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Taher H, Mahyari E, Kreklywich C, Uebelhoer LS, McArdle MR, Moström MJ, Bhusari A, Nekorchuk M, E X, Whitmer T, Scheef EA, Sprehe LM, Roberts DL, Hughes CM, Jackson KA, Selseth AN, Ventura AB, Cleveland-Rubeor HC, Yue Y, Schmidt KA, Shao J, Edlefsen PT, Smedley J, Kowalik TF, Stanton RJ, Axthelm MK, Estes JD, Hansen SG, Kaur A, Barry PA, Bimber BN, Picker LJ, Streblow DN, Früh K, Malouli D. In vitro and in vivo characterization of a recombinant rhesus cytomegalovirus containing a complete genome. PLoS Pathog 2020; 16:e1008666. [PMID: 33232376 PMCID: PMC7723282 DOI: 10.1371/journal.ppat.1008666] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/08/2020] [Accepted: 09/30/2020] [Indexed: 02/07/2023] Open
Abstract
Cytomegaloviruses (CMVs) are highly adapted to their host species resulting in strict species specificity. Hence, in vivo examination of all aspects of CMV biology employs animal models using host-specific CMVs. Infection of rhesus macaques (RM) with rhesus CMV (RhCMV) has been established as a representative model for infection of humans with HCMV due to the close evolutionary relationships of both host and virus. However, the only available RhCMV clone that permits genetic modifications is based on the 68-1 strain which has been passaged in fibroblasts for decades resulting in multiple genomic changes due to tissue culture adaptations. As a result, 68-1 displays reduced viremia in RhCMV-naïve animals and limited shedding compared to non-clonal, low passage isolates. To overcome this limitation, we used sequence information from primary RhCMV isolates to construct a full-length (FL) RhCMV by repairing all mutations affecting open reading frames (ORFs) in the 68-1 bacterial artificial chromosome (BAC). Inoculation of adult, immunocompetent, RhCMV-naïve RM with the reconstituted virus resulted in significant viremia in the blood similar to primary isolates of RhCMV and furthermore led to high viral genome copy numbers in many tissues at day 14 post infection. In contrast, viral dissemination was greatly reduced upon deletion of genes also lacking in 68-1. Transcriptome analysis of infected tissues further revealed that chemokine-like genes deleted in 68-1 are among the most highly expressed viral transcripts both in vitro and in vivo consistent with an important immunomodulatory function of the respective proteins. We conclude that FL-RhCMV displays in vitro and in vivo characteristics of a wildtype virus while being amenable to genetic modifications through BAC recombineering techniques.
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Affiliation(s)
- Husam Taher
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Eisa Mahyari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Craig Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Luke S. Uebelhoer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Matthew R. McArdle
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Matilda J. Moström
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Amruta Bhusari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Michael Nekorchuk
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Xiaofei E
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Travis Whitmer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Elizabeth A. Scheef
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Lesli M. Sprehe
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Dawn L. Roberts
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Colette M. Hughes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Kerianne A. Jackson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Andrea N. Selseth
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Abigail B. Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Hillary C. Cleveland-Rubeor
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Yujuan Yue
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Kimberli A. Schmidt
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Jason Shao
- Statistical Center for HIV/AIDS Research and Prevention, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Paul T. Edlefsen
- Statistical Center for HIV/AIDS Research and Prevention, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Jeremy Smedley
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Timothy F. Kowalik
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Richard J. Stanton
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Michael K. Axthelm
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Jacob D. Estes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Scott G. Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Amitinder Kaur
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, United States of America
| | - Peter A. Barry
- Center for Comparative Medicine and Department of Medical Pathology, University of California, Davis, California, United States of America
| | - Benjamin N. Bimber
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Louis J. Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel N. Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
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2
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Marshall EE, Malouli D, Hansen SG, Gilbride RM, Hughes CM, Ventura AB, Ainslie E, Selseth AN, Ford JC, Burke D, Kreklywich CN, Womack J, Legasse AW, Axthelm MK, Kahl C, Streblow D, Edlefsen PT, Picker LJ, Früh K. Enhancing safety of cytomegalovirus-based vaccine vectors by engaging host intrinsic immunity. Sci Transl Med 2019; 11:eaaw2603. [PMID: 31316006 PMCID: PMC6830438 DOI: 10.1126/scitranslmed.aaw2603] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/14/2019] [Accepted: 06/13/2019] [Indexed: 12/29/2022]
Abstract
Rhesus cytomegalovirus (RhCMV)-based vaccines maintain effector memory T cell responses (TEM) that protect ~50% of rhesus monkeys (RMs) challenged with simian immunodeficiency virus (SIV). Because human CMV (HCMV) causes disease in immunodeficient subjects, clinical translation will depend upon attenuation strategies that reduce pathogenic potential without sacrificing CMV's unique immunological properties. We demonstrate that "intrinsic" immunity can be used to attenuate strain 68-1 RhCMV vectors without impairment of immunogenicity. The tegument proteins pp71 and UL35 encoded by UL82 and UL35 of HCMV counteract cell-intrinsic restriction via degradation of host transcriptional repressors. When the corresponding RhCMV genes, Rh110 and Rh59, were deleted from 68-1 RhCMV (ΔRh110 and ΔRh59), we observed only a modest growth defect in vitro, but in vivo, these modified vectors manifested little to no amplification at the injection site and dissemination to distant sites, in contrast to parental 68-1 RhCMV. ΔRh110 was not shed at any time after infection and was not transmitted to naïve hosts either by close contact (mother to infant) or by leukocyte transfusion. In contrast, ΔRh59 was both shed and transmitted by leukocyte transfusion, indicating less effective attenuation than pp71 deletion. The T cell immunogenicity of ΔRh110 was essentially identical to 68-1 RhCMV with respect to magnitude, TEM phenotype, epitope targeting, and durability. Thus, pp71 deletion preserves CMV vector immunogenicity while stringently limiting vector spread, making pp71 deletion an attractive attenuation strategy for HCMV vectors.
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Affiliation(s)
- Emily E Marshall
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Scott G Hansen
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Roxanne M Gilbride
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Colette M Hughes
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Abigail B Ventura
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Emily Ainslie
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Andrea N Selseth
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Julia C Ford
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - David Burke
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Craig N Kreklywich
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Jennie Womack
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Alfred W Legasse
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Michael K Axthelm
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Christoph Kahl
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Daniel Streblow
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Paul T Edlefsen
- Statistical Center for HIV/AIDS Research and Prevention, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Louis J Picker
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
| | - Klaus Früh
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
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Kolb P, Sijmons S, McArdle MR, Taher H, Womack J, Hughes C, Ventura A, Jarvis MA, Stahl-Hennig C, Hansen S, Picker LJ, Malouli D, Hengel H, Früh K. Identification and Functional Characterization of a Novel Fc Gamma-Binding Glycoprotein in Rhesus Cytomegalovirus. J Virol 2019; 93:e02077-18. [PMID: 30487278 PMCID: PMC6364020 DOI: 10.1128/jvi.02077-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022] Open
Abstract
Receptors recognizing the Fc part of immunoglobulin G (FcγRs) are key determinants in antibody-mediated immune responses. Members of the Herpesviridae interfere with this immune regulatory network by expressing viral FcγRs (vFcγRs). Human cytomegalovirus (HCMV) encodes four distinct vFcγRs that differ with respect to their IgG subtype specificity and their impact on antibody-mediated immune function in vitro The impact of vFcγRs on HCMV pathogenesis and immunomodulation in vivo is not known. The closest evolutionary animal model of HCMV is rhesus CMV (RhCMV) infection of rhesus macaques. To enable the characterization of vFcγR function in this model, we studied IgG binding by RhCMV. We show that lysates of RhCMV-infected cells contain an IgG-binding protein of 30 kDa encoded by the gene Rh05 that is a predicted type I glycoprotein belonging to the RL11 gene family. Upon deletion of Rh05, IgG-Fc binding by RhCMV strain 68-1 is lost, whereas ectopic expression of Rh05 results in IgG binding to transfected cells consistent with Rh05 being a vFcγR. Using a set of reporter cell lines stably expressing human and rhesus FcγRs, we further demonstrate that Rh05 antagonizes host FcγR activation. Compared to Rh05-intact RhCMV, RhCMVΔRh05 showed an increased activation of host FcγR upon exposure of infected cells to IgG from RhCMV-seropositive animals, suggesting that Rh05 protects infected cells from opsonization and IgG-dependent activation of host FcγRs. However, antagonizing host FcγR activation by Rh05 was not required for the establishment and maintenance of infection of RhCMV, even in a seropositive host, as shown by the induction of T cell responses to heterologous antigens expressed by RhCMV lacking the gene region encoding Rh05. In contrast to viral evasion of natural killer cells or T cell recognition, the evasion of antibody-mediated effects does not seem to be absolutely required for infection or reinfection. The identification of the first vFcγR that efficiently antagonizes host FcγR activation in the RhCMV genome will thus permit more detailed studies of this immunomodulatory mechanism in promoting viral dissemination in the presence of natural or vaccine-induced humoral immunity.IMPORTANCE Rhesus cytomegalovirus (RhCMV) offers a unique model for studying human cytomegalovirus (HCMV) pathogenesis and vaccine development. RhCMV infection of nonhuman primates greatly broadened the understanding of mechanisms by which CMVs evade or reprogram T cell and natural killer cell responses in vivo However, the role of humoral immunity and viral modulation of anti-CMV antibodies has not been studied in this model. There is evidence from in vitro studies that HCMVs can evade humoral immunity. By gene mapping and with the help of a novel cell-based reporter assay system we characterized the first RhCMV encoded IgG-Fcγ binding glycoprotein as a potent antagonist of rhesus FcγR activation. We further demonstrate that, unlike evasion of T cell immunity, this viral Fcγ receptor is not required to overcome anti-CMV immunity to establish secondary infections. These findings enable more detailed studies of the in vivo consequences of CMV evasion from IgG responses in nonhuman primate models.
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Affiliation(s)
- Philipp Kolb
- Institute of Virology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Steven Sijmons
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Matthew R McArdle
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Husam Taher
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Jennie Womack
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Colette Hughes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Abigail Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Michael A Jarvis
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | | | - Scott Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Hartmut Hengel
- Institute of Virology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
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The Human Cytomegalovirus Endoplasmic Reticulum-Resident Glycoprotein UL148 Activates the Unfolded Protein Response. J Virol 2018; 92:JVI.00896-18. [PMID: 30045994 DOI: 10.1128/jvi.00896-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/19/2018] [Indexed: 12/30/2022] Open
Abstract
Eukaryotic cells are equipped with three sensors that respond to the accumulation of misfolded proteins within the lumen of the endoplasmic reticulum (ER) by activating the unfolded protein response (UPR), which functions to resolve proteotoxic stresses involving the secretory pathway. Here, we identify UL148, a viral ER-resident glycoprotein from human cytomegalovirus (HCMV), as an inducer of the UPR. Metabolic labeling results indicate that global mRNA translation is decreased when UL148 expression is induced in uninfected cells. Further, we find that ectopic expression of UL148 is sufficient to activate at least two UPR sensors: the inositol-requiring enzyme-1 (IRE1), as indicated by splicing of Xbp-1 mRNA, and the protein kinase R (PKR)-like ER kinase (PERK), as indicated by phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α) and accumulation of activating transcription factor 4 (ATF4). During wild-type HCMV infection, increases in Xbp-1 splicing, eIF2α phosphorylation, and accumulation of ATF4 accompany UL148 expression. UL148-null infections, however, show reduced levels of these UPR indicators and decreases in XBP1s abundance and in phosphorylation of PERK and IRE1. Small interfering RNA (siRNA) depletion of PERK dampened the extent of eIF2α phosphorylation and ATF4 induction observed during wild-type infection, implicating PERK as opposed to other eIF2α kinases. A virus with UL148 disrupted showed significant 2- to 4-fold decreases during infection in the levels of transcripts canonically regulated by PERK/ATF4 and by the ATF6 pathway. Taken together, our results argue that UL148 is sufficient to activate the UPR when expressed ectopically and that UL148 is an important cause of UPR activation in the context of the HCMV-infected cell.IMPORTANCE The unfolded protein response (UPR) is an ancient cellular response to ER stress that is of broad importance to viruses. Certain consequences of the UPR, including mRNA degradation and translational shutoff, would presumably be disadvantageous to viruses, while other attributes of the UPR, such as ER expansion and upregulation of protein folding chaperones, might enhance viral replication. Although HCMV is estimated to express well over 150 different viral proteins, we show that the HCMV ER-resident glycoprotein UL148 contributes substantially to the UPR during infection and, moreover, is sufficient to activate the UPR in noninfected cells. Experimental activation of the UPR in mammalian cells is difficult to achieve without the use of toxins. Therefore, UL148 may provide a new tool to investigate fundamental aspects of the UPR. Furthermore, our findings may have implications for understanding the mechanisms underlying the effects of UL148 on HCMV cell tropism and evasion of cell-mediated immunity.
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Suppression of costimulation by human cytomegalovirus promotes evasion of cellular immune defenses. Proc Natl Acad Sci U S A 2018; 115:4998-5003. [PMID: 29691324 PMCID: PMC5948980 DOI: 10.1073/pnas.1720950115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CD58 is an adhesion molecule that is known to play a critical role in costimulation of effector cells and is intrinsic to immune synapse structure. Herein, we describe a virally encoded gene that inhibits CD58 surface expression. Human cytomegalovirus (HCMV) UL148 was necessary and sufficient to promote intracellular retention of CD58 during HCMV infection. Blocking studies with antagonistic anti-CD58 mAb and an HCMV UL148 deletion mutant (HCMV∆UL148) with restored CD58 expression demonstrated that the CD2/CD58 axis was essential for the recognition of HCMV-infected targets by CD8+ HCMV-specific cytotoxic T lymphocytes (CTLs). Further, challenge of peripheral blood mononuclear cells ex vivo with HCMV∆UL148 increased both CTL and natural killer (NK) cell degranulation against HCMV-infected cells, including NK-driven antibody-dependent cellular cytotoxicity, showing that UL148 is a modulator of the function of multiple effector cell subsets. Our data stress the effect of HCMV immune evasion functions on shaping the immune response, highlighting the capacity for their potential use in modulating immunity during the development of anti-HCMV vaccines and HCMV-based vaccine vectors.
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Antagonism of the Protein Kinase R Pathway in Human Cells by Rhesus Cytomegalovirus. J Virol 2018; 92:JVI.01793-17. [PMID: 29263260 DOI: 10.1128/jvi.01793-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/12/2017] [Indexed: 01/19/2023] Open
Abstract
While cytomegalovirus (CMV) infections are often limited in host range by lengthy coevolution with a single host species, a few CMVs are known to deviate from this rule. For example, rhesus macaque CMV (RhCMV), a model for human CMV (HCMV) pathogenesis and vaccine development, can replicate in human cells, as well as in rhesus cells. Both HCMV and RhCMV encode species-specific antagonists of the broadly acting host cell restriction factor protein kinase R (PKR). Although the RhCMV antagonist of PKR, rTRS1, has very limited activity against human PKR, here, we show it is essential for RhCMV replication in human cells because it prevents human PKR from phosphorylating the translation initiation factor eIF2α, thereby allowing continued translation and viral replication. Although rTRS1 is necessary for RhCMV replication, it is not sufficient to rescue replication of HCMV lacking its own PKR antagonists in human fibroblasts. However, overexpression of rTRS1 in human fibroblasts enabled HCMV expressing rTRS1 to replicate, indicating that elevated levels or early expression of a weak antagonist can counteract a resistant restriction factor like human PKR. Exploring potential mechanisms that might allow RhCMV to replicate in human cells revealed that RhCMV makes no less double-stranded RNA than HCMV. Rather, in human cells, RhCMV expresses rTRS1 at levels 2 to 3 times higher than those of the HCMV-encoded PKR antagonists during HCMV infection. These data suggest that even a modest increase in expression of this weak PKR antagonist is sufficient to enable RhCMV replication in human cells.IMPORTANCE Rhesus macaque cytomegalovirus (RhCMV) offers a valuable model for studying congenital human cytomegalovirus (HCMV) pathogenesis and vaccine development. Therefore, it is critical to understand variations in how each virus infects and affects its host species to be able to apply insights gained from the RhCMV model to HCMV. While HCMV is capable only of infecting cells from humans and very closely related species, RhCMV displays a wider host range, including human as well as rhesus cells. RhCMV expresses an antagonist of a broadly acting antiviral factor present in all mammalian cells, and its ability to counter both the rhesus and human versions of this host factor is a key component of RhCMV's ability to cross species barriers. Here, we examine the molecular mechanisms that allow this RhCMV antagonist to function against a human restriction factor.
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7
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Sturgill ER, Malouli D, Hansen SG, Burwitz BJ, Seo S, Schneider CL, Womack JL, Verweij MC, Ventura AB, Bhusari A, Jeffries KM, Legasse AW, Axthelm MK, Hudson AW, Sacha JB, Picker LJ, Früh K. Natural Killer Cell Evasion Is Essential for Infection by Rhesus Cytomegalovirus. PLoS Pathog 2016; 12:e1005868. [PMID: 27580123 PMCID: PMC5006984 DOI: 10.1371/journal.ppat.1005868] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 08/12/2016] [Indexed: 02/06/2023] Open
Abstract
The natural killer cell receptor NKG2D activates NK cells by engaging one of several ligands (NKG2DLs) belonging to either the MIC or ULBP families. Human cytomegalovirus (HCMV) UL16 and UL142 counteract this activation by retaining NKG2DLs and US18 and US20 act via lysomal degradation but the importance of NK cell evasion for infection is unknown. Since NKG2DLs are highly conserved in rhesus macaques, we characterized how NKG2DL interception by rhesus cytomegalovirus (RhCMV) impacts infection in vivo. Interestingly, RhCMV lacks homologs of UL16 and UL142 but instead employs Rh159, the homolog of UL148, to prevent NKG2DL surface expression. Rh159 resides in the endoplasmic reticulum and retains several NKG2DLs whereas UL148 does not interfere with NKG2DL expression. Deletion of Rh159 releases human and rhesus MIC proteins, but not ULBPs, from retention while increasing NK cell stimulation by infected cells. Importantly, RhCMV lacking Rh159 cannot infect CMV-naïve animals unless CD8+ cells, including NK cells, are depleted. However, infection can be rescued by replacing Rh159 with HCMV UL16 suggesting that Rh159 and UL16 perform similar functions in vivo. We therefore conclude that cytomegaloviral interference with NK cell activation is essential to establish but not to maintain chronic infection. Natural killer (NK) cells are an important subset of the innate immune system that rapidly responds to cellular transformation and infection. The importance of NK cell control of viral infection is dramatically illustrated by our results revealing that cytomegalovirus (CMV) is unable to establish infections in healthy individuals unless NK cell responses are subverted. By studying infection of rhesus macaques with rhesus CMV, a highly representative animal model for human CMV, we identified a key viral factor that allows RhCMV to limit NK cell activation by preventing NK cell activating ligands from trafficking to the cell surface. Importantly, we observed that this avoidance of NK cell activation is essential to establish infection in vivo because RhCMV lacking the NK cell evasion factor was unable to infect animals unless NK cells were depleted. By unmasking such viral stealth strategies it might be possible to harness innate immunity to prevent viral infection, the primary goal of CMV vaccine development.
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Affiliation(s)
- Elizabeth R. Sturgill
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Daniel Malouli
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Scott G. Hansen
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Benjamin J. Burwitz
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Seongkyung Seo
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Christine L. Schneider
- Department of Life Sciences, Carroll University, Waukesha, Wisconsin, United States of America
| | - Jennie L. Womack
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Marieke C. Verweij
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Abigail B. Ventura
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Amruta Bhusari
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Krystal M. Jeffries
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Alfred W. Legasse
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Michael K. Axthelm
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Amy W. Hudson
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Jonah B. Sacha
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Louis J. Picker
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
- * E-mail:
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8
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Russell JNH, Marsh AK, Willer DO, Ambagala APN, Dzamba M, Chan JK, Pilon R, Fournier J, Brudno M, Antony JM, Sandstrom P, Evans BJ, MacDonald KS. A novel strain of cynomolgus macaque cytomegalovirus: implications for host-virus co-evolution. BMC Genomics 2016; 17:277. [PMID: 27044312 PMCID: PMC4820910 DOI: 10.1186/s12864-016-2588-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 03/14/2016] [Indexed: 12/20/2022] Open
Abstract
Background Cytomegaloviruses belong to a large, ancient, genus of DNA viruses comprised of a wide array of species-specific strains that occur in diverse array of hosts. Methods In this study we sequenced the ~217 Kb genome of a cytomegalovirus isolated from a Mauritius cynomolgus macaque, CyCMV Mauritius, and compared it to previously sequenced cytomegaloviruses from a cynomolgus macaque of Filipino origin (CyCMV Ottawa) and two from Indian rhesus macaques (RhCMV 180.92 and RhCMV 68–1). Results Though more closely related to CyCMV Ottawa, CyCMV Mauritius is less genetically distant from both RhCMV strains than is CyCMV Ottawa. Several individual genes, including homologues of CMV genes RL11B, UL123, UL83b, UL84 and a homologue of mammalian COX-2, show a closer relationship between homologues of CyCMV Mauritius and the RhCMVs than between homologues of CyCMV Mauritius and CyCMV Ottawa. A broader phylogenetic analysis of 12 CMV strains from eight species recovers evolutionary relationships among viral strains that mirror those amongst the host species, further demonstrating co-evolution of host and virus. Conclusions Phylogenetic analyses of rhesus and cynomolgus macaque CMV genome sequences demonstrate co-speciation of the virus and host. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2588-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Angie K Marsh
- Department of Immunology, University of Toronto, Toronto, M5S 1A8, ON, Canada
| | - David O Willer
- Department of Medicine, University of Toronto, Toronto, M5S 1A8, ON, Canada.,Department of Microbiology, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
| | - Aruna P N Ambagala
- Department of Medicine, University of Toronto, Toronto, M5S 1A8, ON, Canada.,Department of Microbiology, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada.,Present Address: Canadian Science Centre for Human and Animal Health, National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, R3E 3M4, MB, Canada
| | - Misko Dzamba
- Department of Computer Science, University of Toronto, Toronto, M5S 1A8, ON, Canada
| | - Jacqueline K Chan
- Department of Medicine, University of Toronto, Toronto, M5S 1A8, ON, Canada.,Department of Microbiology, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
| | - Richard Pilon
- National HIV & Retrovirology Laboratories, Public Health Agency of Canada, Ottawa, K1A 0K9, ON, Canada
| | - Jocelyn Fournier
- Scientific Services Division, Health Products & Food Branch, Health Canada, Ottawa, K1A 0L2, ON, Canada
| | - Michael Brudno
- Department of Computer Science, University of Toronto, Toronto, M5S 1A8, ON, Canada
| | - Joseph M Antony
- Department of Medicine, University of Toronto, Toronto, M5S 1A8, ON, Canada.,Department of Microbiology, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
| | - Paul Sandstrom
- National HIV & Retrovirology Laboratories, Public Health Agency of Canada, Ottawa, K1A 0K9, ON, Canada
| | - Ben J Evans
- Biology Department, McMaster University, Life Sciences Building, 1280 Main Street West, Hamilton, L8S 4K1, ON, Canada
| | - Kelly S MacDonald
- Department of Immunology, University of Toronto, Toronto, M5S 1A8, ON, Canada. .,Department of Medicine, University of Toronto, Toronto, M5S 1A8, ON, Canada. .,Department of Microbiology, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada. .,Section of Infectious Diseases, Department of Internal Medicine, University of Manitoba, 745 Bannatyne Ave, Winnipeg, R3E 0J9, MB, Canada. .,Present Address: University of Manitoba, Basic Medical Sciences Building, Room 501, 745 Bannatyne Ave., Winnipeg, R3E 0J9, MB, Canada.
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9
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Yue Y, Kaur A, Lilja A, Diamond DJ, Walter MR, Barry PA. The susceptibility of primary cultured rhesus macaque kidney epithelial cells to rhesus cytomegalovirus strains. J Gen Virol 2016; 97:1426-1438. [PMID: 26974598 DOI: 10.1099/jgv.0.000455] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Kidney epithelial cells are common targets for human and rhesus cytomegalovirus (HCMV and RhCMV) in vivo, and represent an important reservoir for long-term CMV shedding in urine. To better understand the role of kidney epithelial cells in primate CMV natural history, primary cultures of rhesus macaque kidney epithelial cells (MKE) were established and tested for infectivity by five RhCMV strains, including two wild-type strains (UCD52 and UCD59) and three strains containing different coding contents in UL/b'. The latter strains included 180.92 [containing an intact RhUL128-RhUL130-R hUL131 (RhUL128L) locus but deleted for the UL/b' RhUL148-rh167-loci], 68-1 (RhUL128L-defective and fibroblast-tropic) and BRh68-1.2 (the RhUL128L-repaired version of 68-1). As demonstrated by RhCMV cytopathic effect, plaque formation, growth kinetics and early virus entry, we showed that MKE were differentially susceptible to RhCMV infection, related to UL/b' coding contents of the different strains. UCD52 and UCD59 replicated vigorously in MKE, 68-1 replicated poorly, and 180.92 grew with intermediate kinetics. Reconstitution of RhUL128L in 68-1 (BRh68-1.2) restored its replication efficiency in MKE as compared to UCD52 and UCD59, consistent with the essential role of UL128L for HCMV epithelial tropism. Further analysis revealed that the UL/b' UL148-rh167-loci deletion in 180.92 impaired RhUL132 (rh160) expression. Given that 180.92 retains an intact RhUL128L, but genetically or functionally lacks genes from RhUL132 (rh160) to rh167 in UL/b', its attenuated infection efficiency indicated that, along with RhUL128L, an additional protein(s) encoded within the UL/b' RhUL132 (rh160)-rh167 region (potentially, RhUL132 and/or RhUL148) is indispensable for efficient replication in MKE.
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Affiliation(s)
- Yujuan Yue
- Center for Comparative Medicine, University of California, Davis, CA, USA
| | - Amitinder Kaur
- Department of Immunology, Tulane National Primate Research Center, Tulane University, Covington, LA, USA
| | - Anders Lilja
- Hookipa Biotech AG, Helmut-Qualtinger-Gasse 2, Vienna, Austria.,Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA
| | - Don J Diamond
- Division of Translational Vaccine Research, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Mark R Walter
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Peter A Barry
- Center for Comparative Medicine, University of California, Davis, CA, USA.,Department of Pathology and Laboratory Medicine, University of California, Davis, CA, USA.,California National Primate Research Center, University of California, Davis, CA, USA
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10
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A viral regulator of glycoprotein complexes contributes to human cytomegalovirus cell tropism. Proc Natl Acad Sci U S A 2015; 112:4471-6. [PMID: 25831500 DOI: 10.1073/pnas.1419875112] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Viral glycoproteins mediate entry of enveloped viruses into cells and thus play crucial roles in infection. In herpesviruses, a complex of two viral glycoproteins, gH and gL (gH/gL), regulates membrane fusion events and influences virion cell tropism. Human cytomegalovirus (HCMV) gH/gL can be incorporated into two different protein complexes: a glycoprotein O (gO)-containing complex known as gH/gL/gO, and a complex containing UL128, UL130, and UL131 known as gH/gL/UL128-131. Variability in the relative abundance of the complexes in the virion envelope correlates with differences in cell tropism exhibited between strains of HCMV. Nonetheless, the mechanisms underlying such variability have remained unclear. We have identified a viral protein encoded by the UL148 ORF (UL148) that influences the ratio of gH/gL/gO to gH/gL/UL128-131 and the cell tropism of HCMV virions. A mutant disrupted for UL148 showed defects in gH/gL/gO maturation and enhanced infectivity for epithelial cells. Accordingly, reintroduction of UL148 into an HCMV strain that lacked the gene resulted in decreased levels of gH/gL/UL128-131 on virions and, correspondingly, decreased infectivity for epithelial cells. UL148 localized to the endoplasmic reticulum, but not to the cytoplasmic sites of virion envelopment. Coimmunoprecipitation results indicated that gH, gL, UL130, and UL131 associate with UL148, but that gO and UL128 do not. Taken together, the findings suggest that UL148 modulates HCMV tropism by regulating the composition of alternative gH/gL complexes.
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11
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A human herpesvirus 6A-encoded microRNA: role in viral lytic replication. J Virol 2014; 89:2615-27. [PMID: 25520507 DOI: 10.1128/jvi.02007-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
UNLABELLED Human herpesvirus 6A (HHV-6A), a member of the betaherpesvirus family, is associated with several human diseases. Like all herpesviruses, HHV-6A establishes a lifelong, latent infection in its host. Reactivation of HHV-6A is frequent within the immunosuppressed and immunocompromised populations and results in lytic viral replication within multiple organs, often leading to severe disease. MicroRNAs (miRNAs) are key regulators of multiple cellular processes that regulate the translation of specific transcripts. miRNAs carried by herpesviruses play important roles in modulating the host cell, thereby facilitating a suitable environment for productive viral infection and/or latency. Currently, there are approximately 150 known human herpesvirus-encoded miRNAs, although an miRNA(s) encoded by HHV-6A has yet to be reported. We hypothesized that HHV-6A, like other members of the human herpesvirus family, encodes miRNAs, which function to promote viral infection. We utilized deep sequencing of small RNA species isolated from cells harboring HHV-6A to identify five novel small noncoding RNA species that originate from the viral genome, one of which has the characteristics of a viral miRNA. These RNAs are expressed during productive infection by either bacterial artificial chromosome (BAC)-derived virus in Jjhan cells or wild-type HHV-6A strain U1102 virus in HSB2 cells and are associated with the RNA induced silencing complex (RISC) machinery. Growth analyses of mutant viruses that lack each individual miRNA revealed that a viral miRNA candidate (miR-U86) targets the HHV-6A IE gene U86, thereby regulating lytic replication. The identification and biological characterization of this HHV-6A-specific miRNA is the first step to defining how the virus regulates its life cycle. IMPORTANCE A majority of the human population is infected with human herpesvirus 6A (HHV-6A), a betaherpesvirus family member. Infections usually occur in young children, and upon resolution, the virus remains in a latent state within the host. Importantly, during times of weakened immune responses, the virus can reactivate and is correlated with significant disease states. Viruses encode many different types of factors that both undermine the host antiviral response and regulate viral replication, including small RNA species called microRNAs (miRNAs). Here we report that HHV-6A encodes at least one miRNA, which we named miR-U86. We have characterized the requirement of this viral miRNA and its impact on the viral life cycle and found that it functions to regulate a viral protein important for efficient viral replication. Our data suggest that viral miRNAs are important for HHV-6A and that they may serve as an important therapeutic target to inhibit the virus.
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12
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Limited dissemination and shedding of the UL128 complex-intact, UL/b'-defective rhesus cytomegalovirus strain 180.92. J Virol 2014; 88:9310-20. [PMID: 24899204 DOI: 10.1128/jvi.00162-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED The UL128 complex of human cytomegalovirus (CMV) is a major determinant of viral entry into epithelial and endothelial cells and a target for vaccine development. The UL/b' region of rhesus CMV contains several open reading frames, including orthologs of the UL128 complex. We recently showed that the coding content of the rhesus CMV (RhCMV) UL/b' region predicts acute endothelial tropism and long-term shedding in vivo in the rhesus macaque model of CMV infection. The laboratory-passaged RhCMV 180.92 strain has a truncated UL/b' region but an intact UL128 complex. To investigate whether the presence of the UL128 complex alone was sufficient to confer endothelial and epithelial tropism in vivo, we investigated tissue dissemination and viral excretion following experimental RhCMV 180.92 inoculation of RhCMV-seronegative rhesus macaques. We show the presence of at least two virus variants in the RhCMV 180.92 infectious virus stock. A rare variant noted for a nontruncated wild-type-virus-like UL/b' region, rapidly emerged during in vivo replication and showed high-level replication in blood and tissues and excretion in urine and saliva, features similar to those previously reported in naturally occurring wild-type RhCMV infection. In contrast, the predominant truncated version of RhCMV 180.92 showed significantly lower plasma DNAemia and limited tissue dissemination and viral shedding. These data demonstrate that the truncated RhCMV 180.92 variant is attenuated in vivo and suggest that additional UL/b' genes, besides the UL128 complex, are required for optimal in vivo CMV replication and dissemination. IMPORTANCE An effective vaccine against human CMV infection will need to target genes that are essential for virus propagation and transmission. The human CMV UL128 complex represents one such candidate antigen since it is essential for endothelial and epithelial cell tropism, and is a target for neutralizing antibodies in CMV-infected individuals. In this study, we used the rhesus macaque animal model of CMV infection to investigate the in vivo function of the UL128 complex. Using experimental infection of rhesus macaques with a rhesus CMV virus variant that contained an intact UL128 complex but was missing several other genes, we show that the presence of the UL128 complex alone is not sufficient for widespread tissue dissemination and virus excretion. These data highlight the importance of in vivo studies in evaluating human CMV gene function and suggest that additional UL/b' genes are required for optimal CMV dissemination and transmission.
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13
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Eberhardt MK, Barry PA. Pathogen manipulation of cIL-10 signaling pathways: opportunities for vaccine development? Curr Top Microbiol Immunol 2014; 380:93-128. [PMID: 25004815 DOI: 10.1007/978-3-662-43492-5_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Interleukin-10 (IL-10) is a tightly regulated, pleiotropic cytokine that has profound effects on all facets of the immune system, eliciting cell-type-specific responses within cells expressing the IL-10 receptor (IL-10R). It is considered a master immune regulator, and imbalances in IL-10 expression, resulting from either inherent or infectious etiologies, have far reaching clinical ramifications. Regarding infectious diseases, there has been accumulating recognition that many pathogens, particularly those that establish lifelong persistence, share a commonality of their natural histories: manipulation of IL-10-mediated signaling pathways. Multiple viral, bacterial, protozoal, and fungal pathogens appear to have evolved mechanisms to co-opt normal immune functions, including those involving IL-10R-mediated signaling, and immune effector pathways away from immune-mediated protection toward environments of immune evasion, suppression, and tolerance. As a result, pathogens can persist for the life of the infected host, many of whom possess otherwise competent immune systems. Because of pathogenic avoidance of immune clearance, persistent infections can exact incalculable physical and financial costs, and represent some of the most vexing challenges for improvements in human health. Enormous benefits could be gained by the development of efficient prevention and/or therapeutic strategies that block primary infection, or clear the infection. There are now precedents that indicate that modalities focusing on pathogen-mediated manipulation of IL-10 signaling may have clinical benefit.
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Affiliation(s)
- Meghan K Eberhardt
- Center for Comparative Medicine, University of California, Davis, CA, 95616, USA
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14
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Wagner FM, Brizic I, Prager A, Trsan T, Arapovic M, Lemmermann NAW, Podlech J, Reddehase MJ, Lemnitzer F, Bosse JB, Gimpfl M, Marcinowski L, MacDonald M, Adler H, Koszinowski UH, Adler B. The viral chemokine MCK-2 of murine cytomegalovirus promotes infection as part of a gH/gL/MCK-2 complex. PLoS Pathog 2013; 9:e1003493. [PMID: 23935483 PMCID: PMC3723581 DOI: 10.1371/journal.ppat.1003493] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 05/22/2013] [Indexed: 11/26/2022] Open
Abstract
Human cytomegalovirus (HCMV) forms two gH/gL glycoprotein complexes, gH/gL/gO and gH/gL/pUL(128,130,131A), which determine the tropism, the entry pathways and the mode of spread of the virus. For murine cytomegalovirus (MCMV), which serves as a model for HCMV, a gH/gL/gO complex functionally homologous to the HCMV gH/gL/gO complex has been described. Knock-out of MCMV gO does impair, but not abolish, virus spread indicating that also MCMV might form an alternative gH/gL complex. Here, we show that the MCMV CC chemokine MCK-2 forms a complex with the glycoprotein gH, a complex which is incorporated into the virion. We could additionally show that mutants lacking both, gO and MCK-2 are not able to produce infectious virus. Trans-complementation of these double mutants with either gO or MCK-2 showed that both proteins can promote infection of host cells, although through different entry pathways. MCK-2 has been extensively studied in vivo by others. It has been shown to be involved in attracting cells for virus dissemination and in regulating antiviral host responses. We now show that MCK-2, by forming a complex with gH, strongly promotes infection of macrophages in vitro and in vivo. Thus, MCK-2 may play a dual role in MCMV infection, as a chemokine regulating the host response and attracting specific target cells and as part of a glycoprotein complex promoting entry into cells crucial for virus dissemination. Several human herpesviruses form alternative gH/gL complexes which determine the tropism for different cell types. For murine cytomegalovirus (MCMV), a gH/gL/gO complex has recently been characterized. Here, we present the identification and characterization of an alternative gH/gL/MCK-2 complex which promotes MCMV spread and is important for efficient infection of macrophages in vitro and in vivo. Association of the MCMV CC chemokine MCK-2 with a glycoprotein complex promoting virus entry is a novel function for the well-characterized MCK-2. Virus mutants lacking MCK-2 have been shown to exhibit a reduced capacity to attract leukocytes and a disregulated T cell control of the MCMV infection in vivo. These defects can be attributed to the chemokine function of MCK-2. Yet, the observation that MCK-2 knock-out mutants additionally are impaired in infecting leukocytes in vivo is consistent with our new finding that MCK-2 forms a glycoprotein complex promoting entry into monocytic cells. gH/gL complexes associating with multifunctional proteins add a new level of complexity to the interpretation of infection phenotypes of the respective knock-out herpesviruses.
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Affiliation(s)
- Felicia M. Wagner
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ilija Brizic
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Adrian Prager
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Tihana Trsan
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Maja Arapovic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Niels A. W. Lemmermann
- Institute for Virology and Research Center for Immunology (FZI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jürgen Podlech
- Institute for Virology and Research Center for Immunology (FZI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Matthias J. Reddehase
- Institute for Virology and Research Center for Immunology (FZI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Frederic Lemnitzer
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Jens Bernhard Bosse
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Martina Gimpfl
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Lisa Marcinowski
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Margaret MacDonald
- Laboratory of Virology and Infectious Disease, Rockefeller University, New York, New York, United States of America
| | - Heiko Adler
- Research Unit Gene Vectors, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Ulrich H. Koszinowski
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Barbara Adler
- Max von Pettenkofer-Institute for Virology, Ludwig-Maximilians-University Munich, Munich, Germany
- * E-mail:
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15
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Shimizu A, Kobayashi N, Shimada K, Oura K, Tanaka T, Okamoto A, Kondo K. Novel gene therapy viral vector using non-oncogenic lymphotropic herpesvirus. PLoS One 2013; 8:e56027. [PMID: 23409116 PMCID: PMC3569415 DOI: 10.1371/journal.pone.0056027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 01/04/2013] [Indexed: 01/26/2023] Open
Abstract
Despite the use of retroviral vectors, efficiently introducing target genes into immunocytes such as T cells is difficult. In addition, retroviral vectors carry risks associated with the oncogenicity of the native virus and the potential for introducing malignancy in recipients due to genetic carryover from immortalized cells used during vector production. To address these issues, we have established a new virus vector that is based on human herpesvirus 6 (HHV-6), a non-oncogenic lymphotropic herpesvirus that infects CD4+ T cells, macrophages, and dendritic cells. In the present study, we have altered the cell specificity of the resulting recombinant HHV-6 by knocking out the U2–U8 genes. The resulting virus proliferated only in activated cord blood cells and not in peripheral blood cells. Umbilical cord blood cells produced replication-defective recombinant virus in sufficiently high titer to omit the use of immortalized cells during vector production. HHV-6 vectors led to high rates (>90%) of gene transduction in both CD4+ and CD8+ T cells. These viruses showed low-level replication of viral DNA that supported greater expression of the induced genes than that of other methods but that was insufficient to support the production of replication-competent virus. Furthermore, HHV-6 vectors containing short hairpin RNAs against CD4 and HIV Gag remarkably inhibited the production of these proteins and HIV particles. Here we demonstrate the utility of HHV-6 as a new non-carcinogenic viral vector for immunologic diseases and immunotherapy.
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Affiliation(s)
- Akihiro Shimizu
- Department of Virology, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuyuki Kobayashi
- Department of Virology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazuya Shimada
- Department of Virology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kuniaki Oura
- Department of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, Japan
| | - Tadao Tanaka
- Department of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, Japan
| | - Aikou Okamoto
- Department of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazuhiro Kondo
- Department of Virology, The Jikei University School of Medicine, Tokyo, Japan
- * E-mail:
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16
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Abstract
Cytomegalovirus (CMV) infection is the most common opportunistic infection in immunosuppressed individuals, such as transplant recipients or people living with HIV/AIDS, and congenital CMV is the leading viral cause of developmental disabilities in infants. Due to the highly species-specific nature of CMV, animal models that closely recapitulate human CMV (HCMV) are of growing importance for vaccine development. Here we present the genomic sequence of a novel nonhuman primate CMV from cynomolgus macaques (Macaca fascicularis; CyCMV). CyCMV (Ottawa strain) was isolated from the urine of a healthy, captive-bred, 4-year-old cynomolgus macaque of Philippine origin, and the viral genome was sequenced using next-generation Illumina sequencing to an average of 516-fold coverage. The CyCMV genome is 218,041 bp in length, with 49.5% G+C content and 84% protein-coding density. We have identified 262 putative open reading frames (ORFs) with an average coding length of 789 bp. The genomic organization of CyCMV is largely colinear with that of rhesus macaque CMV (RhCMV). Of the 262 CyCMV ORFs, 137 are homologous to HCMV genes, 243 are homologous to RhCMV 68.1, and 200 are homologous to RhCMV 180.92. CyCMV encodes four ORFs that are not present in RhCMV strain 68.1 or 180.92 but have homologies with HCMV (UL30, UL74A, UL126, and UL146). Similar to HCMV, CyCMV does not produce the RhCMV-specific viral homologue of cyclooxygenase-2. This newly characterized CMV may provide a novel model in which to study CMV biology and HCMV vaccine development.
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17
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Rhesus and human cytomegalovirus glycoprotein L are required for infection and cell-to-cell spread of virus but cannot complement each other. J Virol 2010; 85:2089-99. [PMID: 21191007 DOI: 10.1128/jvi.01970-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rhesus cytomegalovirus (RhCMV), the homolog of human cytomegalovirus (HCMV), serves as a model for understanding the pathogenesis of HCMV and for developing candidate vaccines. In order to develop a replication-defective virus as a vaccine candidate, we constructed RhCMV with glycoprotein L (gL) deleted. RhCMV gL was essential for viral replication, and virus with gL deleted could only replicate in cells expressing RhCMV gL. Noncomplementing cells infected with RhCMV with gL deleted released intact, noninfectious RhCMV particles that were indistinguishable from wild-type RhCMV by electron microscopy and could be rescued by treatment of cells with polyethylene glycol. In addition, noncomplementing cells infected with RhCMV with gL deleted produced levels of gB, the major target of neutralizing antibodies, at levels similar to those observed in cells infected with wild-type RhCMV. Since RhCMV and HCMV gL share 53% amino acid identity, we determined whether the two proteins could complement the heterologous virus. Cells transfected with an HCMV bacterial artificial chromosome with gL deleted yielded virus that could replicate in human cells expressing HCMV gL. This is the second HCMV mutant with an essential glycoprotein deleted that has been complemented in cell culture. Finally, we found that HCMV gL could not complement the replication of RhCMV with gL deleted and that RhCMV gL could not complement the replication of HCMV with gL deleted. These data indicate that RhCMV and HCMV gL are both essential for replication of their corresponding viruses and, although the two gLs are highly homologous, they are unable to complement each another.
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18
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Herpesvirus BACs: past, present, and future. J Biomed Biotechnol 2010; 2011:124595. [PMID: 21048927 PMCID: PMC2965428 DOI: 10.1155/2011/124595] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 08/19/2010] [Indexed: 12/12/2022] Open
Abstract
The herpesviridae are a large family of DNA viruses with large and complicated genomes. Genetic manipulation and the generation of recombinant viruses have been extremely difficult. However, herpesvirus bacterial artificial chromosomes (BACs) that were developed approximately 10 years ago have become useful and powerful genetic tools for generating recombinant viruses to study the biology and pathogenesis of herpesviruses. For example, BAC-directed deletion mutants are commonly used to determine the function and essentiality of viral genes. In this paper, we discuss the creation of herpesvirus BACs, functional analyses of herpesvirus mutants, and future applications for studies of herpesviruses. We describe commonly used methods to create and mutate herpesvirus BACs (such as site-directed mutagenesis and transposon mutagenesis). We also evaluate the potential future uses of viral BACs, including vaccine development and gene therapy.
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Efficient replication of rhesus cytomegalovirus variants in multiple rhesus and human cell types. Proc Natl Acad Sci U S A 2008; 105:19950-5. [PMID: 19064925 DOI: 10.1073/pnas.0811063106] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Rhesus cytomegalovirus infection of rhesus macaques has emerged as a model for human cytomegalovirus pathogenesis. The UL128-UL131 locus of the human virus is a primary determinant for viral entry into epithelial cells, an important cell type during cytomegalovirus infection. Rhesus cytomegalovirus strain 68-1 spreads slowly when grown in cultured rhesus epithelial cells, and it does not code for ORFs corresponding to UL128 and the second exon of UL130. We repaired the UL128-UL131 locus of strain 68-1, using rhesus cytomegalovirus strain 180.92 as template, to generate BRh68-1.1. We also repaired a mutation in the UL36 ORF in BRh68-1.1 to make BRh68-1.2. Both repaired derivatives replicate much more efficiently than parental 68-1 virus in rhesus epithelial cells, suggesting that strain 68-1 may be attenuated. Intriguingly, BRh68-1.1 and BRh68-1.2 replicate efficiently in cultured human epithelial cells and endothelial cells. The extended human cell host range of the repaired viruses raises the possibility that rhesus cytomegalovirus-like viruses will be found in humans.
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