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Xu J, Liu X, Zhang X, Marshall B, Dong Z, Smith SB, Espinosa-Heidmann DG, Zhang M. Retinal and Choroidal Pathologies in Aged BALB/c Mice Following Systemic Neonatal Murine Cytomegalovirus Infection. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1787-1804. [PMID: 34197777 PMCID: PMC8485058 DOI: 10.1016/j.ajpath.2021.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/04/2021] [Accepted: 06/14/2021] [Indexed: 11/30/2022]
Abstract
Although pathologies associated with acute virus infections have been extensively studied, the effects of long-term latent virus infections are less well understood. Human cytomegalovirus, which infects 50% to 80% of humans, is usually acquired during early life and persists in a latent state for the lifetime. The purpose of this study was to determine whether systemic murine cytomegalovirus (MCMV) infection acquired early in life disseminates to and becomes latent in the eye and if ocular MCMV can trigger in situ inflammation and occurrence of ocular pathology. This study found that neonatal infection of BALB/c mice with MCMV resulted in dissemination of virus to the eye, where it localized principally to choroidal endothelia and pericytes and less frequently to the retinal pigment epithelium (RPE) cells. MCMV underwent ocular latency, which was associated with expression of multiple virus genes and from which MCMV could be reactivated by immunosuppression. Latent ocular infection was associated with significant up-regulation of several inflammatory/angiogenic factors. Retinal and choroidal pathologies developed in a progressive manner, with deposits appearing at both basal and apical aspects of the RPE, RPE/choroidal atrophy, photoreceptor degeneration, and neovascularization. The pathologies induced by long-term ocular MCMV latency share features of previously described human ocular diseases, such as age-related macular degeneration.
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Affiliation(s)
- Jinxian Xu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Xinglou Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Xinyan Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; Charlie Norwood Veterans Affairs Medical Center, Augusta, Georgia
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Ophthamology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Diego G Espinosa-Heidmann
- James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Ophthamology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia; James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia.
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Mo J, Atherton SS, Wang L, Liu S. Autophagy protects against retinal cell death in mouse model of cytomegalovirus retinitis. BMC Ophthalmol 2019; 19:146. [PMID: 31291924 PMCID: PMC6621936 DOI: 10.1186/s12886-019-1141-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Extensive death of uninfected bystander neuronal cells is an important component of the pathogenesis of cytomegalovirus retinitis (CMV). Our previous results have shown that there is a functional relationship between autophagy and apoptosis during MCMV infection of retinal pigment epithelium (RPE). The purpose of this study was to determine whether autophagy plays a significant role in the death of retinal cells during MCMV retinitis. METHODS The retinas of adult BALB/c mice were infected with MCMV via supraciliary injection. Rapamycin, a mTOR inhibitor, was injected to MCMV-infected BALB/c mice intraperitoneally. Immunohistochemistry and western blot were performed to observe the spread pattern of virus in retinas and the levels of targeted proteins. Plaque assay was performed to determine the virus titer in different groups. Since Atg5 is a key gene regulating autophagy, we bred Atg5flox/flox; Nestin-Cre mice to deeply elucidate the role of autophagy during MCMV retinitis. Atg5flox/flox; Nestin-Cre mice were genotyped and infected with MCMV. Immunohistochemistry was performed to observe the type of virus-infected cells and apoptosis in retinas during MCMV retinitis. RESULTS In MCMV mouse model, MCMV infection in outer nuclear layer (ONL) and inner nuclear layer (INL) in the retinas caused cleaved caspase 3 positive apoptosis, which is not co-localized with early antigen (EA) positive virus infected cells in rapamycin treated group. Rapamycin treatment increased the levels of LC3B-II by inhibiting mTOR and decreased the levels of cleaved caspase-3 during MCMV retinitis. However, virus propagation was not affected by rapamycin. In Atg5flox/flox; Nestin-Cre mice, RPE and glial cells were the main targets of viral infection, and number of EA positive retinal cells and TUNEL positive retinal cells was significantly increased compared to Atg5flox/+; Nestin-Cre mice though there was no difference of virus propagation between Atg5flox/flox; Nestin-Cre mice and Atg5flox/+; Nestin-Cre mice. CONCLUSIONS Autophagy protects retinal cells from MCMV infection induced apoptosis through mTOR-mediated signaling pathway.
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Affiliation(s)
- Juan Mo
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan Province, 450003, People's Republic of China. .,Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - Sally S Atherton
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA
| | - Liya Wang
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan Province, 450003, People's Republic of China
| | - Susu Liu
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan Province, 450003, People's Republic of China
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Xu J, Mo J, Liu X, Marshall B, Atherton SS, Dong Z, Smith S, Zhang M. Depletion of the Receptor-Interacting Protein Kinase 3 (RIP3) Decreases Photoreceptor Cell Death During the Early Stages of Ocular Murine Cytomegalovirus Infection. Invest Ophthalmol Vis Sci 2019; 59:2445-2458. [PMID: 29847649 PMCID: PMC5957522 DOI: 10.1167/iovs.18-24086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose The purpose of this study was to determine if the receptor-interacting protein kinase 3 (RIP3) plays a significant role in innate immune responses and death of bystander retinal neurons during murine cytomegalovirus (MCMV) retinal infection, by comparing the innate immune response and cell death in RIP3-depleted mice (Rip3−/−) and Rip3+/+ control mice. Methods Rip3−/− and Rip3+/+ mice were immunosuppressed (IS) and inoculated with MCMV via the supraciliary route. Virus-injected and mock-injected control eyes were removed at days 4, 7, and 10 post infection (p.i.) and markers of innate immunity and cell death were analyzed. Results Compared to Rip3+/+ mice, significantly more MCMV was recovered and more MCMV-infected RPE cells were observed in injected eyes of Rip3−/− mice at days 4 and 7 p.i. In contrast, fewer TUNEL-stained photoreceptors were observed in Rip3−/− eyes than in Rip3+/+ eyes at these times. Electron microscopy showed that significantly more apoptotic photoreceptor cells were present in Rip3+/+ mice than in Rip3−/− mice. Immunohistochemistry showed that the majority of TUNEL-stained photoreceptors died via mitochondrial flavoprotein apoptosis-inducing factor (AIF)-mediated, caspase 3–independent apoptosis. The majority of RIP3-expressing cells in infected eyes were RPE cells, microglia/macrophages, and glia, whereas retinal neurons contained much lower amounts of RIP3. Western blots showed significantly higher levels of activated nuclear factor–κB and caspase 1 were present in Rip3+/+ eyes compared to Rip3−/− eyes. Conclusions Our results suggest that RIP3 enhances innate immune responses against ocular MCMV infection via activation of the inflammasome and nuclear factor–κB, which also leads to inflammation and death of bystander cells by multiple pathways including apoptosis and necroptosis.
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Affiliation(s)
- Jinxian Xu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Juan Mo
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Xinglou Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sally S Atherton
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sylvia Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.,James and Jean Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
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Marshall B, Mo J, Covar J, Atherton SS, Zhang M. Decrease of murine cytomegalovirus-induced retinitis by intravenous delivery of immediate early protein-3-specific siRNA. Invest Ophthalmol Vis Sci 2014; 55:4151-7. [PMID: 24906861 DOI: 10.1167/iovs.14-14375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Retinitis induced by both human and murine cytomegaloviruses following immunosuppression is characterized by progressive loss of retinal architecture, due to necrosis of virus-infected cells as well as widespread apoptosis of uninfected bystander cells. Because small inhibitory RNA molecules (siRNA) can reduce murine cytomegalovirus (MCMV) gene expression and thereby inhibit virus replication in vitro, we tested siRNAs directed against MCMV immediate early protein-3 (IE-3) to determine if MCMV-induced retinitis could be alleviated in vivo. METHODS Immunosuppressed Balb/c mice (2.0 mg methylprednisolone acetate every 3 days beginning on day -2) were infected with 5 × 10(3) pfu of the K181 strain of MCMV via the supraciliary route. At day 2 post infection, mice were treated with various doses of IE-3-specific siRNA ranging from 0.1 nmol to 10 nmol, in a volume of 20 μL PBS via tail vein injection. Injected eyes were collected at various times post inoculation and subjected to plaque assay for virus titer, MCMV antigen staining, H&E staining, TUNEL assay, and Western blot for MCMV IE-3 protein. RESULTS Small but significant amounts of fluorescently labeled IE-3-specific siRNA localized to the RPE layer 48 hours after intravenous injection. IE-3-specific siRNA significantly reduced virus titers at all concentrations tested (ranging from 0.1 nmol to 10 nmol), but the most potent effect of siRNA was observed at a dose of 1 nmol. We also observed that IE-3-specific siRNA produced a substantial decrease in MCMV titers and a substantial reduction in bystander cell apoptosis over the time course of virus infection. CONCLUSIONS Systemic administration of IE-3-specific siRNA could alleviate MCMV retinitis by inhibiting virus replication and subsequent death of uninfected retinal cells.
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Affiliation(s)
- Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, United States
| | - Juan Mo
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, United States
| | - Jason Covar
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, United States
| | - Sally S Atherton
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, United States
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, United States
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Zhang M, Marshall B, Atherton SS. Murine cytomegalovirus infection and apoptosis in organotypic retinal cultures. Invest Ophthalmol Vis Sci 2008; 49:295-303. [PMID: 18172106 DOI: 10.1167/iovs.07-0612] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE An organotypic retinal culture model was used to determine the pattern of murine cytomegalovirus (MCMV) infection and whether apoptosis is induced in MCMV-infected cultured retinas. METHODS Retinas harvested from C57BL/6 mice were individually cultured at 37 degrees C on 3-microm filter inserts placed in 24-well plates. Some retinas were infected with MCMV (5 x 10(5) PFU/well). At days 4, 7, and 11 after infection (pi), the culture medium and cultured retinas were collected for examination. RESULTS Replicating virus was recovered and viral early antigen (EA)- and late antigen (LA)-positive cells were observed in the MCMV-infected retinal cultures. Most MCMV-infected cells were glia and horizontal cells. Infection resulted in atrophy of the photoreceptor cells and cytomegaly. Apoptosis of uninfected bystander cells, including photoreceptor cells and horizontal cells, was observed. TNF-alpha was produced by activated microglia during MCMV infection of the retina. Mouse apoptosis microarray studies, caspase activity studies, and RT-PCR studies showed that the genes involved in both the death receptor-mediated apoptotic pathway and the mitochondrial pathway were upregulated. CONCLUSIONS Many aspects of MCMV infection of retinal cultures parallel those observed during MCMV retinitis in mice. Thus, this in vitro system may be used to explore the role of apoptosis of uninfected retinal cells and the contribution of cytokines and other modulators to the pathogenesis of CMV retinitis.
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Affiliation(s)
- Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA 30912, USA
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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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Roback JD, Hossain MS, Lezhava L, Gorechlad JW, Alexander SA, Jaye DL, Mittelstaedt S, Talib S, Hearst JE, Hillyer CD, Waller EK. Allogeneic T cells treated with amotosalen prevent lethal cytomegalovirus disease without producing graft-versus-host disease following bone marrow transplantation. THE JOURNAL OF IMMUNOLOGY 2004; 171:6023-31. [PMID: 14634114 DOI: 10.4049/jimmunol.171.11.6023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infusion of donor antiviral T cells can provide protective immunity for recipients of hemopoietic progenitor cell transplants, but may cause graft-vs-host disease (GVHD). Current methods of separating antiviral T cells from the alloreactive T cells that produce GVHD are neither routine nor rapid. In a model of lethal murine CMV (MCMV) infection following MHC-mismatched bone marrow transplantation, infusion of MCMV-immune donor lymphocytes pretreated with the DNA cross-linking compound amotosalen prevented MCMV lethality without producing GVHD. Although 95% of mice receiving 30 x 10(6) pretreated donor lymphocytes survived beyond day +100 without MCMV disease or GVHD, all mice receiving equivalent numbers of untreated lymphocytes rapidly died of GVHD. In vitro, amotosalen blocked T cell proliferation without suppressing MCMV peptide-induced IFN-gamma production by MCMV-primed CD8(+) T cells. In vivo, pretreated lymphocytes reduced hepatic MCMV load by 4-log(10) and promoted full hemopoietic chimerism. Amotosalen-treated, MCMV tetramer-positive memory (CD44(high)) CD8(+) T cells persisted to day +100 following infusion, and expressed IFN-gamma when presented with viral peptide. Pretreated T cells were effective at preventing MCMV lethality over a wide range of concentrations. Thus, amotosalen treatment rapidly eliminates the GVHD activity of polyclonal T cells, while preserving long-term antiviral and graft facilitation effects, and may be clinically useful for routine adoptive immunotherapy.
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Affiliation(s)
- John D Roback
- Department of Pathology and Laboratory Medicine, Transfusion Medicine Program, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Zhang M, Atherton SS. Apoptosis in the retina during MCMV retinitis in immunosuppressed BALB/c mice. J Clin Virol 2002; 25 Suppl 2:S137-47. [PMID: 12361764 DOI: 10.1016/s1386-6532(02)00102-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Cytomegalovirus (CMV) retinitis is the most common opportunistic ocular infection observed in immunosuppressed (IS) adult and pediatric patients. Due to the species restriction of the cytomegaloviruses, mice infected with murine CMV (MCMV) have been used to study the pathogenesis of CMV retinitis. OBJECTIVES The objectives of this study were to determine if retinal glial cells are the targets of MCMV infection and to determine which cells in the retina become apoptotic following inoculation of MCMV via the supraciliary route. STUDY DESIGN Adult female BALB/c mice were IS with methylprednisolone; one half of the mice were injected with MCMV and one half of the mice were injected with an equivalent volume of tissue culture medium via the supraciliary route. Animals were sacrificed and frozen sections of eyes were stained for MCMV early antigen, RPE65, CD45 or TUNEL; additional slides were double stained with combinations of the above reagents. RESULTS AND CONCLUSIONS The results indicate that most apoptotic cells in the retina were not virus infected, most apoptotic cells were not infiltrating CD45 positive leukocytes, and retinal glial cells were infected with MCMV but only late in infection. Together, these results suggest that retinal cells that undergo apoptosis during MCMV infection are neurons and that apoptosis of uninfected bystander cells is an important component of the pathogenesis of CMV retinitis.
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Affiliation(s)
- Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA 30912, USA
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Loh LC, Keeler VD, Shanley JD. Sequence requirements for the nuclear localization of the murine cytomegalovirus M44 gene product pp50. Virology 1999; 259:43-59. [PMID: 10364488 DOI: 10.1006/viro.1999.9700] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The murine cytomegalovirus (MCMV) M44 gene product pp50 is normally present in the nuclei of virus-infected cells. During transient expression of pp50 in COS-1 cells, the phosphoprotein was readily detectable in the nuclei, indicating that it possesses a nuclear localization signal (NLS). Studies on the subcellular locations of N- and C-terminal deletion mutants of pp50 suggested that alterations in both the C terminus and the highly conserved N-terminal domains of pp50 affect nuclear localization. In particular, the C-terminal 11 amino acids of pp50, which includes a "KKQK" motif, were able to mediate the import of a beta-galactosidase fusion protein into the nucleus. The pair of lysine residues in this motif constitutes an essential element of the C-terminal NLS as mutation of this motif to AAQK directly affected the nuclear localization of either pp50 or beta-galactosidase fusion proteins containing the C-terminal portion of pp50. Furthermore our results indicated that the functionality of the C-terminal NLS is dependent on the structural integrity of the highly conserved N-terminal portion of the molecule, as deletion of amino acids 157-201 alone adversely affected nuclear localization. In the absence of a functional C-terminal NLS, the subcellular localization of pp50 is sensitive to potential conformational changes induced by mutations within the N-terminal half of the molecule. Under those circumstances, mutation of the YK residues at position 22-23 or deletion of amino acids 267-283 was sufficient to produce a protein that was impaired in nuclear import or retention.
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Affiliation(s)
- L C Loh
- Department of Microbiology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada.
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Plachter B, Nordin M, Wirgart BZ, Mach M, Stein H, Grillner L, Jahn G. The DNA-binding protein P52 of human cytomegalovirus reacts with monoclonal antibody CCH2 and associates with the nuclear membrane at late times after infection. Virus Res 1992; 24:265-76. [PMID: 1329369 DOI: 10.1016/0168-1702(92)90123-q] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Monoclonal antibody CCH2 is commonly used for the detection of human cytomegalovirus (HCMV) infected cells in tissue sections as well as in cultured cells. The specificity of CCH2 was determined by screening a recombinant lambda-gt11 cDNA gene bank from HCMV-infected fibroblasts. By sequencing a reactive clone, the antigen was identified to be the non-structural DNA binding protein p52 of HCMV (UL44 reading frame). The viral insert from the lambda clone was recloned in bacterial expression vectors. For this, a new vector, pRos-RS, was constructed. The resulting clones were tested in immunoblot analyses. They were reactive with CCH2 as well as with reconvalescent sera positive for antibodies against HCMV, by this proving the specificity of CCH2. Using this monoclonal antibody in confocal microscopy, the subcellular localization of p52 in infected cells was analyzed. In these analyses, p52 was found to be nuclear and to be associated with the nuclear membrane at late times after infection.
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Affiliation(s)
- B Plachter
- Institut für Klinische und Molekulare Virologie, Universität Erlangen-Nürnberg, Germany
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