJ, Bousseau A, Nemecek C, Roy C. 2-Chloro-3-pyridin-3-yl-5,6,7,8-tetrahydroindolizine-1-carboxamide (CMV423), a new lead compound for the treatment of human cytomegalovirus infections. Antiviral Res 2002; 55:413-24. [PMID: 12206879 DOI: 10.1016/s0166-3542(02)00074-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human cytomegalovirus (HCMV) remains one of the major pathogens in immunocompromised patients (AIDS and transplants) and the main cause for congenital infections leading from slight cognitive defects up to severe mental retardation. The drugs that are currently available for the treatment of HCMV infections, i.e. ganciclovir, foscarnet and cidofovir, are all acting at the level of the viral DNA polymerase. Here we describe an entirely new molecule, the 2-chloro-3-pyridin-3-yl-5,6,7,8-tetrahydroindolizine-1-carboxamide (CMV423), that shows very potent in vitro activity against HCMV. CMV423 is highly active against HCMV reference strains and clinical isolates, but also against those strains, isolated from patients or emerging after in vitro selection, that are resistant to either ganciclovir, foscarnet or cidofovir. CMV423 also showed activity in two ex vivo models, that are both highly relevant for the pathophysiology of HCMV, the retinal pigment epithelial and the bone marrow stromal cell assays. Viral antigen expression analysis by flow cytometry, as well as time of addition experiments, confirmed that CMV423 acts on a step of the viral replicative cycle that precedes the DNA polymerase step and, most likely, coincides with the immediate early (IE) antigen synthesis. Finally, CMV423 combined with either ganciclovir, foscarnet or cidofovir in checkerboard experiments demonstrated a highly synergistic activity.
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Affiliation(s)
- Robert Snoeck
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, Belgium.
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Abstract
Human cytomegalovirus (HCMV) is a complex DNA virus encoding more than 200 viral proteins. This highly adapted opportunist agent has developed several ways to evade the immune system. Among all clinical features due to HCMV, retinitis occurs especially in severely immunosuppressed patients, particularly during the end phase of HIV infection. Highly active antiretroviral therapy (HAART) has significantly reduced the incidence of this complication. However, in this HAART era, we observe the emergence of new clinical patterns in patients presenting with cicatricial HCMV retinitis. These patterns could be potentially related to immune mechanisms directed against viral antigens expressed at the surface of retinal cells that are still latently infected without any viral replication. We used a model of human retinal pigment epithelial (RPE) cells to evaluate virus-host interactions in the presence of different cytokines in the eye which play a major role in immunological or infectious conditions. Two different enzymatic pathways seem to be particularly involved during infection. Lack of tryptophan and production of nitric oxide seem to block HCMV replication in RPE cells. We propose a model to explain some of the mechanisms involved during severe immunosuppression and also after immune recovery.
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Affiliation(s)
- B Bodaghi
- Department of Ophthalmology, H¿opital Piti¿e-Salp¿etri¿ere, Paris, France.
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12
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Affiliation(s)
- D J Skiest
- Department of Medicine, University of Texas Southwestern Medical Center, Dallas 75235-9113, USA.
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Bodaghi B, Goureau O, Zipeto D, Laurent L, Virelizier JL, Michelson S. Role of IFN-γ-Induced Indoleamine 2,3 Dioxygenase and Inducible Nitric Oxide Synthase in the Replication of Human Cytomegalovirus in Retinal Pigment Epithelial Cells. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.2.957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
An in vitro model of human CMV infection of primary retinal pigment epithelial (RPE) cells was used to study the effects of cytokines on CMV replication in these cells, which are targets of CMV infection in vivo. IFN-γ and IFN-β were potent inhibitors of CMV replication in RPE cells, while TNF-α, IL-1β, or TGF-β2 did not affect viral replication. Inhibition by IFN-γ, and to a lesser extent IFN-β, was almost completely reversed by addition of l-tryptophan to the culture medium, strongly implicating the indoleamine 2,3 dioxygenase (IDO) pathway. Polyadenylated IDO mRNA accumulation was detected as early as 2 h after IFN stimulation. Furthermore, CMV blocked the production of nitric oxide by the inducible form of nitric oxide synthase. This inhibition depended on a functional viral genome. However, exogenous nitric oxide significantly inhibited viral protein expression in RPE cells. Thus, CMV infection blocks the inducible nitric oxide synthase pathway activated by IFN-γ and IL-1β, but cannot counteract the IFN-induced IDO pathway, which ultimately controls its replication in primary human RPE cells.
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Affiliation(s)
- Bahram Bodaghi
- *Unité d’Immunologie Virale, Institut Pasteur, Paris, France; and
| | - Olivier Goureau
- †Institut National de la Santé et de la Recherche Médicale, U450, Developpement, Vieillissement et Pathologie de la Rétine, Paris, France
| | - Donato Zipeto
- *Unité d’Immunologie Virale, Institut Pasteur, Paris, France; and
| | - Lysiane Laurent
- *Unité d’Immunologie Virale, Institut Pasteur, Paris, France; and
| | | | - Susan Michelson
- *Unité d’Immunologie Virale, Institut Pasteur, Paris, France; and
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Tugizov S, Maidji E, Xiao J, Zheng Z, Pereira L. Human cytomegalovirus glycoprotein B contains autonomous determinants for vectorial targeting to apical membranes of polarized epithelial cells. J Virol 1998; 72:7374-86. [PMID: 9696834 PMCID: PMC109962 DOI: 10.1128/jvi.72.9.7374-7386.1998] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We previously reported that human cytomegalovirus (CMV) glycoprotein B (gB) is vectorially transported to apical membranes of CMV-infected polarized human retinal pigment epithelial cells propagated on permeable filter supports and that virions egress predominantly from the apical membrane domain. In the present study, we investigated whether gB itself contains autonomous information for apical transport by expressing the molecule in stably transfected Madine-Darby canine kidney (MDCK) cells grown on permeable filter supports. Laser scanning confocal immunofluorescence microscopy and domain-selective biotinylation of surface membrane domains showed that CMV gB was transported to apical membranes independently of other envelope glycoproteins and that it colocalized with proteins in transport vesicles of the biosynthetic and endocytic pathways. Determinants for trafficking to apical membranes were located by evaluating the targeting of gB derivatives with deletions in the lumen, transmembrane (TM) anchor, and carboxyl terminus. Derivative gB(Delta717-747), with an internal deletion in the luminal juxtamembrane sequence that preserved the N- and O-glycosylation sites, retained vectorial transport to apical membranes. In contrast, derivatives that lacked the TM anchor and cytosolic domain (gBDelta646-906) or the TM anchor alone (gBDelta751-771) underwent considerable basolateral targeting. Likewise, derivatives lacking the entire cytosolic domain (gBDelta772-906) or the last 73 amino acids (gBDelta834-906) showed disrupted apical transport. Site-specific mutations that deleted or altered the cluster of acidic residues with a casein kinase II phosphorylation site at the extreme carboxyl terminus, which can serve as an internalization signal, caused partial missorting of gB to basolateral membranes. Our studies indicate that CMV gB contains autonomous information for apical targeting in luminal, TM anchor, and cytosolic domain sequences, forming distinct structural elements that cooperate in vectorial transport in polarized epithelial cells.
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Affiliation(s)
- S Tugizov
- Department of Stomatology, School of Dentistry, University of California-San Francisco, San Francisco, California 94143-0512, USA
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15
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Maidji E, Tugizov S, Jones T, Zheng Z, Pereira L. Accessory human cytomegalovirus glycoprotein US9 in the unique short component of the viral genome promotes cell-to-cell transmission of virus in polarized epithelial cells. J Virol 1996; 70:8402-10. [PMID: 8970961 PMCID: PMC190929 DOI: 10.1128/jvi.70.12.8402-8410.1996] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Human cytomegalovirus (CMV) encodes accessory glycoproteins that are dispensable for virus growth in nonpolarized cells in culture. We report that CMV deletion mutants lacking the gene for accessory glycoprotein US9 in the unique short component of the viral genome are impaired in plaque formation in polarized human retinal pigment epithelial (ARPE-19) cells. Comparison of CMV deletion mutants in US9 with herpes simplex virus type 1 deletion mutants lacking glycoproteins gE and gI showed that both of these mutants are impaired in altering junctional complexes and increasing paracellular permeability in polarized ARPE-19 cells cultured on permeable filter supports. Results of functional studies indicate that CMV US9 and homologs of gE have analogous roles in promoting virus spread across lateral membranes of polarized epithelial cells.
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Affiliation(s)
- E Maidji
- Department of Stomatology, School of Dentistry, University of California San Francisco, 94143-0512, USA
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16
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Plachter B, Sinzger C, Jahn G. Cell types involved in replication and distribution of human cytomegalovirus. Adv Virus Res 1996; 46:195-261. [PMID: 8824701 DOI: 10.1016/s0065-3527(08)60073-1] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
As the number of patients suffering from severe HCMV infections has steadily increased, there is a growing need to understand the molecular mechanisms by which the virus causes disease. The factors that control infection at one time and the events leading to virus multiplication at another time are only beginning to be understood. The interaction of HCMV with different host cells is one key for elucidating these processes. Through modern techniques, much has been learned about the biology of HCMV infections in culture systems. In addition to endothelial cells, epithelial cells, and smooth muscle cells, fibroblasts are one cell population preferentially infected in solid tissues in vivo. From these sites of multiplication, the virus may be carried by peripheral monocytes and circulating endothelial cells to reach distant sites of the body. This would explain the multiorgan involvement in acute HCMV infection and the modes of viral transmission. From what has been learned mainly from human fibroblast culture systems, future studies will focus on how HCMV regulates the expression of its putative 200 genes in different host cells at different stages of cell differentiation and activation to result in viral latency and pathogenesis.
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Affiliation(s)
- B Plachter
- Institut für Klinische und Molekulare Virologie, Universität Erlangen-Nürnberg, Germany
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Shahsavari M, Peyman GA, Niesman MR, Miceli MV, Jaynes J. Shiva-1: in vitro and in vivo tests of the effects of a novel, synthetic, lytic peptide on ocular cells. Int Ophthalmol 1995; 19:29-34. [PMID: 8537193 DOI: 10.1007/bf00156416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An investigation was undertaken to determine the toxicity of an intravitreal injection of a novel peptide drug, Shiva-1, in rabbits. The drug, a synthetic peptide modeled after lytic peptides secreted by certain insects, has antiproliferative and antibacterial properties. Initial in vitro experiments showed that the drug, at a concentration of 100 microM, was toxic to both Y-79 retinoblastoma cells and human retinal pigment epithelial cells. A wide range of doses (6-1200 micrograms) was injected into the rabbit vitreous in an attempt to determine the maximum tolerated dose. Retinal toxicity was evaluated clinically, by electroretinography, and by light microscopy. Some localized toxicity was evident at 200 micrograms; all doses of 240 micrograms and above were toxic. While the drug appears to exhibit a narrow range between effective and toxic doses, the results suggest that this and other peptides of similar design merit further investigation for the treatment of proliferative and infectious diseases of the eye.
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Affiliation(s)
- M Shahsavari
- LSU Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans 70112, USA
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Dix RD, Cray C, Cousins SW. Mice immunosuppressed by murine retrovirus infection (MAIDS) are susceptible to cytomegalovirus retinitis. Curr Eye Res 1994; 13:587-95. [PMID: 7956311 DOI: 10.3109/02713689408999892] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Although various methods of immunosuppression have been used to enhance susceptibility of mice to murine cytomegalovirus (MCMV) retinitis, none reproduce the unique complexity of immune deficiency experienced by patients during the progression of AIDS. C57BL/6 mice are susceptible to a retrovirus-induced murine acquired immune deficiency syndrome (MAIDS), characterized by progressive immune dysfunction which shares many features with AIDS. We therefore evaluated the frequency and severity of MCMV retinitis in C57BL/6 mice with MAIDS. Following subretinal inoculation of MCMV, nearly 90% of mice with MAIDS developed a necrotizing retinitis 8 to 10 days postinfection, whereas retinitis was observed in only 8% of age-matched immunocompetent control mice. Histopathologic analysis of the retinitis that developed in mice with MAIDS revealed features similar to those found in AIDS-related CMV retinitis. Eyes from MAIDS animals also contained on average higher amounts of infectious virus when compared with eyes from control animals. We conclude that retrovirus-induced immunosuppression increases susceptibility of C57BL/6 mice to MCMV retinitis.
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Affiliation(s)
- R D Dix
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, FL 33101
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