Avian leukosis virus subgroup J (ALV-J) is an avian retrovirus that can induce myelocytomas. A high-frequency mutation in gene envelope endows ALV-J with the potential for cross-species transmission. We wished to ascertain if the ALV-J can spread across species under selection pressure in susceptible and resistant hosts. First, we inoculated (in turn) two susceptible host birds (specific pathogen-free (SPF) chickens and turkeys). Then, we inoculated three resistant hosts (pheasants, quails and ducks) to detect the viral shedding, pathologic changes, and genetic evolution of different isolates. We found that pheasants and quails were infected under the selective pressure that accumulates stepwise in different hosts, and that ducks were not infected. Infection rates for SPF chickens and turkeys were 100% (16/16), whereas those for pheasants and quails were 37.5% (6/16) and 11.1% (3/27). Infected hosts showed immune tolerance, and inflammation and tissue damage could be seen in the liver, spleen, kidneys and cardiovascular system. Non-synonymous mutation and synonymous ratio (NS/S) analyses revealed the NS/S in hypervariable region (hr) 2 of pheasants and quails was 2.5. That finding suggested that mutation of isolates in pheasants and quails was induced by selective pressure from the resistant host, and that the hr2 region is a critical domain in cross-species transmission of ALV-J. Sequencing showed that ALV-J isolates from turkeys, pheasants and quails had moved away from the original virus, and were closer to the ALV-J prototype strain HPRS-103. However, the HPRS-103 strain cannot infect pheasants and quails, so further studies are needed.
Amino Acid Sequence ; Animals ; Avian Leukosis ; transmission ; virology ; Avian Leukosis Virus ; classification ; genetics ; physiology ; Chickens ; Ducks ; virology ; Galliformes ; virology ; Host Specificity ; Molecular Sequence Data ; Poultry Diseases ; transmission ; virology ; Quail ; virology ; Sequence Alignment ; Turkeys ; virology ; Viral Envelope Proteins ; chemistry ; genetics ; metabolism

Small interfering ribonucleic acid (siRNA)-induced RNA degradation can inhibit viral infection, and has been investigated extensively for its efficacy as antiviral therapy. The potential therapeutic role of lentiviral-mediated short hairpin ribonucleic acid (shRNA) to Newcastle disease virus (NDV) replication in vivo has been explored less often. We constructed two recombinant lentiviral vectors containing shRNA against the phosphoprotein (P) of the NDV, RNAi-341 and RNAi-671. Recombinant shRNA lentivirus vectors were co-transfected into 293T cells, along with helper plasmids, to package the recombinant shRNA lentivirus. Lentivirus-based shRNAs were titrated and transduced into NDV-susceptible chicken embryo fibroblasts (CEFs) and chick embryos. Antiviral activity against the NDV strain was evaluated by virus titration and real-time reverse transcription-polymerase chain reaction. RNAi-341 and RNAi-671 strongly suppressed transient expression of a FLAG-tagged P fusion protein in 293T cells. RNAi-341 and RNAi-671 NDV reduced virus titers by 66.6-fold and 30.6-fold, respectively, in CEFs 16 h after infection. RNAi-341 and RNAi-671 reduced virus titers in specific pathogen-free chick embryos by 99% and 98%, respectively, 48 h after infection. Both shRNAs inhibited accumulation of not only P-gene mRNA, but also nucleocapsid, M-, F-, HN-, and L-gene mRNA. RNAi-341 silenced P-gene mRNA more potently than RNAi-671. These results suggest that shRNAs silencing the P gene had substantial antiviral properties and inhibited NDV replication in CEFs and chick embryos.
Animals ; Chick Embryo ; Chickens ; Down-Regulation ; Fibroblasts ; virology ; Gene Targeting ; Lentivirus ; genetics ; metabolism ; Newcastle Disease ; virology ; Newcastle disease virus ; genetics ; physiology ; Phosphoproteins ; genetics ; metabolism ; Poultry Diseases ; virology ; RNA Interference ; RNA, Small Interfering ; genetics ; metabolism ; Viral Proteins ; genetics ; metabolism ; Virus Replication

The effects of diclazuril on the bursa of Fabricius (BF) structure and secretory IgA (SIgA) expression in chickens infected with Eimeria tenella were examined. The morphology of the BF was observed by hematoxylin and eosin staining, while ultrastructural changes were monitored by transmission electron microscopy. E. tenella infection caused the BF cell volumes to decrease, irregularly arranged, as well as, enlargement of the intercellular space. Diclazuril treatment alleviated the physical signs of damages associated with E. tenella infection. The SIgA expression in BF was analyzed by immunohistochemistry technique. The SIgA expression increased significantly by 350.4% (P<0.01) after E. tenella infection compared to the normal control group. With the treatment of diclazuril, the SIgA was relatively fewer in the cortex, and the expression level was significantly decreased by 46.7% (P<0.01) compared with the infected and untreated group. In conclusion, E. tenella infection in chickens induced obvious harmful changes in BF morphological structure and stimulated the expression of SIgA in the BF. Diclazuril treatment effectively alleviated the morphological changes. This result demonstrates a method to develop an immunological strategy in coccidiosis control.
Animals ; Bursa of Fabricius/anatomy & histology/*parasitology ; Chickens ; Coccidiosis/drug therapy/metabolism/parasitology/*veterinary ; Coccidiostats/administration & dosage/*adverse effects ; Eimeria tenella/*physiology ; Female ; Immunoglobulin A, Secretory/*genetics/metabolism ; Male ; Nitriles/administration & dosage/*adverse effects ; Poultry Diseases/*drug therapy/genetics/metabolism/parasitology ; Triazines/administration & dosage/*adverse effects

As part of our ongoing influenza surveillance program in South China, 19 field strains of H9N2 subtype avian influenza viruses (AIVs) were isolated from dead or diseased chicken flocks in Guangdong province, South China, between 2012 and 2013. Hemagglutinin (HA) genes of these strains were sequenced and analyzed and phylogenic analysis showed that 12 of the 19 isolates belonged to the lineage h9.4.2.5, while the other seven belonged to h9.4.2.6. Specifically, we found that all of the viruses isolated in 2013 belonged to lineage h9.4.2.5. The lineage h9.4.2.5 viruses contained a PSRSSRdownward arrowGLF motif at HA cleavage site, while the lineage h9.4.2.6 viruses contained a PARSSRdownward arrowGLF at the same position. Most of the isolates in lineage h9.4.2.5 lost one potential glycosylation site at residues 200-202, and had an additional one at residues 295-297 in HA1. Notably, 19 isolates had an amino acid exchange (Q226L) in the receptor binding site, which indicated that the viruses had potential affinity of binding to human like receptor. The present study shows the importance of continuing surveillance of new H9N2 strains to better prepare for the next epidemic or pandemic outbreak of H9N2 AIV infections in chicken flocks.
Animals ; *Chickens ; China ; Hemagglutinin Glycoproteins, Influenza Virus/chemistry/*genetics/metabolism ; Influenza A Virus, H9N2 Subtype/*genetics/metabolism ; Influenza in Birds/virology ; Phylogeny ; Poultry Diseases/*virology ; Sequence Analysis, RNA/veterinary

Characteristic clinical manifestations of Newcastle disease include leukopenia and immunosuppression. Peripheral blood mononuclear cells (PBMCs) are the main targets of Newcastle disease virus (NDV) infection. To survey changes in proteomic expression in chicken PBMCs following NDV infection, PBMC proteins from 30 chickens were separated using two-dimensional electrophoresis (2-DE) and subjected to mass spectrometry analysis. Quantitative intensity analysis showed that the expression of 78 proteins increased more than two-fold. Thirty-five proteins exhibited consistent changes in expression and 13 were identified as unique proteins by matrix assisted laser desorption ionization-time of flight mass spectrometer/mass spectrometer including three that were down-regulated and 10 that were up-regulated. These proteins were sorted into five groups based on function: macromolecular biosynthesis, cytoskeleton organization, metabolism, stress responses, and signal transduction. Furthermore, Western blot analysis confirmed the down-regulation of integrin-linked kinase expression and up-regulation of lamin A production. These data provide insight into the in vivo response of target cells to NDV infection at the molecular level. Additionally, results from this study have helped elucidate the molecular pathogenesis of NDV and may facilitate the development of new antiviral therapies as well as innovative diagnostic methods.
Animals ; Avian Proteins/*genetics/metabolism ; *Chickens ; *Gene Expression Regulation ; Leukocytes, Mononuclear/enzymology/virology ; Newcastle Disease/*genetics/virology ; Newcastle disease virus/*physiology ; Poultry Diseases/*genetics/virology ; *Proteome ; Specific Pathogen-Free Organisms ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/veterinary ; Tandem Mass Spectrometry/veterinary

To explore the expression potential of heterogeneous genes using the backbone of infectious bronchitis virus (IBV) Beaudette strain, the ectodomain region of the Spike gene (1,302 bp) of IBV H120 strain was amplified by RT-PCR and replaced into the corresponding location of the IBV Beaudette strain full-length cDNA. This recombinant was designated as BeauR-H120(S1). BeauR-H120(S1) was directly used as the DNA template for the transcription of viral genomic RNA in vitro. Then, the transcription product was transfected into Vero cells by electroporation. At 48 h post-transfection, the transfected Vero cells were harvested, and passaging continued. A syncytium was not observed until the recombinant virus had passed through four passages. The presence of rBeau-H120(S1) was verified by the detection of the replaced ectodomain region of the H120 Spike gene using RT-PCR. Western blot analysis of rBeau-H120 (S1)-infected Vero cell lysates demonstrated that the nucleocapsid (N) protein was expressed, which implied that rBeau-H120(S1) could propagate in Vero cells. The TCIDs0 and EIDs0 data demonstrated that the titer levels of rBeau-H120(S1) reached 10(590+/-0.22)TCID50/mL and 10(6.13+/-0.23)EID50/mL in Vero cells and 9-day-old SPF chicken embryos, respectively. Protection studies showed that the percentage of antibody-positive chickens, which were vaccinated with rBeau-H120(S1) at 7 days after hatching, rose to 90% at 21 days post-inoculation. Inoculation provided an 85% rate of immune protection against a challenge of the virulent IBV M41 strain (103EID50/chicken). This recombinant virus constructed using reverse genetic techniques could be further developed as a novel genetic engineering vaccine against infectious bronchitis.
Animals ; Cercopithecus aethiops ; Chick Embryo ; Chickens ; Coronavirus Infections ; veterinary ; virology ; Infectious bronchitis virus ; chemistry ; genetics ; growth & development ; metabolism ; Poultry Diseases ; virology ; Protein Structure, Tertiary ; Spike Glycoprotein, Coronavirus ; chemistry ; genetics ; metabolism ; Transfection ; Vero Cells

The sequences of the ccrAB genes from bovine-, canine- and chicken-originating methicillin-resistant Staphylococcus (S.) epidermidis (MRSE) and bovine methicillin-resistant Staphylococcus (S.) aureus (MRSA) were compared to investigate the frequency of intra-species horizontal transfer of the staphylococcal cassette chromosome mec (SCCmec) complex. Nineteen MRSE strains were isolated from bovine milk, chickens, and dogs, and their genetic characteristics were investigated by multilocus sequence typing and SCCmec typing. Among the animal MRSE strains, the most frequent SCCmec type was type IV, which consisted of the type B mec complex and ccrAB type 2. The ccrA2 and ccrB2 genes were sequenced from the bovine, chicken and canine MRSE strains and compared with those of the bovine MRSA strains. The sequences generally clustered as MRSA and MRSE groups, regardless of the animal source. Additionally, no bovine MRSE sequence was associated with the bovine MRSA groups. Although most of the bovine MRSE and MRSA isolates possessed SCCmec type IV sequences, our results suggest that the intra-species gene transfer of the SCCmec complex between bovine S. aureus and bovine S. epidermidis strains is not a frequent event.
Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics/metabolism ; Bacterial Typing Techniques/veterinary ; Cattle ; Cattle Diseases/epidemiology/metabolism ; Chickens ; Dog Diseases/epidemiology/metabolism ; Dogs ; *Drug Resistance, Bacterial ; *Gene Transfer, Horizontal ; Methicillin/*pharmacology ; Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification ; Milk/microbiology ; Multilocus Sequence Typing/veterinary ; Poultry Diseases/epidemiology/metabolism ; Prevalence ; Republic of Korea/epidemiology ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus epidermidis/genetics/isolation & purification

A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2(13) per 25 microL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4degrees C. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays.
Animals ; Antibodies, Viral/*blood ; Antigens, Viral/*diagnostic use/genetics/metabolism ; Baculoviridae/genetics ; Chickens ; HN Protein/*diagnostic use/genetics/metabolism ; Hemagglutination Inhibition Tests/*methods/veterinary ; Newcastle Disease/*diagnosis/immunology/virology ; Newcastle disease virus/genetics/*immunology/metabolism ; Poultry Diseases/*diagnosis/immunology/virology ; Recombinant Proteins/diagnostic use/genetics/metabolism ; Sf9 Cells ; Spodoptera

Abstract:Subgroup J avian leukosis virus (ALV-J) infect cells by binding to the chNHE1 receptor protein of the host and causes tumors. The tumor incidence of the ALV-J-infected chickens was observed by histo pathology, and virus was isolated on DF-1 cell line. The ALV-J load and mRNA of chNHElreceptor protein were detected by real time PCR. The relationship between ALV-J load, chNHE1 receptor expression levels and tumor spectrum was analyzed. The results showed that the tumors induced by ALV-J in laying hens and local lines of chicken were different. No significant relationship was observed between ALV-J load and tumor spectrum. ALV-J load was positively correlated with mRNA expression of chNHE1. The mRNA expression of chNHE1 increased when the tumors occurred. Our results suggest the chNHE1 protein is not only the receptor of ALV-J infected host but also play an important role in the process of tumor development. This study provides a scientific basis for further studying of oncogenic mechanism of ALV-J.
Animals ; Avian Leukosis ; genetics ; metabolism ; virology ; Avian Leukosis Virus ; genetics ; physiology ; Chickens ; genetics ; metabolism ; Poultry Diseases ; genetics ; metabolism ; virology ; Receptors, Virus ; genetics ; metabolism ; Sodium-Hydrogen Exchangers ; genetics ; metabolism ; Viral Load

The distribution of glycosylation sites in HA proteins was various among H5 subtype avian influenza viruses (AIVs), however, the role of glycosylation sites to the virus is still unclear. In this study, avian influenza H5N1 viruses with deletion of the glycosylation sites in HA were constructed and rescued by site direct mutation and reverse genetic method, and their biological characteristics and virulence were determined. The result showed that the mutants were confirmed to be corrected by HA gene sequencing and Western blot analysis. The EID50 and TCID50 tested in SPF chick embryo and MDCK cells of a mutant rSdelta158 with deletion of glycosylation site at position 158 were slight lower than that of wild type rescued virus rS, and the plaque diameter of rSdelta158 was significant smaller than that of rS. The EID50 and TCID50 of mutants rSdelta169 and rSdelta290 with deletion of glycosylation sites at position 169 and 290, respectively, were slight higher than that of wild type rescued virus rS, the plaque diameters of rSdelta169 and rSdelta290 were similar as that of rS, but the plaque numbers of rSdelta169 and rSdelta290 were 10-fold higher than that to rS. On the other hand, the rSdelta158, rSdelta169 and rSdelta290 showed similar growth rate in chicken embryo fibroblast as rS. All viruses remained high pathogenicity to SPF chickens. Therefore, the growth of AIV can be affected by changes of glycosylation sites in HA protein, by which the effect is variable in different cells.
Amino Acid Motifs ; Animals ; Cell Line ; Chick Embryo ; Chickens ; Glycosylation ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; metabolism ; Influenza A Virus, H5N1 Subtype ; chemistry ; genetics ; growth & development ; metabolism ; Influenza in Birds ; virology ; Poultry Diseases ; virology