scholarly journals A role of hypoxia-inducible factor 1 alpha in Murine Gammaherpesvirus 68 (MHV68) lytic replication and reactivation from latency

2019 ◽  
Vol 15 (12) ◽  
pp. e1008192 ◽  
Author(s):  
Darlah M. López-Rodríguez ◽  
Varvara Kirillov ◽  
Laurie T. Krug ◽  
Enrique A. Mesri ◽  
Samita Andreansky
Keyword(s):  
Hypoxia Inducible Factor ◽  
Lytic Replication ◽  
Murine Gammaherpesvirus ◽  
Hypoxia Inducible Factor 1 ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

scholarly journals The M4 Gene of Murine Gammaherpesvirus Modulates Productive and Latent Infection In Vivo

2004 ◽  
Vol 78 (2) ◽  
pp. 758-767 ◽  
Author(s):  
A. C. Townsley ◽  
B. M. Dutia ◽  
A. A. Nash
Keyword(s):  
Small Animal ◽  
Lytic Replication ◽  
Productive Infection ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Murine gammaherpesvirus 68 (MHV-68) infection of mice represents a viable small-animal model for the study of gammaherpesvirus pathogenesis. MHV-76 is a deletion mutant of MHV-68, which lacks four MHV-68-specific genes (M1 to M4) and eight viral tRNA-like sequences at the 5′ end of the genome. These genes are implicated in latency and/or immune evasion. Consequently, MHV-76 is attenuated in the acute phase of in vivo infection with respect to MHV-68. Little is known about the role of M4 in viral infection, except that it is expressed as an immediate-early/early transcript during lytic replication of MHV-68 in vitro. To elucidate the contribution M4 makes to in vivo pathogenesis, we created a novel MHV-76 mutant (MHV-76inM4), in which the region of MHV-68 coding for M4 and accompanying putative promoter elements were inserted into the 5′ region of the MHV-76 genome. The growth of MHV-76inM4 in vitro was indistinguishable from that of MHV-76 and MHV-68. However, virus titers from MHV-76inM4-infected BALB/c mice were significantly increased with respect to MHV-76 at early times in the lung. In addition, at days 17 and 21 postinfection, there was a significant elevation in latent viral load in splenocytes of MHV-76inM4-infected mice compared to MHV-76. Like MHV-76-infected mice, MHV-76inM4-infected mice display no evidence of overt splenomegaly, a finding characteristic of MHV-68 infection. M4 expression in vivo was detectable during productive infection in the lung and during the establishment of latency in the spleen, but in general M4 was not detectable during long-term latency (day 100 postinfection).

scholarly journals Identification and functional characterization of the left origin of lytic replication of murine gammaherpesvirus 68

Virology ◽  
2009 ◽  
Vol 387 (2) ◽  
pp. 285-295 ◽  
Author(s):  
Danyang Gong ◽  
Jing Qi ◽  
Vaithilingaraja Arumugaswami ◽  
Ren Sun ◽  
Hongyu Deng
Keyword(s):  
Functional Characterization ◽  
Lytic Replication ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

scholarly journals Forced lytic replication impairs host colonization by a latency-deficient mutant of murine gammaherpesvirus-68

2004 ◽  
Vol 85 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Janet S. May ◽  
Heather M. Coleman ◽  
Belinda Smillie ◽  
Stacey Efstathiou ◽  
Philip G. Stevenson
Keyword(s):  
Lytic Replication ◽  
Deficient Mutant ◽  
Host Colonization ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

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 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 Murine Gammaherpesvirus 68 Expressing Kaposi Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen (LANA) Reveals both Functional Conservation and Divergence in LANA Homologs

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Arundhati Gupta ◽  
Darby G. Oldenburg ◽  
Eduardo Salinas ◽  
Douglas W. White ◽  
J. Craig Forrest
Keyword(s):  
Chronic Infection ◽  
Ex Vivo ◽  
Kaposi Sarcoma ◽  
Lytic Replication ◽  
Nuclear Antigen ◽  
Content Type ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Latency-associated nuclear antigen (LANA) is a multifunctional protein encoded by members of the Rhadinovirus genus of gammaherpesviruses. Studies using murine gammaherpesvirus 68 (MHV68) demonstrated that LANA is important for acute replication, latency establishment, and reactivation in vivo. Despite structural similarities in their DNA-binding domains (DBDs), LANA homologs from Kaposi sarcoma-associated herpesvirus (KSHV) and MHV68 exhibit considerable sequence divergence. We sought to determine if KSHV and MHV68 LANA homologs are functionally interchangeable. We generated an MHV68 virus that encodes KSHV LANA (kLANA) in place of MHV68 LANA (mLANA) and evaluated the virus's capacity to replicate, establish and maintain latency, and reactivate. kLANA knock-in (KLKI) MHV68 was replication competent in vitro and in vivo but exhibited slower growth kinetics and lower titers than wild-type (WT) MHV68. Following inoculation of mice, KLKI MHV68 established and maintained latency in splenocytes and peritoneal cells but did not reactivate efficiently ex vivo. kLANA repressed the MHV68 promoter for ORF50, the gene that encodes the major lytic transactivator protein RTA, while mLANA did not, suggesting a likely mechanism for the KLKI MHV68 phenotypes. Bypassing this repression by providing MHV68 RTA in trans rescued KLKI MHV68 replication in tissue culture and enabled detection of KLKI MHV68 reactivation ex vivo. These data demonstrate that kLANA and mLANA are functionally interchangeable for establishment and maintenance of latency and suggest that repression of lytic replication by kLANA, as previously shown with KSHV, is a kLANA-specific function that is transferable to MHV68. IMPORTANCE Kaposi sarcoma-associated herpesvirus (KSHV) and murine gammaherpesvirus 68 (MHV68) are members of the Rhadinovirus genus of gammaherpesviruses. These viruses establish lifelong infections that place their respective human and murine hosts at risk for cancer. Latency-associated nuclear antigen (LANA) is a conserved Rhadinovirus protein that is necessary for long-term chronic infection by these viruses. To better understand the conserved functions performed by LANA homologs, we generated a recombinant MHV68 virus that encodes the KSHV LANA protein in place of the MHV68 LANA homolog. We determined that the KSHV LANA protein is capable of supporting MHV68 latency in a mouse model of chronic infection but also functions to repress viral replication. This work describes an in vivo model system for defining evolutionarily conserved and divergent functions of LANA homologs in Rhadinovirus infection and disease.

scholarly journals Murine gammaherpesvirus-68 ORF28 encodes a non-essential virion glycoprotein

2005 ◽  
Vol 86 (4) ◽  
pp. 919-928 ◽  
Author(s):  
Janet S. May ◽  
Heather M. Coleman ◽  
Jessica M. Boname ◽  
Philip G. Stevenson
Keyword(s):  
Function Analysis ◽  
Lytic Replication ◽  
Specific Gene ◽  
Virion Protein ◽  
Major Function ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

Murine gammaherpesvirus-68 (MHV-68) ORF28 is a gammaherpesvirus-specific gene of unknown function. Analysis of epitope-tagged ORF28 protein indicated that it was membrane-associated and incorporated into virions in N-glycosylated, O-glycosylated and unglycosylated forms. The extensive glycosylation of the small ORF28 extracellular domain – most forms of the protein appeared to be mainly carbohydrate by weight – suggested that a major function of ORF28 is to attach a variety of glycans to the virion surface. MHV-68 lacking ORF28 showed normal lytic replication in vitro and in vivo and normal latency establishment. MHV-68 ORF28 therefore encodes a small, membrane-bound and extensively glycosylated virion protein, whose function is entirely dispensable for normal, single-cycle host colonization.

scholarly journals Tpl2/AP-1 Enhances Murine Gammaherpesvirus 68 Lytic Replication

2009 ◽  
Vol 84 (4) ◽  
pp. 1881-1890 ◽  
Author(s):  
Xudong Li ◽  
Jun Feng ◽  
Shijia Chen ◽  
Li Peng ◽  
Wei-Wu He ◽  
...  
Keyword(s):  
Gene Expression ◽  
Promoter Activity ◽  
Lytic Replication ◽  
Dependent Manner ◽  
Lytic Gene ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Responsive Element ◽  
Murine Gammaherpesvirus 68 ◽  
Lytic Genes

ABSTRACT How cellular factors regulate gammaherpesvirus lytic replication is not well understood. Here, through functional screening of a cellular kinase expression library, we identified mitogen-activated protein kinase kinase kinase 8 (MAP3K8/Tpl2) as a positive regulator of murine gammaherpesvirus 68 (MHV-68 or γHV-68) lytic gene expression and replication. Tpl2 enhances MHV-68 lytic replication by upregulating lytic gene expression and promoter activities of viral lytic genes, including RTA and open reading frame 57 (ORF57). By screening a cellular transcription factor library, we identified the Fos AP-1 transcription factor as a downstream factor that is both necessary and sufficient for mediating the enhancement of MHV-68 lytic replication by Tpl2. In addition, Tpl2 stimulates the promoter activities of key viral lytic genes, including RTA and ORF57, in an AP-1-dependent manner. We identified an AP-1-responsive element on the MHV-68 RTA promoter as the cis element mediating the upregulation of RTA promoter activity by Tpl2. MHV-68 lytic infection upregulates Fos expression, AP-1 activity, and RTA promoter activity in a Tpl2-dependent manner. We constructed a mutant MHV-68 virus that abolished this AP-1-responsive element. This mutant virus exhibited attenuated lytic replication kinetics, indicative of a critical role of this AP-1-responsive element during lytic replication. Moreover, Tpl2 knockdown inhibited the lytic replication of wild-type MHV-68 (MHV-68-WT) but not that of the MHV-68 mutant virus, indicating that endogenous Tpl2 promotes efficient virus lytic replication through AP-1-dependent upregulation of RTA expression. In summary, through tandem functional screens, we identified the Tpl2/AP-1 signaling transduction pathway as a positive regulator of MHV-68 lytic replication.

scholarly journals Role of CXCR3 in the Immune Response to Murine Gammaherpesvirus 68

2005 ◽  
Vol 79 (14) ◽  
pp. 9351-9355 ◽  
Author(s):  
Bong Joo Lee ◽  
Francesca Giannoni ◽  
Ashley Lyon ◽  
Shinichiro Yada ◽  
Bao Lu ◽  
...  
Keyword(s):  
Immune Response ◽  
Cytolytic Activity ◽  
Murine Gammaherpesvirus ◽  
Latently Infected ◽  
Virus Specific Antibody ◽  
Antibody Titers ◽  
Infected Cells ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT The chemokine IP-10 (CXCL10) and its cellular receptor CXCR3 are upregulated in the lung during murine gammaherpesvirus 68 (MHV-68) infection. In order to determine the role of the CXCR3 chemokine receptor in the immune response to MHV-68, CXCR3−/− mice were infected with the virus. CXCR3−/− mice showed delayed clearance of replicating MHV-68 from the lungs. This correlated with delayed T-cell recruitment to the lungs and reduced cytolytic activity prior to viral clearance. Splenomegaly and the numbers of latently infected cells per spleen were transiently increased. Ηowever, CXCR3−/− mice showed normal virus-specific antibody titers and effective long-term control of MHV-68 infection.

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