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Microbiology Spectrum Jun 2023Glycogen synthase kinase 3β (GSK3β) is a widely distributed multifunctional serine/threonine kinase. In mammals, GSK3β regulates important life activities such as...
Glycogen synthase kinase 3β (GSK3β) is a widely distributed multifunctional serine/threonine kinase. In mammals, GSK3β regulates important life activities such as proinflammatory response, anti-inflammatory response, immunity, and cancer development. However, the biological functions of chicken GSK3β (chGSK3β) are still unknown. In the present study, the full-length cDNA of chGSK3β was first cloned and analyzed. Absolute quantification of chicken chGSK3β in 1-day-old specific-pathogen-free birds has shown that it is widely expressed in all tissues, with the highest level in brain and the lowest level in pancreas. Overexpression of chGSK3β in DF-1 cells significantly decreased the gene expression levels of interferon beta (IFN-β), IFN regulatory factor 7 (IRF7), Toll-like receptor 3 (TLR3), melanoma differentiation-associated protein 5 (MDA5), MX-1, protein kinase R (PKR), and oligoadenylate synthase-like (OASL), while promoting the replication of avian leukosis virus subgroup J (ALV-J). Conversely, levels of most of the genes detected in this study were increased when chGSK3β expression was knocked down using small interfering RNA (siRNA), which also inhibited the replication of ALV-J. These results suggest that chGSK3β plays an important role in the antiviral innate immune response in DF-1 cells, and it will be valuable to carry out further studies on the biological functions of chGSK3β. GSK3β regulates many life activities in mammals. Recent studies revealed that chGSK3β was involved in regulating antiviral innate immunity in DF-1 cells and also could positively regulate ALV-J replication. These results provide new insights into the biofunction of chGSK3β and the virus-host interactions of ALV-J. In addition, this study provides a basis for further research on the function of GSK3 in poultry.
Topics: Animals; Chickens; Avian Leukosis Virus; Glycogen Synthase Kinase 3 beta; Glycogen Synthase Kinase 3; Immunity, Innate; Antiviral Agents; Poultry Diseases; Mammals
PubMed: 36995259
DOI: 10.1128/spectrum.05235-22 -
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 -
Frontiers in Immunology 2023Autophagy plays an important role in host antiviral defense. The avian leukosis virus subgroup J (ALV-J) has been shown to inhibit autophagy while promoting viral...
Autophagy plays an important role in host antiviral defense. The avian leukosis virus subgroup J (ALV-J) has been shown to inhibit autophagy while promoting viral replication. The underlying autophagic mechanisms, however, are unknown. Cholesterol 25-hydroxylase (CH25H) is a conserved interferon-stimulated gene, which converts cholesterol to a soluble antiviral factor, 25-hydroxycholesterol (25HC). In this study, we further investigated the autophagic mechanism of CH25H resistance to ALV-J in chicken embryonic fibroblast cell lines (DF1). Our results found that overexpression of and treatment with 25HC promoted the autophagic markers microtubule-associated protein 1 light chain 3 II (LC3II) and autophagy-related gene 5(ATG5), while decreased autophagy substrate p62/SQSTM1 (p62) expression in ALV-J infection DF-1 cells. Induction of cellular autophagy also reduces the levels of ALV-J gp85 and p27. ALV-J infection, on the other hand, suppresses autophagic marker protein LC3II expression. These findings suggest that CH25H-induced autophagy is a host defense mechanism that aids in ALV-J replication inhibition. In particular, CH25H interacts with CHMP4B and inhibits ALV-J infection in DF-1 cells by promoting autophagy, revealing a novel mechanism by which CH25H inhibits ALV-J infection. Although the underlying mechanisms are not completely understood, CH25H and 25HC are the first to show inhibiting ALV-J infection autophagy.
Topics: Animals; Chick Embryo; Avian Leukosis Virus; Chickens; Autophagy; Transcription Factors; Antiviral Agents; Autophagy-Related Protein 5
PubMed: 36875122
DOI: 10.3389/fimmu.2023.1093289 -
Viruses Jan 2023This study focuses on clarifying the regulation of chicken 14-3-3σ protein on the fibrous histiocyte proliferation caused by ALV-J-SD1005 strain infection. DF-1 cells...
This study focuses on clarifying the regulation of chicken 14-3-3σ protein on the fibrous histiocyte proliferation caused by ALV-J-SD1005 strain infection. DF-1 cells were inoculated with 10 TCID of ALV-J-SD1005 strain; the cell proliferation viability was dramatically increased and 14-3-3σ expressions were dramatically decreased within 48 h after inoculation. Chicken over-expression could significantly decrease the cell proliferation and the ratio of S-phase cells, but increase the ratio of G2/M-phase cells in ALV-J-infected DF-1 cells; by contrast, chicken knockdown expression could cause the opposite effects. Additionally, chicken over-expression could also dramatically down-regulate the expressions of CDK2/CDC2, but up-regulate p53 expressions in the DF-1 cells; in contrast, the knockdown expression could significantly increase the expressions of CDK2/CDC2 and decrease p53 expressions. It can be concluded that chicken 14-3-3σ can inhibit cell proliferation and cell cycle by regulating CDK2/CDC2/p53 expressions in ALV-J-infected DF1 cells. ALV-J-SD1005 strain can promote cell proliferation by reducing expressions. This study helps to clarify the forming mechanism of acute fibrosarcoma induced by ALV-J infection.
Topics: Animals; Avian Leukosis Virus; Chickens; Tumor Suppressor Protein p53; Cell Proliferation; Fibroblasts
PubMed: 36851618
DOI: 10.3390/v15020404 -
Viruses Jan 2023After the onset of the AIDS pandemic, HIV-1 (genus ) became the predominant model for studying retrovirus Env glycoproteins and their role in entry. However, HIV Env is... (Review)
Review
After the onset of the AIDS pandemic, HIV-1 (genus ) became the predominant model for studying retrovirus Env glycoproteins and their role in entry. However, HIV Env is an inadequate model for understanding entry of viruses in the , and genera. For example, oncogenic model system viruses such as Rous sarcoma virus (RSV, ), murine leukemia virus (MLV, ) and human T-cell leukemia viruses (HTLV-I and HTLV-II, ) encode Envs that are structurally and functionally distinct from HIV Env. We refer to these as Gamma-type Envs. Gamma-type Envs are probably the most widespread retroviral Envs in nature. They are found in exogenous and endogenous retroviruses representing a broad spectrum of vertebrate hosts including amphibians, birds, reptiles, mammals and fish. In endogenous form, gamma-type Envs have been evolutionarily coopted numerous times, most notably as placental syncytins (e.g., human SYNC1 and SYNC2). Remarkably, gamma-type Envs are also found outside of the . Gp2 proteins of filoviruses (e.g., Ebolavirus) and snake arenaviruses in the genus are gamma-type Env homologs, products of ancient recombination events involving viruses of different Baltimore classes. Distinctive hallmarks of gamma-type Envs include a labile disulfide bond linking the surface and transmembrane subunits, a multi-stage attachment and fusion mechanism, a highly conserved (but poorly understood) "immunosuppressive domain", and activation by the viral protease during virion maturation. Here, we synthesize work from diverse retrovirus model systems to illustrate these distinctive properties and to highlight avenues for further exploration of gamma-type Env structure and function.
Topics: Female; Pregnancy; Animals; Humans; Mice; Placenta; Gammaretrovirus; Alpharetrovirus; Leukemia Virus, Murine; Ebolavirus; Endogenous Retroviruses; HIV Seropositivity; Glycoproteins; Mammals
PubMed: 36851488
DOI: 10.3390/v15020274 -
Infection, Genetics and Evolution :... Apr 2023Tibetan chicken is found in China Tibet (average altitude; ˃4500 m). However, little is known about avian leukosis virus subgroup J (ALV-J) found in Tibetan chickens....
Tibetan chicken is found in China Tibet (average altitude; ˃4500 m). However, little is known about avian leukosis virus subgroup J (ALV-J) found in Tibetan chickens. ALV-J is a typical alpharetrovirus that causes immunosuppression and myelocytomatosis and thus seriously affects the development of the poultry industry. In this study, Tibet-origin mutant ALV-J was isolated from Tibetan chickens and named RKZ-1-RKZ-5. A Myelocytomatosis outbreak occurred in a commercial Tibetan chicken farm in Shigatse of Rikaze, Tibet, China, in March 2022. About 20% of Tibetan chickens in the farm showed severe immunosuppression, and mortality increased to 5.6%. Histopathological examination showed typical myelocytomas in various tissues. Virus isolation and phylogenetic analysis demonstrated that ALV-J caused the disease. Gene-wide phylogenetic analysis showed the RKZ isolates were the original strains of the previously reported Tibetan isolates (TBC-J4 and TBC-J6) (identity; 94.5% to 94.9%). Furthermore, significant nucleotide mutations and deletions occurred in the hr1 and hr2 hypervariable regions of gp85 gene, 3'UTR, Y Box, and TATA Box of 3'LTR. Pathogenicity experiments demonstrated that the viral load, viremia, and viral shedding level were significantly higher in RKZ-1-infected chickens than in NX0101-infected chickens. Notably, RKZ-1 caused more severe cardiopulmonary damage in SPF chickens. These findings prove the origin of Tibet ALV-J and provide insights into the molecular characteristics and pathogenic ability of ALV-J in the plateau area. Therefore, this study may provide a basis for ALV-J prevention and eradication in Tibet.
Topics: Animals; Chickens; Tibet; Avian Leukosis Virus; Phylogeny; Virulence; China; Avian Leukosis; Poultry Diseases
PubMed: 36775048
DOI: 10.1016/j.meegid.2023.105415 -
The Journal of Biological Chemistry Mar 2023Subgroup K avian leukosis virus (ALV-K) is a novel subgroup of ALV isolated from Chinese native chickens. As for a retrovirus, the interaction between its envelope...
Subgroup K avian leukosis virus (ALV-K) is a novel subgroup of ALV isolated from Chinese native chickens. As for a retrovirus, the interaction between its envelope protein and cellular receptor is a crucial step in ALV-K infection. Tva, a protein previously determined to be associated with vitamin B/cobalamin uptake, has been identified as the receptor of ALV-K. However, the molecular mechanism underlying the interaction between Tva and the envelope protein of ALV-K remains unclear. In this study, we identified the C-terminal loop of the LDL-A module of Tva as the minimal functional domain that directly interacts with gp85, the surface component of the ALV-K envelope protein. Further point-mutation analysis revealed that E53, L55, H59, and G70, which are exposed on the surface of Tva and are spatially adjacent, are key residues for the binding of Tva and gp85 and facilitate the entry of ALV-K. Homology modeling analysis indicated that the substitution of these four residues did not significantly impact the Tva structure but impaired the interaction between Tva and gp85 of ALV-K. Importantly, the gene-edited DF-1 cell line with precisely substituted E53, L55, H59, and G70 was completely resistant to ALV-K infection and did not affect vitamin B/cobalamin uptake. Collectively, these findings not only contribute to a better understanding of the mechanism of ALV-K entry into host cells but also provide an ideal gene-editing target for antiviral study.
Topics: Animals; Avian Leukosis Virus; Chickens; Poultry Diseases; Receptors, Cell Surface; Receptors, Virus; Viral Envelope Proteins; Vitamin B Complex; Vitamin B 12
PubMed: 36717079
DOI: 10.1016/j.jbc.2023.102962 -
Research in Veterinary Science Feb 2023ALV-J-SD1005 strain was subcutaneously inoculated into the necks of 1-day-old HY-Line Brown chickens and caused severe growth retardation, viremia and subcutaneous...
ALV-J-SD1005 strain was subcutaneously inoculated into the necks of 1-day-old HY-Line Brown chickens and caused severe growth retardation, viremia and subcutaneous fibrosarcomas in the necks of all infected chickens from 14 days post inoculation (DPI) to 21 DPI, and also significantly increased the expressions of TRIM25, P53, etc., but significantly decreased the expressions of 14-3-3σ, etc. Overexpression of chicken TRIM25 (chTRIM25) significantly promoted cell proliferation and improved the expressions of P53, CDC2, and CDK2 tumor factors; and significantly inhibited the expression of 14-3-3σ in ALV-J-SD1005-infected DF1 cells; but knockdown of chTRIM25 caused the opposite effects. The results of co-immunoprecipitation (Co-IP) and confocal microscopy confirmed that chTRIM25 can recognize and bind 14-3-3σ protein in ALV-J-SD1005-infected cells, and they were co-located in the cytoplasm. It can be concluded that chTRIM25 participates in the fibrous tissue hyperplasia induced by ALV-J-SD1005 infections in chickens by binding 14-3-3σ protein and regulating the expressions of 14-3-3σ, P53, CDC2, and CDK2.
Topics: Animals; Chickens; Hyperplasia; Avian Leukosis; Tumor Suppressor Protein p53; Neoplasms; Avian Leukosis Virus; Poultry Diseases
PubMed: 36682337
DOI: 10.1016/j.rvsc.2023.01.013 -
Viruses Nov 2022The avian immunosuppressive and neoplastic diseases caused by Marek's disease virus (MDV), avian leucosis virus (ALV), and reticuloendotheliosis virus (REV) are...
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.
Topics: Animals; Chickens; Coinfection; Avian Leukosis; Neoplasms; Herpesvirus 2, Gallid; Reticuloendotheliosis virus; China; Poultry Diseases; Avian Leukosis Virus; Marek Disease
PubMed: 36560601
DOI: 10.3390/v14122599 -
Veterinary Research Dec 2022This research aimed to analyze the regulatory effect of chicken telomerase reverse transcriptase (chTERT) on the Wnt/β-catenin signaling pathway and its effect on the...
This research aimed to analyze the regulatory effect of chicken telomerase reverse transcriptase (chTERT) on the Wnt/β-catenin signaling pathway and its effect on the tumorigenicity of avian leukosis virus subgroup J (ALV-J) through in vivo experiments. The chTERT eukaryotic expression plasmid and its recombinant lentivirus particles were constructed for in vivo transfection of chTERT to analyze the effect of chTERT continuously overexpressed in chickens on the tumorigenicity of ALV-J. During 156 days of the artificial ALV-J tumor-inducing process, 7 solid tumors developed in 3 chickens in the chTERT-overexpression group (n = 26*2) and no tumors developed in the control group (n = 26*2). Another 18 tumors induced by ALV-J were confirmed and collected from breeding poultry farms. And we confirmed that chTERT was significantly highly expressed in ALV-J tumors. The ELISA data suggested that the protein levels of β-catenin and c-Myc in the chicken plasma of the chTERT-overexpressing group with ALV-J infected were consistently and significantly higher than those of the control group. Compared with that of the tumor-adjacent tissues, the activity of the Wnt/β-catenin signaling pathway and expression of the c-Myc was significantly increased in ALV-J tumors. And the percentage of apoptosis in ALV-J tumors significantly lower than that in tumor-adjacent tissues. Immunohistochemistry, Western blot and RT-qPCR suggested that the replication level of ALV-J in tumors was significantly higher than that in tumor-adjacent tissues. This study suggests that chTERT plays a critical role in the tumorigenicity of ALV-J by enhancing the Wnt/β-catenin signaling pathway, which will contribute to further elucidating the tumor-inducing mechanism of ALV-J.
Topics: Animals; Avian Leukosis Virus; Telomerase; Chickens; Wnt Signaling Pathway; Blotting, Western
PubMed: 36461084
DOI: 10.1186/s13567-022-01120-2