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Journal of Virology Jun 2020Tetherin/BST-2 is an antiviral protein that blocks the release of enveloped viral particles by linking them to the membrane of producing cells. At first, BST-2 genes...
Tetherin/BST-2 is an antiviral protein that blocks the release of enveloped viral particles by linking them to the membrane of producing cells. At first, BST-2 genes were described only in humans and other mammals. Recent work identified BST-2 orthologs in nonmammalian vertebrates, including birds. Here, we identify the BST-2 sequence in domestic chicken () for the first time and demonstrate its activity against avian sarcoma and leukosis virus (ASLV). We generated a BST-2 knockout in chicken cells and showed that BST-2 is a major determinant of an interferon-induced block of ASLV release. Ectopic expression of chicken BST-2 blocks the release of ASLV in chicken cells and of human immunodeficiency virus type 1 (HIV-1) in human cells. Using metabolic labeling and pulse-chase analysis of HIV-1 Gag proteins, we verified that chicken BST-2 blocks the virus at the release stage. Furthermore, we describe BST-2 orthologs in multiple avian species from 12 avian orders. Previously, some of these species were reported to lack BST-2, highlighting the difficulty of identifying sequences of this extremely variable gene. We analyzed BST-2 genes in the avian orders Galliformes and Passeriformes and showed that they evolve under positive selection. This indicates that avian BST-2 is involved in host-virus evolutionary arms races and suggests that BST-2 antagonists exist in some avian viruses. In summary, we show that chicken BST-2 has the potential to act as a restriction factor against ASLV. Characterizing the interaction of avian BST-2 with avian viruses is important in understanding innate antiviral defenses in birds. Birds are important hosts of viruses that have the potential to cause zoonotic infections in humans. However, only a few antiviral genes (called viral restriction factors) have been described in birds, mostly because birds lack counterparts of highly studied mammalian restriction factors. Tetherin/BST-2 is a restriction factor, originally described in humans, that blocks the release of newly formed virus particles from infected cells. Recent work identified BST-2 in nonmammalian vertebrate species, including birds. Here, we report the BST-2 sequence in domestic chicken and describe its antiviral activity against a prototypical avian retrovirus, avian sarcoma and leukosis virus (ASLV). We also identify BST-2 genes in multiple avian species and show that they evolve rapidly in birds, which is an important indication of their relevance for antiviral defense. Analysis of avian BST-2 genes will shed light on defense mechanisms against avian viral pathogens.
Topics: Amino Acid Sequence; Animals; Avian Proteins; Avian Sarcoma Viruses; Bone Marrow Stromal Antigen 2; Cell Line; Evolution, Molecular; Fibroblasts; Galliformes; Gene Expression Regulation; HEK293 Cells; HIV-1; Host-Pathogen Interactions; Humans; Passeriformes; Sarcoma, Avian; Selection, Genetic; Sequence Alignment; Sequence Homology, Amino Acid; Signal Transduction; Virus Release; Virus Replication; gag Gene Products, Human Immunodeficiency Virus
PubMed: 32238588
DOI: 10.1128/JVI.00416-20 -
Journal of Virology May 2020Different from other subgroups of avian leukosis viruses (ALVs), ALV-J is highly pathogenic. It is the main culprit causing myeloid leukemia and hemangioma in chickens....
Different from other subgroups of avian leukosis viruses (ALVs), ALV-J is highly pathogenic. It is the main culprit causing myeloid leukemia and hemangioma in chickens. The distinctiveness of the gene of ALV-J, with low homology to those of other ALVs, is linked to its unique pathogenesis, but the underlying mechanism remains unclear. Previous studies show that of ALV-J can be grouped into three species based on the tyrosine motifs in the cytoplasmic domain (CTD) of Gp37, i.e., the inhibitory, bifunctional, and active groups. To explore whether the C terminus or the tyrosine motifs in the CTD of Gp37 affect the pathogenicity of ALV-J, a set of ALV-J infectious clones containing different C termini of Gp37 or the mutants at the tyrosine sites were tested and Viral growth kinetics indicated not only that ALV-J with active is the fastest in replication and ALV-J with inhibitory is the lowest but also that the tyrosine sites essentially affected the replication of ALV-J. Moreover, studies demonstrated that chickens infected by ALV-J with active or bifunctional showed higher viremia, cloacal viral shedding, and viral tissue load than those infected by ALV-J with inhibitory Notably, the chickens infected by ALV-J with active or bifunctional showed significant loss of body weight compared with the control chickens. Taken together, these findings reveal that the C terminus of Gp37 plays a vital role in ALV-J pathogenesis, and change from inhibitory to bifunctional or active increases the pathogenesis of ALV-J. ALV-J can cause severe immunosuppression and myeloid leukemia in infected chickens. However, no vaccine or antiviral drug is available against ALV-J, and the mechanism for ALV-J pathogenesis needs to be elucidated. It is generally believed that and of ALV contribute to its pathogenesis. Here, we found that the C terminus and the tyrosine motifs (YxxM, ITIM, and ITAM-like) in the CTD of Gp37 of ALV-J could affect the pathogenicity of ALV-J and The pathogenicity of ALV-J with Gp37 containing ITIM only was significantly less than ALV-J with Gp37 containing both YxxM and ITIM and ALV-J with Gp37 containing both YxxM and ITAM-like. This study highlights the vital role of the C terminus of Gp37 in the pathogenesis of ALV-J and thus provides a new perspective to elucidate the interaction between ALV-J and its host and a molecular basis to develop efficient strategies against ALV-J.
Topics: Amino Acid Motifs; Animals; Avian Leukosis; Avian Leukosis Virus; Cell Line; Chickens; Mutation; Poultry Diseases; Protein Domains; Viral Envelope Proteins
PubMed: 32213616
DOI: 10.1128/JVI.02180-19 -
Viruses May 2018Several studies have shown that microRNA-targeting is an effective strategy for the selective control of tissue-tropism and pathogenesis of both DNA and RNA viruses....
Several studies have shown that microRNA-targeting is an effective strategy for the selective control of tissue-tropism and pathogenesis of both DNA and RNA viruses. However, the exploitation of microRNA-targeting for the inhibition of transformation by oncogenic viruses has not been studied. The v- oncoprotein encoded by reticuloendotheliosis virus T strain (Rev-T) is a member of the /NF-κB family of transcription factors capable of transforming primary chicken spleen and bone marrow cells. Here, by engineering the target sequence of endogenous microRNA miR-142 downstream of the v- gene in a Replication-Competent ALV (avian leukosis virus) long terminal repeat (LTR) with a splice acceptor (RCAS) vector and using a v--induced transformation model of chicken embryonic splenocyte cultures, we show that hematopoietic-specific miR-142 can inhibit the v--induced transformation, and that this inhibition effect is due to the silencing of v- expression. The data supports the idea that microRNA-targeting can be used to inhibit viral oncogene-induced oncogenesis.
Topics: Animals; Avian Leukosis Virus; Bone Marrow Cells; Carcinogenesis; Cell Transformation, Viral; Cells, Cultured; Chickens; Gene Silencing; MicroRNAs; NF-kappa B; Oncogene Proteins v-rel; Reticuloendotheliosis virus; Spleen; Transcription Factors
PubMed: 29734737
DOI: 10.3390/v10050242 -
Journal of Animal Science Jan 2023Avian leukosis virus subgroup E (ALVE) as a kind of endogenous retroviruses extensively exists in chicken genome. The insertion of ALVE has some effects on chicken...
Avian leukosis virus subgroup E (ALVE) as a kind of endogenous retroviruses extensively exists in chicken genome. The insertion of ALVE has some effects on chicken production traits and appearance. Most of the work on ALVEs has been done with commercial breeds. We present here an investigation of ALVE elements in seven Chinese domestic breeds and four standard breeds. Firstly, we established an ALVE insertion site dataset by using the obsERVer pipeline to identify ALVEs from whole-genome sequence data of eleven chicken breeds, seven Chinese domestic breeds, including Beijing You (BY), Dongxiang (DX), Luxi Game (LX), Shouguang (SG), Silkie (SK), Tibetan (TB) and Wenchang (WC), four standard breeds, including White Leghorn (WL), White Plymouth Rock (WR), Cornish (CS), and Rhode Island Red (RIR). A total of 37 ALVE insertion sites were identified and 23 of them were novel. Most of these insertion sites were distributed in intergenic regions and introns. We then used locus-specific PCR to validate the insertion sites in an expanded population with 18~60 individuals in each breed. The results showed that all predicted integration sites in 11 breeds were verified by PCR. Some ALVE insertion sites were breeds specific, and 16 out of 23 novel ALVEs were found in only one Chinese domestic chicken breed. We randomly selected three ALVE insertions including ALVE_CAU005, ALVE_ros127, and ALVE_ros276, and obtained their insertion sequences by long-range PCR and Sanger sequencing. The insertion sequences were all 7525 bp, which were full-length ALVE insertion and all of them were highly homologous to ALVE1 with similarity of 99%. Our study identified the distribution of ALVE in 11 chicken breeds, which expands the current research on ALVE in Chinese domestic breeds.
Topics: Animals; Chickens; Avian Leukosis Virus; DNA Transposable Elements; Polymerase Chain Reaction; Endogenous Retroviruses
PubMed: 36932970
DOI: 10.1093/jas/skad081 -
Journal of Virology Mar 2022Avian leukosis virus subgroup J (ALV-J) induces myelocytomas, which can metastasize to multiple organs in diseased chickens. Although metastasis is the primary cause of...
Avian leukosis virus subgroup J (ALV-J) induces myelocytomas, which can metastasize to multiple organs in diseased chickens. Although metastasis is the primary cause of death in such cases, the mechanism for it remains unclear. Here, we found that interaction between ALV-J surface protein (SU) and doublecortin-like kinase 1 (DCLK1) promotes epithelial-mesenchymal transition (EMT) and cell proliferation. We found that ALV-J can activate EMT in infected cells. Subsequently, proteomics analysis revealed that DCLK1, a well-established putative tumor stem cell marker, which is highly expressed in ALV-J-infected DF-1 cells and chickens, might be a potential factor mediating EMT. Furthermore, using immunofluorescence and immunoprecipitation, we verified that SU interacts with DCLK1. Functional studies suggested that overexpression of DCLK1 increased viral replication and promoted cell proliferation by accelerating the progression of cells from the G/G phase to the S phase of cell cycle, whereas RNA interference of DCLK1 reduced viral replication and arrested cell proliferation by retarding cell cycle progression from the late G phase into the S phase in ALV-J-infected cells. Moreover, we demonstrate that the increased accumulation of DCLK1 promotes EMT by increasing the expression of N-cadherin, vimentin, MMP2, and transcription factor Snail1 and decreasing the expression of epithelial marker E-cadherin. These results suggest that ALV-J SU interacts with DCLK1, and accelerates cell proliferation, leading to increased viral replication and ultimately activating EMT, which paves the way for tumor metastasis. Tumor metastasis is a major challenge in cancer research, because of its systemic nature and the resistance of disseminated tumor cells to existing therapeutic agents. It is estimated that >90% of mortality from cancer is attributable to metastases. We found that ALV-J can activate EMT, which plays a critical role in cancer metastasis. Subsequently, we identified a tumor stem cell marker, DCLK1, in ALV-J infected cells, which interacts with surface protein (SU) of ALV-J to promote virus replication, activate EMT, and accelerate cell proliferation enabling ALV-J to obtain metastatic ability. Understanding the process of participation of ALV-J in EMT and the route of metastasis will help elucidate the mechanism of virus-induced tumor metastasis and help identify promising molecular targets and key obstacles for ALV-J control and clinical technology development.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Cell Proliferation; Chickens; Doublecortin-Like Kinases; Epithelial-Mesenchymal Transition; Membrane Proteins
PubMed: 35080427
DOI: 10.1128/JVI.01657-21 -
Cells Oct 2022Synergism between avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) has been reported frequently in co-infected chicken flocks. Although...
Synergism between avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) has been reported frequently in co-infected chicken flocks. Although significant progress has been made in understanding the tumorigenesis mechanisms of ALV and REV, how these two simple oncogenic retroviruses induce synergistic oncogenicity remains unclear. In this study, we found that ALV-J and REV synergistically promoted mutual replication, suppressed cellular senescence, and activated epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, structural proteins from ALV-J and REV synergistically activated the expression of Musashi-1(MSI1), which directly targeted pri-miR-147 through its RNA binding site. This inhibited the maturation of miR-147, which relieved the inhibition of NF-κB/KIAA1199/EGFR signaling, thereby suppressing cellular senescence and activating EMT. We revealed a synergistic oncogenicity mechanism induced by ALV-J and REV in vitro. The elucidation of the synergistic oncogenicity of these two simple retroviruses could help in understanding the mechanism of tumorigenesis in ALV-J and REV co-infection and help identify promising molecular targets and key obstacles for the joint control of ALV-J and REV and the development of clinical technologies.
Topics: Animals; Coinfection; Poultry Diseases; NF-kappa B; Avian Leukosis Virus; Chickens; MicroRNAs; Carcinogenesis; ErbB Receptors
PubMed: 36291177
DOI: 10.3390/cells11203312 -
Letters in Applied Microbiology Mar 2022Avian leukosis virus (ALV) poses a major threat to poultry. The chicken gut microbiota plays critical roles in host performance, health and immunity. However, the effect...
Avian leukosis virus (ALV) poses a major threat to poultry. The chicken gut microbiota plays critical roles in host performance, health and immunity. However, the effect of viral infection on the microbiota of Chinese local chickens is not well understood. In this study, we performed high-throughput 16S rRNA gene sequencing and evaluated the gut microbiota profiles using faeces from ALV subgroup J (ALV-J)-infected and healthy Huiyang bearded chickens (Chinese local chickens). At the phylum level, ALV-J infection mainly increased the abundance of Bacteroidetes and Proteobacteria and decreased that of Firmicutes. An analysis at the order, family and genus levels showed that the abundance of Lactobacillales, Lactobacillaceae and Lactobacillus was the highest in normal chicken faeces, accounting for 89·07%, 86·47% and 86·46%, respectively, of phylotypes. Moreover, samples from ALV-J-infected chickens were enriched with Bacteroidales, Clostridiales, Bacteroidaceae, Ruminococcaceae, Lachnospiraceae and Bacteroides. Our findings highlight that ALV-J infection alters the gut microbiota and disrupts the host-microbial homeostasis in chickens, which may be involved in the pathogenesis of ALV-J infection.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; Gastrointestinal Microbiome; Poultry Diseases; RNA, Ribosomal, 16S
PubMed: 34825389
DOI: 10.1111/lam.13617 -
Journal of Virology Sep 2022The geographical spread and inter-host transmission of the subgroup J avian leukosis virus (ALV-J) may be the most important issues for epidemiology. An integrated...
The Emergence, Diversification, and Transmission of Subgroup J Avian Leukosis Virus Reveals that the Live Chicken Trade Plays a Critical Role in the Adaption and Endemicity of Viruses to the Yellow-Chickens.
The geographical spread and inter-host transmission of the subgroup J avian leukosis virus (ALV-J) may be the most important issues for epidemiology. An integrated analysis, including phylogenetic trees, homology modeling, evolutionary dynamics, selection analysis and viral transmission, based on the gp85 gene sequences of the 665 worldwide ALV-J isolates during 1988-2020, was performed. A new Clade 3 has been emerging and was evolved from the dominating Clade 1.3 of the Chinese Yellow-chicken, and the loss of a α-helix or β-sheet of the gp85 protein monomer was found by the homology modeling. The rapid evolution found in Clades 1.3 and 3 may be closely associated with the adaption and endemicity of viruses to the Yellow-chickens. The early U.S. strains from Clade 1.1 acted as an important source for the global spread of ALV-J and the earliest introduction into China was closely associated with the imported chicken breeders in the 1990s. The dominant outward migrations of Clades 1.1 and 1.2, respectively, from the Chinese northern White-chickens and layers to the Chinese southern Yellow-chickens, and the dominating migration of Clade 1.3 from the Chinese southern Yellow-chickens to other regions and hosts, indicated that the long-distance movement of these viruses between regions in China was associated with the live chicken trade. Furthermore, Yellow-chickens have been facing the risk of infections of the emerging Clades 2 and 3. Our findings provide new insights for the epidemiology and help to understand the critical factors involved in ALV-J dissemination. Although the general epidemiology of ALV-J is well studied, the ongoing evolutionary and transmission dynamics of the virus remain poorly investigated. The phylogenetic differences and relationship of the clades and subclades were characterized, and the epidemics and factors driving the geographical spread and inter-host transmission of different ALV-J clades were explored for the first time. The results indicated that the earliest ALV-J (Clade 1.1) from the United States, acted as the source for global spreads, and Clades 1.2, 1.3 and 3 were all subsequently evolved. Also the epidemiological investigation showed that the early imported breeders and the inter-region movements of live chickens facilitated the ALV-J dispersal throughout China and highlighted the needs to implement more effective containment measures.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; China; Phylogeny; Poultry Diseases; United States
PubMed: 35950858
DOI: 10.1128/jvi.00717-22 -
Methods in Molecular Biology (Clifton,... 2015The ability to introduce DNA elements into host cells and analyze the effects has revolutionized modern biology. Here we describe a protocol to generate Moloney murine...
The ability to introduce DNA elements into host cells and analyze the effects has revolutionized modern biology. Here we describe a protocol to generate Moloney murine leukemia virus (MMLV)-based, replication-incompetent pseudotyped retrovirus capable of infecting axolotls and incorporating genetic information into their genome. When pseudotyped with vesicular stomatitis virus (VSV)-G glycoprotein, the retroviruses can infect a broad range of proliferative axolotl cell types. However, if the retrovirus is pseudotyped with an avian sarcoma leukosis virus (ASLV)-A envelope protein, only axolotl cells experimentally manipulated to express the cognate tumor virus A (TVA) receptor can be targeted by infections. These strategies enable robust transgene expression over many cell divisions, cell lineage tracing, and cell subtype targeting for gene expression.
Topics: Alpharetrovirus; Ambystoma mexicanum; Animals; Extremities; Genetic Vectors; HEK293 Cells; Humans; Moloney murine leukemia virus; Open Reading Frames; Plasmids; Transfection; Viral Load
PubMed: 25740482
DOI: 10.1007/978-1-4939-2495-0_10 -
Frontiers in Cellular and Infection... 2021Avian leukosis virus subgroup J (ALV-J) is an oncogenic retrovirus that causes immunosuppression and neoplastic diseases in poultry. Cytokine signal-transduction...
Avian leukosis virus subgroup J (ALV-J) is an oncogenic retrovirus that causes immunosuppression and neoplastic diseases in poultry. Cytokine signal-transduction inhibitor molecule 3 (SOCS3) is an important negative regulator of the JAK2/STAT3 signaling pathway and plays certain roles in ALV-J infection. It is of significance to confirm the roles of in ALV-J infection and study how this gene affects ALV-J infection. In this study, we assessed the expression of the gene and , and investigated the roles of in ALV-J infection using overexpressed or interfered assays with the in DF-1 cells. The results showed that the expression of ALV-J infected chickens was different from uninfected chickens in the spleen, thymus and cecal tonsil. Further, is mainly expressed in the nucleus as determined by immunofluorescence assay. Overexpression of in DF-1 cells promoted the replication of ALV-J virus, and the expression of interferons ( and ), inflammatory factors ( and ) along with interferon-stimulating genes (, , , and ). Conversely, interference of showed the opposite results. We also observed that SOCS3 promoted ALV-J virus replication by inhibiting JAK2/STAT3 phosphorylation. In conclusion, promotes ALV-J replication inhibiting the phosphorylation of the JAK2/STAT3 signaling pathway. These results would advance further understanding of the persistent infection and the viral immune evasion of the ALV-J virus.
Topics: Animals; Avian Leukosis; Avian Leukosis Virus; Chickens; Phosphorylation; Poultry Diseases; Virus Replication
PubMed: 34568100
DOI: 10.3389/fcimb.2021.748795