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

The genomic diversity of Avian leukosis virus subgroup J (ALV-J) was investigated in an experimentally infected chicken. ALV-J variants in tissues from four different organs of the same bird were re-isolated in DF-1 cells, and their gp85 gene was amplified and cloned. Ten clones from each organ were sequenced and compared with the original inoculum strain, NX0101. The minimum homology of each organ ranged from 96.7 to 97.6%, and the lowest homology between organs was only 94.9%, which was much lower than the 99.1% homology of inoculum NX0101, indicating high diversity of ALV-J, even within the same bird. The gp85 mutations from the left kidney, which contained tumors, and the right kidney, which was tumor-free, had higher non-synonymous to synonymous mutation ratios than those in the tumor-bearing liver and lungs. Additionally, the mutational sites of gp85 gene in the kidney were similar, and they differed from those in the liver and lung, implying that organ- or tissue-specific selective pressure had a greater influence on the evolution of ALV-J diversity. These results suggest that more ALV-J clones from different organs and tissues should be sequenced and compared to better understand viral evolution and molecular epidemiology in the field.
Animals ; Avian Leukosis Virus* ; Avian Leukosis* ; Birds ; Chickens* ; Clone Cells ; Kidney ; Liver ; Lung ; Molecular Epidemiology ; Silent Mutation

Recently, avian viral diseases have become one of the main models to study mechanisms of viral infections and pathogenesis. The study of regulatory relationships and mechanisms between viruses and microRNAs has also become the focus. In this review, we briefly summarize the general situations of microRNAs encoded by avian herpesviruses. Also, we analyze the regulatory relationships between tumorigenicity of avian herpesviruses and microRNAs. Additionally, the possible applications for prevention and treatment of viral diseases (such as infectious bursal disease, avian influenza and avian leucosis) using the regulatory mechanisms of microRNAs are also discussed.
Animals ; Avian Leukosis ; Birds ; virology ; Birnaviridae Infections ; Herpesviridae ; genetics ; Influenza in Birds ; MicroRNAs ; genetics

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

To study the correlation between ELISA and IFA tests in detection of ALV-A/B antibody in chicken sera, ELSA S/P values and IFA titers for different serum samples were measured and statistically analyzed. The results indicated that there was a strong positive correlation between ELISA S/P values and IFA titers (r = 0.97435, P < 0.001). Because the positive correlation between ELISA and IFA was so strong and antibody positive rates were identical in two tests, it suggested that IFA could be used as a alternative method to replace ELISA kit when only limited numbers of samples to be tested to reduce the cost and increase the sensitivity.
Animals ; Antibodies, Viral ; blood ; immunology ; Avian Leukosis ; diagnosis ; immunology ; virology ; Avian Leukosis Virus ; classification ; immunology ; isolation & purification ; Cell Line ; Chickens ; Enzyme-Linked Immunosorbent Assay ; methods ; Fluorescent Antibody Technique, Indirect ; methods ; Poultry Diseases ; diagnosis ; immunology ; virology ; Species Specificity

In order to clarify Avian leukosis virus (ALV) characteristics from Chinese native chicken breeds, three ALV JS11C1, JS11C2 and JS11C3 were isolated from Chinese native breed "luhua" by inoculation of DF1 cell culture and detection of p27 antigen. Using PCR amplification of env gene, the amplified gp85 genes were analyzed and compared to all six chicken ALV subgroups reported. The gp85 genes of these three viruses were 1 005bp in length and encoded 335 amino acids, and the gp37 genes were 609bp and encoded 203 amino acids. The homology of gp85 among these three isolated strains was 91.9%-97.0%. Comparing to 18 stains of subgroup A, B, C, D, E published in GenBank, the homology was only in the range of 77.7%-84.6%, significantly lower than the gp85 homology observed within the common chicken subgroups A (88.2%-98.5%), B (91.6%-98.8%), and E (97.9%-99.4%). The gp85 homology compared with subgroup J was only 34.2%-36.5%. These results suggested that three isolated strains from Chinese native breed "luhua" belong to a new subgroup different from all six known subgroups from Chickens, and thus designated as subgroup K.
Animals ; Avian Leukosis ; virology ; Avian Leukosis Virus ; classification ; genetics ; isolation & purification ; metabolism ; Breeding ; Chickens ; genetics ; virology ; Molecular Sequence Data ; Phylogeny ; Poultry Diseases ; virology ; Viral Envelope Proteins ; genetics ; metabolism

The transmembrane protein (TM) encoded by gp37 gene plays a critical role when virus fusion with cell membrane occurs. Several highly conserved regions in TM are important targets for antivirus studies. Studies on structure and function of TM will provide basic information for anti-retrovirus, especially for avian leukosis virus. In the study, gp37 gene was amplified by PCR from the Chinese strain ALV-J-WS0701. The gp37 gene was cloned into pMD18-T vector, and was sequenced. Then, pFast-BacHTb-gp37 vector was constructed and expressed by baculovirus expression vector system. The expression product of gp37 gene was analyzed by indirect immunofluorescence assay and Western blot. The results showed that positive green fluorescence was present in sf9 cells infected with recombinant virus and a protein band with a molecular weight of 21kD was present in Western blot. It is concluded that gp37 gene was expressed in sf9 cells infected with recombinant virus successfully.
Animals ; Avian Leukosis ; virology ; Avian Leukosis Virus ; classification ; genetics ; isolation & purification ; Cell Line ; Chickens ; Cloning, Molecular ; Gene Expression ; Spodoptera ; Viral Envelope Proteins ; genetics ; metabolism

During July to November in 2007, several outbreaks of Hemangiomas in Hy-line Brown laying hens were observed in China. The virus that infected these flocks was identified in cultured DF-1 cells by PCR and indirect fluorescent assay (IFA) with ALV-J specific monoclonal antibody JE-9. The gp85 gene of one strain named WS0705 of ALV-J was cloned and expressed. Phylogenetic analysis showed that gp85 amino sequences of WS0705 strain had the highest homology with that of the prototype HPRS-103. The gp85 gene from a constructed plasmid pMD18-T-WS0705gp85 was cloned into baculovirus transfer vector. rBac-WS0705gp85 was obtained by the Bac-to-Bac baculovirus expression system. The rBac-WS0705gp85 protein was analyzed by indirect immunofluor escence assay and Western blot. The results showed that positive green fluorescent was present in Sf9 cells infected with the recombinant virus and a 35 kD band was present in western blot. It is concluded that WS0705 gp85 gene was expressed in Sf9 cells infected with the recombinant virus and the SU protein of WS0705 can bind specifically to JE9 MAb of ALV-J. The expressed protein can be used to detect hemangiomas induced by ALV-J.
Amino Acid Sequence ; Animals ; Avian Leukosis Virus ; classification ; genetics ; Blotting, Western ; Cell Line ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Gene Expression ; Hemangioma ; virology ; Phylogeny ; Polymerase Chain Reaction ; Sequence Alignment ; Viral Envelope Proteins ; chemistry ; genetics ; isolation & purification ; metabolism

The aggressive and invasive nature of brain tumors has hampered progress in the design and implementation of efficacious therapies. The recent success of targeted therapies in other tumor types makes this an attractive area for research yet complicating matters is the ability of brain tumors to circumvent the targeted pathways to develop drug resistance. Effective therapies will likely need to target more than one signaling pathway or target multiple nodes within a given pathway. Key to identifying these targets is the elucidation of the driver and passenger molecules within these pathways. Animal models provide a useful tool with many advantages in the study of these pathways. These models provide a means to dissect the critical components of tumorigenesis, as well as serve as agents for preclinical testing. This review focuses on the use of the RCAS/tv-a mouse model of brain tumors and describes their unique ability to provide insight into the role of oncogene cooperation in tumor development and progression.
Animals ; Avian Leukosis Virus ; genetics ; Avian Proteins ; genetics ; Brain Neoplasms ; genetics ; pathology ; Disease Models, Animal ; Disease Progression ; Drug Evaluation, Preclinical ; methods ; Genetic Vectors ; Glioma ; genetics ; pathology ; Humans ; Mice ; Mice, Transgenic ; Oncogenes ; genetics ; Receptors, Virus ; genetics

The increasing incidence and mortality associated with advanced stages of melanoma are cause for concern. Few treatment options are available for advanced melanoma and the 5-year survival rate is less than 15%. Targeted therapies may revolutionize melanoma treatment by providing less toxic and more effective strategies. However, maximizing effectiveness requires further understanding of the molecular alterations that drive tumor formation, progression, and maintenance, as well as elucidating the mechanisms of resistance. Several different genetic alterations identified in human melanoma have been recapitulated in mice. This review outlines recent progress made in the development of mouse models of melanoma and summarizes what these findings reveal about the human disease. We begin with a discussion of traditional models and conclude with the recently developed RCAS/TVA somatic cell gene delivery mouse model of melanoma.
9,10-Dimethyl-1,2-benzanthracene ; Animals ; Avian Leukosis Virus ; genetics ; Avian Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Disease Models, Animal ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; Humans ; Melanocytes ; metabolism ; Melanoma ; genetics ; pathology ; Melanoma, Experimental ; chemically induced ; genetics ; Mice ; Mice, Transgenic ; Neoplasm Transplantation ; Receptors, Virus ; genetics ; metabolism ; Skin Neoplasms ; genetics ; pathology ; Tetradecanoylphorbol Acetate ; Transgenes