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Viruses Apr 2022MicroRNAs (miRNAs) are a group of regulatory noncoding RNAs, serving as major regulators with a sequence-specific manner in multifarious biological processes. Although a...
MicroRNAs (miRNAs) are a group of regulatory noncoding RNAs, serving as major regulators with a sequence-specific manner in multifarious biological processes. Although a series of viral families have been proved to encode miRNAs, few reports were available regarding the function of ALV-J-encoded miRNA. Here, we reported a novel miRNA (designated ALV-miRNA-p19-01) in ALV-J-infected DF-1 cells. We found that ALV-miRNA-p19-01 is encoded by the genome of the ALV-J SCAU1903 strain (located at nucleotides site 779 to 801) in a classic miRNA biogenesis manner. The transfection of DF-1 cells with ALV-miRNA-p19-01 enhanced ALV-J replication, while the blockage of ALV-miRNA-p19-01 suppressed ALV-J replication. Furthermore, our data showed that ALV-miRNA-p19-01 promotes ALV-J replication by directly targeting the cellular gene dual specificity phosphatase 6 through regulating ERK2 activity.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; Dual Specificity Phosphatase 6; MicroRNAs; Virus Replication
PubMed: 35458535
DOI: 10.3390/v14040805 -
Nature Communications May 2021Inositol hexakisphosphate (IP6) is an assembly cofactor for HIV-1. We report here that IP6 is also used for assembly of Rous sarcoma virus (RSV), a retrovirus from a...
Inositol hexakisphosphate (IP6) is an assembly cofactor for HIV-1. We report here that IP6 is also used for assembly of Rous sarcoma virus (RSV), a retrovirus from a different genus. IP6 is ~100-fold more potent at promoting RSV mature capsid protein (CA) assembly than observed for HIV-1 and removal of IP6 in cells reduces infectivity by 100-fold. Here, visualized by cryo-electron tomography and subtomogram averaging, mature capsid-like particles show an IP6-like density in the CA hexamer, coordinated by rings of six lysines and six arginines. Phosphate and IP6 have opposing effects on CA in vitro assembly, inducing formation of T = 1 icosahedrons and tubes, respectively, implying that phosphate promotes pentamer and IP6 hexamer formation. Subtomogram averaging and classification optimized for analysis of pleomorphic retrovirus particles reveal that the heterogeneity of mature RSV CA polyhedrons results from an unexpected, intrinsic CA hexamer flexibility. In contrast, the CA pentamer forms rigid units organizing the local architecture. These different features of hexamers and pentamers determine the structural mechanism to form CA polyhedrons of variable shape in mature RSV particles.
Topics: Capsid; Capsid Proteins; Cryoelectron Microscopy; Electron Microscope Tomography; Gene Knockout Techniques; HEK293 Cells; Humans; Models, Molecular; Phosphotransferases (Alcohol Group Acceptor); Phytic Acid; Protein Multimerization; Recombinant Proteins; Rous sarcoma virus; Single Molecule Imaging; Transfection; Virus Assembly; Virus Release
PubMed: 34050170
DOI: 10.1038/s41467-021-23506-0 -
Scientific Reports Apr 2017Avian leukosis virus (ALV) is detrimental to poultry health and causes substantial economic losses from mortality and decreased performance. Because tumorigenesis is a...
Avian leukosis virus (ALV) is detrimental to poultry health and causes substantial economic losses from mortality and decreased performance. Because tumorigenesis is a complex mechanism, the regulatory architecture of the immune system is likely to include the added dimensions of modulation by miRNAs and long-noncoding RNA (lncRNA). To characterize the response to ALV challenge, we developed a novel methodology that combines four datasets: mRNA expression and the associated regulatory factors of miRNA and lncRNA, and ALV gene expression. Specific Pathogen-Free (SPF) layer chickens were infected with ALV-J or maintained as non-injected controls. Spleen samples were collected at 40 days post injection (dpi), and sequenced. There were 864 genes, 7 miRNAs and 17 lncRNAs differentially expressed between infected and non-infected birds. The combined analysis of the 4 RNA expression datasets revealed that ALV infection is detected by pattern-recognition receptors (TLR9 and TLR3) leading to a type-I IFN mediated innate immune response that is modulated by IRF7 and IRF1. Co-expression network analysis of mRNA with miRNA, lncRNA and virus genes identified key elements within the complex networks utilized during ALV response. The integration of information from the host transcriptomic, epigenetic and virus response also has the potential to provide deeper insights into other host-pathogen interactions.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; Gene Expression Profiling; Gene Expression Regulation; Gene Regulatory Networks; Genes, Viral; Host-Pathogen Interactions; Inflammation; MicroRNAs; Principal Component Analysis; RNA, Long Noncoding; RNA, Messenger; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sequence Analysis, RNA; Signal Transduction; Specific Pathogen-Free Organisms; Spleen; Transcriptome
PubMed: 28401895
DOI: 10.1038/srep46156 -
Oncotarget Dec 2016Avian leukosis virus subgroup J (ALV-J) is an oncogenic virus causing hemangiomas and myeloid tumors in chickens. Interleukin-6 (IL-6) is a multifunctional...
Avian leukosis virus subgroup J (ALV-J) is an oncogenic virus causing hemangiomas and myeloid tumors in chickens. Interleukin-6 (IL-6) is a multifunctional pro-inflammatory interleukin involved in many types of cancer. We previously demonstrated that IL-6 expression was induced following ALV-J infection in chickens. The aim of this study is to characterize the mechanism by which ALV-J induces IL-6 expression, and the role of IL-6 in tumor development. Our results demonstrate that ALV-J infection increases IL-6 expression in chicken splenocytes, peripheral blood lymphocytes, and vascular endothelial cells. IL-6 production is induced by the ALV-J envelope protein gp85 and capsid protein p27 via PI3K- and NF-κB-mediated signaling. IL-6 in turn induced expression of vascular endothelial growth factor (VEGF)-A and its receptor, VEGFR-2, in vascular endothelial cells and embryonic vascular tissues. Suppression of IL-6 using siRNA inhibited the ALV-J induced VEGF-A and VEGFR-2 expression in vascular endothelial cells, indicating that the ALV-J-induced VEGF-A/VEGFR-2 expression is mediated by IL-6. As VEGF-A and VEGFR-2 are important factors in oncogenesis, our findings suggest that ALV-J hijacks IL-6 to promote tumorigenesis, and indicate that IL-6 could potentially serve as a therapeutic target in ALV-J infections.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Capsid Proteins; Cell Transformation, Viral; Cells, Cultured; Chickens; Endothelial Cells; Host-Pathogen Interactions; Interleukin-6; NF-kappa B; Phosphatidylinositol 3-Kinase; STAT3 Transcription Factor; Signal Transduction; Spleen; Time Factors; Transfection; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2; Viral Envelope Proteins
PubMed: 27852059
DOI: 10.18632/oncotarget.13282 -
Poultry Science Oct 2016Subgroup J avian leukosis virus (ALV-J) causes a neoplastic disease in infected chickens. The ALV-J strain NX0101, which was isolated from broiler breeders in 2001,...
Viral proliferation and expression of tumor-related gene in different chicken embryo fibroblasts infected with different tumorigenic phenotypes of avian leukosis virus subgroup J.
Subgroup J avian leukosis virus (ALV-J) causes a neoplastic disease in infected chickens. The ALV-J strain NX0101, which was isolated from broiler breeders in 2001, mainly induced formation of myeloid cell tumors. However, strain HN10PY01, which was recently isolated from laying hens, mainly induces formation of myeloid cell tumors and hemangioma. To identify the molecular pathological mechanism underlying changes in host susceptibility and tumor classification induced by these two types of ALV-J strains, chicken embryo fibroblasts derived from chickens with different genetic backgrounds (broiler breeders and laying hens) and an immortalized chicken embryo fibroblasts (DF-1) were prepared and infected with strain NX0101 or HN10PY01, respectively. The 50% tissue culture infective dose (TCID50) and levels of ALV group-specific antigen p27 and heat shock protein 70 in the supernatant collected from the ALV-J infected cells were detected. Moreover, mRNA expression levels of tumor-related genes p53, c-myc, and Bcl-2 in ALV-J-infected cells were quantified. The results indicated that the infection of ALV-J could significantly increase mRNA expression levels of p53, c-myc, and Bcl-2 Strain HN10PY01 exhibited a greater influence on the three tumor-related genes in each of the three types of cells when compared with strain NX0101, and the TCID50 and p27 levels in the supernatant collected from HN10PY01-infected cells were higher than those collected from NX0101-infected cells. These results indicate that the infection of the two ALV-J strains influenced the gene expression levels in the infected cells, while the newly isolated strain HN10PY01 showed higher replication ability in cells and induced higher expression levels of tumor-related genes in infected cells. Furthermore, virus titers and expression levels of tumor-related genes and cellular stress responses of cells with different genetic backgrounds when infected with each of the two ALV-J strain were different, indicating that genetic backgrounds influenced the capabilities of the virus to infect and proliferate. The findings of this study provide useful data to further elucidate the mechanism underlying host susceptibility and tumor classification in ALV-J-infected chickens and cells.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Carcinogenesis; Cells, Cultured; Chick Embryo; Chickens; Female; Fibroblasts; Gene Expression Regulation; Genes, Viral; Phenotype; Poultry Diseases; RNA, Messenger; Virus Replication
PubMed: 27609806
DOI: 10.3382/ps/pew180 -
Poultry Science Jun 2020The chicken reference genome contains 2 endogenous avian leukosis virus subgroup E (ALVE) insertions, but gaps and unresolved repetitive sequences in previous assemblies...
The chicken reference genome contains 2 endogenous avian leukosis virus subgroup E (ALVE) insertions, but gaps and unresolved repetitive sequences in previous assemblies have hindered their precise characterization. Detailed analysis of the most recent reference genome (GRCg6a) now shows both ALVEs within contiguous chromosome assemblies for the first time. ALVE6 (ALVE-JFevA) and ALVE-JFevB are both located on chromosome 1, with ALVE6 close to the p-arm telomere. ALVE-JFevB is a structurally intact element containing the ALVE gag, pol, and env genes and is capable of forming replication competent viruses. In contrast, ALVE6 contains a 3,352 bp 5' truncation and lacks the entire 5' long terminal repeat and gag gene. Despite this, ALVE6 remains able to produce intact envelope protein, likely due to a mutation in the recognition site for a known inhibitory miRNA (miR-155). Whole genome resequencing data sets from layers, broilers, and 3 independent sources of wild-caught red junglefowl were surveyed for the presence of each of these reference genome ALVEs. ALVE-JFevB was found in no other chicken or red junglefowl genomes, whereas ALVE6 was identified in some layers, broilers, and native breeds but not within any other red junglefowl genome. Improved assembly contiguity has facilitated better characterization of the 2 ALVEs of the chicken reference genome. However, both the limited ALVE content and unique presence of ALVE-JFevB suggests that the reference individual is unrepresentative of ancestral Gallus gallus ALVE diversity.
Topics: Animals; Avian Leukosis Virus; Chickens; Genome; Mutagenesis, Insertional
PubMed: 32475424
DOI: 10.1016/j.psj.2019.12.074 -
Biochemical and Biophysical Research... Jan 2020Avian leukosis virus (ALV) is one of the main causative agent of tumor development, which brings enormous economic losses to the poultry industry worldwide. ALV can be...
Avian leukosis virus (ALV) is one of the main causative agent of tumor development, which brings enormous economic losses to the poultry industry worldwide. ALV can be transmitted horizontally and vertically, and the latter often give rise to more adverse pathogenicity. However, the propagation and evolution of ALV underlying vertical transmission remain not-well understood. Herein, an animal model for the evolution of variants of ALV subgroup J (ALV-J) in the vertical transmission was built and different organs from infected hens and plasma from their ALV-positive progenies were collected, and then three segments in the hypervariable regions of ALV (gp85-A, gp85-B, LTR-C) were amplified and sequenced using conventional Sanger sequencing and MiSeq high-throughput sequencing, respectively. The results showed that the genomic diversity of ALV-J occurred in different organs from ALV-J infected hen, and that the dominant variants in different organs of parental hens, especially in follicle, changed significantly compared with original inoculum strain. Notably, the dominant variants in progenies exhibited higher homologies with variants in parental hens' follicle (88.9%-98.9%) than other organs (85.6%-91.1%), and most consistent mutations in the variants were observed between the progenies and parental hen's follicle. Furthermore, HyPhy analysis indicated that the global selection pressure value (ω) in the follicle is significantly higher than those in other organs. In summary, an animal model for vertical transmission was built and our findings revealed the evolution of variants of ALV in the process of vertical transmission, moreover, the variants were most likely to be taken to the next generation via follicle, which may be related to the higher selection pressure follicle underwent.
Topics: Amino Acid Sequence; Animals; Antibody Formation; Avian Leukosis; Avian Leukosis Virus; Chickens; Evolution, Molecular; Female; Mutation; Ovarian Follicle; Phylogeny; Viral Envelope Proteins; Viremia
PubMed: 31733830
DOI: 10.1016/j.bbrc.2019.11.042 -
Communications Biology Mar 2021Despite conserved catalytic integration mechanisms, retroviral intasomes composed of integrase (IN) and viral DNA possess diverse structures with variable numbers of IN...
Despite conserved catalytic integration mechanisms, retroviral intasomes composed of integrase (IN) and viral DNA possess diverse structures with variable numbers of IN subunits. To investigate intasome assembly mechanisms, we employed the Rous sarcoma virus (RSV) IN dimer that assembles a precursor tetrameric structure in transit to the mature octameric intasome. We determined the structure of RSV octameric intasome stabilized by a HIV-1 IN strand transfer inhibitor using single particle cryo-electron microscopy. The structure revealed significant flexibility of the two non-catalytic distal IN dimers along with previously unrecognized movement of the conserved intasome core, suggesting ordered conformational transitions between intermediates that may be important to capture the target DNA. Single amino acid substitutions within the IN C-terminal domain affected intasome assembly and function in vitro and infectivity of pseudotyped RSV virions. Unexpectedly, 17 C-terminal amino acids of IN were dispensable for virus infection despite regulating the transition of the tetrameric intasome to the octameric form in vitro. We speculate that this region may regulate the binding of highly flexible distal IN dimers to the intasome core to form the octameric complex. Our studies reveal key steps in the assembly of RSV intasomes.
Topics: Cryoelectron Microscopy; DNA, Viral; HIV Integrase; Integrase Inhibitors; Integrases; Molecular Docking Simulation; Protein Conformation; Protein Multimerization; Rous sarcoma virus; Single Molecule Imaging; Virus Integration; Virus Replication
PubMed: 33712691
DOI: 10.1038/s42003-021-01855-2 -
Journal of Virology Sep 2019Avian leukosis virus subgroup K (ALV-K) is composed of newly emerging isolates, which, in sequence analyses, cluster separately from the well-characterized subgroups A,...
Avian leukosis virus subgroup K (ALV-K) is composed of newly emerging isolates, which, in sequence analyses, cluster separately from the well-characterized subgroups A, B, C, D, E, and J. However, it remains unclear whether ALV-K represents an independent ALV subgroup with regard to receptor usage, host range, and superinfection interference. In the present study, we examined the host range of the Chinese infectious isolate JS11C1, an ALV-K prototype, and we found substantial overlap of species that were either resistant or susceptible to ALV-A and JS11C1. Ectopic expression of the chicken gene in mammalian cells conferred susceptibility to JS11C1, while genetic ablation of the gene rendered chicken DF-1 cells resistant to infection by JS11C1. Thus, expression is both sufficient and necessary for JS11C1 entry. Receptor sharing was also manifested in superinfection interference, with preinfection of cells with ALV-A, but not ALV-B or ALV-J, blocking subsequent JS11C1 infection. Finally, direct binding of JS11C1 and Tva was demonstrated by preincubation of the virus with soluble Tva, which substantially decreased viral infectivity in susceptible chicken cells. Collectively, these findings indicate that JS11C1 represents a new and ALV subgroup that utilizes Tva for cell entry and binds to a site other than that for ALV-A. ALV consists of several subgroups that are particularly characterized by their receptor usage, which subsequently dictates the host range and tropism of the virus. A few newly emerging and highly pathogenic Chinese ALV strains have recently been suggested to be an independent subgroup, ALV-K, based solely on their genomic sequences. Here, we performed a series of experiments with the ALV-K strain JS11C1, which showed its dependence on the Tva cell surface receptor. Due to the sharing of this receptor with ALV-A, both subgroups were able to interfere with superinfection. Because ALV-K could become an important pathogen and a significant threat to the poultry industry in Asia, the identification of a specific receptor could help in the breeding of resistant chicken lines with receptor variants with decreased susceptibility to the virus.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Avian Proteins; Cell Line; Chickens; Disease Susceptibility; Fibroblasts; Mesocricetus; Receptors, Virus; Species Specificity; Virus Internalization
PubMed: 31217247
DOI: 10.1128/JVI.00580-19 -
Archives of Virology Apr 2022The current prevalence of avian leukosis virus (ALV) in fancy chickens in Germany is unknown. Therefore, 537 cloacal swabs from 50 purebred fancy-chicken flocks in...
The current prevalence of avian leukosis virus (ALV) in fancy chickens in Germany is unknown. Therefore, 537 cloacal swabs from 50 purebred fancy-chicken flocks in Saxony were tested for the presence of the ALV p27 protein using a commercial antigen-capture ELISA. The detection rate was 28.7% at the individual-animal level and 56.0% at the flock level. Phylogenetic analysis of PCR products obtained from 22 different flocks revealed the highest similarity to ALV subtype K. When classifying breeds by their origin, ALV detection rates differed significantly. Evaluation of questionnaire data revealed no significant differences between ALV-positive and negative flocks regarding mortality.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; Germany; Phylogeny
PubMed: 35301570
DOI: 10.1007/s00705-022-05404-y