scholarly journals Elevated Chemokine Responses Are Maintained in Lungs after Clearance of Viral Infection

2002 ◽  
Vol 76 (20) ◽  
pp. 10518-10523 ◽  
Author(s):  
Jason B. Weinberg ◽  
Mary L. Lutzke ◽  
Stacey Efstathiou ◽  
Steven L. Kunkel ◽  
Rosemary Rochford
Keyword(s):  
Gene Expression ◽  
Viral Infection ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Murine Gammaherpesvirus ◽  
Chemokine Expression ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT We observed two patterns of chemokine expression in the lungs of mice infected with murine gammaherpesvirus 68: peaks of chemokine expression correlated with or occurred after the peak of viral gene expression. Chemokine expression remained elevated through 29 days postinfection.

scholarly journals Modulation of B-cell tolerance by Murine Gammaherpesvirus 68 infection: requirement for Orf73 viral gene expression and follicular helper T cells

Immunology ◽  
2013 ◽  
Vol 139 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Stephen B. Gauld ◽  
Jessica L. De Santis ◽  
Joseph M. Kulinski ◽  
Jennifer A. McGraw ◽  
Steven M. Leonardo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Viral Gene Expression ◽  
Helper T Cells ◽  
Viral Gene ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Murine Gammaherpesvirus ◽  
Follicular Helper ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

scholarly journals ORF73-Null Murine Gammaherpesvirus 68 Reveals Roles for mLANA and p53 in Virus Replication

2007 ◽  
Vol 81 (21) ◽  
pp. 11957-11971 ◽  
Author(s):  
J. Craig Forrest ◽  
Clinton R. Paden ◽  
Robert D. Allen ◽  
Julie Collins ◽  
Samuel H. Speck
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Virus Replication ◽  
Stress Responses ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Murine Gammaherpesvirus ◽  
Murine Fibroblasts ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Gammaherpesviruses establish lifelong, latent infections in host lymphocytes, during which a limited subset of viral gene products facilitates maintenance of the viral episome. Among the gamma-2-herpesvirus (rhadinovirus) subfamily, this includes expression of the conserved ORF73-encoded LANA proteins. We previously demonstrated by loss-of-function mutagenesis that the murine gammaherpesvirus 68 (MHV68) ORF73 gene product, mLANA, is required for the establishment of latency following intranasal inoculation of mice (N. J. Moorman, D. O. Willer, and S. H. Speck, J. Virol. 77:10295-10303, 2003). mLANA-deficient viruses also exhibited a defect in acute virus replication in the lungs of infected mice. The latter observation led us to examine the role of mLANA in productive viral replication. We assessed the capacity of mLANA-deficient virus (73.Stop) to replicate in cell culture at low multiplicities of infection (MOIs) and found that 73.Stop growth was impaired in murine fibroblasts but not in Vero cells. A recombinant virus expressing an mLANA-green fluorescent protein (GFP) fusion revealed that mLANA is expressed throughout the virus replication cycle. In addition, 73.Stop infection of murine fibroblasts at high MOIs was substantially more cytotoxic than infection with a genetically repaired marker rescue virus (73.MR), a phenotype that correlated with enhanced kinetics of viral gene expression and increased activation of p53. Notably, augmented cell death, viral gene expression, and p53 induction were independent of viral DNA replication. Expression of a mLANA-GFP fusion protein in fibroblasts correlated with both reduced p53 stabilization and reduced cell death following treatment with p53-inducing agonists. In agreement, accentuated cell death associated with 73.Stop infection was reduced in p53-deficient murine embryonic fibroblasts. Additionally, replication of 73.Stop in p53-deficient cells was restored to levels comparable to those of 73.MR. More remarkably, the absence of p53 led to an overall delay in replication for both 73.Stop and 73.MR viruses, which correlated with delayed viral gene expression, indicating a role for p53 in MHV68 replication. Consistent with these findings, the expression of replication-promoting viral genes was positively influenced by p53 overexpression or treatment with the p53 agonist etoposide. Overall, these data demonstrate the importance of mLANA in MHV68 replication and suggest that LANA proteins limit the induction of cellular stress responses to regulate the viral gene expression cascade and limit host cell injury.

scholarly journals Kinetics of Murine Gammaherpesvirus 68 Gene Expression following Infection of Murine Cells in Culture and in Mice

2001 ◽  
Vol 75 (11) ◽  
pp. 4955-4963 ◽  
Author(s):  
Rosemary Rochford ◽  
Mary L. Lutzke ◽  
Rosiane S. Alfinito ◽  
Anaira Clavo ◽  
Rhonda D. Cardin
Keyword(s):  
Gene Expression ◽  
Rnase Protection Assay ◽  
Viral Gene ◽  
3T3 Cells ◽  
Rnase Protection ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Kinetics Of

ABSTRACT A model system to study the pathogenesis of gammaherpesvirus infections is the infection of mice with murine gammaherpesvirus 68 (MHV-68). To define the kinetics of infection, we developed an RNase protection assay to quantitate gene expression from lytic (K3, Rta, M8, DNA polymerase [DNA pol], and gB) and candidate latency (M2, M3, M9, M11, ORF73, and ORF74) genes. All candidate latency genes were expressed during lytic infection of 3T3 cells. Four kinetic classes of transcripts were observed following infection of 3T3 cells: immediate-early (K3, Rta, M8, and ORF73), early (DNA pol), early-late (M3, M11, and ORF74), and late (M2, M9, and gB). To assess the kinetics of viral gene expression in vivo, lungs, spleens, and mediastinal lymph nodes (MLN) were harvested from MHV-68-infected mice. All transcripts were expressed between 3 and 6 days postinfection (dpi) in the lungs. In the spleen, K3, M3, M8, and M9 transcripts were expressed between 10 and 16 dpi when latency is established. The K3, M3, M8, M9, and M11 transcripts were detected in the MLN from 2 through 16 dpi. This is the first demonstration of MHV-68 gene expression in the MLN. Importantly, our data showed that MHV-68 has different kinetics of gene expression at different sites of infection. Furthermore, we demonstrated that K3, a gene recently shown to encode a protein that downregulates major histocompatibility complex class I on the surface of cells, is expressed during latency, which argues for a role of K3 in immune evasion during latent infection.

scholarly journals Murine Gammaherpesvirus 68 Has Evolved Gamma Interferon and Stat1-Repressible Promoters for the Lytic Switch Gene 50

2010 ◽  
Vol 84 (7) ◽  
pp. 3711-3717 ◽  
Author(s):  
Megan M. Goodwin ◽  
Susan Canny ◽  
Ashley Steed ◽  
Herbert W. Virgin
Keyword(s):  
Viral Gene Expression ◽  
Gamma Interferon ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Viral Gene ◽  
Murine Gammaherpesvirus ◽  
Replication Gene ◽  
Ifn Γ ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Cytokines regulate viral gene expression with important consequences for viral replication and pathogenesis. Gamma interferon (IFN-γ) is a key regulator of chronic murine gammaherpesvirus 68 (γHV68) infection and a potent inhibitor of γHV68 reactivation from latency. Macrophages are the cell type that is responsive to the IFN-γ-mediated control of γHV68 reactivation; however, the molecular mechanism of this IFN-γ action is undefined. Here we report that IFN-γ inhibits lytic replication of γHV68 in primary bone marrow-derived macrophages and decreases transcript levels for the essential lytic switch gene 50. Interestingly, IFN-γ suppresses the activity of the two known gene 50 promoters, demonstrating that an inflammatory cytokine can directly regulate the promoters for the γHV68 lytic switch gene. Stat1, but not IFN-α/β signaling, is required for IFN-γ action. Moreover, Stat1 deficiency increases basal γHV68 replication, gene 50 expression, and promoter activity. Together, these data identify IFN-γ and Stat1 as being negative regulators of the γHV68 lytic cycle and raise the possibility that γHV68 maintains IFN-γ/Stat1-responsive gene 50 promoters to facilitate cell-extrinsic control over the interchange between the lytic and latent cycles.

scholarly journals Lytic infection with murine gammaherpesvirus 68 activates host and viral RNA polymerase III promoters and enhances non-coding RNA expression

2021 ◽  
Author(s):  
Ashley N. Knox ◽  
Alice Mueller ◽  
Eva M. Medina ◽  
Eric T. Clambey ◽  
Linda F. van Dyk
Keyword(s):  
Gene Expression ◽  
Flow Cytometry ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Murine Gammaherpesvirus ◽  
Polymerase Iii ◽  
Gammaherpesvirus 68 ◽  
Pol Iii

RNA polymerase III (pol III) transcribes multiple non-coding (nc) RNAs that are essential for cellular function. Pol III-dependent transcription is also engaged during certain viral infections, including the gammaherpesviruses (γHVs), where pol III-dependent viral ncRNAs promote pathogenesis. Additionally, several host ncRNAs are upregulated during γHV infection and play integral roles in pathogenesis by facilitating viral establishment and gene expression. Here, we sought to investigate how pol III promoters and transcripts are regulated during gammaherpesvirus infection using the murine gammaherpesvirus 68 (γHV68) system. To compare the transcription of host and viral pol III-dependent ncRNAs, we analyzed a series of pol III promoters for host and viral ncRNAs using a luciferase reporter optimized to measure pol III activity. We measured promoter activity from the reporter gene at the translation level via luciferase activity and at the transcription level via RT-qPCR. We further measured endogenous ncRNA expression at single cell-resolution by flow cytometry. These studies demonstrated that lytic infection with γHV68 increased the transcription from multiple host and viral pol III promoters, and further identified the ability of accessory sequences to influence both baseline and inducible promoter activity after infection. RNA flow cytometry revealed the induction of endogenous pol III-derived ncRNAs that tightly correlated with viral gene expression. These studies highlight how lytic gammaherpesvirus infection alters the transcriptional landscape of host cells to increase pol III-derived RNAs, a process that may further modify cellular function and enhance viral gene expression and pathogenesis. IMPORTANCE Gammaherpesviruses are a prime example of how viruses can alter the host transcriptional landscape to establish infection. Despite major insights into how these viruses modify RNA polymerase II-dependent generation of messenger RNAs, how these viruses influence the activity of host RNA polymerase III remains much less clear. Small non-coding RNAs produced by RNA polymerase III are increasingly recognized to play critical regulatory roles in cell biology and virus infection. Studies of RNA polymerase III dependent transcription are complicated by multiple promoter types and diverse RNAs with variable stability and processing requirements. Here, we characterized a reporter system to directly study RNA polymerase III-dependent responses during gammaherpesvirus infection and utilized single-cell flow cytometry-based methods to reveal that gammaherpesvirus lytic replication broadly induces pol III activity to enhance host and viral non-coding RNA expression within the infected cell.

scholarly journals COX-2 Induction during Murine Gammaherpesvirus 68 Infection Leads to Enhancement of Viral Gene Expression

2003 ◽  
Vol 77 (23) ◽  
pp. 12753-12763 ◽  
Author(s):  
Tonia L. Symensma ◽  
DeeAnn Martinez-Guzman ◽  
Qingmei Jia ◽  
Eric Bortz ◽  
Ting-Ting Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Production ◽  
De Novo ◽  
Luciferase Reporter ◽  
Viral Gene ◽  
Murine Gammaherpesvirus ◽  
Infected Cells ◽  
Cox 2 ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT The murine gammaherpesvirus 68 (MHV-68 or γHV-68) model provides many advantages for studying virus-host interactions involved in gammaherpesvirus replication, including the role of cellular responses to infection. We examined the effects of cellular cyclooxygenase-2 (COX-2) and its by-product prostaglandin E2 (PGE2) on MHV-68 gene expression and protein production following de novo infection of cultured cells. Western blot analyses revealed an induction of COX-2 protein in MHV-68-infected cells but not in cells infected with UV-irradiated MHV-68. Luciferase reporter assays demonstrated activation of the COX-2 promoter during MHV-68 replication. Two nonsteroidal anti-inflammatory drugs, a COX-2-specific inhibitor (NS-398) and a COX-1-COX-2 inhibitor (indomethacin), substantially reduced MHV-68 protein production in infected cells. Inhibition of viral protein expression and virion production by NS-398 was reversed in the presence of exogenous PGE2. Global gene expression analysis using an MHV-68 DNA array showed that PGE2 increased production of multiple viral gene products, and NS-398 inhibited production of many of the same genes. These studies suggest that COX-2 activity and PGE2 production may play significant roles during MHV-68 de novo infection.

scholarly journals Gamma Interferon Blocks Gammaherpesvirus Reactivation from Latency

2006 ◽  
Vol 80 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Ashley L. Steed ◽  
Erik S. Barton ◽  
Scott A. Tibbetts ◽  
Daniel L. Popkin ◽  
Mary L. Lutzke ◽  
...  
Keyword(s):  
Immune Surveillance ◽  
Viral Gene Expression ◽  
Gamma Interferon ◽  
Viral Gene ◽  
Herpesvirus Infection ◽  
Murine Gammaherpesvirus ◽  
Ifn Γ ◽  
Gammaherpesvirus 68 ◽  
Novel Strategy

ABSTRACT Establishment of latent infection and reactivation from latency are critical aspects of herpesvirus infection and pathogenesis. Interfering with either of these steps in the herpesvirus life cycle may offer a novel strategy for controlling herpesvirus infection and associated disease pathogenesis. Prior studies show that mice deficient in gamma interferon (IFN-γ) or the IFN-γ receptor have elevated numbers of cells reactivating from murine gammaherpesvirus 68 (γHV68) latency, produce infectious virus after the establishment of latency, and develop large-vessel vasculitis. Here, we demonstrate that IFN-γ is a powerful inhibitor of reactivation of γHV68 from latency in tissue culture. In vivo, IFN-γ controls viral gene expression during latency. Importantly, depletion of IFN-γ in latently infected mice results in an increased frequency of cells reactivating virus. This demonstrates that IFN-γ is important for immune surveillance that limits reactivation of γHV68 from latency.

scholarly journals Transcription Program of Murine Gammaherpesvirus 68

2003 ◽  
Vol 77 (19) ◽  
pp. 10488-10503 ◽  
Author(s):  
DeeAnn Martinez-Guzman ◽  
Tammy Rickabaugh ◽  
Ting-Ting Wu ◽  
Helen Brown ◽  
Steven Cole ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Line ◽  
Recombinant Virus ◽  
Lytic Replication ◽  
Dna Arrays ◽  
Transcription Activator ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Transcription Program

ABSTRACT Murine gammaherpesvirus 68 (MHV-68 [also referred to as γHV68]) is phylogenetically related to Kaposi's sarcoma-associated herpesvirus (KSHV [also referred to as HHV-8]) and Epstein-Barr virus (EBV). However, unlike KSHV or EBV, MHV-68 readily infects fibroblast and epithelial cell lines derived from several mammalian species, providing a system to study productive and latent infections as well as reactivation of gammaherpesviruses in vivo and in vitro. To carry out rapid genome-wide analysis of MHV-68 gene expression, we made DNA arrays containing nearly all of the known and predicted open reading frames (ORFs) of the virus. RNA obtained from an MHV-68 latently infected cell line, from cells lytically infected with MHV-68 in culture, and from the lung tissue of infected mice was used to probe the MHV-68 arrays. Using a tightly latent B-cell line (S11E), the MHV-68 latent transcription program was quantitatively described. Using BHK-21 cells and infected mice, we demonstrated that latent genes are transcribed during lytic replication and are relatively independent of de novo protein synthesis. We determined that the transcription profiles at the peak of lytic gene expression are similar in cultured fibroblast and in the lung of infected mice. Finally, the MHV-68 DNA arrays were used to examine the gene expression profile of a recombinant virus that overexpresses replication and transcription activator (RTA), C-RTA/MHV-68, during lytic replication in cell culture. The recombinant virus replicates faster then the parental strain and the DNA arrays revealed that nearly every MHV-68 ORF examined was activated by RTA overexpression. Examination of the gene expression patterns of C-RTA/MHV-68 over a time course led to the finding that the M3 promoter is RTA responsive in the absence of other viral factors.

scholarly journals Oxymatrine Inhibits Bocavirus MVC Replication, Reduces Viral Gene Expression and Decreases Apoptosis Induced by Viral Infection

2019 ◽  
Vol 34 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Yanqin Ding ◽  
Na Li ◽  
Jinhan Sun ◽  
Linran Zhang ◽  
Jianhui Guo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Viral Infection ◽  
Viral Gene Expression ◽  
Viral Gene

scholarly journals Murine Gammaherpesvirus 68 LANA and SOX Homologs Counteract ATM-Driven p53 Activity during Lytic Viral Replication

2015 ◽  
Vol 90 (5) ◽  
pp. 2571-2585 ◽  
Author(s):  
Jeffrey M. Sifford ◽  
James A. Stahl ◽  
Eduardo Salinas ◽  
J. Craig Forrest
Keyword(s):  
Gene Expression ◽  
Ataxia Telangiectasia ◽  
Tumor Suppressor P53 ◽  
Ataxia Telangiectasia Mutated ◽  
Murine Gammaherpesvirus ◽  
Damage Response ◽  
Infected Cells ◽  
P53 Activation ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACTTumor suppressor p53 is activated in response to numerous cellular stresses, including viral infection. However, whether murine gammaherpesvirus 68 (MHV68) provokes p53 during the lytic replication cycle has not been extensively evaluated. Here, we demonstrate that MHV68 lytic infection induces p53 phosphorylation and stabilization in a manner that is dependent on the DNA damage response (DDR) kinase ataxia telangiectasia mutated (ATM). The induction of p53 during MHV68 infection occurred in multiple cell types, including splenocytes of infected mice. ATM and p53 activation required early viral gene expression but occurred independently of viral DNA replication. At early time points during infection, p53-responsive cellular genes were induced, coinciding with p53 stabilization and phosphorylation. However, p53-related gene expression subsided as infection progressed, even though p53 remained stable and phosphorylated. Infected cells also failed to initiate p53-dependent gene expression and undergo apoptosis in response to treatment with exogenous p53 agonists. The inhibition of p53 responses during infection required the expression of the MHV68 homologs of the shutoff and exonuclease protein (muSOX) and latency-associated nuclear antigen (mLANA). Interestingly, mLANA, but not muSOX, was necessary to prevent p53-mediated death in MHV68-infected cells under the conditions tested. This suggests that muSOX and mLANA are differentially required for inhibiting p53 in specific settings. These data reveal that DDR responses triggered by MHV68 infection promote p53 activation. However, MHV68 encodes at least two proteins capable of limiting the potential consequences of p53 function.IMPORTANCEGammaherpesviruses are oncogenic herpesviruses that establish lifelong chronic infections. Defining how gammaherpesviruses overcome host responses to infection is important for understanding how these viruses infect and cause disease. Here, we establish that murine gammaherpesvirus 68 induces the activation of tumor suppressor p53. p53 activation was dependent on the DNA damage response kinase ataxia telangiectasia mutated. Although active early after infection, p53 became dominantly inhibited as the infection cycle progressed. Viral inhibition of p53 was mediated by the murine gammaherpesvirus 68 homologs of muSOX and mLANA. The inhibition of the p53 pathway enabled infected cells to evade p53-mediated cell death responses. These data demonstrate that a gammaherpesvirus encodes multiple proteins to limit p53-mediated responses to productive viral infection, which likely benefits acute viral replication and the establishment of chronic infection.

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