scholarly journals Induction of Protective Immunity against Murine Gammaherpesvirus 68 Infection in the Absence of Viral Latency

2009 ◽  
Vol 84 (5) ◽  
pp. 2453-2465 ◽  
Author(s):  
Qingmei Jia ◽  
Michael L. Freeman ◽  
Eric J. Yager ◽  
Ian McHardy ◽  
Leming Tong ◽  
...  
Keyword(s):  
Human Herpesvirus ◽  
Lytic Replication ◽  
Wild Type Virus ◽  
Wild Type ◽  
Transcription Activator ◽  
Vaccine Strategy ◽  
Murine Gammaherpesvirus ◽  
Barr Virus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Human gammaherpesviruses, Epstein-Barr virus, and human herpesvirus 8/Kaposi's sarcoma-associated herpesvirus are important pathogens associated with diseases, including lymphomas and other malignancies. Murine gammaherpesvirus 68 (MHV-68) is used as an experimental model system to study the host immune control of infection and explore novel vaccine strategies based on latency-deficient live viruses. We studied the properties and the potential of a recombinant MHV-68 (AC-RTA) in which the genes required for persistent infection were replaced by a constitutively expressed viral transcription activator, RTA, which dictates the virus to lytic replication. After intranasal infection of mice, replication of AC-RTA in the lung was attenuated, and no AC-RTA virus or viral DNA was detected in the isolated splenocytes, indicating a lack of latency in the spleen. Infection of the AC-RTA virus elicited both cellular immune responses and virus-specific IgG at a level comparable to that elicited by infection of the wild-type virus. Importantly, vaccination of AC-RTA was able to protect mice against subsequent challenge by the wild-type MHV-68. AC-RTA provides a vaccine strategy for preventing infection of human gammaherpesviruses. Furthermore, our results suggest that immunity to the major latent antigens is not required for protection.

scholarly journals Murine Gammaherpesvirus 68 Cyclin D Homologue Is Required for Efficient Reactivation from Latency

2000 ◽  
Vol 74 (15) ◽  
pp. 7016-7023 ◽  
Author(s):  
Ann T. Hoge ◽  
Sara B. Hendrickson ◽  
William H. Burns
Keyword(s):  
Acute Infection ◽  
Human Herpesvirus ◽  
Wild Type Virus ◽  
Cyclin D ◽  
Type Virus ◽  
Wild Type ◽  
Virus Growth ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Murine gammaherpesvirus 68 (MHV68) is a gammaherpesvirus that was first isolated from murid rodents. MHV68 establishes a latent infection in the spleen and other lymphoid organs. Several gammaherpesviruses, including herpesvirus saimiri, human herpesvirus 8, and MHV68, encode proteins with extensive homology to the D-type cyclins. To study the function of the cyclin homologue, a recombinant MHV68 has been constructed that lacks the cyclin homologue and expresses β-galactosidase as a marker (MHV68cy−). MHV68cy− grows in vitro with kinetics and to titers similar to those of the wild type. BALB/c mice infected with mixtures of equivalent amounts of the wild type and MHV68cy− show deficient growth of the MHV68cy− in an acute infection. Infection of SCID mice with virus mixtures also showed decreased MHV68cy−virus growth, indicating that the deficiency is not mediated by T or B cells. Although mice infected with mixtures containing 100 times as much MHV68cy− had greater splenic titers of the mutant virus than wild-type virus in acute infection, at 28 days postinfection splenocytes from these mice reactivated primarily wild-type virus. Quantitative PCR data indicate that equivalent genomes were present in the latent state. Reinsertion of the cyclin homologue into the cyclin-deleted virus restored the wild-type phenotype. These results indicate that the MHV68 cyclin D homologue mediates important functions in the acute infection and is required for efficient reactivation from latency.

scholarly journals Glycoprotein M Is an Essential Lytic Replication Protein of the Murine Gammaherpesvirus 68

2005 ◽  
Vol 79 (6) ◽  
pp. 3459-3467 ◽  
Author(s):  
Janet S. May ◽  
Susanna Colaco ◽  
Philip G. Stevenson
Keyword(s):  
Homologous Recombination ◽  
Viral Genome ◽  
Lytic Replication ◽  
Expression Cassette ◽  
Wild Type ◽  
Murine Gammaherpesvirus ◽  
Virion Morphogenesis ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT All herpesviruses encode a homolog of glycoprotein M (gM), which appears to function in virion morphogenesis. Despite its conservation, gM is inessential for the lytic replication of alphaherpesviruses. In order to address the importance of gM in gammaherpesviruses, we disrupted it in the murine gammaherpesvirus 68 (MHV-68). The mutant virus completely failed to propagate in normally permissive fibroblasts. The defective genome was rescued by either homologous recombination to restore the wild-type gM in situ or the insertion of an ectopic, intergenic expression cassette encoding gM into the viral genome. Thus, gM was essential for the lytic replication of MHV-68.

scholarly journals The ORF49 Protein of Murine Gammaherpesvirus 68 Cooperates with RTA in Regulating Virus Replication

2007 ◽  
Vol 81 (18) ◽  
pp. 9870-9877 ◽  
Author(s):  
Sangmi Lee ◽  
Hye-Jeong Cho ◽  
Jung-Jin Park ◽  
Yong-Sun Kim ◽  
Seungmin Hwang ◽  
...  
Keyword(s):  
Virus Replication ◽  
Wild Type Virus ◽  
Wild Type ◽  
Mapping Study ◽  
Murine Gammaherpesvirus ◽  
Downstream Target ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Target Promoters

ABSTRACT Our functional mapping study of murine gammaherpesvirus 68 (MHV-68, or γHV-68) revealed that a mutant harboring a transposon at the ORF49 locus (ORF49null) evidenced a highly attenuated in vitro growth. ORF49 resides adjacent to and in an opposite direction from RTA, the primary switch of the gammaherpesvirus life cycle. A FLAG-tagged ORF49 protein was able to transcomplement ORF49null, and a revertant of ORF49null restored its attenuated growth to a level comparable to that of the wild type. The FLAG-tagged ORF49 protein promoted the ability of RTA to activate downstream target promoters and enhanced virus replication from the ORF50null virus in the presence of RTA. Furthermore, ORF49 enhanced wild-type virus replication by increasing the RTA transcript levels. Our data indicate that ORF49 may perform an important function in MHV-68 replication in cooperation with RTA.

scholarly journals Identification of Novel Rodent Herpesviruses, Including the First Gammaherpesvirus of Mus musculus

2007 ◽  
Vol 81 (15) ◽  
pp. 8091-8100 ◽  
Author(s):  
Bernhard Ehlers ◽  
Judit Küchler ◽  
Nezlisah Yasmum ◽  
Güzin Dural ◽  
Sebastian Voigt ◽  
...  
Keyword(s):  
Mus Musculus ◽  
Human Herpesvirus ◽  
Murine Cytomegalovirus ◽  
Long Distance ◽  
Murine Gammaherpesvirus ◽  
Barr Virus ◽  
Epstein Barr ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Pcr Targeting

ABSTRACT Rodent herpesviruses such as murine cytomegalovirus (host, Mus musculus), rat cytomegalovirus (host, Rattus norvegicus), and murine gammaherpesvirus 68 (hosts, Apodemus species) are important tools for the experimental study of human herpesvirus diseases. However, alphaherpesviruses, roseoloviruses, and lymphocryptoviruses, as well as rhadinoviruses, that naturally infect Mus musculus (house mouse) and other Old World mice are unknown. To identify hitherto-unknown rodent-associated herpesviruses, we captured M. musculus, R. norvegicus, and 14 other rodent species in several locations in Germany, the United Kingdom, and Thailand. Samples of trigeminal ganglia, dorsal root ganglia, brains, spleens, and other organs, as well as blood, were analyzed with a degenerate panherpesvirus PCR targeting the DNA polymerase (DPOL) gene. Herpesvirus-positive samples were subjected to a second degenerate PCR targeting the glycoprotein B (gB) gene. The sequences located between the partial DPOL and gB sequences were amplified by long-distance PCR and sequenced, resulting in a contiguous sequence of approximately 3.5 kbp. By DPOL PCR, we detected 17 novel betaherpesviruses and 21 novel gammaherpesviruses but no alphaherpesvirus. Of these 38 novel herpesviruses, 14 were successfully analyzed by the complete bigenic approach. Most importantly, the first gammaherpesvirus of Mus musculus was discovered (Mus musculus rhadinovirus 1 [MmusRHV1]). This virus is a member of a novel group of rodent gammaherpesviruses, which is clearly distinct from murine herpesvirus 68-like rodent gammaherpesviruses. Multigenic phylogenetic analysis, using an 8-kbp locus, revealed that MmusRHV1 diverged from the other gammaherpesviruses soon after the evolutionary separation of Epstein-Barr virus-like lymphocryptoviruses from human herpesvirus 8-like rhadinoviruses and alcelaphine herpesvirus 1-like macaviruses.

scholarly journals Murine Gammaherpesvirus 68 ORF48 Is an RTA-Responsive Gene Product and Functions in both Viral Lytic Replication and Latency duringIn VivoInfection

2015 ◽  
Vol 89 (11) ◽  
pp. 5788-5800 ◽  
Author(s):  
Jing Qi ◽  
Chuanhui Han ◽  
Danyang Gong ◽  
Ping Liu ◽  
Sheng Zhou ◽  
...  
Keyword(s):  
Lytic Replication ◽  
Laboratory Mice ◽  
Transcription Activator ◽  
Murine Gammaherpesvirus ◽  
Responsive Gene ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Lytic Genes

ABSTRACTReplication and transcription activator (RTA) of gammaherpesvirus is an immediate early gene product and regulates the expression of many downstream viral lytic genes. ORF48 is also conserved among gammaherpesviruses; however, its expression regulation and function remained largely unknown. In this study, we characterized the transcription unit ofORF48from murine gammaherpesvirus 68 (MHV-68) and analyzed its transcriptional regulation. We showed that RTA activates theORF48promoter via an RTA-responsive element (48pRRE). RTA binds to 48pRRE directlyin vitroand also associates with ORF48 promoterin vivo. Mutagenesis of 48pRRE in the context of the viral genome demonstrated that the expression of ORF48 is activated by RTA through 48pRRE duringde novoinfection. Through site-specific mutagenesis, we generated an ORF48-null virus and examined the function of ORF48in vitroandin vivo. The ORF48-null mutation remarkably reduced the viral replication efficiency in cell culture. Moreover, through intranasal or intraperitoneal infection of laboratory mice, we showed that ORF48 is important for viral lytic replication in the lung and establishment of latency in the spleen, as well as viral reactivation from latency. Collectively, our study identifiedORF48as an RTA-responsive gene and showed that ORF48 is important for MHV-68 replication bothin vitroandin vivo.IMPORTANCEThe replication and transcription activator (RTA), conserved among gammaherpesviruses, serves as a molecular switch for the virus life cycle. It works as a transcriptional regulator to activate the expression of many viral lytic genes. However, only a limited number of such downstream genes have been uncovered for MHV-68. In this study, we identifiedORF48as an RTA-responsive gene of MHV-68 and mapped theciselement involved. By constructing a mutant virus that is deficient in ORF48 expression and through infection of laboratory mice, we showed that ORF48 plays important roles in different stages of viral infectionin vivo. Our study provides insights into the transcriptional regulation and protein function of MHV-68, a desired model for studying gammaherpesviruses.

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 A Gammaherpesvirus 68 Gene 50 Null Mutant Establishes Long-Term Latency in the Lung but Fails To Vaccinate against a Wild-Type Virus Challenge

2006 ◽  
Vol 80 (3) ◽  
pp. 1592-1598 ◽  
Author(s):  
Janice M. Moser ◽  
Michael L. Farrell ◽  
Laurie T. Krug ◽  
Jason W. Upton ◽  
Samuel H. Speck
Keyword(s):  
B Cells ◽  
Virus Replication ◽  
Antiviral Drug ◽  
Lytic Replication ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68

ABSTRACT The gammaherpesvirus immediate-early genes are critical regulators of virus replication and reactivation from latency. Rta, encoded by gene 50, serves as the major transactivator of the lytic program and is highly conserved among all the gammaherpesviruses, including Epstein-Barr virus, Kaposi's sarcoma-associated herpesvirus, and murine gammaherpesvirus 68 (γHV68). Introduction of a translation stop codon in γHV68 gene 50 (gene 50.stop γHV68) demonstrated that Rta is essential for virus replication in vitro. To investigate the role that virus replication plays in the establishment and maintenance of latency, we infected mice with gene 50.stop γHV68. Notably, the gene 50.stop virus established a long-term infection in lung B cells following intranasal infection of mice but was unable to establish latency in the spleen. This complete block in the establishment of latency in the spleen was also seen when lytic virus production was inhibited by treating mice infected with wild-type virus with the antiviral drug cidofovir, implicating virus replication and not an independent function of Rta in the establishment of splenic latency. Furthermore, we showed that gene 50.stop γHV68 was unable to prime the immune system and was unable to protect against a challenge with wild-type γHV68, despite its ability to chronically infect lung B cells. These data indicate gammaherpesviruses that are unable to undergo lytic replication in vivo may not be viable vaccine candidates despite the detection of cells harboring viral genome at late times postinfection.

scholarly journals Downregulation of Poly(ADP-Ribose) Polymerase 1 by a Viral Processivity Factor Facilitates Lytic Replication of Gammaherpesvirus

2015 ◽  
Vol 89 (18) ◽  
pp. 9676-9682 ◽  
Author(s):  
Woo-Chang Cheong ◽  
Joo-Hee Park ◽  
Hye-Ri Kang ◽  
Moon Jung Song
Keyword(s):  
Kaposi's Sarcoma ◽  
Inhibitory Effect ◽  
Lytic Replication ◽  
Dependent Manner ◽  
Transcription Activator ◽  
Murine Gammaherpesvirus ◽  
Processivity Factor ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Parp 1

ABSTRACTIn Kaposi's sarcoma-associated herpesvirus (KSHV), poly(ADP-ribose) polymerase 1 (PARP-1) acts as an inhibitor of lytic replication. Here, we demonstrate that KSHV downregulated PARP-1 upon reactivation. The viral processivity factor of KSHV (PF-8) interacted with PARP-1 and was sufficient to degrade PARP-1 in a proteasome-dependent manner; this effect was conserved in murine gammaherpesvirus 68. PF-8 knockdown in KSHV-infected cells resulted in reduced lytic replication upon reactivation with increased levels of PARP-1, compared to those in control cells. PF-8 overexpression reduced the levels of the poly(ADP-ribosyl)ated (PARylated) replication and transcription activator (RTA) and further enhanced RTA-mediated transactivation. These results suggest a novel viral mechanism for overcoming the inhibitory effect of a host factor, PARP-1, thereby promoting the lytic replication of gammaherpesvirus.IMPORTANCEGammaherpesviruses are important human pathogens, as they are associated with various kinds of tumors and establish latency mainly in host B lymphocytes. Replication and transcription activator (RTA) of Kaposi's sarcoma-associated herpesvirus (KSHV) is a central molecular switch for lytic replication, and its expression is tightly regulated by many host and viral factors. In this study, we investigated a viral strategy to overcome the inhibitory effect of poly(ADP-ribose) polymerase 1 (PARP-1) on RTA's activity. PARP-1, an abundant multifunctional nuclear protein, was downregulated during KSHV reactivation. The viral processivity factor of KSHV (PF-8) directly interacted with PARP-1 and was sufficient and necessary to degrade PARP-1 protein in a proteasome-dependent manner. PF-8 reduced the levels of PARylated RTA and further promoted RTA-mediated transactivation. As this was also conserved in another gammaherpesvirus, murine gammaherpesvirus 68, our results suggest a conserved viral modulation of a host inhibitory factor to facilitate its lytic replication.

scholarly journals Virus–Host Interplay Between Poly (ADP-Ribose) Polymerase 1 and Oncogenic Gammaherpesviruses

2022 ◽  
Vol 12 ◽  
Author(s):  
Woo-Chang Chung ◽  
Moon Jung Song
Keyword(s):  
Life Cycle ◽  
Lytic Replication ◽  
Murine Gammaherpesvirus ◽  
Barr Virus ◽  
Virus Life Cycle ◽  
Damage Response ◽  
Epstein Barr ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68 ◽  
Adp Ribosyltransferase

The gammaherpesviruses, include the Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, and murine gammaherpesvirus 68. They establish latent infection in the B lymphocytes and are associated with various lymphoproliferative diseases and tumors. The poly (ADP-ribose) polymerase-1 (PARP1), also called ADP-ribosyltransferase diphtheria-toxin-like 1 (ARTD1) is a nuclear enzyme that catalyzes the transfer of the ADP-ribose moiety to its target proteins and participates in important cellular activities, such as the DNA-damage response, cell death, transcription, chromatin remodeling, and inflammation. In gammaherpesvirus infection, PARP1 acts as a key regulator of the virus life cycle: lytic replication and latency. These viruses also develop various strategies to regulate PARP1, facilitating their replication. This review summarizes the roles of PARP1 in the viral life cycle as well as the viral modulation of host PARP1 activity and discusses the implications. Understanding the interactions between the PARP1 and oncogenic gammaherpesviruses may lead to the identification of effective therapeutic targets for the associated diseases.

scholarly journals The Murine Gammaherpesvirus 68 ORF27 Gene Product Contributes to Intercellular Viral Spread

2005 ◽  
Vol 79 (8) ◽  
pp. 5059-5068 ◽  
Author(s):  
Janet S. May ◽  
Jennifer Walker ◽  
Susanna Colaco ◽  
Philip G. Stevenson
Keyword(s):  
Gene Product ◽  
Lytic Replication ◽  
Murine Gammaherpesvirus ◽  
Barr Virus ◽  
Viral Spread ◽  
Virion Release ◽  
Direct Spread ◽  
Epstein Barr ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Herpesviruses remain predominantly cell associated within their hosts, implying that they spread between cells by a mechanism distinct from free virion release. We previously identified the efficient release of murine gammaherpesvirus 68 (MHV-68) virions as a function of the viral gp150 protein. Here we show that the MHV-68 ORF27 gene product, gp48, contributes to the direct spread of viruses from lytically infected to uninfected cells. Monoclonal antibodies to gp48 identified it on infected cell surfaces and in virions. gp48-deficient viruses showed no obvious deficit in virion cell binding, single-cycle replication, or virion release but had reduced lytic propagation between cells. After intranasal infection of mice, ORF27-deficient viruses were impaired predominantly in lytic replication in the lungs. There was a small deficit in latency establishment, but long-term latency appeared normal. Since ORF27 has homologs in both Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, it is likely part of a conserved mechanism employed by gammaherpesviruses to disseminate lytically in their hosts.

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