RESUMEN
Marek's disease virus (MDV) has become an increasingly virulent pathogen in the poultry industry despite vaccination efforts to control it. Brazil has experienced a significant rise of Marek's disease (MD) outbreaks in recent years. Our study aimed to analyze the complete meq gene sequences to understand the molecular epidemiological basis of MD outbreaks in Brazilian vaccinated layer farms. We detected a high incidence rate of visceral MD (67.74%) and multiple circulating MDV strains. The most prevalent and geographically widespread genotype presented several clinical and molecular characteristics of a highly virulent strain and evolving under positive selective pressure. Phylogenetic and phylogeographic analysis revealed a closer relationship with strains from the USA and Japan. This study sheds light on the circulation of MDV strains capable of infecting vaccinated birds. We emphasize the urgency of adopting preventive measures to manage MDV outbreaks threatening the poultry farming industry.
Asunto(s)
Mardivirus , Enfermedad de Marek , Enfermedades de las Aves de Corral , Animales , Aves de Corral , Pollos/genética , Brasil/epidemiología , Filogenia , Mardivirus/genética , Enfermedad de Marek/epidemiología , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Granjas , Oncogenes , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/prevención & controlRESUMEN
Marek's disease (MD) is a neoplastic disease that significantly affects the poultry industry. Long non-coding RNAs (lncRNAs) are crucial regulatory factors in various biological processes, including tumourigenesis. However, the involvement of novel lncRNAs in the course of MD virus (MDV) infection is still underexplored. Here, we present the first comprehensive characterization of differentially expressed lncRNAs in chicken spleen at different stages of MDV infection. A series of differentially expressed lncRNAs was identified at each stage of MDV infection through screening. Notably, our investigation revealed a novel lncRNA, lncRNA 803, which exhibited significant differential expression at different stages of MDV infection and was likely to be associated with the p53 pathway. Further analyses demonstrated that the overexpression of lncRNA 803 positively regulated the expression of p53 and TP53BP1 in DF-1 cells, leading to the inhibition of apoptosis. This is the first study to focus on the lncRNA expression profiles in chicken spleens during MDV pathogenesis. Our findings highlight the potential role of the p53-related novel lncRNA 803 in MD pathogenesis and provide valuable insights for decoding the molecular mechanism of MD pathogenesis involving non-coding RNA.RESEARCH HIGHLIGHTS Differentially expressed lncRNAs in spleens of chickens infected with Marek's disease virus at different stages were identified for the first time.The effects of novel lncRNA 803 on p53 pathway and apoptosis of DF-1 cells were reported for the first time.
Asunto(s)
Apoptosis , Pollos , Enfermedad de Marek , Enfermedades de las Aves de Corral , ARN Largo no Codificante , Bazo , Proteína p53 Supresora de Tumor , Animales , ARN Largo no Codificante/genética , Enfermedad de Marek/virología , Enfermedad de Marek/genética , Pollos/virología , Bazo/virología , Bazo/patología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Línea Celular , Herpesvirus Gallináceo 2/genética , Herpesvirus Gallináceo 2/fisiologíaRESUMEN
IMPORTANCE: Marek's disease virus (MDV) is a highly infectious and oncogenic virus that can induce severe T cell lymphomas in chickens. MDV encodes more than 100 genes, most of which have unknown functions. This work indicated that the LORF9 gene is necessary for MDV early cytolytic replication in B lymphocytes. In addition, we have found that the LORF9 deletion mutant has a comparative immunological protective effect with CVI988/Rispens vaccine strain against very virulent MDV challenge. This is a significant discovery that LORF9 can be exploited as a possible target for the development of an MDV gene deletion vaccine.
Asunto(s)
Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Enfermedades de las Aves de Corral , Animales , Linfocitos B , Pollos , Eliminación de Gen , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Vacunas contra la Enfermedad de Marek/genética , Replicación ViralRESUMEN
Marek's disease (MD) is a severe infectious and immunosuppressive neoplastic condition that significantly impacts the global poultry industry. Investigating the role of non-coding RNA in pathogenic mechanisms of MD virus (MDV) offers valuable insights for the effective prevention and management of MD. A higher expression of the novel lncRNA-9802 can be found in spleen tissues of MDV-infected chickens from our prior research, and there is a potential association between lncRNA-9802 and cell proliferation. In this study, we further demonstrated that over-expression of lncRNA-9802 could promote the proliferation of DF-1 cells. It has been established that lncRNA-9802 mediated its effects by binding to miR-1646, and further modulated the expression of the Bax and Bcl-2 genes. Deciphering the role of the recently discovered MD-associated lncRNA-9802/miR-1646 axis provides valuable theoretical basis for decoding the molecular mechanisms underlying MDV pathogenesis.
Asunto(s)
Herpesvirus Gallináceo 2 , Enfermedad de Marek , MicroARNs , ARN Largo no Codificante , Animales , Proteína X Asociada a bcl-2 , Proliferación Celular , Pollos , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/genética , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , Transducción de SeñalRESUMEN
IMPORTANCE: Marek's disease virus (MDV) is a ubiquitous chicken pathogen that inflicts a large economic burden on the poultry industry, despite worldwide vaccination programs. MDV is only partially controlled by available vaccines, and the virus retains the ability to replicate and spread between vaccinated birds. Following an initial infection, MDV enters a latent state and integrates into host telomeres and this may be a prerequisite for malignant transformation, which is usually fatal. To understand the mechanism that underlies the dynamic relationship between integrated-latent and reactivated MDV, we have characterized integrated MDV (iMDV) genomes and their associated telomeres. This revealed a single orientation among iMDV genomes and the loss of some terminal sequences that is consistent with integration by homology-directed recombination and excision via a telomere-loop-mediated process.
Asunto(s)
Pollos , Genoma Viral , Herpesvirus Gallináceo 2 , Recombinación Homóloga , Enfermedad de Marek , Telómero , Integración Viral , Animales , Pollos/virología , Genoma Viral/genética , Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/genética , Enfermedad de Marek/virología , Enfermedades de las Aves de Corral/genética , Enfermedades de las Aves de Corral/virología , Telómero/genética , Vacunas Virales/inmunología , Activación Viral , Latencia del Virus , Integración Viral/genéticaRESUMEN
Marek's disease (MD) is a lymphoproliferative neoplastic disease caused by Marek's disease virus (MDV). Previous studies have showed that DNA methylation was involved in MD development, but systematic studies are still lacking. Herein, we performed whole genome bisulfite sequencing (WGBS) and RNA-seq in MDV-infected tumorous spleens (IN), noninfected spleens (NoIN), and survivor (SUR) spleens of chickens to identify the genes playing important roles in MD tumor transformation. We generated the first genome-wide DNA methylation profile of MDV-infected, noninfected, and survivor chickens. Combined the WGBS and RNA-Seq, we found that the expression of 25% differential expression genes (DEGs) were significantly correlated with methylation of CpG sites in their gene bodies or promoters. Further, we focused on the DEGs with differentially methylated regions (DMRs) on genes' body and promoter, and it showed the expression of 60% DEGs were significantly correlated with methylation of CpG sites in DMRs. Finally, we identified 8 genes, including CD4, CTLA4, DTL, HMGB1, LGMN, NUP210, RAD52, and ZAP70, and their expression was negatively correlated with methylation of DMRs in their promoters in both IN vs. NoIN and IN vs. SUR. These 8 genes showed specifically high expression in IN groups and clustered in module turquoise analyzed by WGCNA. Out of 8 genes, CD4 and HMGB1 were drop in QTLs associated with MD resistance. Thus, we overexpressed the 2 genes to simulate their high expression in the IN group and found they significantly promoted MDCC-MSB-1 cell proliferation, which revealed they might play promoting roles in MD tumorigenesis in IN due to their high expression induced by hypomethylation.
Asunto(s)
Proteína HMGB1 , Herpesvirus Gallináceo 2 , Enfermedad de Marek , Neoplasias , Animales , Enfermedad de Marek/genética , Pollos/genética , Transcriptoma , Bazo , Metilación de ADN , Proteína HMGB1/genética , Herpesvirus Gallináceo 2/genética , Carcinogénesis/genética , Neoplasias/veterinariaRESUMEN
Marek's disease (MD) is a lymphoproliferative disease of chickens induced by Marek's disease virus (MDV), an oncogenic α-herpesvirus. MDV has increased in virulence, prompting continued efforts in both improved vaccines and enhanced genetic resistance. Model pairs of genetically MD-resistant and MD-susceptible chickens that were either MHC-matched or MHC-congenic allowed characterization of T cell receptor (TCR) repertoires associated with MDV infection. MD-resistant chickens showed higher usage of Vß-1 TCRs than susceptible chickens in both the CD8 and CD4 subsets in the MHC-matched model, and in the CD8 subset only in the MHC-congenic model, with a shift towards Vß-1+ CD8 cells during MDV infection. Long and short read sequencing identified divergent TCRß loci between MHC-matched MD-resistant and MD-susceptible chickens, with MD-resistant chickens having more TCR Vß1 genes. TCR Vß1 CDR1 haplotype usage in MD-resistant x MD-susceptible F1 birds by RNAseq indicated that the most commonly used CDR1 variant was unique to the MD-susceptible line, suggesting that selection for MD resistance in the MHC-matched model optimized the TCR repertoire away from dominant recognition of one or more B2 haplotype MHC molecules. Finally, TCR downregulation during MDV infection in the MHC-matched model was strongest in the MD-susceptible line, and MDV reactivation downregulated TCR expression in a tumor cell line.
Asunto(s)
Resistencia a la Enfermedad , Herpesvirus Gallináceo 2 , Enfermedad de Marek , Receptores de Antígenos de Linfocitos T alfa-beta , Animales , Linfocitos T CD8-positivos , Pollos , Enfermedad de Marek/genética , Enfermedad de Marek/inmunología , Resistencia a la Enfermedad/genéticaRESUMEN
Serum amyloid A (SAA), an acute response phase protein (APP), is crucial for the innate immune response during pathogenic microorganisms' invasion. Marek's disease virus (MDV) is a highly oncogenic alphaherpesvirus that activates multiple innate immune molecules, including SAA, in the host during infection. However, the pathway through which SAA participates in MDV-induced host innate immunity remains unknown. The present study aimed to elucidate the pathway through which SAA exerts its anti-MDV function. We observed that MDV infection in vivo and in vitro significantly elevated SAA expression. Furthermore, through SAA overexpression and knockdown experiments, we demonstrated that SAA could inhibit MDV replication. Subsequently, we found that SAA activated Toll-Like Receptor 2/4 (TLR2/4) -mediated Interferon Beta (IFN-ß) promoter activity and IFN regulatory factor 7 (IRF7) promoter activity. During MDV infection, SAA enhanced TLR2/4-mediated IFN-ß signal transduction and messenger RNAs (mRNAs) expression of type I IFN (IFN-I) and interferon-stimulated genes (ISGs). Finally, TLR2/4 inhibitor OxPAPC inhibits the anti-MDV activity of SAA. These results demonstrated that SAA inhibits MDV replication and enhancing TLR2/4-mediated IFN-ß signal transduction to promote IFNs and ISGs expression. This finding is the first to demonstrate the signaling pathway by which SAA exerts its anti-MDV function. It also provides new insights into the control of oncogenic herpesviruses from the perspective of acute response phase proteins.
Asunto(s)
Herpesvirus Gallináceo 2 , Interferón Tipo I , Enfermedad de Marek , Animales , Pollos , Herpesvirus Gallináceo 2/genética , Interferón Tipo I/metabolismo , Interferón beta/genética , Interferón beta/metabolismo , Enfermedad de Marek/genética , Proteína Amiloide A Sérica/genética , Proteína Amiloide A Sérica/metabolismo , Transducción de Señal , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/metabolismoRESUMEN
Over the past two decades, numerous non-coding RNAs (ncRNAs) have been identified in different biological systems including virology, especially in large DNA viruses such as herpesviruses. As a representative oncogenic alphaherpesvirus, Marek's disease virus (MDV) causes an important immunosuppressive and rapid-onset neoplastic disease of poultry, namely Marek's disease (MD). Vaccinations can efficiently prevent the onset of MD lymphomas and other clinical disease, often heralded as the first successful example of vaccination-based control of cancer. MDV infection is also an excellent model for research into virally-induced tumorigenesis. Recently, great progress has been made in understanding the functions of ncRNAs in MD biology. Herein, we give a review of the discovery and identification of MDV-encoded viral miRNAs, focusing on the genomics, expression profiles, and emerging critical roles of MDV-1 miRNAs as oncogenic miRNAs (oncomiRs) or tumor suppressor genes involved in the induction of MD lymphomas. We also described the involvements of host cellular miRNAs, lincRNAs, and circRNAs participating in MDV life cycle, pathogenesis, and/or tumorigenesis. The prospects, strategies, and new techniques such as the CRISPR/Cas9-based gene editing applicable for further investigation into the ncRNA-mediated regulatory mechanisms in MDV pathogenesis/oncogenesis were also discussed, together with the possibilities of future studies on antiviral therapy and the development of new efficient MD vaccines.
Asunto(s)
Herpesvirus Gallináceo 2 , Linfoma , Enfermedad de Marek , MicroARNs , Animales , Transformación Celular Neoplásica , Pollos/genética , Herpesvirus Gallináceo 2/genética , Herpesvirus Gallináceo 2/metabolismo , Enfermedad de Marek/genética , MicroARNs/genética , MicroARNs/metabolismoRESUMEN
The chicken MHC is known to confer decisive resistance or susceptibility to various economically important pathogens, including the iconic oncogenic herpesvirus that causes Marek's disease (MD). Only one classical class I gene, BF2, is expressed at a high level in chickens, so it was relatively easy to discern a hierarchy from well-expressed thermostable fastidious specialist alleles to promiscuous generalist alleles that are less stable and expressed less on the cell surface. The class I molecule BF2*1901 is better expressed and more thermostable than the closely related BF2*1501, but the peptide motif was not simpler as expected. In this study, we confirm for newly developed chicken lines that the chicken MHC haplotype B15 confers resistance to MD compared with B19. Using gas phase sequencing and immunopeptidomics, we find that BF2*1901 binds a greater variety of amino acids in some anchor positions than does BF2*1501. However, by x-ray crystallography, we find that the peptide-binding groove of BF2*1901 is narrower and shallower. Although the self-peptides that bound to BF2*1901 may appear more various than those of BF2*1501, the structures show that the wider and deeper peptide-binding groove of BF2*1501 allows stronger binding and thus more peptides overall, correlating with the expected hierarchies for expression level, thermostability, and MD resistance. Our study provides a reasonable explanation for greater promiscuity for BF2*1501 compared with BF2*1901, corresponding to the difference in resistance to MD.
Asunto(s)
Enfermedad de Marek , Animales , Alelos , Aminoácidos , Membrana Celular , Pollos , Enfermedad de Marek/genética , Antígenos de Histocompatibilidad Clase I/inmunologíaRESUMEN
Dynamic alteration of the epitranscriptome exerts regulatory effects on the lifecycle of oncogenic viruses in vitro. However, little is known about these effects in vivo because of the general lack of suitable animal infection models of these viruses. Using a model of rapid-onset Marek's disease lymphoma in chickens, we investigated changes in viral and host messenger RNA (mRNA) N6-methyladenosine (m6 A) modification during Marek's disease virus (MDV) infection in vivo. We found that the expression of major epitranscriptomic proteins varies among viral infection phases, reprogramming both the viral and the host epitranscriptomes. Specifically, the methyltransferase-like 3 (METTL3)/14 complex was suppressed during the lytic and reactivation phases of the MDV lifecycle, whereas its expression was increased during the latent phase and in MDV-induced tumors. METTL3/14 overexpression inhibits, whereas METTL3/14 knockdown enhances, MDV gene expression and replication. These findings reveal the dynamic features of the mRNA m6 A modification program during viral replication in vivo, especially in relation to key pathways involved in tumorigenesis.
Asunto(s)
Enfermedad de Marek , Animales , Enfermedad de Marek/genética , Virus Oncogénicos/genética , Pollos , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Marek's disease virus (MDV) induces immunosuppression and neoplastic disease in chickens. The virus is controllable via an attenuated meq deletion mutant virus, which has the disadvantage of retaining the ability to induce lymphoid organ atrophy. To overcome this deficiency and produce more vaccine candidates, a recombinant MDV was generated from the highly virulent Md5BAC strain, in which both meq and a cytolytic replication-related gene, pp38, were deleted. Replication of the double deletion virus, Md5BAC ΔmeqΔpp38, was comparable with that of the parental virus in vitro. The double deletion virus was shown to be fully attenuated and to reduce lymphoid organ atrophy in vivo. Crucially, Md5BAC ΔmeqΔpp38 confers superior protection against highly virulent virus compared with a commercial vaccine strain, CVI988/Rispens. Transcriptomic profiling indicated that Md5BAC ΔmeqΔpp38 induced a different host immune response from CVI988/Rispens. In summary, a novel, effective, and safe vaccine candidate for prevention and control of MD caused by highly virulent MDV is reported. IMPORTANCE MDV is a highly contagious immunosuppressive and neoplastic pathogen. The virus can be controlled through vaccination via an attenuated meq deletion mutant virus that retains the ability to induce lymphoid organ atrophy. In this study, we overcame the deficiency by generating meq and pp38 double deletion mutant virus. Indeed, the successfully generated meq and pp38 double deletion mutant virus had significantly reduced replication capacity in vivo but not in vitro. It was fully attenuated and conferred superior protection efficacy against very virulent MDV challenge. In addition, the possible immunological protective mechanism of the double deletion mutant virus was shown to be different from that of the gold standard MDV vaccine, CVI988/Rispens. Overall, we successfully generated an attenuated meq deletion mutant virus and widened the range of potential vaccine candidates. Importantly, this study provides for the first time the theoretical basis of vaccination induced by fully attenuated gene-deletion mutant virus.
Asunto(s)
Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Proteínas Oncogénicas Virales , Enfermedades de las Aves de Corral , Animales , Enfermedad de Marek/prevención & control , Enfermedad de Marek/genética , Eliminación de Gen , Proteínas Oncogénicas Virales/genética , Pollos , Herpesvirus Gallináceo 2/genética , Vacunas contra la Enfermedad de Marek/genética , AtrofiaRESUMEN
Marek's Disease (MD) has a significant impact on both the global poultry economy and animal welfare. The disease pathology can include neurological damage and tumour formation. Sexual dimorphism in immunity and known higher susceptibility of females to MD makes the chicken Z chromosome (GGZ) a particularly attractive target to study the chicken MD response. Previously, we used a Hy-Line F6 population from a full-sib advanced intercross line to map MD QTL regions (QTLRs) on all chicken autosomes. Here, we mapped MD QTLRs on GGZ in the previously utilized F6 population with individual genotypes and phenotypes, and in eight elite commercial egg production lines with daughter-tested sires and selective DNA pooling (SDP). Four MD QTLRs were found from each analysis. Some of these QTLRs overlap regions from previous reports. All QTLRs were tested by individuals from the same eight lines used in the SDP and genotyped with markers located within and around the QTLRs. All QTLRs were confirmed. The results exemplify the complexity of MD resistance in chickens and the complex distribution of p-values and Linkage Disequilibrium (LD) pattern and their effect on localization of the causative elements. Considering the fragments and interdigitated LD blocks while using LD to aid localization of causative elements, one must look beyond the non-significant markers, for possible distant markers and blocks in high LD with the significant block. The QTLRs found here may explain at least part of the gender differences in MD tolerance, and provide targets for mitigating the effects of MD.
Asunto(s)
Enfermedad de Marek , Sitios de Carácter Cuantitativo , Animales , Femenino , Masculino , Sitios de Carácter Cuantitativo/genética , Enfermedad de Marek/genética , Factores Sexuales , Caracteres Sexuales , Pollos/genética , Cromosomas Sexuales/genéticaRESUMEN
Marek's disease (MD) was an immunosuppression disease induced by Marek's disease virus (MDV). MD caused huge economic loss to the global poultry industry, but it also provided an ideal model for studying diseases induced by the oncogenic virus. Alternative splicing (AS) simultaneously produced different isoform transcripts, which are involved in various diseases and individual development. To investigate AS events in MD, RNA-Seq was performed in tumorous spleens (TS), spleens from the survivors (SS) without any lesion after MDV infection, and non-infected chicken spleens (NS). In this study, 32,703 and 25,217 AS events were identified in TS and SS groups with NS group as the control group, and 1198, 1204, and 348 differently expressed (DE) AS events (p-value < 0.05 and FDR < 0.05) were identified in TS vs. NS, TS vs. SS, SS vs. NS, respectively. Additionally, Function enrichment analysis showed that ubiquitin-mediated proteolysis, p53 signaling pathway, and phosphatidylinositol signaling system were significantly enriched (p-value < 0.05). Small structural variations including SNP and indel were analyzed based on RNA-Seq data, and it showed that the TS group possessed more variants on the splice site region than those in SS and NS groups, which might cause more AS events in the TS group. Combined with previous circRNA data, we found that 287 genes could produce both circular and linear RNAs, which suggested these genes were more active in MD lymphoma transformation. This study has expanded the understanding of the MDV infection process and provided new insights for further analysis of resistance/susceptibility mechanisms.
Asunto(s)
Empalme Alternativo/genética , Pollos/genética , Pollos/virología , Enfermedad de Marek/genética , Bazo/virología , Animales , Perfilación de la Expresión Génica/métodos , Mardivirus/patogenicidad , Enfermedad de Marek/virología , Polimorfismo de Nucleótido Simple/genética , ARN/genética , Sitios de Empalme de ARN/genética , ARN Circular/genética , Transducción de Señal/genéticaRESUMEN
The avian α-herpesvirus known as Marek's disease virus (MDV) linearly integrates its genomic DNA into host telomeres during infection. The resulting disease, Marek's disease (MD), is characterized by virally-induced lymphomas with high mortality. The temporal dynamics of MDV-positive (MDV+) transformed cells and expansion of MD lymphomas remain targets for further understanding. It also remains to be determined whether specific host chromosomal sites of MDV telomere integration confer an advantage to MDV-transformed cells during tumorigenesis. We applied MDV-specific fluorescence in situ hybridization (MDV FISH) to investigate virus-host cytogenomic interactions within and among a total of 37 gonad lymphomas and neoplastic splenic samples in birds infected with virulent MDV. We also determined single-cell, chromosome-specific MDV integration profiles within and among transformed tissue samples, including multiple samples from the same bird. Most mitotically-dividing cells within neoplastic samples had the cytogenomic phenotype of 'MDV telomere-integrated only', and tissue-specific, temporal changes in phenotype frequencies were detected. Transformed cell populations composing gonad lymphomas exhibited significantly lower diversity, in terms of heterogeneity of MDV integration profiles, at the latest stages of tumorigenesis (>50 days post-infection (dpi)). We further report high interindividual and lower intraindividual variation in MDV integration profiles of lymphoma cells. There was no evidence of integration hotspots into a specific host chromosome(s). Collectively, our data suggests that very few transformed MDV+ T cell populations present earlier in MDV-induced lymphomas (32-50 dpi), survive, and expand to become the dominant clonal population in more advanced MD lymphomas (51-62 dpi) and establish metastatic lymphomas.
Asunto(s)
Herpesvirus Gallináceo 2/genética , Linfoma/genética , Enfermedad de Marek/genética , Enfermedades de las Aves de Corral/genética , Animales , Carcinogénesis/genética , Pollos/genética , Pollos/virología , Herpesvirus Gallináceo 2/patogenicidad , Interacciones Huésped-Patógeno/genética , Hibridación Fluorescente in Situ , Linfoma/etiología , Linfoma/patología , Linfoma/virología , Enfermedad de Marek/complicaciones , Enfermedad de Marek/patología , Enfermedad de Marek/virología , Enfermedades de las Aves de Corral/virología , Neoplasias del Bazo/etiología , Neoplasias del Bazo/genética , Neoplasias del Bazo/patología , Linfocitos T/virología , Telómero/genética , Telómero/virología , Integración Viral/genéticaRESUMEN
Marek's disease virus (MDV) induces severe immunosuppression and lymphomagenesis in the chicken, its natural host, and results in a condition that investigated the pathogenesis of MDV and have begun to focus on the expression profiling of circular RNAs (circRNAs). However, little is known about how the expression of circRNAs is referred to as Marek's disease. Previous reports have is regulated during MDV replication. Here, we carried out a comprehensive profiling analysis of N6-methyladenosine (m6A) modification on the circRNA transcriptome in infected and uninfected chicken embryonic fibroblast (CEF) cells. Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) revealed that m6A modification was highly conserved in circRNAs. Comparing to the uninfected group, the number of peaks and conserved motifs were not significantly different in cells that were infected with MDV, although reduced abundance of circRNA m6A modifications. However, gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses revealed that the insulin signaling pathway was associated with the regulation of m6A modified circRNAs in MDV infection. This is the first report to describe alterations in the transcriptome-wide profiling of m6A modified circRNAs in MDV-infected CEF cells.
Asunto(s)
Herpesvirus Gallináceo 2/genética , Enfermedad de Marek/virología , ARN Circular/genética , Animales , Células Cultivadas , Pollos , Fibroblastos/virología , Perfilación de la Expresión Génica , Enfermedad de Marek/genéticaRESUMEN
Viral diseases pose major threats to humans and other animals, including the billions of chickens that are an important food source as well as a public health concern due to zoonotic pathogens. Unlike humans and other typical mammals, the major histocompatibility complex (MHC) of chickens can confer decisive resistance or susceptibility to many viral diseases. An iconic example is Marek's disease, caused by an oncogenic herpesvirus with over 100 genes. Classical MHC class I and class II molecules present antigenic peptides to T lymphocytes, and it has been hard to understand how such MHC molecules could be involved in susceptibility to Marek's disease, given the potential number of peptides from over 100 genes. We used a new in vitro infection system and immunopeptidomics to determine peptide motifs for the 2 class II molecules expressed by the MHC haplotype B2, which is known to confer resistance to Marek's disease. Surprisingly, we found that the vast majority of viral peptide epitopes presented by chicken class II molecules arise from only 4 viral genes, nearly all having the peptide motif for BL2*02, the dominantly expressed class II molecule in chickens. We expressed BL2*02 linked to several Marek's disease virus (MDV) peptides and determined one X-ray crystal structure, showing how a single small amino acid in the binding site causes a crinkle in the peptide, leading to a core binding peptide of 10 amino acids, compared to the 9 amino acids in all other reported class II molecules. The limited number of potential T cell epitopes from such a complex virus can explain the differential MHC-determined resistance to MDV, but raises questions of mechanism and opportunities for vaccine targets in this important food species, as well as providing a basis for understanding class II molecules in other species including humans.
Asunto(s)
Pollos/inmunología , Herpesvirus Gallináceo 2/inmunología , Antígenos de Histocompatibilidad Clase II , Enfermedad de Marek/inmunología , Animales , Presentación de Antígeno/genética , Presentación de Antígeno/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Bolsa de Fabricio/inmunología , Células Cultivadas , Pollos/genética , Pollos/virología , Resistencia a la Enfermedad/genética , Resistencia a la Enfermedad/inmunología , Haplotipos , Herpesvirus Gallináceo 2/química , Antígenos de Histocompatibilidad Clase II/química , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Epítopos Inmunodominantes/química , Epítopos Inmunodominantes/genética , Epítopos Inmunodominantes/inmunología , Epítopos Inmunodominantes/metabolismo , Enfermedad de Marek/genética , Enfermedad de Marek/virología , Modelos Moleculares , Péptidos/química , Péptidos/genética , Péptidos/inmunología , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/virología , Proteínas Virales/química , Proteínas Virales/genética , Proteínas Virales/inmunologíaRESUMEN
BACKGROUND: The newly discovered reversible N6-methyladenosine (m6A) modification plays an important regulatory role in gene expression. Long non-coding RNAs (lncRNAs) participate in Marek's disease virus (MDV) replication but how m6A modifications in lncRNAs are affected during MDV infection is currently unknown. Herein, we profiled the transcriptome-wide m6A modification in lncRNAs in MDV-infected chicken embryo fibroblast (CEF) cells. RESULTS: Methylated RNA immunoprecipitation sequencing results revealed that the lncRNA m6A modification is highly conserved with MDV infection increasing the expression of lncRNA m6A modified sites compared to uninfected cell controls. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that lncRNA m6A modifications were highly associated with signaling pathways associated with MDV infection. CONCLUSIONS: In this study, the alterations seen in transcriptome-wide m6A occurring in lncRNAs following MDV-infection suggest this process plays important regulatory roles during MDV replication. We report for the first time profiling of the alterations in transcriptome-wide m6A modification in lncRNAs of MDV-infected CEF cells.
Asunto(s)
Herpesvirus Gallináceo 2 , Enfermedad de Marek , ARN Largo no Codificante , Adenosina/análogos & derivados , Animales , Embrión de Pollo , Pollos/genética , Enfermedad de Marek/genética , ARN Largo no Codificante/genética , Transcriptoma , Replicación ViralRESUMEN
DEAD-box helicase 5 (DDX5) plays a significant role in tumorigenesis and regulates viral replication of several viruses. An avian oncogenic herpesvirus, Marek's disease virus (MDV), is widely known to cause immunosuppression and lymphoma in chickens. However, the underlying mechanisms of how DDX5 plays a role in viral replication remain unclear. In this study, we show that MDV inhibits the production of interferon beta (IFN-ß) in chicken embryo fibroblasts (CEFs) by increasing the expression level and promoting the nuclear aggregation of DDX5. We further reveal how DDX5 down-regulates melanoma differentiation-associated gene 5/toll-like receptor 3 signaling through the fundamental transcription factor, interferon regulatory factor 1. MDV replication is suppressed, and the production of IFN-ß is promoted in the DDX5 absented CEFs. Taken together, our investigations demonstrate that MDV inhibits IFN-ß production by targeting DDX5-mediated signaling to facilitate viral replication, which offers a novel insight into the mechanism by which an avian oncogenic herpesvirus replicates in chicken cells.
Asunto(s)
Proteínas Aviares/inmunología , ARN Helicasas DEAD-box/inmunología , Fibroblastos/inmunología , Herpesvirus Gallináceo 2/inmunología , Interferón beta/inmunología , Replicación Viral/inmunología , Animales , Proteínas Aviares/genética , Proteínas Aviares/metabolismo , Western Blotting , Células Cultivadas , Embrión de Pollo , Pollos/genética , Pollos/inmunología , Pollos/virología , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , Fibroblastos/metabolismo , Fibroblastos/virología , Regulación de la Expresión Génica/inmunología , Herpesvirus Gallináceo 2/fisiología , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata/genética , Inmunidad Innata/inmunología , Interferón beta/genética , Interferón beta/metabolismo , Enfermedad de Marek/genética , Enfermedad de Marek/inmunología , Enfermedad de Marek/virología , RNA-Seq/métodos , Transcriptoma/inmunologíaRESUMEN
Marek's disease virus (MDV), the causative agent of Marek's disease (MD), results in highly infectious phymatosis, lymphatic tissue hyperplasia, and neoplasia. MD is associated with high morbidity and mortality rate. Non-coding RNAs (ncRNAs) entails long non-coding RNA (lncRNA) and microRNA (miRNA). Numerous studies have reported that specific miRNAs and lncRNAs participate in multiple cellular processes, such as proliferation, migration, and tumor cell invasion. Specialized miRNAs and lncRNAs militate a similar role in MD tumor oncogenesis. Despite its growing popularity, only a few reviews are available on ncRNA in MDV tumor oncogenes. Herein, we summarized the role of the miRNAs and lncRNAs in MD tumorigenesis. Altogether, we brought forth the research issues, such as MD prevention, screening, regulatory network formation, novel miRNAs, and lncRNAs analysis in MD that needs to be explored further. This review provides a theoretical platform for the further analysis of miRNAs and lncRNAs functions and the prevention and control of MD and malignancies in domestic animals.