isolation and characterization of a virus-specific ribonucleoprotein complex from reticuloendotheliosis virus-transformed chicken bone marrow cells.chicken bone marrow cells transformed by reticuloendotheliosis virus (rev) produce in the cytoplasm a ribonucleoprotein (rnp) complex which has a sedimentation value of approximately 80 to 100s and a density of 1.23 g/cm3. this rnp complex is not derived from the mature virion. an endogenous rna-directed dna polymerase activity is associated with the rnp complex. the enzyme activity was completely neutralized by anti-rev dna polymerase antibody but not by anti-avian myeloblastosis virus dna poly ...197881319
nucleotide sequences derived from pheasant dna in the genome of recombinant avian leukosis viruses with subgroup f specificity.recombination between viral and cellular genes can give rise to new strains of retroviruses. for example, rous-associated virus 61 (rav-61) is a recombinant between the bryan high-titer strain of rous sarcoma virus (rsv) and normal pheasant dna. nucleic acid hybridization techniques were used to study the genome of rav-61 and another rav with subgroup f specificity (rav-f) obtained by passage of rsv-rav-0 in cells from a ring-necked pheasant embryo. the nucleotide sequences acquired by these two ...1977199737
differentiation of pathogenic and non-pathogenic serotype 1 marek's disease viruses (mdvs) by the polymerase chain reaction amplification of the tandem direct repeats within the mdv genome.there are no simple, direct methods to reliably distinguish oncogenic serotype 1 marek's disease viruses (mdvs) from their attenuated variants. the present study was an attempt to apply polymerase chain reaction (pcr) to develop a rapid and sensitive assay for the presence of the mdv genome. pcr oligos were chosen to flank the 132-base-pair tandem direct repeats in the serotype 1 mdv genome. the pcr reaction was specific for serotype 1 mdvs, amplifying fragments corresponding to one to three cop ...19921329706
the v-rel oncogene encodes a cell-specific transcriptional activator of certain promoters.transformation by the v-rel oncogene of avian reticuloendotheliosis virus strain t (rev-t) is primarily cell-specific. while v-rel efficiently transforms chicken spleen and bone marrow stem cells in vitro and induces rapid lethal lymphomas in young birds, it does not rapidly transform chicken embryo fibroblasts. the nuclear localization of the v-rel gene product in non-transformed fibroblasts along with its ability to function as a transforming protein in the nucleus of chicken spleen cells sugg ...19882856247
detection and characterization of the protein encoded by the chicken c-rel protooncogene.we have identified the protein encoded by chicken c-rel, the cellular homolog of the v-rel oncogene carried by reticuloendotheliosis virus. the protein has been detected in two avian lymphoid cell lines and in chick embryo fibroblasts. it has a molecular weight of 68,000, suggesting that the viral gene (which encodes a protein of 59,000 molecular weight) is a truncated form of its cellular homolog. the c-rel protein is found in the soluble cytoplasmic fraction of chicken lymphoid cells and is no ...19882851122
p59v-rel, the transforming protein of reticuloendotheliosis virus, is complexed with at least four other proteins in transformed chicken lymphoid cells.previous studies have identified the protein product of v-rel, the oncogene carried by reticuloendotheliosis virus (rev), as a 59,000-dalton phosphoprotein located predominantly in the cytosol of transformed chicken lymphoid cells. in immune precipitates of p59v-rel, there is a closely associated protein kinase activity. in chicken lymphoid cells that do not contain rev, p68c-rel is found free in the cytosol not associated with other proteins and not detectably phosphorylated. in this study, we ...19882846883
expression of the v-rel oncogene in reticuloendotheliosis virus-transformed fibroblasts.reticuloendotheliosis virus (rev-t) induces a rapidly fatal lymphoma in chickens through the expression of its oncogene, v-rel, rev-t also morphologically transforms avian fibroblasts in vitro. these transformed cells displayed limited anchorage-independent growth and reached higher saturation density than uninfected or rev-a-infected fibroblasts. morphologically transformed fibroblasts were tumorigenic when injected into the wing web of chickens. in transformed fibroblasts, the v-rel oncogene w ...19882829425
rearrangements of chicken immunoglobulin genes in lymphoid cells transformed by the avian retroviral oncogene v-rel.the retroviral oncogene v-rel transforms poorly characterized lymphoid cells. we have explored the nature of these cells by analyzing the configuration and expression of immunoglobulin genes in chicken hemopoietic cells transformed by v-rel. none of the transformed cells expressed their immunoglobulin genes. the cells fell into three classes: class i cells have their immunoglobulin genes potentially in an embryonic configuration; class ii and class iii cells have lost one copy of the lambda ligh ...19882829193
[enhanced pathenogicity of chicken anemia agent (caa) in dual infections with marek's disease virus (mdv), infectious bursal disease virus (ibdv) or reticuloendotheliosis virus (rev)]. 19863014789
demonstration of precipitating antibodies to reticuloendotheliosis virus in egg yolk. 19872825629
clinical effects, virological and serological responses in chickens following in-ovo inoculation of reticuloendotheliosis virus.six-day-old embryonated specific pathogen free chicken eggs were inoculated with reticuloendotheliosis virus (rev) into the yolk sac and were incubated until they hatched. the hatchability of eggs inoculated with rev was significantly less (p less than 0.025) than that of media-inoculated controls. although there were no significant differences in the body weights of these chickens at hatching, there were differences (p less than 0.001) at 6, 25 and 51 days of age between the infected and contro ...19872825400
modulation of immune suppression and enhanced tumorigenesis in retrovirus tumor challenged chickens treated with vitamin e.vitamin e(dl-alpha-tocopherol) dissolved in ethanol with polyethylene glycol as the vehicle and administered by intraperitoneal injections of 0.1 mg/gm body weight at two day intervals, was demonstrated to be a potent immunomodulating reagent in young chickens challenged with avian reticuloendotheliosis virus-transformed tumor cells. vitamin e treatment enhanced the mitogen-induced proliferative responses of spleen cells from age matched, unchallenged chickens; reduced the tumor cell-induced sup ...19892562427
serological analysis of the deoxyribonucleic acid polymerase of avian oncornaviruses. ii. comparison of avian deoxyribonucleic acid polymerases.monospecific antiserum prepared against the isolated deoxyribonucleic acid (dna) polymerase of avian myeloblastosis virus (amv) neutralized the endogenous ribonucleic acid-instructed dna polymerase activity of detergent-disrupted virus. the viral polymerase was serologically unrelated to the seven major structural polypeptides of amv. furthermore, the viral enzyme was distinguished from normal cellular dna polymerases by serological criteria; thus, antiserum against the viral enzyme neutralized ...19724117966
acquisition of new proviral copies in avian lymphoid cells transformed by reticuloendotheliosis virus.the expression of the v-rel oncogene of avian reticuloendotheliosis virus (rev-t) transforms and immortalizes very immature avian lymphoid cells. in rev-t-transformed lymphoid cells which were persistently infected with reticuloendotheliosis-associated virus (rev-a), the rev-t proviral copy number increases after the initial integration event. in 23 independently derived rev-t-transformed cell lines, 15 of the 18 virus-producing cell lines had acquired additional proviruses. the rate at which th ...19892464702
reticuloendotheliosis virus (strain t). vi. an immunogen versus reticuloendotheliosis and rous sarcoma. 19734348952
vectors and genes for improvement of animal strains.strain improvement of agriculturally important animals will require efficient techniques for gene delivery, the ability to regulate the expression of the newly introduced genes and, most important, the identification of genes whose appropriate expression could cause improvement of the animal. we have developed a series of avian retroviral vectors that can be used to introduce new genetic information into the germ line of chickens, for which transgenics cannot be created by direct microinjection ...19902213714
quantitative infectivity studies of avian reticuloendotheliosis virus (strain t) in certain hematophagous arthropods. 19714400753
reticuloendotheliosis in breeder turkeys.reticuloendotheliosis virus (rev) was isolated at 21 weeks from a flock of breeder turkeys with lymphoid neoplasms. except for about 2% mortality due to tumors mainly between 20 and 30 weeks of age, the livability and egg production of the flock were normal. egg transmission as a source of infection seemed unlikely, because no rev antibodies or production problems were observed in two sister flocks (hatchmates) and in three progeny flocks, and because eggs obtained from the breeder flock at 45 w ...19846091607
inhibition of human immunodeficiency virus infectivity by chloroquine.the effect of chloroquine, a drug known to affect intracellular exocytic pathways, was studied in two retroviral systems: human immunodeficiency virus (hiv-1) and avian reticuloendotheliosis virus (rev-a). with chloroquine treatment of virus-infected cells, significant size reduction of the cell- and virus-associated surface glycoproteins, gp90 of rev-a and gp120 of hiv-1, was observed. in the case of hiv-1, extracellular virions derived from treated cells contained very little gp120. infectivit ...19901692728
expression of v-rel in a replication competent virus: transformation and biochemical characterization.the avian reticuloendotheliosis virus strain t (rev-t) transforms bone marrow cells and may cause phenotypic changes in fibroblasts. both events are thought to result from expression of the v-rel oncoprotein, a member of the nf-kappa b family of transcription factors. most rev stocks contain a cytopathic and immunosuppressive helper virus (rev-a) unrelated to standard avian retroviruses, and thus the degree to which v-rel expression alone contributes to the transformed phenotype in bone marrow c ...19911656369
reticuloendotheliosis virus long terminal repeat elements are efficient promoters in cells of various species and tissue origin, including human lymphoid cells.promiscuous transcriptional activity of the reticuloendotheliosis virus (rev) long terminal repeat (ltr) was detected in transient expression assays using ltr-chloramphenicol acetyltransferase-encoding gene chimeras, and cells of diverse species and tissue type; levels of expression from two different rev ltrs correlate with reports of pathogenicity of the respective viruses in vivo. revs do not encode a transactivator targeted to the viral ltr, and cells infected with marek's disease virus, a h ...19921332912
transcriptional interaction between retroviral long terminal repeats (ltrs): mechanism of 5' ltr suppression and 3' ltr promoter activation of c-myc in avian b-cell lymphomas.chicken syncytial viruses induce bursal lymphomas by integrating into the c-myc locus and activating myc expression by 3' long terminal repeat (ltr) promoter insertion. in contrast to wild-type proviruses, in which transcription initiates predominantly in the 5'ltr, these myc-associated proviruses exhibit a predominance of transcription from the 3' ltr and little transcription from the 5' ltr. most of these proviruses contain deletions within the 5' end of their genome that spare the 5' ltr. we ...19921321271
performance of 3 successive generations of specified-pathogenfree chickens maintained as a closed antibodies against salmonella pullorum, mycoplasma gallisepticum, mycoplasma synoviae, haemophilus gallinarum, fowl pox virus, marek's disease virus, herpes virus of turkey, infectious laryngotracheitis virus, avian adenovirus, avian reovirus, infectious bursal disease virus, reticuloendotheliosis virus, avian leukosis virus, avian encephalomyelitis virus and newcastle disease virus were detectable in the sera obtained from these chickens in 3 generations at various ages. antibodies against i ...19806253742
reticuloendotheliosis and 'pullet disease' in israel. 19921313616
dna of noninfectious and infectious integrated spleen necrosis virus (snv) is colinear with unintegrated snv dna and not grossly abnormal.the cleavage sites of eight restriction endonucleases in linear spleen necrosis virus (snv) dna were mapped, and the map was oriented with respect to viral rna. with the aid of this map, several structural features of the viral dna were elucidated: unintegrated linear snv dna is terminally redundant; the majority of snv dna molecules integrated in chicken dna, which were previously shown to be present in many sites in cellular dna, are colinear with unintegrated viral dna; no tandem integration ...1979217546
pathological changes in chickens inoculated with reticuloendotheliosis-virus-contaminated marek's disease vaccine.a disease characterized by delayed growth, anemia, abnormal feathers, and leg paralysis occurred among chickens inoculated with marek's disease vaccine over a period from spring to fall in 1974. these chickens were recognized among flocks inoculated with the vaccine produced by two vaccine makers. the affected ones were examined pathologically. gross examination revealed a slight enlargement of peripheral nerves and atrophy of the spleen, thymus, and bursa of fabricius. histopathologically, the ...1977203872
sites of integration of infectious dna of avian reticuloendotheliosis viruses in different avian cellular dnas.the pattern of integration for the infectious dna of two avian reticuloendotheliosis viruses whose dna is not inactivated by digestion with the restriction endonuclease, eco ri was determined. high molecular weight dna from infected chicken, turkey and pheasant cells was digested with eco ri, electrophoresed through agarose gels and assayed for infectivity. the same patterns of integration of infectious viral dna were found for these species of avian cells infected at high or low multiplicities ...1978203406
enhancement and interference in chickens inoculated with marek's disease herpesvirus and oncornaviruses.enhancement of mortality rates and symptomatology was observed in isolator-held lsi-spf chickens concurrently inoculated with mdhv and avian oncornaviruses (rav-1, rav-2, rav-7, rav-50, or rev). interference with md antigen production also was demonstrated in extracts of the feather follicle epithelium from chickens inoculated with both mdhv and rav-1.1975174137
comparative ultrastructural study of four reticuloendothelias viruses.the morphology and development of four members of the reticuloendotheliosis virus group were studied by transmission electron microscopy. virions of duck spleen necrosis virus, duck infectious anemia virus, chicken syncytial virus, and reticuloendotheliosis virus strain t are sperical with a diameter of approximately 110 nm. they are covered with surface projections about 6 nm long and 10 nm in diameter. the center-to-center distance of surface projections is about 14 nm. the budding virions con ...1975170410
helper viruses associated with avian acute leukemia viruses inhibit the cellular immune response. 19826278717
replication of reticuloendotheliosis viruses in cell culture: chronic infection.after an initial acute infection with cell killing, chicken or duck embryo fibroblasts infected in culture with reticuloendotheliosis viruses set up a chronic infection with no cell killing or morphological transformation. essentially all of the chronically infected cells produced virus. the virus production was not sensitive to cytosine arabinoside or mitomycin c as was virus production in an acute infection. the chronically infected cells had a strong group-specific resistancto the c.p.e. of s ...1975167114
a new, not virus related reverse transcriptase in the chicken system. 197664385
serotherapy of avian reticuloendotheliosis virus-induced tumors.immune serum, obtained from animals that had survived sublethal challenge with re virus, was very effective in achieving tumor cures in chickens infected with this virus. the therapeutic effect could also be obtained by the immunoglobulin fraction of immune serum. the serum did not influence the development of an unrelated malignancy. serotherapy studies in bx and tx recipients indicate that the b-cell or t-cell system of the host does not significantly contribute to the curative activity of imm ...197663259
diseases and management of backyard chicken flocks in chitungwiza, gather information on backyard chicken flocks in chitungwiza, an urban center in zimbabwe, 85 flock owners were interviewed. the mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. mean age at slaughter was 12.4 weeks (range 8-24). none of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. most owners co ...19947832719
pheasant virus: new class of ribodeoxyvirus.cocultivation of cells derived from embryos of golden pheasants or amherst pheasants with chicken embryo cells infected with bryan strain of rous sarcoma virus resulted in the detection of viruses which appear to be endogenous in these pheasant cells. the pheasant viruses (pv) were similar to avian leukosis-sarcoma viruses (alsv) in their gross morphology, in the size of their rna, in the presence of a virion-associated rna-dependent dna polymerase (dna nucleotidyltransferase; deoxynucleoside tr ...197657621
the reticuloendotheliosis viruses. 197553119
oncogene expression in reticuloendotheliosis virus-transformed lymphoid cell lines and avian tissues.the genome of reticuloendotheliosis virus (rev-t) contains a unique oncogene, designated v-rel, which is inserted into the env region. employing a cloned rel dna probe, a single 2.9- to 3.0-kilobase v-rel mrna was identified in poly(a)+ rna from rev-t-transformed lymphoid cell lines. a 4.0-kilobase rel-specific transcript corresponding to the cellular homolog of the v-rel oncogene was identified in msb-1 cells, a herpesvirus-transformed lymphoid cell line. cytodot hybridization was used to quant ...19862867231
avian reticuloendotheliosis virus (strain t). i. virological characterization. 19714334076
structure and regulation of the gene encoding avian inhibitor of nuclear factor kappa b-alpha.the rel/nf-kappa b family of transcription factors exist in the cytoplasm as inactive complexes in association with an inhibitory protein called i kappa b-alpha. we have isolated a clone containing the avian i kappa b-alpha gene from a chicken genomic library. avian i kappa b-alpha is devoid of any recognizable promoter elements, i.e., tata and caat boxes; however, the 5'-utr of the gene contains the initiator elements frequently found in tata-less genes. avian i kappa b-alpha contains seven put ...19958543172
in vitro transcription analysis of the viral promoter involved in c-myc activation in chicken b lymphomas: detection and mapping of two rna initiation sites within the reticuloendotheliosis virus long terminal repeat.chicken syncytial virus, a member of the reticuloendotheliosis virus family, induces b-cell lymphomas in chickens that arise by transcriptional activation of the chicken c-myc gene. in vitro transcription studies on cloned tumor dna containing a deleted chicken syncytial virus provirus integrated upstream from, and in the same transcriptional orientation as, the chicken c-myc coding region were utilized to map possible transcriptional promoters and initiation sites. in vitro transcripts extendin ...19852983111
detection and characterization of the protein encoded by the v-rel identify the protein encoded by v-rel, the oncogene of reticuloendotheliosis virus (rev-t), antisera have been raised to three synthetic peptides derived from the translation of our previously published v-rel dna sequence [r.m. stephens, n.r. rice, r.r. hiebsch, h.r. bose, jr., and r.v. gilden, proc. natl. acad. sci. usa 80, 6229-6233 (1983)]. sera to all three peptides precipitate a 59,000 da protein from rev-t-transformed chicken lymphoid cells. this protein is not detectable in uninfected ...19863004027
resistance of line 6(3) chickens to reticuloendotheliosis-virus-induced bursa-associated lymphomas.chickens of lines 6(3) and 151(5) x 7(1) were inoculated with the chick syncytial strain of reticuloendotheliosis virus (rev) or with the rous-associated virus-i 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 6(3) chickens was compared with that in line 151(5) x 7(1) chickens. inoculation of rev at hatching resul ...19863013782
activation of oncogenicity of the c-rel proto-oncogene.reticuloendotheliosis virus strain t (rev-t) induces a lethal lymphoma in young birds and transforms avian lymphoid cells in vitro. the transforming gene of rev-t, v-rel, was derived from the turkey proto-oncogene c-rel. comparison of the nucleotide sequences of v-rel and c-rel indicates that in addition to several internal amino acid changes relative to c-rel, p59v-rel has amino acid sequences at both ends derived from the reticuloendotheliosis virus strain a-related virus env gene (k. c. wilhe ...19863025667
virus specific syngeneic killing of reticuloendotheliosis virus transformed cell line target cells by spleen cells. 19873496613
identification of the v-rel protein in rev-t transformed chicken bone marrow cells and expression in cos1 cells.the product of the v-rel oncogene has been identified as a 55,000 dalton protein using antiserum prepared against a synthetic polypeptide whose sequence was deduced from the dna sequence of v-rel. this antiserum was used in a western blot assay to identify the product of v-rel in chicken bone marrow cells transformed with reticuloendotheliosis virus, strain t (rev-t), and in cos1 cells transfected with an expression vector containing the v-rel gene. transient expression of v-rel under the transc ...19863947347
oncogenic retroviruses of cattle, chickens and turkeys: potential infectivity and oncogenicity for humans.reticuloendotheliosis virus naturally infects and cause lymphoid leukosis in chickens and turkeys. we investigated whether it can infect/transfect a variety of human cells in vitro. successful infection and transfection were achieved with limited replication of virus. these findings, together with the knowledge that other oncogenic retroviruses of chickens and cattle, viz. the avian leukosis/sarcoma viruses and bovine leukemia virus show similar infectivity/oncogencity in vitro for humans, and t ...19968733164
reticuloendotheliosis virus nucleic acid sequences in cellular dna.reticuloendotheliosis virus 60s rna labeled with (125)i, or reticuloendotheliosis virus complementary dna labeled with (3)h, were hybridized to dnas from infected chicken and pheasant cells. most of the sequences of the viral rna were found in the infected cell dnas. the reticuloendotheliosis viruses, therefore, replicate through a dna intermediate. the same labeled nucleic acids were hybridized to dna of uninfected chicken, pheasant, quail, turkey, and duck. about 10% of the sequences of reticu ...19744372393
specific antigenic relationships between the rna-dependent dna polymerases of avian reticuloendotheliosis viruses and mammalian type c retroviruses.immunoglobulin g directed against the dna polymerase of rauscher murine leukemia virus (r-mulv) could bind to 125i-labeled dna polymerase of spleen necrosis virus (snv), a member of the reticuloendotheliosis virus (rev) species. competition radioimmunoassays showed the specificity of this cross-reaction. the antigenic determinants common to snv and r-mulv dna polymerases were shared completely by the dna polymerases of gross mulv, moloney mulv, rd 114 virus, rev-t, and duck infectious anemia vir ...19806154804
analysis of the nucleic acid components in reticuloendotheliosis virus.reticuloendotheliosis virus (rev) is known to be capable of transforming chicken bone marrow cells in vivo and embryo fibroblasts in vitro. as with spleen necrosis virus, we have found that sequences related to rev are found in dna of several uninfected avian species. for example, about 15% of the [3h]cdna synthesized in the endogenous reverse transcriptase reaction reassociated with dna of uninfected chickens. kinetic analysis revealed only a few (less than five) such sequences per haploid geno ...19806245235
tolerance, viral shedding, and neoplasia in chickens infected with non-defective reticuloendotheliosis viruses.chickens inoculated as embryos with non-defective reticuloendotheliosis viruses (ndrevs) generally developed a "tolerant" infection characterized by lack of immunofluorescent antibody and by a viremia that persisted through 93 weeks. chickens inoculated at hatching generally developed a "non-tolerant" infection characterized by antibody development that gradually waned as the chickens aged and by a transient or intermittent viremia. although chickens tolerantly infected with ndrev strain t were ...19816266388
secretion of a virus-regulated factor by clonal variants of reticuloendotheliosis virus-transformed hematopoietic cells. 19816267788
hematopoietic cells transformed in vitro by revt avian reticuloendotheliosis virus express characteristics of very immature lymphoid cells. 19816274086
formation of infectious progeny virus after insertion of herpes simplex thymidine kinase gene into dna of an avian retrovirus.we have prepared several infectious stocks of an avian retrovirus, spleen necrosis virus, containing the herpes simplex virus type 1 thymidine kinase (tk) gene. the viruses were produced after cotransfection of chicken cells with dna from recombinants between cloned spleen necrosis virus and tk dnas and dna of cloned reticuloendotheliosis virus strain a. removal of sequences in the tk gene for the end of tk mrna increased a thousand fold the yield of infectious recombinant virus. infection of ch ...19816276009
in vitro and in vivo investigations on reticuloendotheliosis virus infection.experimental transmission of reticuloendotheliosis (re) in 1-day-old spf chickens was achieved by intraperitoneal inoculation of cell-associated and cell-free re virus (rev). rev-inoculated chickens exhibited an immune response throughout the entire observation period. viremia persisted for 5--6 months in chickens hatched from rev-inoculated spf embryonated eggs. the natural occurrence of re was detected in turkey flocks of farms bc.19816277083
establishment of b-lymphoblastoid cell lines from marek's disease virus-induced tumors in turkeys.four lymphoblastoid cell lines were established from tumours of turkeys inoculated with high doses of the ga strain of marek's disease virus (mdv). unlike other md lymphoblastoid cell lines of chicken origin, these mdv transformed turkey line appear to be b lymphocytes and produce immunoglobulin. growth characteristics of these cell lines are slightly different; however, they all produce low levels of mdv-specific antigen and carry the complete genome of the virus as determined by virus rescue i ...19826277804
structure and dimorphism of c-rel (turkey), the cellular homolog to the oncogene of reticuloendotheliosis virus strain t.a locus has been identified in turkey dna that contains nucleotide sequences homologous to the oncogene (v-rel) in the avian retrovirus, reticuloendotheliosis virus strain t. this locus, c-rel, has been molecularly cloned from an apparently heterozygous turkey. c-rel is approximately 23 kilobase pairs in length, with at least seven apparent introns, and contains sequences sufficient to account for all of v-rel. nucleic acid sequence differences exist between v-rel and homologous regions of c-rel ...19846319751
monoclonal antibody to chicken fetal antigens on normal erythroid cells and hematopoietic-lymphoid tumor cell lines.hybridoma cell lines secreting antibodies to chicken fetal antigens (cfas) were generated by the fusion of mouse p3x63ag8 myeloma cells with spleen cells from a mouse immunized with intact sc chicken strain one-day-hatched red blood cells. immunodepletion studies show monoclonal anti-cfa to be detecting a subset of the mr 50,000 cfa molecules recognized by polyclonal anti-cfa. monoclonal anti-cfa is erythroid specific against in vivo-derived hematopoietic-lymphoid cells. exceptions to the erythr ...19826751524
detection of antibodies to avian leukosis/sarcoma viruses (alsv) and reticuloendotheliosis viruses (rev) in humans by elisa.we used a modified commercial elisa kit to test for antibodies to avian leukosis/sarcoma and reticuloendotheliosis viral antigens in the sera of 45 poultry workers and their matched controls. we found that 42% of sera from poultry workers had anti-avian leukosis sarcoma viruses (anti-alsv) and 20% had anti-reticuloendotheliosis viruses (anti-rev), antibody titers that were higher than the highest titer recorded in control subjects, and hence were regarded as positive. to determine the specificit ...19957585725
antibody response elicited against empty reticuloendotheliosis virus particles in two inbred lines of chicken.immunisation of houghton white leghorn line 15i and 6(1) chickens with empty reticuloendotheliosis virus particles elicited a primary antibody response which is probably directed against the viral envelope glycoproteins gp73/71 and gp22. antibodies in line 15i birds were shown to be non-neutralising and did not protect against the tumourigenic effects of reticuloendotheliosis virus, strain t. however, immunised line 6(1) chicks did not exhibit the runting syndrome associated with reticuloendothe ...19938273276
efficient insertion from an internal long terminal repeat (ltr)-ltr sequence on a reticuloendotheliosis virus vector is imprecise and cell examine the fidelity and efficiency of integration from a covalently closed long terminal repeat (ltr)-ltr sequence in vivo, we isolated individual spleen necrosis virus proviruses that arose following infection of chicken embryo fibroblasts (cefs) and sequenced the provirus-cell dna junctions. some but not all cef preparations allowed efficient insertion from the internal sequence. moreover, in contrast to integration from the normal ends of the viral dna, which occurs with precision with re ...19938382311
fowlpox virus recombinants expressing the envelope glycoprotein of an avian reticuloendotheliosis retrovirus induce neutralizing antibodies and reduce viremia in chickens.eight stable fowlpox virus (fpv) recombinants which express the envelope glycoprotein of the spleen necrosis virus (snv) strain of reticuloendotheliosis virus (rev), an avian retrovirus, were constructed. these recombinants differ in the genomic location of the inserted genes, in the orientation of the insert relative to flanking viral sequences, and in the promoter used to drive expression of the env gene. of these variables, promoter strength seems to be the most crucial. the p7.5 promoter of ...19938388488
the immunodominant proteins of reticuloendotheliosis virus.the antigenic profiles of three rev prototype strains, csv, snv and rev-t and eight israeli isolates were analysed by sds-page and immunoblotting with convalescent chicken serum, three mabs, 11a25, 11c237 and 11c100, a rabbit antiserum to rev-t whole virus (cui et al., 1986) and a rabbit antiserum to rev-a p30 gag protein (tsai et al., 1985). under both reducing (+dtt) and non-reducing conditions of sds-page, a major immunodominant 75-100 kda band was shared by all strains examined. in contrast ...19968734645
reduction of type v collagen using a dominant-negative strategy alters the regulation of fibrillogenesis and results in the loss of corneal-specific fibril morphology.a number of factors have been implicated in the regulation of tissue-specific collagen fibril diameter. previous data suggest that assembly of heterotypic fibrils composed of two different fibrillar collagens represents a general mechanism regulating fibril diameter. specifically, we hypothesize that type v collagen is required for the assembly of the small diameter fibrils observed in the cornea. to test this, we used a dominant-negative retroviral strategy to decrease the levels of type v coll ...19968947562
retroviral insertional mutagenesis of a herpesvirus: a marek's disease virus mutant attenuated for oncogenicity but not for immunosuppression or in vivo replication.our earlier studies have shown that retrovirus insertion into herpesvirus is an efficient process that engenders recombinant herpesviruses with altered biological properties. the rm1 clone is derived from the jm strain of marek's disease virus (mdv) through retrovirus insertional mutagenesis and contains sequences of reticuloendotheliosis virus inserted at the junction of the internal repeat and unique short regions of the genome. in previous studies, the rm1 clone appeared attenuated for oncoge ...19979201407
differences in kappab dna-binding properties of v-rel and c-rel are the result of oncogenic mutations in three distinct functional regions of the rel protein.the oncogene v-rel of reticuloendotheliosis virus, strain t, is derived from an avian c-rel proto-oncogene. c-rel encodes a member of the rel/nf-kappab family of transcription factors. the highly oncogenic v-rel differs from c-rel which has low transforming potential by the acquisition of numerous mutations. in this manuscript, we demonstrate that the oncogenic mutations in v-rel directly alter the ability of this protein to bind to dna. electrophoretic mobility shift analysis with rel proteins ...19979205096
c-jun involvement in vitamin e succinate induced apoptosis of reticuloendotheliosis virus transformed avian lymphoid cells.previous studies have shown that treatment of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells with 10 microg/ml (18.8 microm) of rrr-alpha-tocopheryl succinate (vitamin e succinate, ves) for 3 days induced approximately 50% of the cells to undergo apoptosis. elevated and prolonged expression of c-jun mrna and protein was temporally correlated with ves-induced cell death. data presented in this paper show that the elevated and prolonged expression of c-jun me ...19979244357
viral diseases of the immune system and strategies to control infectious bursal disease by vaccination.viral infections which are immunosuppressive can affect the economics of poultry production, often as a result of the chicken's increased susceptibility to secondary infections and sub-optimal response to vaccinations. the mechanism of this immunosuppression has been studied in detail for certain chicken viruses. the replicating virus can have both direct and indirect effects on the cells of the immune system. the special role of the bursa of fabricius, as a lympho-epithelial organ, will be ment ...19979276986
avian tumor viruses: persistent and evolving pathogens.most neoplasias of lymphoid and other hematopoietic cells in commercial poultry are caused by viruses which belong to one of four distinct groups. marek's disease virus (mdv) is an oncogenic herpesvirus. avian leukosis virus (alv), reticuloendotheliosis virus (rev) and lymphoproliferative disease virus (lpdv) are oncogenic retroviruses. each group is distinguished by nucleic acid type, molecular structure, antigenicity, epidemiology, host range and other characteristics. however, most of these v ...19979276987
field and vaccine strains of fowlpox virus carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus.for baculoviruses and herpesviruses, integration of transposons or retroviruses into the virus genome has been documented. we report here that field and vaccine strains of fowlpox virus (fpv) carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus (rev). using pcr and hybridization analysis we observed that vaccine and field strains of fpv carry rev sequences integrated into a previously uncharacterized region of the right 1/3 of the fpv genome. long-range pcr, hybridiz ...19979281517
rapid induction of lymphoid leukosis and ascites by avian leukosis virus from a lymphoid leukosis cell examine whether a lymphoid leukosis (ll) cell line releases an ll-specific avian leukosis virus (alv) or not, two viral materials, culture fluid and a concentrated viral material from an ll-cell line, were inoculated into a total of 74 day-old chicks of line 15i in 5 experiments. spectrum of diseases induced, their incidence and incubation periods to onset were examined. fifteen chicks were inoculated with the culture fluid and 9 (60%) developed ascites [59-119 days post inoculation (dpi); ge ...19989492364
some evidence of mechanical transmission of reticuloendotheliosis virus by mosquitoes.the possible role of mosquitoes in the mechanical transmission of reticuloendotheliosis virus (rev) in chickens was examined. a carbon-dioxide-baited trap was used to capture mosquitoes in poultry pens for one year to determine the seasonal occurrence and the species of mosquitoes prevalent in the area. homogenates of captured mosquitoes were used for rev isolation in chicken embryo fibroblast cultures. sera from sentinel chickens were also examined for rev antibodies. population peaks of mosqui ...19846098251
isolation of serotype 2 marek's disease virus from a cell line of avian lymphoid determine a serotype of marek's disease virus (mdv) persistently infected in a lymphoid leukosis (ll)-cell line, lscc-bk3, clone a (bk3a), and to examine the pathogenicity of the virus, an attempt was made to isolate mdv from culture fluid of the ll-cell line, using chick embryo fibroblast cultures resistant to infection with subgroup a avian leukosis virus (alv) to eliminate subgroup a alv. the mdv isolate, serologically identified as serotype 2 mdv and designated as the 2h strain, was free ...19989524935
monoclonal antibodies with specificity for three different serotypes of marek's disease viruses in chickens.a total of 50 antibody-secreting hybridoma cells against marek's disease virus (mdv) and turkey herpesvirus (hvt) have been produced. eleven hybridomas were used for serotyping a panel of 15 pathogenic and nonpathogenic strains of mdv and hvt, representing three serotypes. the antibodies from the culture medium have fluorescence antibody (fa) titers of up to 100 and those from mouse ascitic fluid have titers ranging from 10(4) to 10(6). monoclonal antibody t81 is type-common, i.e., it reacts at ...19836184394
resistance to salmonella enteritidis organ invasion in day-old turkeys and chickens by transformed t-cell line-produced lymphokines.we previously reported an increased resistance to salmonella enteritidis (se) organ invasion in chicks and turkey poults injected prophylactically with se-immune lymphokines (ilk). in the present study, concanavalin a (con-a)-activated splenic t cells isolated from se-hyperimmunized hens were transformed in vitro with reticuloendotheliosis virus strain t (rev-t) (chicken syncitial virus). these transformed t cells were then maintained as a long-term (> 1 yr) cell line for the harvest of immune l ...19989777155
mechanisms of the eimeria tenella growth inhibitory activity induced by concanavalin a and reticuloendotheliosis virus supernatants with interferon gamma activity in chicken macrophages and fibroblasts.pretreatment of chicken bone marrow macrophages and embryo fibroblasts with supernatants containing chicken interferon gamma (ifn-gamma) for 24 hr prior to inoculation inhibited intracellular eimeria tenella replication, measured by [3h] uracil incorporation. the supernatants (sns) were obtained from culture of lymphoblastoid cells transformed by a reticuloendotheliosis virus (rev) and chicken splenocytes stimulated with concanavalin a (con a). the mechanisms of the e. tenella growth inhibitory ...199910216761
development of the hot spot-combined pcr assay for detection of retroviral insertions into marek's disease virus.a two-step pcr, the hot spot-combined pcr assay, was developed for the identification and characterization of recombinant viruses in marek's disease (herpes) and retrovirus co-infections. in the first pcr the herpesvirus genomic fragment, that was recognized in previous studies as a hot spot site for retroviral integration was amplified [reviewed in bronovskis, p., kung, h.-j., 1996. retrotransposition and herpesvirus evolution. virus genes 11, 259-270]. the products served for a second amplific ...199910894628
in vivo events of retroviral long terminal repeat integration into marek's disease virus in commercial poultry: detection of chimeric molecules as a marker.the present study demonstrated, for the first time, that not only in vitro, but also in vivo, coinfections with marek's disease virus (mdv) and each of the three avian retroviruses (reticuloendotheliosis virus [rev], avian lymphoid leukosis virus [alv], and alv-j) lead to retroviral long terminal repeat (ltr) integration into mdv. a total of 306 chicken and 59 turkey commercial flocks, submitted for differential avian oncogenic virus diagnosis, served to evaluate the flock mixed virus infection ...200111332471
reticuloendotheliosis in hungarian partridge.a large commercial flock of hungarian partridge (perdix perdix) experienced elevated mortality associated with a wasting disease in may 1998. postmortem examination of females consistently revealed a distended crop and abnormal gray-white tissue infiltrating the wall of the crop and thoracic esophagus. neoplasia in male partridge was observed in the liver. microscopic examination of the crop and thoracic esophagus revealed transmural masses of immature lymphocytes with frequent mitotic figures. ...200212038145
differential regulation of the inhibitor of apoptosis ch-iap1 by v-rel and the proto-oncogene c-rel.the v-rel oncogene encoded by reticuloendotheliosis virus is the acutely transforming member of the rel/nf-kappab family of transcription factors. v-rel is a truncated and mutated form of c-rel and transforms cells by inducing the aberrant expression of genes regulated by rel/nf-kappab proteins. the expression of ch-iap1, a member of the inhibitor-of-apoptosis family, is highly elevated in cells expressing v-rel and contributes to the immortalization of cells transformed by this oncoprotein. in ...200212414938
isolation and characterization of chicken interleukin-17 cdna.interleukin-17 (il-17) is a proinflammatory cytokine produced by activated t cells. a 917-bp cdna encoding the il-17 gene was isolated from our est cdna library prepared from intestinal intraepithelial lymphocytes (iels) of eimeria-infected chickens. it contained a 507-bp open reading frame (orf) predicted to encode a protein of 169 amino acids (aa) with a molecular mass of 18.9 kda, a 27-residue nh(2)-terminal signal peptide, a single potential n-linked glycosylation site, and 6 cysteine residu ...200212513911
serological investigations of infectious bursal disease virus and reticuloendotheliosis virus infections in new zealand chickens. 198216030899
novel criteria for the diagnosis of marek's disease virus-induced lymphomas.several novel criteria have been tested to assist in the differential diagnosis of tumours induced by marek's disease virus (mdv) from those induced by avian leukosis virus (alv) and reticuloendotheliosis virus (rev). a collection of tumours induced by inoculation of specific strains of mdv, alv and rev, alone or in combination, were tested for quantification of mdv dna by real-time polymerase chain reaction, expression of the mdv oncogene meq, expression of several cell markers associated with ...200516147570
construction and characterization of a fowlpox virus field isolate whose genome lacks reticuloendotheliosis provirus nucleotide sequences.fowlpox virus (fwpv) has been isolated from vaccinated chicken flocks during subsequent fowlpox outbreaks that were characterized by a high degree of mortality and significant economic losses. this inability of current vaccines to induce adequate immunity in poultry could be reflective of an antigenic and/or biologic distinctiveness of fwpv field isolates. in this regard, whereas an infectious reticuloendotheliosis virus (rev) provirus is present in the majority of the field viruses' genomes, on ...200516252496
phylogenetic analyses indicate little variation among reticuloendotheliosis viruses infecting avian species, including the endangered attwater's prairie chicken.reticuloendotheliosis virus infection, which typically causes systemic lymphomas and high mortality in the endangered attwater's prairie chicken, has been described as a major obstacle in repopulation efforts of captive breeding facilities in texas. although antigenic relationships among reticuloendotheliosis virus (rev) strains have been previously determined, phylogenetic relationships have not been reported. the pol and env of rev proviral dna from prairie chickens (pc-r92 and pc-2404), from ...200616497405
sarcomas and myelocytomas induced by a retrovirus related to myeloblastosis-associated virus type 1 in white leghorn egg layer outbreak of subcutaneous sarcomas in commercial white leghorn egg layers was observed in the northeastern united states during late 2004. subcutaneous tumors were confined to three flocks distributed in two locations and belonging to the same company. the tumors were first observed grossly by farm personnel at approximately 7 wk of age and persisted throughout the economic life of the flocks. most of the tumors observed during the growing period were present on the facial region or around the ...200616863068
nonbursal lymphomas induced by nondefective reticuloendotheliosis previous studies we described bursal lymphomas similar to those of lymphoid leukosis in line 15x7 chickens inoculated with nondefective reticuloendotheliosis (re) virus. a different type of neoplastic disease syndrome induced by nondefective re virus is described in the present study. the tumours were characterised as lymphomas and most commonly involved the thymus, heart, liver, and spleen; the bursa invariably appeared normal or atrophied. mortality from nonbursal lymphomas occurred as earl ...198618766547
insect contribution to horizontal transmission of reticuloendotheliosis virus.the involvement of insects in reticuloendotheliosis virus (rev) transmission was examined by testing insects trapped at commercial farms and by controlled feeding experiments using mosquitoes, culex pipiens l. and house flies, musca domestica l. we established sensitive methods of rev detection, including reverse transcription-polymerase chain reaction (pcr) for rev-ltr and rev-gag genes, rev antigenemia measurements by enzyme-linked immunosorbent assay, and virus isolation in tissue cultures. a ...200515799521
a novel method to analyze viral antigen-specific cytolytic activity in the chicken utilizing flow order to overcome some of the main drawbacks that have emerged in the conventional assays for cytotoxic t-lymphocytes (ctls) in the chicken, a novel approach to analyze viral antigen-specific cytolytic activity utilizing flow cytometry was developed. in this method, the target cells were distinguished from the effector cells by pre-labelling them with a fluorescent dye pkh67. cell death was detected with propidium iodide which labels the dna of damaged cells. flow cytometric assay also enable ...200312969631
a duplex real-time polymerase chain reaction assay for the simultaneous detection of long terminal repeat regions and envelope protein gene sequences of reticuloendotheliosis virus in avian blood samples.the reticuloendotheliosis virus (rev) group of retroviruses infects a wide range of avian species, including chickens, turkeys, ducks, geese, quail, and prairie chickens. the objective of the present study was to develop a highly sensitive and specific diagnostic test for the detection of rev in whole blood samples. in order to increase the diagnostic sensitivity, a duplex real-time polymerase chain reaction (pcr) that detects both the envelope protein gene (env) and the long terminal repeat (lt ...201121908350
full genome sequence and some biological properties of reticuloendotheliosis virus strain apc-566 isolated from endangered attwater's prairie chickens.reticuloendotheliosis virus (rev) causes runting, high mortality, immunosuppression, and chronic neoplasia associated with t and/or b cell lymphomas in a variety of domestic and wild birds, including attwater's prairie chickens (apc) (tympanuchus cupido attwateri). the complete proviral sequence of a recent rev isolate from apc (rev apc-566) was determined. this virus was isolated from an apc maintained in captivity in a reproduction program intended to avoid its extinction. rev apc-566 was dete ...200717098316
serological and virological surveys of reticuloendotheliosis in chickens in taiwan.reticuloendotheliosis virus (rev) is widespread in the world. no related data has been reported in taiwan. to determine the rev infection status, antibody determination and virus isolation were performed on chickens in taiwan. the results revealed that serological flock prevalence for the rev antibody reached 92.8% (39/42) amongst breeders (> 16 weeks old). two different rev isolates were identified by reverse transcriptase-polymerase chain reaction, electron microscopic, immunofluorescent, and ...200617213700
enzootic reticuloendotheliosis in the endangered attwater's and greater prairie chickens.reticuloendotheliosis (re) in captive greater prairie chickens (gpc, tympanuchus cupido pinnatus) and attwater's prairie chickens (apc, tympanuchus cupido attwateri) was first reported in 1998. re is caused by avian reticuloendotheliosis virus (rev), an oncogenic and immunosuppressive retrovirus infecting multiple species of wild and domestic birds. during august 2004 through may 2006 a captive population of prairie chickens was affected simultaneously with a neoplastic condition and also avian ...200617274288
experimental infection of attwater's/greater prairie chicken hybrids with the reticuloendotheliosis virus.reticuloendotheliosis virus (rev), a common pathogen of poultry, has been associated with runting and neoplasia in an endangered subspecies of grouse, the attwater's prairie chicken. the pathogenesis of rev infection was examined in experimentally infected prairie chickens. three groups of four attwater's/greater prairie chicken hybrids were infected intravenously with varying doses (tissue culture infective dose [tcid50], 200, 1000, and 5000) of a prairie chicken-isolated rev. a fourth group of ...200617274303
pathogenicity and transmission of reticuloendotheliosis virus isolated from endangered prairie chickens.the pathogenicity and transmission of a field isolate of reticuloendotheliosis virus (rev) was studied using an experimental model in japanese quail. oncogenicity was also evaluated after inoculations in chickens and turkeys. the original rev (designated apc-566) was isolated from attwater's prairie chickens (tympanuchus cupido attwateri), an endangered wild avian species of the southern united states. the transmissibility of the rev isolate was studied in young naive japanese quail in contact w ...200717461264
detection and differentiation of re-emerging fowlpox virus (fwpv) strains carrying integrated reticuloendotheliosis virus (fwpv-rev) by real-time pcr.current strains of fowlpox virus (fwpv) carrying circulating reticuloendotheliosis virus (fwpv-rev) sequence are becoming more pathogenic to poultry. this is evidenced by the fact that vaccination with current available fwpv vaccines provides limited protection against them. to characterize rev insertions in a collection of both older and more recent field isolates, we developed three different types of adjacent oligoprobes and primer sets from specific genomic locations of fwpv and rev: rev-env ...200817913400
field isolates of fowlpox virus contaminated with reticuloendotheliosis virus.the polymerase chain reaction (pcr) method was used to examine samples from field cases of fowlpox for the presence of reticuloendotheliosis virus (rev). the s-strain fowlpox vaccine, known to be contaminated with rev, served as a positive control. fowlpox virus was grown from field samples and vaccines by inoculation of embryonated hen eggs by the chorioallantoic membrane (cam) route. dna was extracted from the cam lesions and examined for rev proviral sequences using primers specific for the l ...199818483965
[reticuloendotheliosis virus infection in ducks--an epidemiological studies].to study the epidemiological status of reticuloendotheliosis virus (rev) infection in ducks.200818590239
an enzyme-linked immunosorbent assay for detection of reticuloendotheliosis virus infection in enzyme-linked immunosorbent assay (elisa) for the detection of reticuloendotheliosis virus (rev) is described. the assay is based on antiserum produced in rabbits against the group-specific (gs) antigen of rev which has a molecular weight of 30 kda (p30). the p30 for immunisation was obtained by electro-elution from polyacrylamide gels after separation of purified rev by electrophoresis. western blotting indicated that the antiserum produced was specific for p30 of rev. the double antibody sa ...198718766649
isolation of a reticuloendotheliosis-like virus from naturally occurring lymphoreticular tumours of domestic goose.naturally occurring lymphoreticular tumours were found in an adult goose flock. diffuse and/or nodular lymphoma-like tumours occurred in the spleen, liver, pancreas, intestines and rarely in other internal organs. osteopetrosis-like lesions and signs of other diseases such as amidostomosis, enteritis, arthritis and air sacculitis were also observed. the tumourous lesions consisted of proliferations of undifferentiated lymphoblasts and slightly differentiated plasmablasts of the bursal system of ...198818766685
effects of reticuloendotheliosis virus on the response of chickens to infectious laryngotracheitis virus.effects of reticuloendotheliosis virus (rev) on the response to infectious laryngotracheitis virus (iltv) were investigated in young chickens with and without maternally derived antibody (mab) to rev. in the first experiment a group of 1-day-old chickens without rev mab were inoculated at 1 day of age with rev whilst another group of similar chickens were left uninoculated. all chickens were vaccinated with iltv at 7 days of age. there was a significantly higher proportion of infectious laryngot ...198218770210
Displaying items 1 - 100 of 110