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characteristics of two new reticuloendotheliosis virus isolates of turkeys.reticuloendotheliosis (re) virus strains mn81 and mn67 isolated from epiornithics of re in turkeys were partially characterized. strains mn81 and mn67 replicated in chicken embryo fibroblast,duck embryo fibroblast and turkey embryo-fibroblast cultures and produced syncytial cytopathic effects in duck embryo fibroblast and turkey embryo fibroblast cultures. the virions of mn81 and mn67 measured approximately 100 nm in diameter, resembled re virus strain t, and could be distinguished from avian le ...197715487
dna polymerase of reticuloendotheliosis virus: inability to detect endogenous rna-directed dna synthesis. 197548308
a comparative study of the avian reticuloendotheliosis virus: relationship to murine leukemia virus and viruses of the avian sarcoma-leukosis complex. 197548309
rna-directed dna polymerase activity of reticuloendotheliosis virus: characterization of the endogenous and exogenous reactions.reticuloendotheliosis virus (rev) contains an endogenously instructed, rna-directed dna polymerase activity. both the endogenous and exogenous dna polymerase activities exhibited up to 10-fold greater activity at the optimum concentration of manganous ion (0.025 mm for exogenous; 0.25 mm for endogenous) than at any concentration of magnesium ion. antiserum to the dna polymerase of an rev group virus (spleen necrosis virus) inhibited both endogenous and exogenous dna polymerase activity of rev, w ...197551935
characterization of endogenous rna-directed dna polymerase activity of reticuloendotheliosis viruses.reticuloendotheliosis viruses (rev) contain an endogenous rna-directed dna polymerase activity. the endogenous dna polymerase activity can be elicited in purified preparations of rev by treatment with nonionic detergents. the enzyme activity has a strong preference for manganous ions. therefore, appreciable endogenous dna polymerase activity can be demonstrated only if the reaction mixture contains appropriate concentrations of manganous ions. enzyme activity can be inhibited by pretreatment wit ...197551936
the reticuloendotheliosis viruses. 197553119
group-specific antigen shared by the members of the reticuloendotheliosis virus complex.the polypeptides of reticuloendotheliosis virus (rev) were separated by gel filtration in the presence of guanidine hydrochloride. the eight peaks obtained by gel filtration were then analyzed by polyacrylamide gel electrophoresis and four appeared to contain single polypeptides. the material identified as p29 was used to prepare antiserum. this protein constitutes the major internal non-glycosylated polypeptide in the virion. double immunodiffusion indicated that the antiserum was specific for ...197656462
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
an rna-dependent dna polymerase, different from the known viral reverse transcriptases, in the chicken system.the properties of an rna-dependent dna polymerase (an rna-dependent dna nucleotidyltransferase), which occurs ubiquitously in the allantoic fluid of uninfected, leukosis-virus-free eggs, are described. it is shown that the enzyme can synthesize faithful transcripts from natural rna (globin mrna). by biochemical and immunological methods, the enzyme can be clearly distinguished from the reverse transcriptases of the known chicken rna tumor viruses and therefore seems to be a member of a so far un ...197661587
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
a new, not virus related reverse transcriptase in the chicken system. 197664385
the reverse transcriptase. 197766065
characterization of a new reverse transcriptase of possibly cellular origin in the chicken system.the properties of an rna-dependent dna polymerase, which occurs ubiquitously in the allantoic fluid of uninfected, leukosis-virus-free eggs, are described. it is shown that the enzyme can synthesize faithful transcripts from natural rna (globin mrna). with biochemical and immunological methods, the enzyme can be clearly distinguished from the reverse transcriptases of the known chicken rna tumour viruses and therefore seems to be a member of a so far unknown class of chicken polymerases. our dat ...197766920
a very sensitive biochemical assay for detecting and quantitating avian oncornaviruses. 197769360
immunological characterization of the rna-dependent dna polymerase from reticuloendotheliosis virus. 197774790
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
rna-directed dna polymerase from particles released by normal goose cells.cells from a goose embryo were shown to release particle-associated rna-directed dna polymerase and rnase h activities that required the presence of nonidet p-40 for detection. the particles were not infectious and did not have endogenous dna synthesis. the goose particle dna polymerase was related to the dna polymerase of spleen necrosis virus with respect to size and was inhibited by immunoglobulin g to spleen necrosis virus dna polymerase. however, goose cells producing dna polymerase-contain ...197987517
reticuloendotheliosis virus: detection of immunological relationship to mammalian type c retroviruses.reticuloendotheliosis virus (rev) p30 shares cross-reactive determinants and a common nh2-terminal tripeptide with mammalian type c viral p30's. an interspecies competition radioimmunoassay was developed, using iodinated rev p30 and a broadly reactive antiserum to mammalian virus p30's. the avian leukosis-sarcoma viruses and mammalian non-type c retroviruses did not compete in this assay. previous data indicating that the rev group is not represented completely in normal avian cell dna lead us t ...197987519
comparison of the small rnas of polymerase-deficient and polymerase-positive rous sarcoma virus and another species of avian retrovirus.the small rnas contained in virions of avian leukosis and sarcoma viruses are a virus-specific subset of the total small rna population of the host cell. the reverse transcriptase protein must be present in the budding virion for this selection to take place. virions of the alpha form of the bryan strain of rous sarcoma virus, which lack detectable reverse transcriptase, incorporated an unselected population of small rnas identical to total chicken cell small rna. virions of reticuloendotheliosi ...197987521
avian reticuloendotheliosis viruses: evolutionary linkage with mammalian type c retroviruses.reticuloendotheliosis viruses have been shown to be causative of tumors in a variety of avian species. the major structural protein of these non-genetically transmitted viruses is demonstrated to possess antigenic determinants common to those of all known mammalian type c viruses. these findings establish a mammalian origin for this oncogenic avian retrovirus group. none of the known mammalian type c virus groups demonstrated a closer immunological relationship to avian reticuloendotheliosis vir ...197989204
biochemical characterization of the type c retrovirus associated with lymphoproliferative disease of turkeys.turkeys inoculated with spleen extracts from lymphoproliferative disease (lpd)-affected birds developed viremia, followed by typical lpd lesions. electron microscopy and biochemical characterization established that the virus present in the blood of infected turkeys is a type c retrovirus. the viral particles possess a buoyant density of 1.17 g/ml in sucrose gradients; they contain high-molecular-weight rna and an rna-instructed dna polymerase with efficient exogenous and endogenous activity. th ...197990160
pheasant virus dna polymerase is related to avian leukosis virus dna polymerase at the active site.the dna polymerase from amherst pheasant virus (apv), a member of the pheasant virus species of retroviruses, was compared to the dna polymerases of avian leukosis viruses (alv) and a reticuloendotheliosis virus (spleen necrosis virus (snv)). immunoglobulin inhibition tests and competition immunoassays showed that apv and alv dna polymerases are closely related at their active sites. the determinants common to their active sites are not shared by snv dna polymerase. bu using a species-specific r ...197994361
studies on the replication of reticuloendotheliosis virus: detection of viral-specific dna sequences in infected chick cells. 1975165622
isolation and characterization of viruses from natural outbreaks of reticuloendotheliosis in turkeys.we have described the in vitro isolation of type-c rna viruses from two outbreaks of a fatal neoplastic disease in turkeys we diagnosed as reticuloendotheliosis. the virus had a density of 1.16 g/ml in sucrose gradients, had a dna polymerase capable of using both endogenous and exogenous (synthetic) templates, and was infectious in vitro for turkey and chick cells. the culture-propagated virus was oncogenic for turkeys. the virus isolates were unrelated to avian leukosis virus and antigenically ...1975166189
in vitro studies on allotype suppression. iii. compounds of antiallyotype serum active in release from allotype suppression.spleen cells of b4b6 rabbits, shown to be deficient in their ability to produce b4ig due to prenatal exposure to anti-b4, formed anti-t2 antibodies marked with the b4 determinant in response to solubilized t2 phage (s-t2) only when cultured in the presence of antibodies specific for the nonsuppressed type (b6), thus confirming and extending the previously reported observation of release from b4 suppression in cultured cells of b4-suppressed b4b5 rabbits treated with anti-b5 serum. only antiallo ...1975167094
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
infectious dna from cells infected with rous sarcoma virus, reticuloendotheliosis virus or rous-associated virus-o.we have described an efficient and quantitative assay for infectious dna of the avian ribodeoxyviruses and have applied this method to study the possible existence of infectious viral dnas in uninfected cells. infectious dna from cells infected with rsv or rev consisted of a single unit of dna with a specific infectivity of 10(-5)-10(-6). the minimum molecular weight of rsv dna required for infection of chicken cells was about 6 million, while the minimum molecular weight of infectious rev dna w ...1975169004
polypeptide and rna composition of the reticuloendotheliosis viruses.the rna and polypeptide composition of chick syncytial virus (csv) and duck infectious anemia virus (diav) was investigated and compared to that of reticuloendotheliosis virus (rev) strain t, the prototype of the newly recognized rev group of viruses. csv and diav contain genomic rna species which cosediment with those of rev in sucrose gradients. five or six polypeptides, two of which are glycoproteins, were consistently found in csv and diav preparations. the major nonglycosylated polypeptides ...1975172472
naturally occurring reticuloendotheliosis in turkeys: transmission.this report describes the natural occurrence and experimental transmission of reticuloendotheliosis in a turkey flock. in the naturally affected turkeys, lesions were present in the liver, spleen, heart, intestines, and peripheral nerves, and were composed mainly of lymphoreticular cells. the disease was experimentally reproduced in turkey poults with cellfree tissue extracts of infected birds. a type-c rna virus similar to reticuloendotheliosis virus (strain t) was present in the tissues of tur ...1976176388
genomic complexities of murine leukemia and sarcoma, reticuloendotheliosis, and visna viruses.the genetic complexities of several ribodeoxyviruses were measured by quantitative analysis of unique rnase t1-resistant oligonucleotides from 60-70s viral rnas. moloney murine leukemia virus was found to have an rna complexity of 3.5 x 10(6) daltons, whereas moloney murine sarcoma virus had a significantly smaller genome size of 2.3 x 10(6). reticuleondotheliosis and visna virus rnas had complexities of 3.9 x 10(6), respectively. analysis of rnase a-resistant oligonucleotides of rous sarcoma vi ...1976176429
a lymphoproliferative disease in japanese quail.a naturally occurring lymphoproliferative disease was found in 3 flocks of japanese quail in mexico. the tumorlike lesions were detected mainly in livers and spleens. histopathology revealed a pleomorphic lymphoproliferative infiltration with dark-staining large cells, lymphocytes of different sizes, and reticulumlike cells. marek's disease (md) herpesvirus was not isolated from 74 quail tested, nor were antibodies to md detected in 84 sera. antibodies to reticuloendotheliosis (3/24) and avain l ...1976176987
reticuloendotheliosis group virus pathogenic to chicken isolated from material infected with turkey herpesvirus (hvt). 1976180962
rna polymerase activity in purified virions of avian reticuloendotheliosis viruses.an rna polymerase activity that synthesizes a u-rich rna hydrogen bonded to a large viral rna molecule was found in the cores of virions of avian reticuloendotheliosis viruses (rev). the rna polymerase activity was separable from the dna polymerase activity of rev virions. the 5'-terminus of the newly synthesized rna was a. in addition, a trna nucleotidyl transferase activity, which added -cpcpa ends to trna, appears to be present in the rev virions.1976183017
a study of plaque formation with avian rna tumor viruses. 1976183351
studies on the etiology of lymphomas in turkeys: isolation of reticuloendotheliosis in virus.studies of tissues from 25 normal turkey flocks and of 15 selected turkey lymphoid tumors revealed no marek's disease or lymphoid leukosis viruses, although reticuloendotheliosis viruses (rev) were isolated from 3 flocks (2 with a history of neoplastic disease). the rev isolates were culturally and antigenically similar to the prototype rev strain t but were of low pathogenicity. attempts failed to transmit 6 lymphoid tumors of diverse origin by inoculation into 2 strains of recipient turkeys. t ...1976186011
inoculation experiment of marek's disease vaccine contaminated with a reticuloendotheliosis virus.two-day-old chicks were inoculated with one or ten doses of marek's disease (md) vaccine originated from the herpesvirus of turkeys (hvt) and contaminated with a reticuloendotheliosis virus (rev). as a result, they presented such symptoms as abnormality in the vane of remiges, undergrowth, anemia, and leg paralysis. these symptoms were the same as those induced by the same vaccine among chicks in the field. control chicks which had been placed in the same house as those inoculated with the vacci ...1976189219
isolation of a reticuloendotheliosis virus from chickens inoculated with marek's disease vaccine.over a period from spring to fall in 1974, a disease with delayed growth, anemia, abnormal feathers, and leg paralysis as main symptoms broke out in flocks of chickens inoculated with marek's disease vaccine. a virus was isolated from affected birds in the field and the same lot of marek's disease vaccine as inoculated into these birds. it had a common antigenicity to the t strain of reticuloendotheliosis virus (rev) and could not be discriminated from this strain on the basis of morphology or p ...1976189220
infectious dna of spleen necrosis virus is integrated at a single site in the dna of chronically infected chicken fibroblasts.the infectious dnas of a number of avian leukosis-sarcoma and reticuloendotheliosis viruses were digested with six nucleotide-specific restriction endonucleases, and the digests were tested for infectivity. all of the enzymes inactivated the viral infectivities except for ecori, which did not inactivate the infectivity of the dna of two of the reticuloendotheliosis viruses, spleen necrosis and chick syncytial viruses. the infectious dna of spleen necrosis virus after digestion with ecori had a b ...1977189309
pathogenesis of abnormal feathers in chickens inoculated with reticuloendotheliosis virus.abnormal feathers, characterized by thinness and increased transparency of the calamus and rachis, and loss of barbs, were induced at a high frequency by inoculating day-old chicks with reticuloendotheliosis virus (rev) propagated in chicken-embryo fibroblast (cef) cultures. the few birds that survived inoculation with oncogenic stock of rev derived from liver tissue of an infected chick developed similar abnormalities. lesions of an inflammatory-degenerative type were observed in close associat ...1977190996
pseudotypes of vesicular stomatitis virus with the mixed coat of reticuloendotheliosis virus and vesicular stomatitis virus.vesicular stomatitis virus (vsv) forms pseudotypes with envelope components of reticuloendotheliosis virus (rev). the vsv pseudotype possesses the limited host range and antigenic properties of rev. approximately 70% of the vsv, indiana serotype, and 45% of vsv, new jersey serotype, produced from the rev strain t-transformed chicken bone marrow cells contain mixed envelope components of both vsv and rev. vsv pseudotypes with mixed envelope antigens can be neutralized with excess amounts of eithe ...1977191647
experimental transmission of reticuloendotheliosis in turkeys with the cell-culture-propagated reticuloendotheliosis viruses of turkey origin. 1977194046
formation of reticuloendotheliosis virus pseudotypes of rous sarcoma virus.superinfection of chicken embryo fibroblasts transformed by the defective bryan strain of rous sarcoma virus (bh-rsv) with two different reticuloendotheliosis viruses (revs), rev strain t (rev-t) or spleen necrosis virus (snv), resulted in the production of infectious sarcoma virus pseudotypes. these pseudotypes were neutralized by antiserum prepared against snv and were unable to infect chicken cells preinfected with either rev-t or snv. these results suggest that defective bh-rsv is able to us ...1977195082
phenotypic mixing between reticuloendotheliosis virus and avian sarcoma viruses. 1977195392
contact-mediated suppression of mitogen-induced responsiveness by spleen cells in reticuloendotheliosis virus-induced tumorigenesis. 1977199358
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
transformation of chick embryo fibroblasts by reticuloendotheliosis virus. 1977201089
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
high-molecular-weight rnas of akr, nzb, and wild mouse viruses and avian reticuloendotheliosis virus all have similar dimer structures.several 50 to 70s tumor viral rnas have previously been shown by electron microscopy to be dimers, with the two monomer subunits joined near their 5' ends. five additional naturally occurring type c rna tumor viruses have now been examined: akr, and endogenous murine ecotropic virus; nzb, an endogenous murine xenotropic virus; and ecotropic and an amphotropic virus isolated from a wild mouse; and the avian reticuloendotheliosis virus (rev). all five 50 to 70s rnas have similar 5'-to-5' dimer str ...1978205678
amino-terminal amino acid sequence of the major structural polypeptides of avian retroviruses: sequence homology between reticuloendotheliosis virus p30 and p30s of mammalian retroviruses.the major structural polypeptides, p30 of reticuloendotheliosis virus (rev) (strain t) and p27 of avian sarcoma virus b77, have been compared with regard to amino acid composition. nh2-terminal amino acid sequence, and immunological crossreactions. the amino acid composition of the two polypeptides is distinct, and a comparison of the first 30 nh2-terminal amino acids of rev p30 with that for the first 25 of b77 p27 yields only three homologous residues. in competition radioimmunoassays the poly ...1978208072
sites of integration of reticuloendotheliosis virus dna in chicken dna.the pattern of integration of spleen necrosis virus (snv) dna in dna from a large population of snv-infected chicken cells was studied by nucleic acid hybridization with iodinated viral rna by the blotting technique of southern. snv dna was found to be integrated at multiple sites in acutely infected chicken cells. concomitant with the transition from acute to chronic infection, a shift in the pattern of integration was observed. the majority of integrated snv dna found in acutely infected cells ...1978210459
characterization of the interaction of reticuloendotheliosis virus with the avian lymphoid system. 1978212207
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
transformation by reticuloendotheliosis virus: development of a focus assay and isolation of a nontransforming virus. 1979219596
morphologic characterization of proliferative cells and virus particles in turkeys with lymphoproliferative disease.the tumors found in turkeys having lymphoproliferative disease (lpd) are histologically characterized by a pleomorphic population of cells of the lymphoid series. electron microscopy has shown that, despite marked differences in shape and size, the proliferating cells share basic ultrastructural features, indicating their lymphoid origin. virus particles morphologically and morphogenetically characteristic of type c oncorna-viruses of retraviridae were found in different organs and plasma sample ...1979220455
lymphomas resembling lymphoid leukosis in chickens inoculated with reticuloendotheliosis virus.chickens inoculated as embyros or at hatching with the chick syncytial strain of reticuloendotheliosis virus developed a high incidence of lymphoid neoplasms between the 17th and 43rd weeks of age, involving principally the liver and bursa of fabricius. on the basis of organ distribution, latent period, pathology and surface igm production, the lymphomas closely resembled those of lymphoid leukosis. one inoculated chicken developed a myxosarcoma. no tumors were observed in uninoculated controls. ...1979222694
infection studies on a reticuloendotheliosis virus contaminant of a commercial marek's disease vaccine.reticuloendotheliosis virus (rev) was isolated in cell cultures from commercial marek's disease (herpesvirus of turkeys) vaccine and re-isolated from the organs of vaccinated chickens. runting and feathering abnormalities were produced when 1-day-old specific pathogen free chickens were inoculated with rev. histopathological lesions in infected chickens were hypoplasia of the thymus, bursa and spleen, and inflammation of the proventriculus, kidneys and liver. serological responses to rev were de ...1979223539
immunosuppression induced by avian reticuloendotheliosis virus: mechanism of induction of the suppressor cell. 1979224111
cell killing by spleen necrosis virus is correlated with a transient accumulation of spleen necrosis virus dna.spleen necrosis virus productively infects avian and rat cells. the average number of molecules of unintegrated and integrated viral dna in cells at different times after infection was determined by hybridization and transfection assays. shortly after infection, there was a transient accumulation of an average of about 150 to 200 molecules of unintegrated linear spleen necrosis virus dna per chicken, turkey, or pheasant cell. no such accumulation was seen in infected rat cells. soon after infect ...1979225560
isolation and development of a reticuloendotheliosis virus-transformed lymphoblastoid cell line from chicken spleen cells.the establishment and characterization of a reticuloendotheliosis virus (strain t)-transformed lymphoblastoid cell line, designated tv-1, was reported. these cells, isolated from the spleen of a moribund chick infected with reticuloendotheliosis virus, were maintained in suspension culture for over 74 weeks at a stable generation time of 15 h. the cells were found to carry a female karyotype. both tv-1 cells and cell-free tv-1 culture supernatant produced lesions and mortality patterns in chicks ...1979226481
molecular evidence for a type c retrovirus etiology of the lymphoproliferative disease of turkeys.recently, we isolated from the blood of lymphoproliferative disease (lpd)-affected turkeys a type c retrovirus distinct from the avian leukosis-sarcoma virus complex and the reticuloendotheliosis virus group. we present molecular evidence for the implication of this virus in the lpd of turkeys. using complementary dna of lpd viral rna, we found that the lpd viral genome is specifically and efficiently transcribed (2,500 copies per cell) in lpd tumor cells. moreover, the lpd tumor cells contained ...1979229245
transmission of an australian strain of reticuloendotheliosis virus to adult japanese quail. 1979231962
the effect of avian retroviruses on limb bud chondrogenesis in vitro.mesenchymal cells isolated from stage 24 embryonic chicken limb buds were infected with the temperature-sensitive transformation mutants of rous sarcoma virus tsny68, tsny10 and tsla25 at the nonpermissive temperature for transformation (41 degrees c). virus infection greatly inhibited subsequent limb bud chondrogenesis under nontransforming conditions, as indicated by a reduction in the rate of 35so4 incorporation into cell-associated proteoglycans. the inhibition of chondrogenesis was directly ...1979519754
depression of mitogen response in spleen cells from reticuloendotheliosis virus-infected chickens and their suppressive effect on normal lymphocyte response.spleen cells and peripheral blood lymphocytes from chickens infected with reticuloendotheliosis virus (rev) were depressed in their responsiveness to phytohemagglutinin (pha). when spleen cells from uninfected chickens were co-cultured with spleen cells from chickens infected with rev at 2 weeks of age, the pha response by the normal cells was completely suppressed. although spleen cells from chickens infected with rev at 6 or 9 weeks of age were also suppressed in their ability to respond to ph ...1978641350
polypeptide composition of spleen necrosis virus, a reticuloendotheliosis virus.the polypeptide composition of virions of spleen necrosis virus, a reticuloendotheliosis virus, was determined using electrophoresis on sodium dodecyl sulfate-containing, 10 percent polyacrylamide gels. ten polypeptides were resolved. four of these were present in minor and somewhat variable amounts. two proteins, gp71 and gp22, contained d-glucosamine and were located on the outer surface of the lipid envelope, as demonstrated by lactoperoxidase-catalyzed iodination and by bromelain digestion. ...19751142473
characterization of reticuloendotheliosis virus-transformed avian t-lymphoblastoid cell lines infected with marek's disease virus.the expression of marek's disease virus (mdv) transcripts and protein products was investigated in reticuloendotheliosis virus-transformed avian t-lymphoblastoid cell line recc-cu91, which was superinfected with mdv. the presence of mdv in the superinfected cell line, renamed recc-cu210, was demonstrated by southern hybridization with 32p-labeled bamhi-h and -b fragments of the bamhi mdv dna library. examination of recc-cu210 for the expression of mdv-specific rna transcripts encoded by the inte ...19921279200
a spleen necrosis virus-based retroviral vector which expresses two genes from a dicistronic mrna.we have investigated a novel strategy for coexpressing two genes from a retroviral vector. the 5' nontranslated leader region of at least some picornavirus rnas contains a sequence that can act as an internal ribosome entry site allowing initiation of translation at a downstream aug codon in a 5' cap-independent manner. to investigate whether such a sequence can function in the context of a retroviral vector, we constructed a spleen necrosis virus-based vector carrying two selectable marker gene ...19921310190
retrovirus insertion into herpesvirus in vitro and in vivo.retroviruses and herpesviruses are naturally occurring pathogens of humans and animals. coinfection of the same host with both these viruses is common. we report here that a retrovirus can integrate directly into a herpesvirus genome. specifically, we demonstrate insertion of a nonacute retrovirus, reticuloendotheliosis virus (rev), into a herpesvirus, marek disease virus (mdv). both viruses are capable of inducing t lymphomas in chickens and often coexist in the same animal. rev dna integration ...19921310544
reticuloendotheliosis in a wild turkey (meleagris gallopavo) from coastal georgia.an emaciated wild turkey (meleagris gallopavo) exhibiting neurologic signs was found on ossabaw island, chatham county, georgia (usa) on 11 april 1989. the neurologic abnormalities observed included ataxia, drooping wings, head tremors, torticollis, and circling. at necropsy, discrete yellowish-white nodules, varying in size from 2 to 5 mm, were present in the spleen. white nodular lesions approximately 2 mm in diameter were observed beneath the mucosal surface of the distal esophagus. histopath ...19921312647
reticuloendotheliosis and 'pullet disease' in israel. 19921313616
spleen necrosis virus, an avian immunosuppressive retrovirus, shares a receptor with the type d simian retroviruses.the reticuloendotheliosis viruses (rev) are a family of highly related retroviruses isolated from gallinaceous birds. on the basis of sequence comparison and overall genome organization, these viruses are more similar to the mammalian type c retroviruses than to the avian sarcoma/leukemia viruses. the envelope of a member of the rev family, spleen necrosis virus (snv), is about 50% identical in amino acid sequence to the envelope of the type d simian retroviruses. although snv does not productiv ...19921313915
reticuloendotheliosis type c and primate type d oncoretroviruses are members of the same receptor interference group.the reticuloendotheliosis viruses (revs), originally isolated from avian species, constitute a group of retroviruses which are more closely related to mammalian retroviruses than to other avian retroviruses. the envelope glycoproteins of members of the rev group display a striking amino acid sequence identity with a group of primate oncoretroviruses which belong to a single receptor interference group and include all of the type d and some type c primate oncoretroviruses. members of the rev grou ...19921316460
alterations within pp59v-rel-containing protein complexes following the stimulation of rev-t-transformed lymphoid cells with zinc.pp59v-rel exists in association with specific cellular proteins within lymphoid cells transformed by reticuloendotheliosis virus (rev-t). these include the cellular rel homolog (p75c-rel) as well as a 40-kda avian homolog to i kappa b. the brief exposure of rev-t-transformed lymphoid cells to micromolar concentrations of znso4 induces profound alterations within these protein complexes. most of the constituents of the rel protein complexes (to include pp59v-rel, p75c-rel, and p115) translocate f ...19921316681
stable transfection of reticuloendotheliosis virus-transformed lymphoblastoid cell lines.lymphoblastoid t cell lines were established by infection of chicken splenocytes with reticuloendotheliosis virus (rev). the target cells first were cultured in interleukin-containing conditioned medium or were stimulated by concanavalin a, or both. most cell lines were t cells expressing cd3 and one of the t cell receptors, and all cell lines were positive for major histocompatibility complex (mhc) class ii antigens. several rev-transformed cell lines were stably transfected using electroporati ...19921320872
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
the v-rel oncogene: insights into the mechanism of transcriptional activation, repression, and transformation.the v-rel oncogene product from the avian reticuloendotheliosis virus strain t corresponds to a member of the rel-related family of enhancer-binding proteins that includes both the mammalian 50- and 65-kda subunits of the nf-kappa b transcription factor complex. however, in contrast to nf-kappa b, v-rel has been shown to function as a dominant-negative repressor of kappa b-dependent transcription in many mature cell types. we now demonstrate that a highly conserved motif within the rel homology ...19921321284
the rel family: models for transcriptional regulation and oncogenic transformation. 19921327144
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
analytical study of avian reticuloendotheliosis virus dimeric rna generated in vivo and in vitro.the retroviral genome consists of two identical rna molecules associated at their 5' ends by a stable structure called the dimer linkage structure. the dimer linkage structure, while maintaining the dimer state of the retroviral genome, might also be involved in packaging and reverse transcription, as well as recombination during proviral dna synthesis. to study the dimer structure of the retroviral genome and the mechanism of dimerization, we analyzed features of the dimeric genome of reticuloe ...19921331519
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
cell-mediated cytolysis of lymphoblastoid cells expressing marek's disease virus-specific phosphorylated polypeptides.cell-mediated immune responses against marek's disease virus (mdv)-antigens were examined using reticuloendotheliosis virus (rev)-transformed lymphoblastoid cell line cu91 and three cell lines derived from cu91. cu210 was established by establishing a latent mdv infection in cu91. transfection of cu210 with pnl1, a selectable plasmid or with pnl1 and the cloned bamhi a fragment of mdv dna resulted in the establishment of cu212 and cu211, respectively. cu211 expressed a mdv-specific phosphorylate ...19921336254
characterization and comparison of avian and murine helper cell lines for production of replication-defective retroviruses for avian transformation.several approaches were taken to identify improved helper cell lines for the production of replication-defective avian retroviral vectors for avian transformation. both qt6 and d17 cells were engineered to become helper cell lines for the production of reticuloendotheliosis virus vectors. the results showed that the majority of lines from the d17, qt6, and d17c3 cells produced titers in the 10(2) to 10(3) cfu/ml range, with one qt6 line producing 10(5) cfu/ml. this high producer line was relativ ...19911652135
gene expression from heterologous promoters in a replication-defective avian retrovirus vector in quail cells.avian retrovirus vectors, with potential for use in avian transformation, were constructed to evaluate the relative efficiency of promoters placed internal to the viral long terminal repeats (ltr). the vectors are replication-defective reticuloendotheliosis plasmids that contain the neomycin phosphotransferase gene under control of the 5' ltr and an internal promoter that directs expression of the chloramphenicol acetyltransferase gene. the internal promoters were the sv40 early, the mouse metal ...19911652136
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
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
reticuloendotheliosis virus rev-t(rev-a)-induced neoplasia: development of tumors within the t-lymphoid and myeloid lineages.infection of 1-day-old chicks with reticuloendotheliosis virus strain t induces a neoplastic disease that kills the chicks 7 to 14 days postinfection. in association with reticuloendotheliosis-associated virus (rev-a), reticuloendotheliosis virus t (rev-t) induces tumors that are predominantly immunoglobulin m (igm) negative. we examined a variety of rev-t(rev-a)-induced tumors and tumor-derived cell lines and concluded that the principal igm-negative tumors that develop in rev-t(rev-a)-infected ...19901700831
characterization of large deletions occurring during a single round of retrovirus vector replication: novel deletion mechanism involving errors in strand transfer.retroviruses mutate at a high rate during replication. we used a spleen necrosis virus-based vector system and helper cell line to characterize mutations occurring during a single round of retrovirus replication. the vector used, jd216hyneo, codes for two drug resistance genes, hygromycin resistance (hygro) and neomycin resistance (neo). the downstream neo gene is expressed only when a mutation alleviates a block to splicing which is located in the upstream hygro gene. the mutations allowing spl ...19911714517
interaction of the v-rel protein with an nf-kappa b dna binding site.the avian reticuloendotheliosis virus t contains within its genome the oncogene rel. the expression of this gene is responsible for the induction of lymphoid tumors in birds. recently, the rel gene was shown to be related to the p50 dna binding subunit of the transcription factor complex nf-kappa b. binding sites for the nf-kappa b complex are found in the enhancer regions of a number of genes, including the immunoglobulin kappa gene and the human immunodeficiency virus long terminal repeat. in ...19911848011
a member of the set of kappa b binding proteins, hiven86a, is a product of the human c-rel proto-oncogene.hiven86a is an inducible member of a set of cellular proteins that specifically bind to the kappa b enhancer (franza et al., 1987; franza, 1988; franza, 1990; ballard et al., 1989; bohnlein et al., 1988). this enhancer motif has been detected in numerous cellular and viral transcription control domains (boshart et al., 1985; sen & baltimore, 1986; nabel & baltimore, 1987). recently, cdnas have been cloned (kieran et al., 1990; baldwin & sharp, 1987) that encode the 50 kd dna binding subunit of m ...19912030915
avian reticuloendotheliosis virus-transformed lymphoid cells contain multiple pp59v-rel complexes.the v-rel oncogene of avian reticuloendotheliosis virus type t (rev-t) encodes a 59-kilodalton (kda) phosphoprotein located principally in the cytosol of transformed lymphoid cells. all of the detectable pp59v-rel was present in high-molecular-weight complexes containing at least five cellular proteins (p124, p115, p75c-rel, p70hsc, and pp40). antiserum was developed against the 40-kda protein, the most abundant cellular protein associated with the complex. the 40-kda phosphoprotein was complexe ...19902153225
the v-rel oncogene product is complexed with cellular proteins including its proto-oncogene product and heat shock protein 70.the oncogene product, pp59v-rel, of avian reticuloendotheliosis virus (rev-t) is complexed in the cytosol of rev-t transformed lymphoid cells with cellular proteins. monoclonal antibodies and antisera directed against different regions of pp59v-rel coimmunoprecipitate five cellular proteins (p124, p115, p75, p70, and p40) in addition to pp59v-rel. cellular proteins with the same apparent molecular mass also copurify with pp59v-rel during sequential sephacryl s200 and immunoaffinity chromatograph ...19902155506
reduced duck hepatitis b virus viraemia in ducklings coinfected with the immunodepressive reticuloendotheliosis virus.coinfection of avian hosts by duck hepatitis b virus (dhbv) and reticuloendotheliosis virus (rev) was studied to assess the effect of immunodepression by rev on the replication of dhbv. one-day-old ducklings, domestic chickens, and turkey poults were inoculated either with dhbv or dhbv and rev and were bled and weighed at regular intervals. dhbv infection as manifested by viraemia and dhbv dna in liver was established only in ducklings. all chickens and turkeys were negative for dhbv dna in seru ...19902160513
the n-terminal env-derived amino acids of v-rel are required for full transforming activity.expression of the v-rel oncogene of the reticuloendotheliosis virus, strain t (rev-t), can mediate the transformation of chicken spleen and bone marrow cells. although the majority of the coding sequence of the v-rel oncogene is derived from the cellular rel sequence, the n- and c-terminal amino acids are coded for by remnants of the rev env gene. the resulting v-rel protein can be described as an env-rel-(out of frame env) fusion protein. terminal deletion mutants were constructed to determine ...19902162102
mutational analysis of v-rel, the oncogene of reticuloendotheliosis virus strain t.reticuloendotheliosis virus strain t (rev-t) is a highly oncogenic retrovirus that induces a lethal lymphoma in young galliform birds and also transforms and immortalizes avian lymphoid cells in vitro. rev-t presumably arose when a reticuloendotheliosis virus (rev) incorporated a portion of the turkey c-rel gene into its genome, forming the v-rel oncogene. the predicted v-rel protein (p59v-rel) has 14 amino acid substitutions and 3 amino acid deletions relative to the predicted turkey c-rel prot ...19902189101
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
growth-inhibitory effects of vitamin e succinate on retrovirus-transformed tumor cells in vitro.vitamin e succinate inhibited proliferation of c4#1 cells, an established avian retrovirus [reticuloendotheliosis virus (rev)]-transformed immature lymphoid tumor cell line, in a dose-dependent manner. the cytostatic effects of vitamin e succinate were reversible in that treated cells regained their ability to divide after vitamin e succinate removal. possible mechanism(s) for the antiproliferative actions of vitamin e succinate were investigated. analyses of c4#1 cell surface membrane antigen p ...19902367234
monoclonal antibodies against avian reticuloendotheliosis virus: identification of strain-specific and strain-common epitopes.we report the generation and partial characterization of a panel of 11 monoclonal antibodies (mca) made against the nondefective strain t reticuloendotheliosis virus (rev). in an enzyme-linked immunosorbent assay (elisa), nine mca cross-reacted with both homologous strain t and heterologous strain chick syncytial virus (cs), whereas two mca were strain specific and reacted with strain t but not with cs. competitive antibody inhibitory elisa tests demonstrated that the nine mca recognized at leas ...19862422277
sequence relationships of type d retroviruses which cause simian acquired immunodeficiency syndrome.simian acquired immunodeficiency syndrome (saids) in macaque monkeys is caused by type d retroviruses; three independent virus isolates are identified as srv-1 (saids retrovirus-serotype 1), srv-2, and mpmv (mason-pfizer monkey virus). virions from these three isolates have serologically related core antigens, but distinct surface proteins. also, srv-2 is unique since it apparently induces retroperitoneal fibromatosis in addition to saids. the complete dna sequence of molecularly cloned srv-2 is ...19872435057
detection of c-rel-related transcripts in mouse hematopoietic tissues, fractionated lymphocyte populations, and cell lines.a portion of the human cellular homolog of v-rel, the transforming gene of the leukemogenic retrovirus reticuloendotheliosis virus, strain t, was used to survey rnas from several mouse tissues, selected lymphocyte populations, and hematopoietic cell lines for c-rel expression. relatively high levels of a high-molecular-weight transcript were observed in peripheral b and t cells, whereas lower levels were detectable in functionally immature thymocytes. these results suggested that, unlike c-myb a ...19872436042
generation of competent virus in the rev helper cell line c3.we have studied the generation of replication-competent virus in cultures of the helper cell line c3, which harbors a packaging-defective provirus derived from reticuloendotheliosis virus. we transfected the c3 line with a defective provirus encoding the chicken growth hormone gene and carrying the hsv-1 tk gene. the appearance of competent virus was assayed by infection of spafas c/e cef, monitoring reverse transcriptase activity, and rescue of the tktu assayed on brltk- cells. our results indi ...19872441523
transcription from a spleen necrosis virus 5' long terminal repeat is suppressed in mouse cells.to determine the block(s) to spleen necrosis virus (snv) replication in mouse cells, we studied the expression of a dominant selectable marker, neo, or a gene whose product is easily assayed, the chloramphenicol acetyltransferase (cat) gene, in snv-derived and murine leukemia virus-derived vectors. using transient (cat) and stable (neor phenotype) transfection assays, we showed that the snv promoter was used in mouse cells only when the 3' snv long terminal repeat (ltr) was absent. infection of ...19872444716
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