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1.
PLoS One ; 18(1): e0280923, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36706167

RESUMO

This report characterizes the first lethal outbreak of Marek's disease on a large farm of mixed-breed adult ducks (>18,000) and identifies the pathogen that resulted in high mortality (35%). Clinical signs included inappetence, respiratory distress, depression, muscle weakness, and ataxia. Post mortem revealed enlarged fragile liver mottled with miliary whitish spots and an enlarged spleen. Histopathology revealed hepatocellular necrosis with eosinophilic intra-nuclear inclusion bodies, necrosis of splenic follicles and degeneration/necrosis of renal tubules. The disease was tentatively diagnosed as a herpesvirus infection, confirmed by virus isolation from the liver. DNA was isolated from 15-year-old archival formalin-fixed tissues from infected ducks and subjected to next generation sequencing (NGS). Despite highly degraded DNA, short stretches of G- and C-rich repeats (TTAGGG and TAACCC) were identified as telomeric repeats frequently found in herpesviruses. Megablast and further investigative bioinformatics identified presence of Marek's disease virus (MDV), a Gallid alphaherpesvirus type 2 (GAHV-2), as the cause of the acute fatal infection. The source of infection may be attributed to a dead migratory flamingo found close to the duck enclosures three days prior to the outbreak; hence, GAHV-2 may also be responsible for the fatal infection of the flamingo accentuated by heat stress. Considering the possible spread of this highly contagious and lethal virus from a flamingo to the ducks, and the increasing zoonosis of animal viruses into humans, such as monkey B alphaherpesvirus transmission from macaques to humans with ~80% fatality, this observation has important ramifications for human health and safety of the poultry industry.


Assuntos
Herpesviridae , Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Adulto , Humanos , Adolescente , Patos/genética , Doença de Marek/epidemiologia , Doença de Marek/diagnóstico , Doença de Marek/patologia , Galinhas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Herpesviridae/genética , Herpesvirus Galináceo 2/genética , Surtos de Doenças/veterinária
2.
Viruses ; 14(12)2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36560601

RESUMO

The avian immunosuppressive and neoplastic diseases caused by Marek's disease virus (MDV), avian leucosis virus (ALV), and reticuloendotheliosis virus (REV) are seriously harmful to the global poultry industry. In recent years, particularly in 2020-2022, outbreaks of such diseases in chicken flocks frequently occurred in China. Herein, we collected live diseased birds from 30 poultry farms, out of 42 farms with tumour-bearing chicken flocks distributed in central China, to investigate the current epidemiology and co-infections of these viruses. The results showed that in individual diseased birds, the positive infection rates of MDV, ALV, and REV were 69.5% (203/292), 14.4% (42/292), and 4.7% (13/277), respectively, while for the flocks, the positive infection rates were 96.7% (29/30), 36.7% (11/30), and 20% (6/30), respectively. For chicken flocks, monoinfection of MDV, ALV, or REV was 53.3% (16/30), 3.3% (1/30), and 0% (0/30), respectively, but a total of 43.3% (13/30) co-infections was observed, which includes 23.3% (7/30) of MDV+ALV, 10.0% (3/30) of MDV+REV, and 10.0% (3/30) of MDV+ALV+REV co-infections. Interestingly, no ALV+REV co-infection or REV monoinfection was observed in the selected poultry farms. Our data indicate that the prevalence of virulent MDV strains, partially accompanied with ALV and/or REV co-infections, is the main reason for current outbreaks of avian neoplastic diseases in central China, providing an important reference for the future control of disease.


Assuntos
Vírus da Leucose Aviária , Leucose Aviária , Coinfecção , Herpesvirus Galináceo 2 , Doença de Marek , Neoplasias , Doenças das Aves Domésticas , Vírus da Reticuloendoteliose , Animais , Galinhas , Coinfecção/epidemiologia , Coinfecção/veterinária , Coinfecção/complicações , Leucose Aviária/epidemiologia , Neoplasias/epidemiologia , Neoplasias/veterinária , China/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Vírus da Leucose Aviária/genética , Doença de Marek/epidemiologia
3.
Vet Ital ; 58(1): 77-85, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36398666

RESUMO

Marek's disease (MD) is a devastating neoplastic disease of poultry caused by MD virus (MDV). MD is one of the several diseases limiting the thriving Nigerian poultry industry. MD is mostly diagnosed in Nigeria based on history and gross lesions without laboratory investigations leading to underreporting of the disease. This study investigated MD outbreaks in poultry farms using polymerase chain reaction (PCR) and histopathology. Tumourous visceral organs were collected from dead chickens presented to veterinary clinics from 110 farms in Plateau State, North Central Nigeria from April 2013 to August 2014. Clinical signs observed in affected chickens were paralysis, stunting and uneven growth. Whilst the gross lesions observed were hepatomegaly, splenomegaly with lymphoma, prominent peripheral nerves and cachexia. The meq gene of MDV­1 was detected by PCR in 55.0% (n = 11/20) of broilers and 71.1% (n = 64/90) of vaccinated layer chicken samples collected. Microscopy revealed severe diffuse lymphocytic infiltrations in the heart, spleen and liver of chickens with tumourous gross lesions. Based on history, gross lesions, detection of meq gene of MDV­1 by PCR and histopathology results, MD was confirmed in the affected farms. Despite vaccination, outbreaks of MD still occurs in poultry farms in Nigeria. This study represents the first confirmatory diagnosis of MD in vaccinated poultry in Nigeria.


Assuntos
Doença de Marek , Doenças das Aves Domésticas , Animais , Doença de Marek/epidemiologia , Aves Domésticas , Nigéria/epidemiologia , Galinhas , Fazendas , Surtos de Doenças/veterinária
4.
Vet Ital ; 58(1): 117-124, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36398672

RESUMO

The present study investigates an outbreak of classical Marek's disease (MD) in backyard Cochin chickens reared for hobby in Italy. Examined chickens showed spastic paralysis of the legs and at necropsy, enlargement and discoloration of the peripheral nerves and plexuses that matched microscopic A­ and B­ type MD lesions. Molecular analysis of the meq gene of the detected Gallid alphaherpesvirus 2 (GaHV­2) strain, showed typical markers of low virulence and the strain shared the entire meq gene sequence with strains circulating in Italian backyard chickens. Furthermore, the haplotype B19 of the major histocompatibility complex (MHC) was defined in the affected chickens, showing that the birds possessed a genetic profile of high susceptibility to MD, allowing the appearance of a classical nervous clinical form after infection with an apparently low pathogenicity GaHV­2 strain. Trade of live ornamental purebred chickens occurs frequently between hobby farmers and biosecurity practices, such as quarantine periods, should be applied to avoid the introduction of infected animals. Veterinarians should raise awareness of this issue and promote the use of vaccines against MD.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Doença de Marek/epidemiologia , Galinhas , Herpesvirus Galináceo 2/genética , Virulência/genética
5.
Front Immunol ; 13: 973762, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189228

RESUMO

The major histocompatibility complex (MHC) haplotype is one of the major determinants of genetic resistance and susceptibility of chickens to Marek's disease (MD) which is caused by an oncogenic herpesvirus; Marek's disease virus (MDV). To determine differential functional abilities of T cells associated with resistance and susceptibility to MD, we identified immunodominant CD4+TCRvß1 T cell epitopes within the pp38 antigen of MDV in B19 and B21 MHC haplotype chickens using an ex vivo ELISPOT assay for chicken IFN-gamma. These novel pp38 peptides were used to characterize differential functional abilities of T cells as associated with resistance and susceptibility to MD. The results demonstrated an upregulation of cytokines (IL-2, IL-4, IL-10) and lymphocyte lysis-related genes (perforin and granzyme B) in an antigen specific manner using RT-PCR. In the MD-resistant chickens (B21 MHC haplotype), antigen-specific and non-specific response was highly skewed towards Th2 response as defined by higher levels of IL-4 expression as well as lymphocyte lysis-related genes compared to that in the MD-susceptible chicken line (B19 MHC haplotype). Using CD107a degranulation assay, the results showed that MDV infection impairs cytotoxic function of T cells regardless of their genetic background. Taken together, the data demonstrate an association between type of T cell response to pp38 and resistance to the disease and will shed light on our understanding of immune response to this oncogenic herpesvirus and failure to induce sterile immunity.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Animais , Antivirais , Galinhas , Citocinas , Epitopos de Linfócito T , Granzimas , Interleucina-10 , Interleucina-2 , Interleucina-4/genética , Perforina
6.
Viruses ; 14(9)2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36146821

RESUMO

The importance of the bursa of Fabricius (BF) for the pathogenesis of Marek's disease (MD) has been studied since the late 1960's. In this review, the results of these studies are analyzed in the context of the developing knowledge of the immune system of chickens and the pathogenesis of MD from 1968 to 2022. Based on the available techniques to interfere with the development of the BF, three distinct periods are identified and discussed. During the initial period between 1968 and 1977, the use of neonatal bursectomy, chemical methods and irradiation were the main tools to interfere with the B lymphocyte development. The application of these techniques resulted in contradictory results from no effects to an increase or decrease in MD incidence. Starting in the late 1970's, the use of bursectomy in 18-day-old embryos led to the development of the "Cornell model" for the pathogenesis of MD, in which the infection of B lymphocytes is an important first step in MD virus (MDV) replication causing the activation of thymus-derived lymphocytes (T cells). Following this model, these activated T cells, but not resting T cells, are susceptible to MDV infection and subsequent transformation. Finally, B-cell knockout chickens lacking the J gene segment of the IgY heavy chain gene were used to further define the role of the BF in the pathogenesis of MD.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Animais , Linfócitos B/patologia , Bolsa de Fabricius/patologia , Galinhas , Herpesvirus Galináceo 2/genética , Linfócitos T/patologia
7.
Viruses ; 14(9)2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36146851

RESUMO

Marek's disease virus (MDV) is an important oncogenic α-herpesvirus that induces Marek's disease (MD), characterized by severe immunosuppression and rapid-onset T-cell lymphomas in its natural chicken hosts. Historically, MD is regarded as an ideal biomedical model for studying virally induced cancers. Monoclonal antibodies (mAbs) against viral or host antigenic epitopes are crucial for virology research, especially in the exploration of gene functions, clinical therapy, and the development of diagnostic reagents. Utilizing the CRISPR/Cas9-based gene-editing technology, we produced a pp38-deleted MDV-1 mutant-GX0101Δpp38-and used it for the rapid screening and identification of pp38-specific mAbs from a pool of MDV-specific antibodies from 34 hybridomas. The cross-staining of parental and mutated MDV plaques with hybridoma supernatants was first performed by immunofluorescence assay (IFA). Four monoclonal hybridomas-namely, 4F9, 31G7, 34F2, and 35G9-were demonstrated to secrete specific antibodies against MDV-1's pp38 protein, which was further confirmed by IFA staining and confocal analysis. Further experiments using Western blotting, immunoprecipitation (IP), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and immunohistochemistry (IHC) analysis demonstrated that the pp38-specific mAb 31G7 has high specificity and wide application potential for further research in MD biology. To the best of our knowledge, this is the first demonstration of the use of CRISPR/Cas9-based gene-editing technology for efficient screening and identification of mAbs against a specific viral protein, and provides a meaningful reference for the future production of antibodies against other viruses-especially for large DNA viruses such as herpesviruses.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Animais , Anticorpos Monoclonais , Antígenos Virais , Sistemas CRISPR-Cas , Galinhas , Cromatografia Líquida , Epitopos/genética , Herpesvirus Galináceo 2/genética , Espectrometria de Massas em Tandem , Tecnologia , Proteínas Virais/genética
8.
Avian Dis ; 66(3): 1-5, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36106908

RESUMO

Marek's disease (MD) is a highly contagious, lymphoproliferative poultry disease caused by the oncogenic herpesvirus, serotype 1 Marek's disease virus (MDV-1), or Gallid herpesvirus 2 (GaHV-2). MDV strains have shown a continued evolution of virulence leading to immune failure, and MD cases continue to occur or surge. Meq, the major MDV-1 oncoprotein, induces T-cell neoplastic transformation through several mechanisms including inhibition of apoptosis, cell cycle regulation, and serum-anchorage independent growth. There is no current information on the MDV serotypes and pathotypes circulating in vaccinated commercial farms in Iran, where the birds are vaccinated at the hatchery with GaHV-2 and Meleagrid herpesvirus 1 (MeHV-1) vaccines. This study reports the molecular characterization of a GaHV-2 strain detected in 19 flocks of Iranian layer farms exhibiting MDV-1-like clinical signs and visceral lymphomas. Based on sequencing and phylogenetic analysis of the Meq gene, the Iranian GaHV-2 isolates could be divided into two separate clades regarding molecular features. The clade containing strains was closely related to Italian, Indian, and Hungarian virulent isolates, and the clade was related to American very virulent plus (vv+) isolates. For the first time, the MDV-1 virus was characterized by an outbreak in poultry flocks in Iran. Although MDV-1 strains obtained in Iran's present outbreak are presumably related to virulent (v) and vv+ pathotypes based on nucleotide, amino acid, and phylogenetic analysis of the viruses, they are not confirmed so far. Thus, it is highly recommended to perform further analyses to demonstrate the pathotype characteristics in vivo.


Caracterización molecular y análisis filogenético del virus de la enfermedad de Marek en Irán. La enfermedad de Marek (MD) es una enfermedad altamente contagiosa linfoproliferativa en la avicultura causada por el herpesvirus oncogénico, el virus de la enfermedad de Marek de serotipo 1 (MDV-1) o Gallid herpesvirus 2 (GaHV-2). Las cepas del virus de Marek han mostrado una evolución continua de virulencia que conduce a una falla inmunológica, y los casos de Marek continúan ocurriendo o aumentando. El gene Meq, codifica la principal oncoproteína de MDV-1, induce la transformación neoplásica de células T a través de varios mecanismos que incluyen la inhibición de la apoptosis, la regulación del ciclo celular y el crecimiento independiente del anclaje sérico. No hay información actual sobre los serotipos y patotipos del virus de Marek que circulan en las granjas comerciales vacunadas en Irán, donde las aves se vacunan en la planta de incubación con las vacunas GaHV-2 y Meleagrid herpesvirus 1 (MeHV-1). Este estudio reporta la caracterización molecular de una cepa del Gallid herpesvirus 2 detectada en 19 lotes de granjas de aves de postura iraníes que presentaron signos clínicos sugestivos del serotipo 1 del virus de la enfermedad de Marek y linfomas viscerales. Según la secuenciación y el análisis filogenético del gene Meq, los aislamientos iraníes de GaHV-2 podrían dividirse en dos clados separados con respecto a las características moleculares. El clado que contenía las cepas estaba estrechamente relacionado con los aislados virulentos de Italia, India y de Hungria y el clado estaba relacionado con los aislados americanos muy virulentos plus (vv+). Por primera vez, el serotipo 1 del virus de la enfermedad de Marek se caracterizó por un brote en parvadas avícolas en Irán. Aunque las cepas del virus de Marek, serotipo 1 obtenidas en el brote actual de Irán están presuntamente relacionadas con patotipos virulentos (v) y muy virulentos plus según el análisis de nucleótidos, aminoácidos y filogenético de los virus, hasta el momento no se han confirmado. Por lo tanto, se recomienda realizar más análisis para demostrar las características del patotipo in vivo.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Aminoácidos , Animais , Galinhas , Irã (Geográfico)/epidemiologia , Nucleotídeos , Proteínas Oncogênicas/genética , Filogenia , Aves Domésticas
9.
Viruses ; 14(8)2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-36016273

RESUMO

In recent years, outbreaks of Marek's disease (MD) have been frequently reported in vaccinated chicken flocks in China. Herein, we have demonstrated that four Marek's disease virus (MDV) isolates, HN502, HN302, HN304, and HN101, are all pathogenic and oncogenic to hosts. Outstandingly, the HN302 strain induced 100% MD incidence, 54.84% mortality, and 87.10% tumor incidence, together with extensive atrophy of immune organs. Pathotyping of HN302 was performed in comparison to a standard very virulent (vv) MDV strain Md5. We found that both CVI988 and HVT vaccines significantly reduced morbidity and mortality induced by HN302 or Md5 strains, but the protection indices (PIs) provided by these two vaccines against HN302 were significantly lower (27.03%) or lower (33.33%) than that against Md5, which showed PIs of 59.89% and 54.29%, respectively. These data suggested that HN302 possesses a significant higher virulence than Md5 and at least could be designated as a vvMDV strain. Together with our previous phylogenetic analysis on MDV-1 meq genes, we have presently suggested HN302 to be a typical highly virulent MDV variant belonging to an independent Chinese branch. To our knowledge, this is the first report to provide convincible evidence to identify a pathogenic MDV variant strain with a higher virulence than Md5 in China, which may have emerged and circulating in poultry farms in China for a long time and involved in the recent MD outbreaks.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Galinhas , Herpesvirus Galináceo 2/genética , Filogenia , Virulência
10.
Microb Pathog ; 170: 105688, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35917989

RESUMO

Marek's disease virus (MDV), a highly contagious cell associated virus, is the etiological agent of Marek's disease (MD), a lymphoproliferative and neuropathic disease of domestic chickens. Clinical signs of MD include transient paralysis, bursal/thymic atrophy, and T cell lymphomas. MicroRNAs (miRNAs) are short single-stranded non-coding RNAs that regulate gene expression by transcriptional suppression or mRNA degradation. Herpesviruses, including MDV, encode for miRNAs that are known to play essential roles in viral pathogenicity, oncogenesis, and evasion of immune responses. In this study, we performed miRNA sequencing in thymuses of control and MDV-infected chickens of MD-resistant (63) and susceptible (72) lines at 21 days post infection (dpi). The thymus is a lymphoid organ that undergoes severe atrophy due to MDV-induced apoptotic mediated destruction of T cells. Sequence analysis identified 658 total chicken miRNAs in the thymuses of control and MDV-infected birds of both lines. Of these, 453 were novel and 205 were known microRNAs. All novel miRNAs mapped to chicken genome with no sequence homology to existing miRNAs in the chicken miRbase. Comparative analysis between the thymuses of control and infected birds of resistant and susceptible lines identified 78 differentially expressed microRNAs that might provide insights into mechanisms of thymus atrophy.


Assuntos
Doença de Marek , MicroRNAs , Animais , Atrofia/patologia , Galinhas , Doença de Marek/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Linfócitos T/metabolismo
11.
PLoS Pathog ; 18(8): e1010745, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36037230

RESUMO

In vivo bioluminescence imaging facilitates the non-invasive visualization of biological processes in living animals. This system has been used to track virus infections mostly in mice and ferrets; however, until now this approach has not been applied to pathogens in avian species. To visualize the infection of an important avian pathogen, we generated Marek's disease virus (MDV) recombinants expressing firefly luciferase during lytic replication. Upon characterization of the recombinant viruses in vitro, chickens were infected and the infection visualized in live animals over the course of 14 days. The luminescence signal was consistent with the known spatiotemporal kinetics of infection and the life cycle of MDV, and correlated well with the viral load measured by qPCR. Intriguingly, this in vivo bioimaging approach revealed two novel sites of MDV replication, the beak and the skin of the feet covered in scales. Feet skin infection was confirmed using a complementary fluorescence bioimaging approach with MDV recombinants expressing mRFP or GFP. Infection was detected in the intermediate epidermal layers of the feet skin that was also shown to produce infectious virus, regardless of the animals' age at and the route of infection. Taken together, this study highlights the value of in vivo whole body bioimaging in avian species by identifying previously overlooked sites of replication and shedding of MDV in the chicken host.


Assuntos
Herpesviridae , Herpesvirus Galináceo 2 , Doença de Marek , Animais , Galinhas , Furões , Camundongos
12.
BMC Genomics ; 23(1): 509, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35836133

RESUMO

BACKGROUND: Duck plague virus (DPV), belonging to herpesviruses, is a linear double-stranded DNA virus. There are many reports about the outbreak of the duck plague in a variety of countries, which caused huge economic losses. Recently, increasing reports revealed that multiple long non-coding RNAs (lncRNAs) can possess great potential in the regulation of host antiviral immune response. Furthermore, it remains to be determined which specific molecular mechanisms are responsible for the DPV-host interaction in host immunity. Here, lncRNAs and mRNAs in DPV infected duck embryonic fibroblast (DEF) cells were identified by high-throughput RNA-sequencing (RNA-seq). And we predicted target genes of differentially expressed genes (DEGs) and formed a complex regulatory network depending on in-silico analysis and prediction. RESULT: RNA-seq analysis results showed that 2921 lncRNAs were found at 30 h post-infection (hpi). In our study, 218 DE lncRNAs and 2840 DE mRNAs were obtained in DEF after DPV infection. Among these DEGs and target genes, some have been authenticated as immune-related molecules, such as a Macrophage mannose receptor (MR), Anas platyrhynchos toll-like receptor 2 (TLR2), leukocyte differentiation antigen, interleukin family, and their related regulatory factors. Furthermore, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis, we found that the target genes may have important effects on biological development, biosynthesis, signal transduction, cell biological regulation, and cell process. Also, we obtained, the potential targeting relationship existing in DEF cells between host lncRNAs and DPV-encoded miRNAs by software. CONCLUSIONS: This study revealed not only expression changes, but also the possible biological regulatory relationship of lncRNAs and mRNAs in DPV infected DEF cells. Together, these data and analyses provide additional insight into the role of lncRNAs and mRNAs in the host's immune response to DPV infection.


Assuntos
Patos/embriologia , Fibroblastos/virologia , Doença de Marek/virologia , Doenças das Aves Domésticas/virologia , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Animais , Surtos de Doenças/veterinária , Patos/genética , Patos/virologia , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Infecções por Herpesviridae/metabolismo , Mardivirus , Doença de Marek/epidemiologia , Doença de Marek/imunologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/imunologia , RNA Longo não Codificante/análise , RNA Longo não Codificante/genética , RNA Mensageiro/análise , RNA Mensageiro/genética
13.
J Comp Pathol ; 195: 7-11, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35817540

RESUMO

Marek's disease (MD) is caused by virulent strains of Gallid alphaherpesvirus type 2 (MD virus serotype 1; MDV 1) and frequently causes a lymphoproliferative disorder in poultry and other galliform birds worldwide. However, within the peafowl (Phasianinae) subfamily, there are only rare confirmed reports of MD. Here we report MD in an Indian peafowl (Pavo cristatus), which clinically presented with hindlimb paraparesis and intraocular swelling of the right eye. Soft, off-white to tan masses within the right eye, sciatic nerves and coelomic cavity were identified at post-mortem examination which effaced the cranial pole of the kidneys and diffusely effaced the testes. Lymphoid neoplasia was identified histologically at all of these sites and there was extensive hepatic lymphoid cell infiltration, which had not been grossly evident. The T-cell origin of the lymphoid cells was confirmed by immunohistochemistry for CD3 antigen. A virulent strain of MDV 1 was detected by real-time polymerase chain reaction in DNA samples extracted from the kidney and testes. As MD is rare in peafowl it should be considered as a differential diagnosis for intraocular and coelomic masses with associated clinical signs.


Assuntos
Oftalmopatias , Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Galinhas , Oftalmopatias/veterinária , Herpesvirus Galináceo 2/genética , Doença de Marek/diagnóstico , Doença de Marek/patologia , Paraparesia/veterinária , Doenças das Aves Domésticas/patologia
14.
Virulence ; 13(1): 1184-1198, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35795905

RESUMO

Co-infection of Marek's disease virus (MDV) and reticuloendotheliosis virus (REV) synergistically drives disease progression, yet little is known about the mechanism of the synergism. Here, we found that co-infection of REV and MDV increased their replication via the RIOK3-Akt pathway. Initially, we noticed that the viral titres of MDV and REV significantly increased in REV and MDV co-infected cells compared with single-infected cells. Furthermore, tandem mass tag peptide labelling coupled with LC/MS analysis showed that Akt was upregulated in REV and MDV co-infected cells. Overexpression of Akt promoted synergistic replication of MDV and REV. Conversely, inhibition of Akt suppressed synergistic replication of MDV and REV. However, PI3K inhibition did not affect synergistic replication of MDV and REV, suggesting that the PI3K/Akt pathway is not involved in the synergism of MDV and REV. In addition, we revealed that RIOK3 was recruited to regulate Akt in REV and MDV co-infected cells. Moreover, wild-type RIOK3, but not kinase-dead RIOK3, mediated Akt phosphorylation and promoted synergistic replication of MDV and REV. Our results illustrate that MDV and REV activated a novel RIOK3-Akt signalling pathway to facilitate their synergistic replication.


Assuntos
Coinfecção , Herpesvirus Galináceo 2 , Doença de Marek , Proteínas Serina-Treonina Quinases/metabolismo , Vírus da Reticuloendoteliose , Animais , Galinhas , Doenças Genéticas Ligadas ao Cromossomo X , Herpesvirus Galináceo 2/metabolismo , Humanos , Doença de Marek/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Vírus da Reticuloendoteliose/genética , Vírus da Reticuloendoteliose/metabolismo , Imunodeficiência Combinada Severa , Replicação Viral/fisiologia
15.
Avian Dis ; 66(2): 230-236, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35838750

RESUMO

Marek's disease (MD) is a common lymphomatous and neuropathic disease of birds, especially chickens, and has caused significant losses to chicken production as a result of high mortality and morbidity. This study aims to determine the status of MD in backyard flocks in the Mekong Delta of Vietnam and to analyze clinical cases occurring during a year. The study was carried out from August 2018 to July 2019, during which time 16 suspected cases of chicken flocks with MD were observed, 40 chickens were subjected to anatomopathological examination, and PCR was performed for diagnosis of MD and determination of Marek's disease virus (MDV) serotypes. The results showed that all of the examined flocks were confirmed as experiencing MD. Nearly all cases were in an acute form with typical lesions of visceral lymphomas. Besides the presence of Marek's disease virus serotype 1 (MDV-1) from 100.0% of tested chicken flocks (16/16), nononcogenic turkey herpesvirus serotype 3 (MDV-3) was also found from 8 of 16 (50.0%) of examined chicken flocks. Morbidity and mortality at sampling time varied from 1% to 42.11% and 0.6% to 10%, respectively. Chicken flocks with MD vaccination had lower morbidity and mortality. These first findings confirm endemic MD in backyard chicken populations in Vietnam and confirm it continues to be a threat to chickens in backyard flocks and poultry production in general.


Presentación de la enfermedad de Marek en parvadas de pollos de traspatio en Vietnam. La enfermedad de Marek (MD) es una enfermedad linfoproliferativa y neuropática común de las aves, especialmente de los pollos y ha causado pérdidas significativas en la producción de pollos como resultado de la alta mortalidad y morbilidad. Este estudio tiene como objetivo determinar el estado de la enfermedad de Marek en parvadas de traspatio en el delta del Mekong en Vietnam y analizar los casos clínicos que ocurren durante un año. El estudio se llevó a cabo de agosto de 2018 a julio de 2019, tiempo durante el cual se observaron 16 casos sospechosos de parvadas de pollos con enfermedad de Marek, 40 pollos fueron sometidos a examen anatomopatológico y se les realizó PCR para el diagnóstico de enfermedad de Marek y determinación del serotipo del virus. Los resultados confirmaron que todas las parvadas examinadas presentaban enfermedad de Marek y casi todos los casos presentaban una forma aguda con lesiones típicas de linfomas viscerales, especialmente en el hígado. Además de la presencia del serotipo 1 del virus de la enfermedad de Marek (MDV-1) en el 100% de las parvadas de pollos analizadas (16/16), también se encontró el serotipo 3 del herpesvirus del pavo no oncogénico (MDV-3) en 8 de 16 (50.0 %) de las parvadas de pollo examinadas. La morbilidad y la mortalidad en el momento del muestreo variaron del 1% al 42.11% y del 0.6% al 10%, respectivamente. Las parvadas de pollos con vacunación contra la enfermedad de Marek tuvieron menor morbilidad y mortalidad. Estos primeros hallazgos confirman la presencia endémica del virus de la enfermedad de Marek en las poblaciones de pollos de traspatio en Vietnam y confirman que continúa siendo una amenaza para los pollos en parvadas de traspatio y para la producción avícola en general.


Assuntos
Herpesvirus Galináceo 2 , Linfoma , Doença de Marek , Doenças das Aves Domésticas , Animais , Galinhas , Vietnã/epidemiologia , Herpesvirus Galináceo 2/genética , Perus , Linfoma/veterinária
16.
Front Immunol ; 13: 908305, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35693787

RESUMO

The major histocompatibility complex (MHC) is crucial for appropriate immune responses against invading pathogens. Chickens possess a single predominantly-expressed class I molecule with strong associations between disease resistance and MHC haplotype. For Marek's disease virus (MDV) infections of chickens, the MHC haplotype is one of the major determinants of genetic resistance and susceptibility. VALO specific pathogen free (SPF) chickens are widely used in biomedical research and vaccine production. While valuable findings originate from MDV infections of VALO SPF chickens, their MHC haplotypes and associated disease resistance remained elusive. In this study, we used several typing systems to show that VALO SPF chickens possess MHC haplotypes that include B9, B9:02, B15, B19 and B21 at various frequencies. Moreover, we associate the MHC haplotypes to MDV-induced disease and lymphoma formation and found that B15 homozygotes had the lowest tumor incidence while B21 homozygotes had the lowest number of organs with tumors. Finally, we found transmission at variable levels to all contact birds except B15/B21 heterozygotes. These data have immediate implications for the use of VALO SPF chickens and eggs in the life sciences and add another piece to the puzzle of the chicken MHC complex and its role in infections with this oncogenic herpesvirus.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Animais , Carcinogênese/genética , Galinhas/genética , Resistência à Doença/genética , Haplótipos , Herpesvirus Galináceo 2/genética , Antígenos de Histocompatibilidade , Complexo Principal de Histocompatibilidade/genética
17.
Virulence ; 13(1): 980-989, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35658809

RESUMO

One of the greatest achievements of the last century is the development of vaccines against viral diseases. Vaccines are essential for battling infectious diseases and many different formulations are available, including live attenuated vaccines. However, the use of live attenuated vaccines has the potential for adverse effects, including reversion of pathogenicity, recombination, and functional complementation in the host. Marek's disease is a serious disease in poultry controlled by live attenuated vaccines that has resulted in increased virulence over the decades. Recombination between circulating field viruses or vaccines is a proposed mechanism for the increase in virulence, however, complementation between vaccines and field strains has not been demonstrated in chickens. Here, we describe functional complementation of vaccines with virulent virus to functionally complement transmission and spread in the host. Using the natural virus-host model of Marek's disease in chickens, our results show dual infection of target cells in chickens with vaccine and virulent virus providing the opportunity for recombination or complementation to transpire. Interestingly, our controlled results showed no evidence of recombination between vaccine and virulent virus, but functional complementation occurred in two independent experiments providing proof for complementation during natural infection in vaccinated individuals. These results suggest complementation as a potential mechanism for vaccine-mediated viral evolution and the potential for complementation should be taken into consideration when developing novel vaccines.


Assuntos
Coinfecção , Doença de Marek , Doenças das Aves Domésticas , Vacinas Virais , Vírus , Animais , Galinhas , Doença de Marek/prevenção & controle , Vacinas Atenuadas/genética , Vacinas Virais/genética
18.
Vet Microbiol ; 268: 109409, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35364366

RESUMO

Marek's disease (MD) is a neoplastic disease of chickens caused by an avian alphaherpesvirus, Marek's disease virus (MDV, also known as Gallid alphaherpesvirus 2 [GaHV2]). A total of 14 microRNA (miRNA) precursors and 26 mature miRNAs have been identified in MDV genome, which were grouped in three distinct clusters. In recent years, our studies revealed the role of MDV encoded cluster 3 miRNAs (or miR-M8-M10) and the specific function of its three members, miR-M6, miR-M7 and miR-M10, in regulating MDV replication and pathogenesis. In this study, we characterized the unique function of the other two members, miR-M8 and miR-M13, in cluster 3 miRNAs. Our results show that miR-M8 and miR-M13 are not important for MDV plaque formation and genome replication in vitro. Animal experiment results show that deletion of miR-M8-5p and miR-M13-5p eliminates the bursa atrophy, but not thymus atrophy, of MDV inoculated chickens. In addition, we found that the survival curve and MD incidences were not affected by disruption of miR-M8 and miR-M13. Taken together, this study uncovers the unique role of miR-M8 and miR-M13 in MDV replication and pathogenesis, which filled the gap in the research of MDV encoded miRNAs.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , MicroRNAs , Animais , Atrofia/veterinária , Galinhas , Herpesvirus Galináceo 2/genética , MicroRNAs/genética
19.
BMC Vet Res ; 18(1): 155, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477401

RESUMO

BACKGROUND: Marek's disease (MD) is a highly contagious lymphoproliferative disease of chickens caused by an alphaherpesvirus, Marek's disease virus (MDV). MD is presently controlled by systematic vaccination of animals, which protects efficiently against the development of clinical disease. However, MDV vaccines do not prevent the multiplication and spread of MDV field strains and may favor the emergence of strains with increased virulence. Therefore, MDV persists to be a major problem for the poultry industry and the development of new alternative strategies to control MDV is needed. Seaweed extracts have previously been shown to exert immunomodulatory and antiviral activities, especially against herpesviruses. The objective of the present study was to explore the effect of Ulva armoricana extracts on MDV infection in vitro. RESULTS: We could demonstrate that the ulvan extract as well as its vitamin-enriched formulation reduce the viral load by about 80% at 24 h post-infection in infected chicken fibroblasts at concentrations that are innocuous for the cells. We also observed a substantial decrease in MDV plaque size suggesting that ulvans impede MDV cell-to-cell spread in vitro. Moreover, we showed that ulvan extract could promote MDV reactivation in lymphoid cells. CONCLUSIONS: Our data provide the first evidence that the use of the ulvan extract could be a good alternative to limit MDV infection in poultry.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Ulva , Animais , Galinhas , Linfócitos , Doença de Marek/prevenção & controle , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Aves Domésticas
20.
Braz J Microbiol ; 53(3): 1683-1689, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35484378

RESUMO

As neoplastic viruses have been affecting Iranian chicken farms more frequently in recent years, the first step in prevention may therefore be to genetically characterize and systematically identify their source and origin. Recently, we published a phylogenetic analysis based on the meq gene of Gallid alphaherpesvirus 2, commonly known as serotype 1 Marek's disease virus (MDV-1), that circulated in Iranian backyard and commercial chickens. In the current study, we are reporting for the first time the identification of a 298 aa meq protein containing only two PPPP motifs from an MDV-1-infected unvaccinated backyard turkey. This protein length has never been reported from any turkey species before. According to phylogenetic analysis, a close genetic relationship (0.68%) to several chicken-origin isolates such as the American vv + 648A strain was found. In addition, we identified a standard meq protein from a MDV-1-infected commercial chicken farm. In corroboration with our previous finding from other Iranian provinces, it is likely that the highly identical MDV-1 viruses currently circulating in Iranian chicken farms, which may be indicative of human role in the spread of the virus, have similar Eurasian origin. Our data suggest that regardless of the meq size, MDV-1 circulating in Iran are from different origins. On the other hand, meq sequences from bird species other than chicken have been reported but are very few. Our investigation suggests MDV-1 circulating in turkey do not have species-specific sequences.


Assuntos
Herpesvirus Galináceo 2 , Doença de Marek , Doenças das Aves Domésticas , Animais , Galinhas , Herpesvirus Galináceo 2/genética , Humanos , Irã (Geográfico)/epidemiologia , Doença de Marek/epidemiologia , Doença de Marek/prevenção & controle , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia
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