Dynamics of protein 27 of avian leukosis virus and transforming growth factor beta2 in lymphoid leukosis susceptible and resistant broiler chicken breeding stock (original) (raw)
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Veterinary Research Communications - VET RES COMMUN, 1999
The dynamics of the serum concentration of protein 27 (P27) of avian leukosis virus and transforming growth factor ß2 (TGF-ß2) were compared during the period between 29 and 59 weeks of age in two flocks of broiler chicken breeding stock undergoing outbreaks of severe lymphoid leukosis (LL) associated with persistent high mortality (susceptible) and in another two flocks of breeding stock with the presence of avian leukosis virus in association with low mortality due to LL (resistant). The average mean concentration of serum P27 in the LL-susceptible flocks was significantly higher (2 (1282 pg/ml) among all flocks and at all sampling times. The significance of TGF-ß2 in inhibition of lymphoid tumour development is discussed.
Turkish Journal of Veterinary and Animal Sciences, 2006
The aim of this study was to investigate the presence of antibodies to ALV-J in broilers and broiler breeders. For this, 5 broiler units and 1 broiler breeding unit in the Marmara region were visited. Seventy 4-6-week-old chicks from the broiler units, consisting of 14 chicks from each broiler unit, were selected. Seventeen chickens from the broiler breeding unit were also selected. The chicks from the broiler units were necropsied and all internal organs were checked for the presence of tumors. Blood sera collected from all animals were analyzed for the presence of antibodies to avian leukosis virus subgroup-J (ALV-J) by a commercial ELISA (IDEXX). Growth retardation, depression, diarrhea and respiratory disorders were seen in chicks from the broiler units. No tumors were observed in the internal organs. However, pseudomembranes on the liver of 3 chicks and Gumboro-like lesions in the bursa of Fabricius in 5 chicks were seen. No antibodies to ALV-J were detected in any of the broiler chicks' sera. However, antibodies to ALV-J were detected in 13 (76%) of the17 broiler breeders, which indicates the necessity to apply eradication programs for ALV-J in breeding flocks in Turkey.
Epidemiological features and pathological study of avian leukosis in turkeys' flocks
Aim: The purpose of this study was focused on the identification of tumor diseases in turkeys on the basis of a detailed description of epidemiological features, clinical signs, lesions, and histopathological changes. Materials and Methods: Outbreak of a tumor disease in turkeys was investigated in various regions of Eastern Algeria. Four turkeys' flocks aged from 17 weeks were affected, resulting to mortality often over 10%, on a period of 15 days. The main epidemiological characters, clinical signs, and lesions were observed throughout all the course of the disease. Serum samples were collected from affected turkeys in each flock to detect p27 antigen in enzyme-linked immunosorbent assay (ELISA) test to diagnose avian leukosis virus (ALV). Portions of sciatic nerves and livers are taken from dead turkeys for microscopic examination. Results: The disease was characterized by clinical signs such as anorexia, weakness, and diarrhea. Necropsy of the dead birds showed hepatomegaly and gross splenomegaly with neoplastic nodules or gray foci and diffuse infiltration in the myocardium and lungs. ALV antigen test using ELISA confirmed the presence of virus leukosis. Histopathological sections of the liver had proliferations of lymphoblastoid cells and absence of any modifications or lymphocytic infiltration in peripheral nerves. Conclusion: The present study confirms that this disease condition is caused by lymphoid leukosis.
Veterinary Pathology, 2009
The role of subgroup J avian leukosis virus (ALV J) infection profile in the development of histiocytic sarcomatosis (HS) in chickens was evaluated using retrospective analysis of 2 experiments involving in ovo and at-hatch inoculation of commercial meat-type and ADOL line 0 chickens with 100 or 10,000 TCID 50 of various strains ALV J. HS was observed only in persistently viremic, meat-type chickens that were inoculated at hatch, but not in immunotolerized (persistently viremic, with no antibodies), in ovo inoculated chickens. However, the immunotolerized, in ovo inoculated chickens developed a high incidence of myeloid tumors. HS appeared to arise from the splenic ellipsoids and red pulp, and metastasized to liver, kidney, and other organs. The neoplastic cells were diffusely positive for ChL5, CD45, and MHC class II with multifocal infiltration of T and B lymphocytes. Expression of viral antigen gp85 within HS was very low compared with that noted in ALV J-induced myelocytomas. The above observations suggest that the mechanisms of oncogenesis of HS might be different from that of other ALV J-induced tumors.
Development of lymphocyte subpopulations in local breed chickens
Veterinary World, 2021
Background and Aim: Local breeds of chicken are known to have relatively higher disease resistance to many endemic diseases and diseases that are highly virulent in commercial chickens. This study aimed to address the lymphocyte subpopulations in three constitutive immune system organs (thymus, bursa of Fabricius, and spleen) in 30, 8-week-old, male local breed chickens. Materials and Methods: The T (CD3+) and B lymphocytes (Bu-1+) were identified through one-color, direct immunofluorescent staining of the thymus, bursa, and spleen lymphocytes. Likewise, two-color, direct immunofluorescent staining was performed to identify the CD4- and/or CD8-defined T lymphocytes. The proportions of T and B lymphocytes and CD4- and/or CD8 defined chicken lymphocyte subsets in lymphoid suspensions prepared from the thymus, bursa, and spleen were determined by flow cytometry. Results: CD3+ cells, particularly those positive for CD4+CD8–, were dominant in the thymus, whereas cells expressing the Bu-1...
Avian Diseases, 2004
In Experiment 1, a monoclonal antibody against the envelope glycoprotein (gp85) of subgroup J avian leukosis virus (ALV-J) was used to study the distribution of ALV-J in various tissues of White Leghorn chickens inoculated as embryos with the strain ADOL-Hc1 of ALV-J. At 2 and 6 wk of age, various tissues from infected and control uninfected chickens were tested for the presence of ALV-J gp85 by immunohistochemistry. In Experiment 2, using the methyl green-pyronine (MGP) stain, sections of bursa of Fabricius (BF) from chickens of line 15I 5 3 7 1 , inoculated with ALV-J or Rous-associated virus-1 (RAV-1), a subgroup A ALV, at hatch were examined for transformation of bursal follicles at 4 and 10 wk of age. In Experiment 1, specific staining indicative of the presence of ALV-J gp85 was noted at both 2 and 6 wk of age in the adrenal gland, bursa, gonads, heart, kidney, liver, bone marrow, nerve, pancreas, proventriculus, spleen, and thymus. In Experiment 2, by 10 wk of age, transformed bursal follicles were detected in MGP-stained sections of BF in only one of five (20%) chickens inoculated with ALV-J at hatch, compared with five of five (100%) chickens inoculated with RAV-1. The data demonstrate distribution of ALV-J gp85 in various tissues of White Leghorn chickens experimentally inoculated as embryos with the virus. The data also confirm our previous observation that ALV-J is capable of inducing transformation of bursal follicles, albeit the incidence is less frequent than that induced by subgroup A ALV. C Corresponding author.
Resistance of line 63 chickens to reticuloendotheliosis-virus-induced bursa-associated lymphomas
International Journal of Cancer, 1986
Chickens of lines 63 and 1515 × 71 were inoculated with the chick syncytial strain of reticuloendotheliosis virus (REV) or with the Rous-associated virus-1 of avian leukosis virus (ALV) at hatching. At 4, 10, 16, and 36 weeks post inoculation (PI), chickens were tested for REV-and ALV-induced viremia and antibody. The incidence of REV-or ALV-induced bursa-associated lymphomas in line 63 chickens was compared with that in line 1515 × 71 chickens. Inoculation of REV at hatching resulted in immunological tolerance to the virus in line 63 but not in line 1515 × 71 chickens. Between 70% and 100% of line 63 chickens remained viremic and lacked REV antibody throughout the experimental period of 36 weeks. In contrast, ALV-inoculated chickens of both lines had antibody by 16 weeks PI. The frequencies of REV-and ALV-induced bursa-associated lymphomas in line 63 chickens were significantly lower than in line 1515 × 71 chickens. Further, the incidence of bursa-associated lymphomas induced by REV in line 1515 × 71 chickens was significantly lower than that induced by ALV. These results suggest that: (1) the genetic constitution of the host may influence the immunological response to REV infection; (2) chickens resistant to ALV-induced bursa-associated lymphomas are equally resistant to such lymphomas induced by another unrelated avian retrovirus, REV; and (3) ALV is a more potent inducer of bursa-associated lymphomas than REV.
Genetics Selection Evolution, 1994
DNA sequences related to avian leukosis virus (ev genes) were identified in the genome of chickens from 6 experimental strains including 3 randombred lines (Wyandotte, Fayoumi and White Leghorn), 2 divergently selected Rhode Island Red lines and a synthetic broiler line. Digestion of genomic DNA with Sad and BamHI enzymes and hybridization with either RAV-2 sequences or an LTR-gag probe revealed 66 different SacI bands, 53 of which could be associated with particular BamHI bands such that the ev loci could be defined at the molecular level. The distribution patterns were very strain-specific. Average band frequency and heterozygosity level could be correlated with the genetic history of the lines and their inbreeding level which varied from 0.04 to 0.28. Withinfamily segregation did not show any allelic relationship between retroviral insertions that were considered to be 2 genes. The Fayoumi line showed the largest variation in ev number per bird and contained a few birds free of any endogenous viral sequences, designated ev0. The broiler line showed the highest ev number. Very few ev loci were shared by different lines; only ev6 was found in all strains. Comparison with the established classification in White Leghorns was not straightforward and further analysis of DNA polymorphism and viral expression is needed. chicken / DNA polymorphism / genetic variability / endogenous retrovirus Résumé -Analyse comparative des gènes viraux endogènes apparentés aux virus leucosiques aviaires dans des lignées expérimentales de poule domestique. Les gènes viraux endogènes (ev) apparentés aux virus des leucoses et sarcomes aviaires ont été identifiés sur un échantillon de reproducteurs et de leurs descendants issus de 6 populations expérimentales de poule qui différaient par leur origine génétique (Leghorn blanche, Wyandotte, Fayoumi, 2 lignées de Rhode Island Red, une lignée synthétique de poule de chair notée Yll), leur niveau moyen de consanguinité (estimations de 0,04 à 0,28) et la sélection subie. La digestion de l'ADN génomique par les enzymes SacI ou BamHI suivie de l'hybridation avec les sondes RAV ou LTR-gag dérivées du virus du sarcome de Rous a révélé 66 fragments avec Sac7 dont 53 ont pu être associés avec un fragment BamHI afin de caractériser les gènes ev au niveau moléculaire. Chaque population a présenté une distribution qui lui est propre. Les différences de fréquences géniques et d'hétérozygotie sont assez bien reliées aux taua de consanguinité des populations. L'étude de la ségrégation familiale n'a montré aucune relation d'allélisme entre ce que nous avions considéré comme 2 gènes ev. Le nombre de gènes ev par animal était particulièrement variable dans la souche Fayoumi qui présentait quelques animaux sans copies virales endogènes (notés ev0). La souche Y11 a montré le plus grand nombre d'insertions virales. Les populations d'origine génétique différente ont très peu de gènes ev en commun ce qui n'a pas permis le calcul d'une distance génétique; seul le gène ev6 est partagé par toutes, fait remarquable dont la signification est discutée. Parmi les 53 loci identifiés avec 2 enzymes de restriction, la majorité apparaît différente des gènes ev déjà décrits dans la souche Leghorn blanche actuellement utilisée comme référence pour la nomenclature internationale. poulet / polymorphisme d'ADN / variabilité génétique / rétrovirus endogène INTRODUCTION
Avian Diseases, 2008
Primary chicken embryo fibroblasts (CEF) from special specific pathogen-free chicken lines are used for detection of contamination of adult or embryonic tissues, meconium, or tissue culture fluids with avian leukosis viruses (ALV). The suitability and efficiency of such tests depend on the susceptibility of CEF to the various subgroups of exogenous as well as endogenous ALV. The ideal CEF for such tests should be not only susceptible to all retroviruses, but also free of endogenous viruses so that such tests are immune to any interference that may occur between the endogenous and the tested (exogenous) viruses. CEF and/or chickens free of endogenous viruses are also desirable for gene transfer studies using retroviral vectors, such as RNA interference (RNAi) experiments and transgenic work. The absence of ev genes in CEF or chickens can empower clean detection of successful RNAi construct delivery or gene transfer. CEF free of ev genes are also essential reagents routinely used in growing and detecting unknown retroviruses in varied viral assays. This report documents the development of a new line of chickens, 0.TVB*S1, that is free of endogenous viruses and susceptible to all subgroups of ALV identified in chickens.