1
|
Varicella-Zoster Virus ORF63 Protects Human Neuronal and Keratinocyte Cell Lines from Apoptosis and Changes Its Localization upon Apoptosis Induction. J Virol 2018; 92:JVI.00338-18. [PMID: 29593042 DOI: 10.1128/jvi.00338-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 03/14/2018] [Indexed: 01/01/2023] Open
Abstract
There are many facets of varicella-zoster virus (VZV) pathogenesis that are not fully understood, such as the mechanisms involved in the establishment of lifelong latency, reactivation, and development of serious conditions like postherpetic neuralgia (PHN). Virus-encoded modulation of apoptosis has been suggested to play an important role in these processes. VZV open reading frame 63 (ORF63) has been shown to modulate apoptosis in a cell-type-specific manner, but the impact of ORF63 on cell death pathways has not been examined in isolation in the context of human cells. We sought to elucidate the effect of VZV ORF63 on apoptosis induction in human neuron and keratinocyte cell lines. VZV ORF63 was shown to protect differentiated SH-SY5Y neuronal cells against staurosporine-induced apoptosis. In addition, VZV infection did not induce high levels of apoptosis in the HaCaT human keratinocyte line, highlighting a delay in apoptosis induction. VZV ORF63 was shown to protect HaCaT cells against both staurosporine- and Fas ligand-induced apoptosis. Confocal microscopy was utilized to examine VZV ORF63 localization during apoptosis induction. In VZV infection and ORF63 expression alone, VZV ORF63 became more cytoplasmic, with aggregate formation during apoptosis induction. Taken together, this suggests that VZV ORF63 protects both differentiated SH-SY5Y cells and HaCaT cells from apoptosis induction and may mediate this effect through its localization change during apoptosis. VZV ORF63 is a prominent VZV gene product in both productive and latent infection and thus may play a critical role in VZV pathogenesis by aiding neuron and keratinocyte survival.IMPORTANCE VZV, a human-specific alphaherpesvirus, causes chicken pox during primary infection and establishes lifelong latency in the dorsal root ganglia (DRG). Reactivation of VZV causes shingles, which is often followed by a prolonged pain syndrome called postherpetic neuralgia. It has been suggested that the ability of the virus to modulate cell death pathways is linked to its ability to establish latency and reactivate. The significance of our research lies in investigating the ability of ORF63, a VZV gene product, to inhibit apoptosis in novel cell types crucial for VZV pathogenesis. This will allow an increased understanding of critical enigmatic components of VZV pathogenesis.
Collapse
|
2
|
How do we fit ferroptosis in the family of regulated cell death? Cell Death Differ 2017; 24:1991-1998. [PMID: 28984871 DOI: 10.1038/cdd.2017.149] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/18/2017] [Accepted: 08/06/2017] [Indexed: 02/07/2023] Open
Abstract
In the last few years many new cell death modalities have been described. To classify different types of cell death, the term 'regulated cell death' was introduced to discriminate it from 'accidental cell death'. Regulated cell death involves the activation of genetically encoded molecular machinery that couples the presence of some signal to cell death. These forms of cell death, like apoptosis, necroptosis and pyroptosis have important physiological roles in development, tissue repair, and immunity. Accidental cell death occurs in response to physical or chemical insults and occurs independently of molecular signalling pathways. Ferroptosis, an emerging and recently (re)discovered type of regulated cell death occurs through Fe(II)-dependent lipid peroxidation when the reduction capacity of a cell is insufficient. Ferroptosis is coined after the requirement for free ferrous iron. Here, we will consider the extent to which ferroptosis is similar to other regulated cell deaths and explore emerging ideas about the physiological role of ferroptosis.
Collapse
|
3
|
Martenot C, Gervais O, Chollet B, Houssin M, Renault T. Haemocytes collected from experimentally infected Pacific oysters, Crassostrea gigas: Detection of ostreid herpesvirus 1 DNA, RNA, and proteins in relation with inhibition of apoptosis. PLoS One 2017; 12:e0177448. [PMID: 28542284 PMCID: PMC5436676 DOI: 10.1371/journal.pone.0177448] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/27/2017] [Indexed: 11/18/2022] Open
Abstract
Recent transcriptomic approaches focused on anti-viral immunity in molluscs lead to the assumption that the innate immune system, such as apoptosis, plays a crucial role against ostreid herpesvirus type 1 (OsHV-1), infecting Pacific cupped oyster, Crassostrea gigas. Apoptosis constitutes a major mechanism of anti-viral response by limiting viral spread and eliminating infected cells. In this way, an OsHV-1 challenge was performed and oysters were monitored at three times post injection to investigate viral infection and host response: 2h (early after viral injection in the adductor muscle), 24h (intermediate time), and 48h (just before first oyster mortality record). Virus infection, associated with high cumulative mortality rates (74% and 100%), was demonstrated in haemocytes by combining several detection techniques such as real-time PCR, real-time RT PCR, immunofluorescence assay, and transmission electron microscopy examination. High viral DNA amounts ranged from 5.46×104 to 3.68×105 DNA copies ng-1 of total DNA, were detected in dead oysters and an increase of viral transcripts was observed from 2, 24, and 48hpi for the five targeted OsHV-1 genes encoding three putative membrane proteins (ORFs 25, 41, and 72), a putative dUTPase (ORF 75), and a putative apoptosis inhibitor (ORF 87). Apoptosis was studied at molecular and cellular levels with an early marker (phosphatidyl-serine externalisation measured by flow cytometry and epifluorescence microscopy) and a later parameter (DNA fragmentation by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay (TUNEL)). The down-regulation of genes encoding proteins involved in the activation of the apoptotic pathway (TNF and caspase 3) and the up-regulation of genes encoding anti-apoptotic proteins (IAP-2, and Bcl-2) suggested an important anti-apoptosis phenomenon in haemocytes from OsHV-1 infected oysters at 24 and 48hpi. Additionally, more phosphatidyl-serines were externalized and more cells with DNA fragmentation were observed in haemocytes collected from artificial seawater injected oysters than in haemocytes collected from OsHV-1 infected oysters at 24 and 48hpi, suggesting an inhibition of the apoptotic process in presence of the virus. In conclusion, this study is the first to focus on C. gigas haemocytes, cells involved in the host immune defense, during an OsHV-1 challenge in controlled conditions by combining various and original approaches to investigate apoptosis at molecular and cellular levels.
Collapse
Affiliation(s)
- Claire Martenot
- Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), Laboratoire de Génétique et Pathologie des Mollusques Marins, La Tremblade, France
- * E-mail:
| | - Ophélie Gervais
- Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), Laboratoire de Génétique et Pathologie des Mollusques Marins, La Tremblade, France
| | - Bruno Chollet
- Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), Laboratoire de Génétique et Pathologie des Mollusques Marins, La Tremblade, France
| | | | - Tristan Renault
- Ifremer, Département Ressources Biologiques et Environnement, Nantes, France
| |
Collapse
|
4
|
Lagunoff M. Activation of cellular metabolism during latent Kaposi's Sarcoma herpesvirus infection. Curr Opin Virol 2016; 19:45-9. [PMID: 27434732 DOI: 10.1016/j.coviro.2016.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/22/2016] [Accepted: 06/29/2016] [Indexed: 02/07/2023]
Abstract
Herpesviruses can establish latent infections in the host with severely limited viral gene expression. Kaposi's Sarcoma-associated herpesvirus (KSHV) is found predominantly in the latent state in the main KS tumor cell, a cell of endothelial origin. While many viruses alter host cell metabolism during productive infection, latent KSHV infection of endothelial cells activates metabolic pathways that are activated in many cancer cells. Inhibition of these major metabolic pathways leads to apoptotic cell death of the latently infected cells. The study of KSHV activation of metabolism may lead to novel therapeutic options for eliminating latent infection of gamma-herpesviruses and could also lead to a deeper mechanistic understanding of how to target cancer cell metabolism.
Collapse
Affiliation(s)
- Michael Lagunoff
- Department of Microbiology, University of Washington, 1959 N.E. Pacific St., Box 347252, Seattle, WA 98195, United States.
| |
Collapse
|
5
|
In situ localization and tissue distribution of ostreid herpesvirus 1 proteins in infected Pacific oyster, Crassostrea gigas. J Invertebr Pathol 2016; 136:124-35. [PMID: 27066775 DOI: 10.1016/j.jip.2016.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 11/20/2022]
Abstract
Immunohistochemistry (IHC) assays were conducted on paraffin sections from experimentally infected spat and unchallenged spat produced in hatchery to determine the tissue distribution of three viral proteins within the Pacific oyster, Crassostrea gigas. Polyclonal antibodies were produced from recombinant proteins corresponding to two putative membrane proteins and one putative apoptosis inhibitor encoded by ORF 25, 72, and 87, respectively. Results were then compared to those obtained by in situ hybridization performed on the same individuals, and showed a substantial agreement according to Landis and Koch numeric scale. Positive signals were mainly observed in connective tissue of gills, mantle, adductor muscle, heart, digestive gland, labial palps, and gonads of infected spat. Positive signals were also reported in digestive epithelia. However, few positive signals were also observed in healthy appearing oysters (unchallenged spat) and could be due to virus persistence after a primary infection. Cellular localization of staining seemed to be linked to the function of the viral protein targeted. A nucleus staining was preferentially observed with antibodies targeting the putative apoptosis inhibitor protein whereas a cytoplasmic localization was obtained using antibodies recognizing putative membrane proteins. The detection of viral proteins was often associated with histopathological changes previously reported during OsHV-1 infection by histology and transmission electron microscopy. Within the 6h after viral suspension injection, positive signals were almost at the maximal level with the three antibodies and all studied organs appeared infected at 28h post viral injection. Connective tissue appeared to be a privileged site for OsHV-1 replication even if positive signals were observed in the epithelium cells of different organs which may be interpreted as a hypothetical portal of entry or release for the virus. IHC constitutes a suited method for analyzing the early infection stages of OsHV-1 infection and a useful tool to investigate interactions between OsHV-1 and its host at a protein level.
Collapse
|
6
|
Monie TP, Bryant CE. Caspase-8 functions as a key mediator of inflammation and pro-IL-1β processing via both canonical and non-canonical pathways. Immunol Rev 2016; 265:181-93. [PMID: 25879293 DOI: 10.1111/imr.12284] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Caspase-8 is an apical component of cell death pathways. Activated caspase-8 can drive classical caspase-dependent apoptosis and actively inhibits cell death mediated by RIPK3-driven necroptosis. Genetic deletion of Casp8 results in embryonic lethality as a result of uncontrolled necroptosis. This lethality can be rescued by simultaneous deletion of Ripk3. Recently, caspase-8 has been additionally connected to inflammatory pathways within the cell. In particular, caspase-8 has been shown to be crucially involved in the induction of pro-IL-1β synthesis and processing via both non-canonical and canonical pathways. In this review, we bring together current knowledge regarding the role of caspase-8 in cellular inflammation with a particular emphasis on the interplay between caspase-8 and the classical and non-canonical inflammasomes.
Collapse
Affiliation(s)
- Tom P Monie
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | |
Collapse
|
7
|
Miest JJ, Adamek M, Pionnier N, Harris S, Matras M, Rakus KŁ, Irnazarow I, Steinhagen D, Hoole D. Differential effects of alloherpesvirus CyHV-3 and rhabdovirus SVCV on apoptosis in fish cells. Vet Microbiol 2014; 176:19-31. [PMID: 25596969 DOI: 10.1016/j.vetmic.2014.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 01/06/2023]
Abstract
Whilst Herpesviridae, which infect higher vertebrates, actively influence host immune responses to ensure viral replication, it is mostly unknown if Alloherpesviridae, which infect lower vertebrates, possess similar abilities. An important antiviral response is clearance of infected cells via apoptosis, which in mammals influences the outcome of infection. Here, we utilise common carp infected with CyHV-3 to determine the effect on the expression of genes encoding apoptosis-related proteins (p53, Caspase 9, Apaf-1, IAP, iNOS) in the pronephros, spleen and gills. The influence of CyHV-3 on CCB cells was also studied and compared to SVCV (a rhabdovirus) which induces apoptosis in carp cell lines. Although CyHV-3 induced iNOS expression in vivo, significant induction of the genetic apoptosis pathway was only seen in the pronephros. In vitro CyHV-3 did not induce apoptosis or apoptosis-related expression whilst SVCV did stimulate apoptosis. This suggests that CyHV-3 possesses mechanisms similar to herpesviruses of higher vertebrates to inhibit the antiviral apoptotic process.
Collapse
Affiliation(s)
- Joanna J Miest
- Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, ST5 5BG Keele, United Kingdom.
| | - Mikolaj Adamek
- Fish Diseases Research Unit, Institute of Parasitology, University of Veterinary Medicine in Hanover, Bünteweg 17, 30559 Hanover, Germany.
| | - Nicolas Pionnier
- Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, ST5 5BG Keele, United Kingdom.
| | - Sarah Harris
- Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, ST5 5BG Keele, United Kingdom; Fish Diseases Research Unit, Institute of Parasitology, University of Veterinary Medicine in Hanover, Bünteweg 17, 30559 Hanover, Germany.
| | - Marek Matras
- Laboratory of Fish Diseases, National Veterinary Research Institute, Partyzantów 57, 24-100 Puławy, Poland.
| | - Krzysztof Ł Rakus
- Polish Academy of Sciences, Institute of Ichthyobiology & Aquaculture in Gołysz, Kalinowa 2, 43-520 Chybie, Poland.
| | - Ilgiz Irnazarow
- Polish Academy of Sciences, Institute of Ichthyobiology & Aquaculture in Gołysz, Kalinowa 2, 43-520 Chybie, Poland.
| | - Dieter Steinhagen
- Fish Diseases Research Unit, Institute of Parasitology, University of Veterinary Medicine in Hanover, Bünteweg 17, 30559 Hanover, Germany.
| | - Dave Hoole
- Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, ST5 5BG Keele, United Kingdom.
| |
Collapse
|
8
|
Segarra A, Mauduit F, Faury N, Trancart S, Dégremont L, Tourbiez D, Haffner P, Barbosa-Solomieu V, Pépin JF, Travers MA, Renault T. Dual transcriptomics of virus-host interactions: comparing two Pacific oyster families presenting contrasted susceptibility to ostreid herpesvirus 1. BMC Genomics 2014; 15:580. [PMID: 25012085 PMCID: PMC4111845 DOI: 10.1186/1471-2164-15-580] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/01/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Massive mortality outbreaks affecting Pacific oyster (Crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). However, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted in order to test the susceptibility of several bi-parental oyster families to this virus and to analyze host-pathogen interactions using in vivo transcriptomic approaches. RESULTS The divergent response of these oyster families in terms of mortality confirmed that susceptibility to OsHV-1 infection has a significant genetic component. Two families with contrasted survival rates were selected. A total of 39 viral genes and five host genes were monitored by real-time PCR. Initial results provided information on (i) the virus cycle of OsHV-1 based on the kinetics of viral DNA replication and transcription and (ii) host defense mechanisms against the virus. CONCLUSIONS In the two selected families, the detected amounts of viral DNA and RNA were significantly different. This result suggests that Pacific oysters are genetically diverse in terms of their susceptibility to OsHV-1 infection. This contrasted susceptibility was associated with dissimilar host gene expression profiles. Moreover, the present study showed a positive correlation between viral DNA amounts and the level of expression of selected oyster genes.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Tristan Renault
- Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), Unité Santé Génétique et Microbiologie des Mollusques (SG2M), Laboratoire de Génétique et Pathologie des Mollusques Marins (LGPMM), Avenue de Mus de Loup, 17390 La Tremblade, France.
| |
Collapse
|
9
|
Abstract
UNLABELLED Lymphocyte colonization by gammaherpesviruses (γHVs) is an important target for cancer prevention. However, how it works is not clear. Epstein-Barr virus drives autonomous B cell proliferation in vitro but in vivo may more subtly exploit the proliferative pathways provided by lymphoid germinal centers (GCs). Murid herpesvirus 4 (MuHV-4), which realistically infects inbred mice, provides a useful tool with which to understand further how a γHV colonizes B cells in vivo. Not all γHVs necessarily behave the same, but common events can with MuHV-4 be assigned an importance for host colonization and so a potential as therapeutic targets. MuHV-4-driven B cell proliferation depends quantitatively on CD4(+) T cell help. Here we show that it also depends on T cell-independent survival signals provided by the B cell-activating factor (BAFF) receptor (BAFF-R). B cells could be infected in BAFF-R(-/-) mice, but virus loads remained low. This corresponded to a BAFF-R-dependent defect in GC colonization. The close parallels between normal, antigen-driven B cell responses and virus-infected B cell proliferation argue that in vivo, γHVs mostly induce infected B cells into normal GC reactions rather than generating large numbers of autonomously proliferating blasts. IMPORTANCE γHVs cause cancers by driving the proliferation of infected cells. B cells are a particular target. Thus, we need to know how virus-driven B cell proliferation works. Controversy exists as to whether viral genes drive it directly or less directly orchestrate the engagement of normal, host-driven pathways. Here we show that the B cell proliferation driven by a murid γHV requires BAFF-R. This supports the idea that γHVs exploit host proliferation pathways and suggests that interfering with BAFF-R could more generally reduce γHV-associated B cell proliferation.
Collapse
|
10
|
Structural proteins of Kaposi's sarcoma-associated herpesvirus antagonize p53-mediated apoptosis. Oncogene 2014; 34:639-49. [PMID: 24469037 DOI: 10.1038/onc.2013.595] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 11/15/2013] [Accepted: 12/13/2013] [Indexed: 01/10/2023]
Abstract
The tumor suppressor p53 is a central regulatory molecule of apoptosis and is commonly mutated in tumors. Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies express wild-type p53. Accordingly, KSHV encodes proteins that counteract the cell death-inducing effects of p53. Here, the effects of all KSHV genes on the p53 signaling pathway were systematically analyzed using the reversely transfected cell microarray technology. With this approach we detected eight KSHV-encoded genes with potent p53 inhibiting activity in addition to the previously described inhibitory effects of KSHV genes ORF50, K10 and K10.5. Interestingly, the three most potent newly identified inhibitors were KSHV structural proteins, namely ORF22 (glycoprotein H), ORF25 (major capsid protein) and ORF64 (tegument protein). Validation of these results with a classical transfection approach showed that these proteins inhibited p53 signaling in a dose-dependent manner and that this effect could be reversed by small interfering RNA-mediated knockdown of the respective viral gene. All three genes inhibited p53-mediated apoptosis in response to Nutlin-3 treatment in non-infected and KSHV-infected cells. Addressing putative mechanisms, we could show that these proteins could also inhibit the transactivation of the promoters of apoptotic mediators of p53 such as BAX and PIG3. Altogether, we demonstrate for the first time that structural proteins of KSHV can counteract p53-induced apoptosis. These proteins are expressed in the late lytic phase of the viral life cycle and are incorporated into the KSHV virion. Accordingly, these genes may inhibit cell death in the productive and in the early entrance phase of KSHV infection.
Collapse
|
11
|
Mocarski ES, Upton JW, Kaiser WJ. Viral infection and the evolution of caspase 8-regulated apoptotic and necrotic death pathways. Nat Rev Immunol 2011; 12:79-88. [PMID: 22193709 PMCID: PMC4515451 DOI: 10.1038/nri3131] [Citation(s) in RCA: 327] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pathogens specifically target both the caspase 8-dependent apoptotic cell death pathway and the necrotic cell death pathway that is dependent on receptor-interacting protein 1 (RIP1; also known as RIPK1) and RIP3 (also known as RIPK3). The fundamental co-regulation of these two cell death pathways emerged when the midgestational death of mice deficient in FAS-associated death domain protein (FADD) or caspase 8 was reversed by elimination of RIP1 or RIP3, indicating a far more entwined relationship than previously appreciated. Thus, mammals require caspase 8 activity during embryogenesis to suppress the kinases RIP1 and RIP3 as part of the dialogue between two distinct cell death processes that together fulfil reinforcing roles in the host defence against intracellular pathogens such as herpesviruses.
Collapse
Affiliation(s)
- Edward S Mocarski
- Department of Microbiology and Immunology, Emory Vaccine Center, 1462 Clifton Rd. NE, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | - Jason W Upton
- Section of Molecular Genetics and Microbiology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin 78712, USA
| | - William J Kaiser
- Department of Microbiology and Immunology, Emory Vaccine Center, 1462 Clifton Rd. NE, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| |
Collapse
|
12
|
Yatim N, Albert M. Dying to Replicate: The Orchestration of the Viral Life Cycle, Cell Death Pathways, and Immunity. Immunity 2011; 35:478-90. [DOI: 10.1016/j.immuni.2011.10.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 09/20/2011] [Accepted: 10/14/2011] [Indexed: 12/11/2022]
|
13
|
Barton E, Mandal P, Speck SH. Pathogenesis and host control of gammaherpesviruses: lessons from the mouse. Annu Rev Immunol 2011; 29:351-97. [PMID: 21219186 DOI: 10.1146/annurev-immunol-072710-081639] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Gammaherpesviruses are lymphotropic viruses that are associated with the development of lymphoproliferative diseases, lymphomas, as well as other nonlymphoid cancers. Most known gammaherpesviruses establish latency in B lymphocytes. Research on Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV68/γHV68/MHV4) has revealed a complex relationship between virus latency and the stage of B cell differentiation. Available data support a model in which gammaherpesvirus infection drives B cell proliferation and differentiation. In general, the characterized gammaherpesviruses exhibit a very narrow host tropism, which has severely limited studies on the human gammaherpesviruses EBV and Kaposi's sarcoma-associated herpesvirus. As such, there has been significant interest in developing animal models in which the pathogenesis of gammaherpesviruses can be characterized. MHV68 represents a unique model to define the effects of chronic viral infection on the antiviral immune response.
Collapse
Affiliation(s)
- Erik Barton
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
| | | | | |
Collapse
|
14
|
|
15
|
Liang X, Pickering MT, Cho NH, Chang H, Volkert MR, Kowalik TF, Jung JU. Deregulation of DNA damage signal transduction by herpesvirus latency-associated M2. J Virol 2006; 80:5862-74. [PMID: 16731925 PMCID: PMC1472574 DOI: 10.1128/jvi.02732-05] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infected cells recognize viral replication as a DNA damage stress and elicit a DNA damage response that ultimately induces apoptosis as part of host immune surveillance. Here, we demonstrate a novel mechanism where the murine gamma herpesvirus 68 (gammaHV68) latency-associated, anti-interferon M2 protein inhibits DNA damage-induced apoptosis by interacting with the DDB1/COP9/cullin repair complex and the ATM DNA damage signal transducer. M2 expression constitutively induced DDB1 nuclear localization and ATM kinase activation in the absence of DNA damage. Activated ATM subsequently induced Chk activation and p53 phosphorylation and stabilization without eliciting H2AX phosphorylation and MRN recruitment to foci upon DNA damage. Consequently, M2 expression inhibited DNA repair, rendered cells resistant to DNA damage-induced apoptosis, and induced a G(1) cell cycle arrest. Our results suggest that gammaHV68 M2 blocks apoptosis-mediated intracellular innate immunity, which might ultimately contribute to its role in latent infection.
Collapse
Affiliation(s)
- Xiaozhen Liang
- Department of Microbiology and Molecular Genetics, New England Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
Cytomegaloviruses (CMVs), a subset of betaherpesviruses, employ multiple strategies to suppress apoptosis in infected cells and thus to delay their death. Human cytomegalovirus (HCMV) encodes at least two proteins that directly interfere with the apoptotic signaling pathways, viral inhibitor of caspase-8-induced apoptosis vICA (pUL36), and mitochondria-localized inhibitor of apoptosis vMIA (pUL37 x 1). vICA associates with pro-caspase-8 and appears to block its recruitment to the death-inducing signaling complex (DISC), a step preceding caspase-8 activation. vMIA binds and sequesters Bax at mitochondria, and interferes with BH3-only-death-factor/Bax-complex-mediated permeabilization of mitochondria. vMIA does not seem to either interact with Bak, a close structural and functional homologue of Bax, or to suppress Bak-mediated permeabilization of mitochondria and Bak-mediated apoptosis. All sequenced betaherpesviruses, including CMVs, encode close homologues of vICA, and those vICA homologues that have been tested, were found to be functional cell death suppressors. Overt sequence homologues of vMIA were found only in the genomes of primate CMVs, but recent observations made with murine CMV (MCMV) indicate that non-primate CMVs may also encode a cell death suppressor functionally resembling vMIA. The exact physiological roles and relative contributions of vMIA and vICA in suppressing death of CMV-infected cells in vivo have not been elucidated. There is strong evidence that the cell death suppressing function of vMIA is indispensable, and that vICA is dispensable for replication of HCMV. In addition to suppressed caspase-8 activation and sequestered Bax, CMV-infected cells display several other phenomena, less well characterized, that may diminish, directly or indirectly the extent of cell death.
Collapse
Affiliation(s)
- V S Goldmacher
- ImmunoGen, Inc., 128 Sidney St., Cambridge, MA 02139, USA.
| |
Collapse
|