scholarly journals Critical Role of the Virus-Encoded MicroRNA-155 Ortholog in the Induction of Marek's Disease Lymphomas

2011 ◽  
Vol 7 (2) ◽  
pp. e1001305 ◽  
Author(s):  
Yuguang Zhao ◽  
Hongtao Xu ◽  
Yongxiu Yao ◽  
Lorraine P. Smith ◽  
Lydia Kgosana ◽  
...  
Keyword(s):  
Critical Role ◽  
Marek's Disease ◽  
Marek’S Disease

scholarly journals Depletion of CD8αβ+ T Cells in Chickens Demonstrates Their Involvement in Protective Immunity towards Marek’s Disease with Respect to Tumor Incidence and Vaccinal Protection

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 557
Author(s):  
Supawadee Umthong ◽  
John R. Dunn ◽  
Hans H. Cheng
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Protective Immunity ◽  
Lymphoproliferative Disease ◽  
Tumor Formation ◽  
Marek's Disease ◽  
Control Measures ◽  
Marek’S Disease ◽  
Cell Mediated Immune Response

Marek’s disease (MD) is a lymphoproliferative disease in chickens caused by Marek’s disease virus (MDV), a highly oncogenic alphaherpesvirus. Since 1970, MD has been controlled through widespread vaccination of commercial flocks. However, repeated and unpredictable MD outbreaks continue to occur in vaccinated flocks, indicating the need for a better understanding of MDV pathogenesis to guide improved or alternative control measures. As MDV is an intracellular pathogen that infects and transforms CD4+ T cells, the host cell-mediated immune response is considered to be vital for controlling MDV replication and tumor formation. In this study, we addressed the role of CD8+ T cells in vaccinal protection by widely-used monovalent (SB-1 and HVT) and bivalent (SB-1+HVT) MD vaccines. We established a method to deplete CD8+ T cells in chickens and found that their depletion through injection of anti-CD8 monoclonal antibodies (mAb) increased tumor induction and MD pathology, and reduced vaccinal protection to MD, which supports the important role of CD8+ T cells for both MD and vaccinal protection.

scholarly journals Experimental Allergic Neuritis in the Chicken

1967 ◽  
Vol 4 (5) ◽  
pp. 464-476
Author(s):  
M. Petek ◽  
G. L. Quaglio
Keyword(s):  
Peripheral Nerves ◽  
Marek's Disease ◽  
Experimental Allergic Neuritis ◽  
Marek’S Disease ◽  
Autoimmune Processes ◽  
Lymphoid Infiltration ◽  
Experimental Allergic ◽  
Experimental Autoimmune ◽  
Allergic Neuritis

Experimental allergic neuritis was reproduced in chickens, by inoculation of chicken and guinea pig nerves in complete Freund's adjuvant. Paralysis was observed in a percentage of inoculated birds. Histopathologically this experimental autoimmune disease was characterized by severe demyelination of peripheral nerves in all experimental animals. In addition, oedema and/or lymphoid infiltration occurred in some of the animals. The similarity of experimental allergic neuritis to the inflammatory lesions of Marek's disease is stressed and the possible role of autoimmune processes in the pathogenesis of Marek's disease is discussed.

scholarly journals Marek's Disease Virus-Encoded MicroRNA 155 Ortholog Critical for the Induction of Lymphomas Is Not Essential for the Proliferation of Transformed Cell Lines

2019 ◽  
Vol 93 (17) ◽  
Author(s):  
Yaoyao Zhang ◽  
Na Tang ◽  
Jun Luo ◽  
Man Teng ◽  
Katy Moffat ◽  
...  
Keyword(s):  
T Cell ◽  
Disease Virus ◽  
Cell Lines ◽  
Critical Role ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
T Cell Lymphomas

ABSTRACT MicroRNAs (miRNAs) are small noncoding RNAs with profound regulatory roles in many areas of biology, including cancer. MicroRNA 155 (miR-155), one of the extensively studied multifunctional miRNAs, is important in several human malignancies such as diffuse large B cell lymphoma and chronic lymphocytic leukemia. Moreover, miR-155 orthologs KSHV-miR-K12-11 and MDV-miR-M4, encoded by Kaposi’s sarcoma-associated herpesvirus (KSHV) and Marek’s disease virus (MDV), respectively, are also involved in oncogenesis. In MDV-induced T-cell lymphomas and in lymphoblastoid cell lines derived from them, MDV-miR-M4 is highly expressed. Using excellent disease models of infection in natural avian hosts, we showed previously that MDV-miR-M4 is critical for the induction of T-cell lymphomas as mutant viruses with precise deletions were significantly compromised in their oncogenicity. However, those studies did not elucidate whether continued expression of MDV-miR-M4 is essential for maintaining the transformed phenotype of tumor cells. Here using an in situ CRISPR/Cas9 editing approach, we deleted MDV-miR-M4 from the MDV-induced lymphoma-derived lymphoblastoid cell line MDCC-HP8. Precise deletion of MDV-miR-M4 was confirmed by PCR, sequencing, quantitative reverse transcription-PCR (qRT-PCR), and functional analysis. Continued proliferation of the MDV-miR-M4-deleted cell lines demonstrated that MDV-miR-M4 expression is not essential for maintaining the transformed phenotype, despite its initial critical role in the induction of lymphomas. Ability to examine the direct role of oncogenic miRNAs in situ in tumor cell lines is valuable in delineating distinct determinants and pathways associated with the induction or maintenance of transformation in cancer cells and will also contribute significantly to gaining further insights into the biology of oncogenic herpesviruses. IMPORTANCE Marek’s disease virus (MDV) is an alphaherpesvirus associated with Marek’s disease (MD), a highly contagious neoplastic disease of chickens. MD serves as an excellent model for studying virus-induced T-cell lymphomas in the natural chicken hosts. Among the limited set of genes associated with MD oncogenicity, MDV-miR-M4, a highly expressed viral ortholog of the oncogenic miR-155, has received extensive attention due to its direct role in the induction of lymphomas. Using a targeted CRISPR-Cas9-based gene editing approach in MDV-transformed lymphoblastoid cell lines, we show that MDV-miR-M4, despite its critical role in the induction of tumors, is not essential for maintaining the transformed phenotype and continuous proliferation. As far as we know, this was the first study in which precise editing of an oncogenic miRNA was carried out in situ in MD lymphoma-derived cell lines to demonstrate that it is not essential in maintaining the transformed phenotype.

scholarly journals Expression of the Conserved Herpesvirus Protein Kinase (CHPK) of Marek’s Disease Alphaherpesvirus in the Skin Reveals a Mechanistic Importance for CHPK during Interindividual Spread in Chickens

2019 ◽  
Vol 94 (5) ◽  
Author(s):  
Andrea Krieter ◽  
Nagendraprabhu Ponnuraj ◽  
Keith W. Jarosinski
Keyword(s):  
Cell Culture ◽  
Protein Kinase ◽  
Critical Role ◽  
Tumor Formation ◽  
Natural Host ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Aberrant Expression ◽  
Content Type ◽  
Conserved Genes

ABSTRACT The Herpesviridae encode many conserved genes, including the conserved herpesvirus protein kinase (CHPK) that has multifunctional properties. In most cases, herpesviruses lacking CHPK can propagate in cell culture to various degrees, depending on the virus and cell culture system. However, in the natural animal model system of Marek’s disease alphaherpesvirus (MDV) in chickens, CHPK is absolutely required for interindividual spread from chicken to chicken. The lack of biological reagents for chicken and MDV has limited our understanding of this important gene during interindividual spread. Here, we engineered epitope-tagged proteins in the context of virus infection in order to detect CHPK in the host. Using immunofluorescence assays and Western blotting during infection in cell culture and in chickens, we determined that the invariant lysine 170 (K170) of MDV CHPK is required for interindividual spread and autophosphorylation of CHPK and that mutation to methionine (M170) results in instability of the CHPK protein. Using these newly generated viruses allowed us to examine the expression of CHPK in infected chickens, and these results showed that mutant CHPK localization and late viral protein expression were severely affected in feather follicles wherein MDV is shed, providing important information on the requirement of CHPK for interindividual spread. IMPORTANCE Marek’s disease in chickens is caused by Gallid alphaherpesvirus 2, better known as Marek’s disease alphaherpesvirus (MDV). Current vaccines only reduce tumor formation but do not block interindividual spread from chicken to chicken. Understanding MDV interindividual spread provides important information for the development of potential therapies to protect against Marek’s disease while also providing a reliable natural host in order to study herpesvirus replication and pathogenesis in animals. Here, we studied the conserved Herpesviridae protein kinase (CHPK) in cell culture and during infection in chickens. We determined that MDV CHPK is not required for cell-to-cell spread, for disease induction, and for oncogenicity. However, it is required for interindividual spread, and mutation of the invariant lysine (K170) results in stability issues and aberrant expression in chickens. This study is important because it addresses the critical role CHPK orthologs play in the natural host.

scholarly journals Marek’s disease virus US3 protein kinase phosphorylates chicken HDAC 1 and 2 and regulates viral replication and pathogenesis

2021 ◽  
Vol 17 (2) ◽  
pp. e1009307
Author(s):  
Yifei Liao ◽  
Blanca Lupiani ◽  
Mohammad AI-Mahmood ◽  
Sanjay M. Reddy
Keyword(s):  
Protein Kinase ◽  
Disease Virus ◽  
Specific Inhibitor ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Virus Growth ◽  
Histone Deacetylase 1

Marek’s disease virus (MDV) is a potent oncogenic alphaherpesvirus that elicits a rapid onset of malignant T-cell lymphomas in chickens. Three MDV types, including GaHV-2 (MDV-1), GaHV-3 (MDV-2) and MeHV-1 (HVT), have been identified and all encode a US3 protein kinase. MDV-1 US3 is important for efficient virus growth in vitro. To study the role of US3 in MDV replication and pathogenicity, we generated MDV-1 US3-null virus and chimeric viruses by replacing MDV-1 US3 with MDV-2 or HVT US3. Using MD as a natural virus-host model, we showed that both MDV-2 and HVT US3 partially rescued the growth deficiency of MDV-1 US3-null virus. In addition, deletion of MDV-1 US3 attenuated the virus resulting in higher survival rate and lower MDV specific tumor incidence, which could be partially compensated by MDV-2 and HVT US3. We also identified chicken histone deacetylase 1 (chHDAC1) as a common US3 substrate for all three MDV types while only US3 of MDV-1 and MDV-2 phosphorylate chHDAC2. We further determined that US3 of MDV-1 and HVT phosphorylate chHDAC1 at serine 406 (S406), while MDV-2 US3 phosphorylates S406, S410, and S415. In addition, MDV-1 US3 phosphorylates chHDAC2 at S407, while MDV-2 US3 targets S407 and S411. Furthermore, biochemical studies show that MDV US3 mediated phosphorylation of chHDAC1 and 2 affect their stability, transcriptional regulation activity, and interaction network. Using a class I HDACs specific inhibitor, we showed that MDV US3 mediated phosphorylation of chHDAC1 and 2 is involved in regulation of virus replication. Overall, we identified novel substrates for MDV US3 and characterized the role of MDV US3 in MDV pathogenesis.

scholarly journals The Tegument Protein pUL47 of Marek’s Disease Virus Is Necessary for Horizontal Transmission and Is Important for Expression of Glycoprotein gC

2020 ◽  
Vol 95 (2) ◽  
pp. e01645-20
Author(s):  
Aurélien Chuard ◽  
Katia Courvoisier-Guyader ◽  
Sylvie Rémy ◽  
Stephen Spatz ◽  
Caroline Denesvre ◽  
...  
Keyword(s):  
Disease Virus ◽  
Horizontal Transmission ◽  
Marek's Disease Virus ◽  
Viral Transmission ◽  
Natural Host ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease

ABSTRACTViral tropism and transmission of herpesviruses are best studied in their natural host for maximal biological relevance. In the case of alphaherpesviruses, few reports have focused on those aspects, primarily because of the few animal models available as natural hosts that are compatible with such studies. Here, using Marek’s disease virus (MDV), a highly contagious and deadly alphaherpesvirus of chickens, we analyze the role of tegument proteins pUL47 and pUL48 in the whole life cycle of the virus. We report that a virus lacking the UL48 gene (vΔUL48) is impaired in growth in cell culture and has diminished virulence in vivo. In contrast, a virus lacking UL47 (vΔUL47) is unaffected in its growth in vitro and is as virulent in vivo as the wild-type (WT) virus. Surprisingly, we observed that vΔUL47 was unable to be horizontally transmitted to naive chickens, in contrast to the WT virus. In addition, we show that pUL47 is important for the splicing of UL44 transcripts encoding glycoprotein gC, a protein known as being essential for horizontal transmission of MDV. Importantly, we observed that the levels of gC are lower in the absence of pUL47. Notably, this phenotype is similar to that of another transmission-incompetent mutant ΔUL54, which also affects the splicing of UL44 transcripts. This is the first study describing the role of pUL47 in both viral transmission and the splicing and expression of gC.IMPORTANCE Host-to-host transmission of viruses is ideally studied in vivo in the natural host. Veterinary viruses such as Marek’s disease virus (MDV) are, therefore, models of choice to explore these aspects. The natural host of MDV, the chicken, is small, inexpensive, and economically important. MDV is a deadly and contagious herpesvirus that can kill infected animals in less than 4 weeks. The virus naturally infects epithelial cells of the feather follicle epithelium from where it is shed into the environment. In this study, we demonstrate that the viral protein pUL47 is an essential factor for bird-to-bird transmission of the virus. We provide some molecular basis to this function by showing that pUL47 enhances the splicing and the expression of another viral gene, UL44, which is essential for viral transmission. pUL47 may have a similar function in human herpesviruses such as varicella-zoster virus or herpes simplex viruses.

scholarly journals Attenuation of Marek's Disease Virus by Deletion of Open Reading Frame RLORF4 but Not RLORF5a

2005 ◽  
Vol 79 (18) ◽  
pp. 11647-11659 ◽  
Author(s):  
Keith W. Jarosinski ◽  
Nikolaus Osterrieder ◽  
Venugopal K. Nair ◽  
Karel A. Schat
Keyword(s):  
Virus Isolation ◽  
Cultured Cells ◽  
Artificial Chromosome ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Reading Frame ◽  
Multiple Organs ◽  
Kinetics Of

ABSTRACT Marek's disease (MD) in chickens is caused by the alphaherpesvirus MD virus (MDV) and is characterized by the development of lymphoblastoid tumors in multiple organs. The recent identification and cloning of RLORF4 and the finding that four of six attenuated strains of MDV contained deletions within RLORF4 suggested that it is involved in the attenuation process of MDV. To assess the role of RLORF4 in MD pathogenesis, its coding sequence was deleted in the pRB-1B bacterial artificial chromosome clone. Additionally, RLORF5a was deleted separately to examine its importance for oncogenesis. The sizes of plaques produced by MDV reconstituted from pRB-1BΔRLORF5a (rRB-1BΔRLORF5a) were similar to those produced by the parental pRB-1B virus (rRB-1B). In contrast, virus reconstituted from pRB-1BΔRLORF4 (rRB-1BΔRLORF4) produced significantly larger plaques. Replication of the latter virus in cultured cells was higher than that of rRB-1B or rRB-1BΔRLORF5a using quantitative PCR (qPCR) assays. In vivo, both deletion mutants and rRB-1B replicated at comparable levels at 4, 7, and 10 days postinoculation (p.i.), as determined by virus isolation and qPCR assays. At 14 days p.i., the number of PFU of virus isolated from chickens infected with rRB-1BΔRLORF4 was comparable to that from chickens infected with highly attenuated RB-1B and significantly lower than that from rRB-1B-infected birds. The number of tumors and kinetics of tumor production in chickens infected with rRB-1BΔRLORF5a were similar to those of P2a chickens infected with rRB-1B. In stark contrast, none of the chickens inoculated with rRB-1BΔRLORF4 died up to 13 weeks p.i.; however, two chickens had tumors at the termination of the experiment. The data indicate that RLORF4 is involved in attenuation of MDV, although the function of RLORF4 is still unknown.

scholarly journals The role of Meq-vIL8 in regulating Marek’s disease virus pathogenesis

2020 ◽  
Author(s):  
Yifei Liao ◽  
Kanika Bajwa ◽  
Mohammad Al-Mahmood ◽  
Isabel M. Gimeno ◽  
Sanjay M. Reddy ◽  
...  
Keyword(s):  
Disease Virus ◽  
Late Phase ◽  
Donor Site ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Splice Donor Site ◽  
Marek’S Disease Virus ◽  
Marek’S Disease

Marek’s disease virus (MDV) is a highly cell-associated oncogenic alphaherpesvirus that causes T cell lymphoma in chickens. MDV-encoded Meq and vIL8 proteins play important roles in transformation and early cytolytic infection, respectively. Previous studies identified a spliced transcript, meq-vIL8, formed by alternative splicing of meq and vIL8 genes in MDV lymphoblastoid tumour cells. To determine the role of Meq-vIL8 in MDV pathogenesis, we generated a recombinant MDV (MDV-meqΔSD) by mutating the splice donor site in the meq gene to abrogate the expression of Meq-vIL8. As expected, our results show that MDV-meqΔSD virus grows similarly to the parental and revertant viruses in cell culture, suggesting that Meq-vIL8 is dispensable for MDV growth in vitro. We further characterized the pathogenic properties of MDV-meqΔSD virus in chickens. Our results show that lack of Meq-vIL8 did not affect virus replication during the early cytolytic phase, as determined by immunohistochemistry analysis and/or viral genome copy number, but significantly enhanced viral DNA load in the late phase of infection in the spleen and brain of infected chickens. In addition, we observed that abrogation of Meq-vIL8 expression reduced the mean death time and increased the prevalence of persistent neurological disease, common features of highly virulent strains of MDV, in inoculated chickens. In conclusion, our study shows that Meq-vIL8 is an important virulence factor of MDV.

Sign in / Sign up

Export Citation Format

Share Document