-
Viruses Aug 2023Avian leukosis (AL), caused by avian leukosis virus (ALV), is a contagious tumor disease that results in significant economic losses for the poultry industry. Currently,...
Avian leukosis (AL), caused by avian leukosis virus (ALV), is a contagious tumor disease that results in significant economic losses for the poultry industry. Currently, ALV-A, B, J, and K subgroups are the most common in commercial poultry and cause possible coinfections. Therefore, close monitoring is necessary to avoid greater economic losses. In this study, a novel multiplex quantitative polymerase chain reaction (qPCR) assay was developed to detect ALV-A, ALV-B, ALV-J, and ALV-K with limits of detection of 40, 11, 13.7, and 96 copies/µL, respectively, and no cross-reactivity with other ALV subtypes and avian pathogens. We detected 852 cell cultures inoculated with clinical samples using this method, showing good consistency with conventional PCR and ELISA. The most prevalent ALV strain in Hubei Province, China, was still ALV-J (11.74%). Although single infections with ALV-A, ALV-B, and ALV-K were not found, coinfections with different subgroup strains were identified: 0.7% for ALV-A/J, 0.35% for ALV-B/J, 0.25% for ALV-J/K, and 0.12% for ALV-A/B/K and ALV-A/B/J. Therefore, our novel multiplex qPCR may be a useful tool for molecular epidemiology, clinical detection of ALV, and ALV eradication programs.
Topics: Animals; Avian Leukosis Virus; Coinfection; Avian Leukosis; Cell Culture Techniques; Multiplex Polymerase Chain Reaction
PubMed: 37766196
DOI: 10.3390/v15091789 -
Journal of Virology Aug 2023Avian leukemia virus subgroup J (ALV-J) causes various diseases associated with tumor formation and decreased fertility and induced immunosuppressive disease, resulting...
Avian leukemia virus subgroup J (ALV-J) causes various diseases associated with tumor formation and decreased fertility and induced immunosuppressive disease, resulting in significant economic losses in the poultry industry globally. Virus usually exploits the host cellular machinery for their replication. Although there are increasing evidences for the cellular proteins involving viral replication, the interaction between ALV-J and host proteins leading to the pivotal steps of viral life cycle are still unclear. Here, we reported that ribonucleoside-diphosphate reductase subunit M2 (RRM2) plays a critical role during ALV-J infection by interacting with capsid protein P27 and activating Wnt/β-catenin signaling. We found that the expression of RRM2 is effectively increased during ALV-J infection, and that RRM2 facilitates ALV-J replication by interacting with viral capsid protein P27. Furthermore, ALV-J P27 activated Wnt/β-catenin signaling by promoting β-catenin entry into the nucleus, and RRM2 activated Wnt/β-catenin signaling by enhancing its phosphorylation at Ser18 during ALV-J infection. These data suggest that the upregulation of RRM2 expression by ALV-J infection favors viral replication in host cells via activating Wnt/β-catenin signaling. IMPORTANCE Our results revealed a novel mechanism by which RRM2 facilitates ALV-J growth. That is, the upregulation of RRM2 expression by ALV-J infection favors viral replication by interacting with capsid protein P27 and activating Wnt/β-catenin pathway in host cells. Furthermore, the phosphorylation of serine at position 18 of RRM2 was verified to be the important factor regulating the activation of Wnt/β-catenin signaling. This study provides insights for further studies of the molecular mechanism of ALV-J infection.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; beta Catenin; Capsid Proteins; Chickens; Wnt Signaling Pathway; Ribonucleoside Diphosphate Reductase
PubMed: 37582207
DOI: 10.1128/jvi.00267-23 -
Veterinary Microbiology Sep 2023While the presence of host cell proteins in virions and their role in viral life cycles have been demonstrated in various viruses, such characteristics have remained...
While the presence of host cell proteins in virions and their role in viral life cycles have been demonstrated in various viruses, such characteristics have remained largely unknown in avian leukosis virus (ALV). To investigate whether this is the case in ALV, we purified high-integrity and high-purity virions from the avian leukosis virus subgroup J (ALV-J) and subjected them to proteome analysis using nano LC-MS/MS. This analysis identified 53 cellular proteins that are incorporated into mature ALV-J virions, and we verified the reliability of the packaged cellular proteins through subtilisin digestion and immunoblot analysis. Functional annotation revealed the potential functions of these proteins in the viral life cycle and tumorigenesis. Overall, our findings have important implications for understanding the interaction between ALV-J and its host, and provide new insights into the cellular requirements that define ALV-J infection.
Topics: Animals; Chickens; Avian Leukosis Virus; Tandem Mass Spectrometry; Proteomics; Reproducibility of Results; Avian Leukosis
PubMed: 37536160
DOI: 10.1016/j.vetmic.2023.109821 -
Journal of Veterinary Diagnostic... Sep 2023The fowl glioma-inducing virus prototype (FGVp) and its variants, which belong to avian leukosis virus subgroup A (ALV-A), induce cardiomyocyte abnormalities and gliomas...
The fowl glioma-inducing virus prototype (FGVp) and its variants, which belong to avian leukosis virus subgroup A (ALV-A), induce cardiomyocyte abnormalities and gliomas in chickens. However, the molecular mechanisms underlying these myocardial changes remain unclear, and ALV-induced tumorigenesis, which is caused by proviral insertional mutagenesis, does not explain the early development of cardiac changes in infected chickens. We established a quantitative PCR (qPCR) assay to measure ALV-A proviral loads in the brains and hearts of FGV-infected Japanese bantam chickens and compared these results with morphologic lesions. Four of 22 bantams had both gliomas and cardiac lesions. Hearts with cardiac lesions had a higher proviral load (10.3 ± 2.7 proviral copies/nucleus) than those without cardiac lesions (0.4 ± 0.4), suggesting that the proviral load in hearts is correlated with the frequency of myocardial changes. Our qPCR method may be useful in the study of ALV-induced cardiomyocyte abnormalities.
Topics: Animals; Avian Leukosis Virus; Chickens; Glioma; Poultry Diseases; Proviruses; Viral Load
PubMed: 37452573
DOI: 10.1177/10406387231186954 -
Virus Genes Oct 2023We used untargeted RNA sequencing to characterize three Avulavirinae isolates from pooled samples obtained from wild mallards in Belgium in 2021. The complete genome...
We used untargeted RNA sequencing to characterize three Avulavirinae isolates from pooled samples obtained from wild mallards in Belgium in 2021. The complete genome sequences of two avian Orthoavulavirus-1 (AOAV-1) strains and one avian Paraavulavirus-4 (APMV-4) strain were determined confirming hemagglutination inhibition testing of the virus isolates. In addition, the applied sequencing strategy identified an avian influenza virus (AIV) coinfection in all three virus isolates, confirming weak-positive AIV realtime RT-PCR results from the original sample material. In one AOAV-1 isolate, partial sequences covering all genome segments of an AIV of subtype H11N9 could be de novo assembled from the sequencing data. Besides an AIV coinfection, RNA metagenomic data from the APMV-4 isolate also showed evidence of Alpharetrovirus and Megrivirus coinfection. In total, two AOAV-1 of Class II, genotype I.2 and one APMV-4 complete genome sequences were assembled and compared to publicly available sequences, highlighting the importance of surveillance for poultry pathogens in wild birds. Beyond the insights from full genome characterization of virus isolates, untargeted RNA sequencing strategies provide additional insights in the RNA virome of clinical samples as well as their derived virus isolates that are particularly useful when targeting wild avifauna reservoirs of poultry pathogens.
Topics: Animals; Avulavirus; Paramyxoviridae; Belgium; Coinfection; Phylogeny; Ducks; Poultry; Newcastle disease virus; Influenza in Birds; Sequence Analysis, RNA; RNA
PubMed: 37392346
DOI: 10.1007/s11262-023-02015-w -
Journal of Molecular Biology Aug 2023Biomolecular condensates (BMCs) play important roles incellular structures includingtranscription factories, splicing speckles, and nucleoli. BMCs bring together...
Biomolecular condensates (BMCs) play important roles incellular structures includingtranscription factories, splicing speckles, and nucleoli. BMCs bring together proteins and other macromolecules, selectively concentrating them so that specific reactions can occur without interference from the surrounding environment. BMCs are often made up of proteins that contain intrinsically disordered regions (IDRs), form phase-separated spherical puncta, form liquid-like droplets that undergo fusion and fission, contain molecules that are mobile, and are disrupted with phase-dissolving drugs such as 1,6-hexanediol. In addition to cellular proteins, many viruses, including influenza A, SARS-CoV-2, and human immunodeficiency virus type 1 (HIV-1) encode proteins that undergo phase separation and rely on BMC formation for replication. In prior studies of the retrovirus Rous sarcoma virus (RSV), we observed that the Gag protein forms discrete spherical puncta in the nucleus, cytoplasm, and at the plasma membrane that co-localize with viral RNA and host factors, raising the possibility that RSV Gag forms BMCs that participate in the intracellular phase of the virion assembly pathway. In our current studies, we found that Gag contains IDRs in the N-terminal (MAp2p10) and C-terminal (NC) regions of the protein and fulfills many criteria of BMCs. Although the role of BMC formation in RSV assembly requires further study, our results suggest the biophysical properties of condensates are required for the formation of Gag complexes in the nucleus and the cohesion of these complexes as they traffic through the nuclear pore, into the cytoplasm, and to the plasma membrane, where the final assembly and release of virus particles occurs.
Topics: Humans; Biomolecular Condensates; Gene Products, gag; Rous sarcoma virus; Intrinsically Disordered Proteins; Phase Transition
PubMed: 37328094
DOI: 10.1016/j.jmb.2023.168182 -
Avian Pathology : Journal of the W.V.P.A Aug 2023We previously described cardiomyocyte abnormality caused by Km_5666 strain, a variant of fowl glioma-inducing virus (FGV) prototype, which is an avian leukosis virus...
We previously described cardiomyocyte abnormality caused by Km_5666 strain, a variant of fowl glioma-inducing virus (FGV) prototype, which is an avian leukosis virus (ALV). However, the cardiac involvement appeared to be eradicated from the flock after a few years. An epidemiological survey from 2017 to 2020 was performed to elucidate the current prevalence of the cardiopathogenic strains in this flock. Four of the 71 bantams pathologically examined showed both glioma and cardiomyocyte abnormality, from which three ALV strains were detected. DNA sequencing revealed that several different ALV strains coexisted in each bantam and that the conserved Km_5666 virus fluid also contained at least two different ALV strains. We generated three infectious molecular clones from these samples, named KmN_77_clone_A, KmN_77_clone_B, and Km_5666_clone. The SU of KmN_77_clone_A shared high sequence identity with that of Km_5666 (94.1%). In contrast, the SU of KmN_77_clone_B showed >99.2% nucleotide similarity with that of an FGV variant without cardiopathogenicity. Furthermore, Km_5666_clone experimentally reproduced both gliomas and cardiomyocyte abnormality in chickens. From these results, it is suggested that the pathogenic determinant of cardiomyocyte abnormality is located in SU similar to that of Km_5666. The cloning technique described here is beneficial for evaluating the viral pathogenicity in cases where affected birds are coinfected with several different ALV strains.
Topics: Animals; Avian Leukosis Virus; Chickens; Avian Leukosis; Glioma; Clone Cells; Poultry Diseases
PubMed: 37194644
DOI: 10.1080/03079457.2023.2215187