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reverse transcriptase activity in vaccines derived from chick cells. 19968978928
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
detection of antibodies to avian leukosis/sarcoma viruses and reticuloendotheliosis viruses in humans by western blot assay.serologic evidence of antibodies in humans to avian leukosis/sarcoma viruses (alsv) and reticuloendotheliosis viruses (rev) has in general been negative. because of the difficulty in infecting mammalian cells in vitro with these viruses, it is generally held that they do not infect humans. we first provided presumptive evidence of serologic response to these viruses in human sera of workers in poultry slaughtering plants, using an elisa. we now provide confirmatory evidence using western blot as ...19958925516
rrr-alpha-tocopheryl succinate induces apoptosis in avian retrovirus-transformed lymphoid cells.the rrr-alpha-tocopheryl succinate form of vitamin e [vitamin e succinate (ves)] inhibits the proliferation of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells in a dose-dependent manner, blocks the cells in the g2/m cell cycle phase, and induces the cells to undergo apoptosis. apoptosis was documented by demonstrating changes that are characteristic of this type of cell death, including morphological analyses of chromatin condensation by 4',6-diamidine-2'-ph ...19968837858
syngeneic marek's disease virus (mdv)-specific cell-mediated immune responses against immediate early, late, and unique mdv proteins.marek's disease (md) infection has been controlled effectively by vaccination using nononcogenic and/or attenuated oncogenic marek's disease virus (mdv) vaccines. thus far, there is little knowledge on the role of cell-mediated immune (cmi) responses during mdv infection or vaccination. to elucidate the importance of mdv proteins in cmi responses, the pp38, meq, icp4, or icp22 genes of an oncogenic strain, ga and the gb, orf a, a41, or l1 genes of a highly oncogenic strain, rb1b were stably tran ...19968806490
a non-radioactive method for identifying enzyme-amplified products of the reticuloendotheliosis proviral env and ltr genes using psoralen-biotin labelled probes.a novel polymerase chain reaction (pcr) system based on the env gene of reticuloendotheliosis virus (rev) strain rev-a for the detection of proviral dna is described. the designed pcr product of 807 bp was identified using an internal probe of 278 bp produced by nested pcr from rev-infected dna cef. the env-gene pcr was then compared with the previously described pcr for proviral rev-long terminal repeat and the pcr product served also as the probe. the probes were labelled with the psoralen-bio ...19968793837
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
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
detection of contamination of vaccines with the reticuloendotheliosis virus by reverse transcriptase polymerase chain reaction (rt-pcr).the reverse transcriptase polymerase chain reaction (rt-pcr) was applied to detect contamination of marek's disease (md) vaccine with reticuloendotheliosis virus (rev). the env primers were used for the 1st rt-pcr to amplify the dna fragments of rev-a and -t. the rel and env primers were used for nested-pcr to confirm the sites deleted from rev-t and rev-a. specific amplification products were detected in the 1st rt-pcr with these primers. by nested pcr with the env and the rel primer pairs, the ...19968725107
use of the polymerase chain reaction for the detection of reticuloendotheliosis virus in marek's disease vaccines and chicken tissues.reticuloendotheliosis virus (rev) proviral dna appears to be a frequent contaminant in marek's disease (md) vaccines. a polymerase chain reaction (pcr) was established and evaluated for its ability to detect rev proviral dna in infected cell cultures and chicken tissues. deoxynucleotide primers were selected from the highly conserved gag region of the rev genome. the amplification products were identified by electrophoresis, nested pcr and by hybridization with a digoxigenine-labelled oligonucle ...19968693845
lymphoid leukosis viruses, their recognition as 'persistent' viruses and comparisons with certain other retroviruses of veterinary importance.diseases caused by lymphoid leukosis virus (llv), a retrovirus, take a long time after infection to develop and have a wide variety of pathological manifestations. this long latent period is characteristic of 'persistent virus infections'. disease produced by llv infection and its underlying mechanisms is compared with 'persistent' infections caused by other retroviruses in birds and mammals of veterinary importance. the diseases considered for comparison are those caused by reticuloendotheliosi ...19968693704
the v-rel oncogene promotes malignant t-cell leukemia/lymphoma in transgenic mice.the oncogene product from the avian reticuloendotheliosis virus strain t, v-rel, is a member of the rel/ nf-kappa b family of transcription factors. the mechanism by which v-rel induces oncogenic transformation remains unclear. several attempts to transform mammalian cells with v-rel have failed, suggesting that v-rel transformation may be a species-specific event. however, here we demonstrate that v-rel, but not a truncated c-rel, expressed under the control of the lck promoter, efficiently ind ...19968670867
selective activation of the proto-oncogene c-jun promoter by the transforming protein v-rel.the transcription factor v-rel is a transforming protein of the reticuloendotheliosis virus. we found that v-rel activates the promoter of the proto-oncogene c-jun. two elements in the c-jun promoter were required for the activation by v-rel. one was a kb-site (v-rel binding site), and the other was a c-jun promoter region between -52 and +148 (c-jun promoter (-52/+148)). two promoters with the kb-site(s), those of human immunodeficiency virus (hiv) and sv40, were not activated by v-rel, but the ...19968668346
[effect of internal sequences in the moloney murine leukemia virus genome on replication].construction and using of retrovirus vectors derived from the moloney murine leukemia virus (momulv) are described. these vectors, designated minimal vectors, contain the left and right long terminal repeats (ltrs), a binding site for proline trna, a polypurine tract (ppt), and a dominant marker for selective introduction of vectors into a packaging cell line, but lack the internal sequences of the virus genome. the experiments showed that the minimal vectors can be replicated and that their tit ...19958666218
retroviral insertional activation in a herpesvirus: transcriptional activation of us genes by an integrated long terminal repeat in a marek's disease virus clone.insertional activation of host proto-oncogenes has been recognized as a basic mechanism by which nonacute retroviruses induce cancer. our previous work has demonstrated that retroviruses can efficiently integrate into dna virus genomes. specifically, coinfection of cultured fibroblasts with a chicken herpesvirus, marek's disease virus (mdv), and a chicken retrovirus results in frequent stable retroviral insertions into the herpesvirus genome. such insertions could alter the expression of herpesv ...19968642673
rrr-alpha-tocopheryl succinate inhibits dna synthesis and enhances the production and secretion of biologically active transforming growth factor-beta by avian retrovirus-transformed lymphoid cells.the rrr-alpha-tocopheryl succinate form of vitamin e, referred to as vitamin e succinate (ves), inhibits the proliferation of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells in a dose-dependent manner in vitro. analyses of conditioned medium (cm) from ves growth-inhibited cells revealed a potent antiproliferative activity. characterization of the antiproliferative activity as transforming growth factor-beta (tgf-beta) was established by 1) growth inhibition ...19958584453
marek's disease virus (mdv) icp4, pp38, and meq genes are involved in the maintenance of transformation of mdcc-msb1 mdv-transformed lymphoblastoid cells.an antisense strategy has been used to identify genes important for the maintenance of transformation of mdcc-msb1 (msb1) marek's disease virus-transformed lymphoblastoid cells. oligodeoxynucleotides antisense to the predicted translation initiation regions of icp4 and pp38 mrnas inhibited proliferation of msb1 cells but not mdcc-cu91 (cu91) reticuloendotheliosis virus-transformed cells. control oligodeoxynucleotides having the same base composition but a different sequence did not inhibit msb1 ...19968551572
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
the matrix region is responsible for the differential ability of two retroviruses to function as helpers for vector propagation.we have investigated the ability of two related reticuloendotheliosis viruses to propagate a spleen necrosis virus (snv) based retroviral vector in canine osticosarcoma (d17) cells. reticuloendotheliosis virus strain a (rev-a) consistently propagated the vector more efficiently than snv in cell culture. to identify the area of the viral genome responsible for the superior helper function of rev-a, we constructed chimeric viruses between snv and rev-a. analysis of helper function indicated that a ...19938421894
retrovirus insertion into herpesvirus: characterization of a marek's disease virus harboring a solo ltr.we recently reported the phenomenon of retroviral insertion into a herpesvirus (isfort et al., (1992) proc. natl. acad. sci. usa 89, 991-995). we have now isolated marek's disease virus (mdv) clones that carry retroviral inserts. retroviral ltr insertion has the potential to activate or inactivate herpesvirus genes leading to alterations of the biological properties of the herpesviruses. the structure and the expression pattern of a virus clone carrying a solitary ltr insertion was characterized ...19938390750
consistent chromosomal aberration in cell lines transformed with marek's disease herpesvirus: evidence of genomic dna amplification.a specific chromosomal aberration was observed in 14 of 15 avian lymphoblastoid cell lines transformed with marek's disease herpesvirus. this aberration, designated dup(1p)(p22-p23), appeared as an extra g-positive band and interband on the short arm of one chromosome i homolog. using fluorescent in situ hybridization, we identified amplified genomic dna sequences in this region. this amplification involves sequences linked to an endogenous retrovirus locus and genes in the histone multigene fam ...19938390410
alteration of location of dimer linkage sequence in retroviral rna: little effect on replication or homologous recombination.retrovirus particles contain a dimer of retroviral genomic rna. a defined region of the retrovirus genome has previously been shown to be important for both dimerization and encapsidation. to study the importance of the position of this encapsidation and dimerization signal for retroviral replication and homologous recombination, we used a previously described spleen necrosis virus-based helper cell system. this system allows retroviral vectors with multiple genetic markers to be studied after a ...19938388494
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
retroviral insertions into a herpesvirus are clustered at the junctions of the short repeat and short unique sequences.we previously described the integration of a nonacute retrovirus, reticuloendotheliosis virus (rev), into the genome of a herpesvirus, marek disease virus (mdv), following both long-term and short-term coinfection in cultured fibroblasts. the long-term coinfection occurred in the course of attenuating the oncogenicity of the jm strain of mdv and was sustained for > 100 passages. the short-term coinfection, which spanned only 16 passages, was designed to recreate the insertion phenomenon under co ...19938387199
efficient insertion from an internal long terminal repeat (ltr)-ltr sequence on a reticuloendotheliosis virus vector is imprecise and cell specific.to 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
retroviral transformation in vitro of chicken t cells expressing either alpha/beta or gamma/delta t cell receptors by reticuloendotheliosis virus strain t.exposure of normal juvenile chicken bone marrow cells to the replication defective avian reticuloendotheliosis virus strain t (rev-t) (chicken syncytial virus [csv]) in vitro resulted in the generation of transformed cell lines containing t cells. the transformed t cells derived from bone marrow included cells expressing either alpha/beta or gamma/delta t cell receptors (tcrs) in proportions roughly equivalent to the proportions of tcr-alpha/beta and tcr-gamma/delta t cells found in the normal b ...19938382253
a double hairpin structure is necessary for the efficient encapsidation of spleen necrosis virus retroviral rna.we conducted a mutational analysis within the previously defined encapsidation sequence (e) for spleen necrosis virus (snv), an avian retrovirus. we found that two regions are necessary for efficient snv replication. the first region is a double hairpin structure as proposed by konings et al. (1992, j. virol., 66, 632-640); the second region is located downstream of the hairpins. we showed further that the double hairpin structure is required for efficient snv rna encapsidation. our work is the ...19948313915
characterization of a marek's disease virus bamhi-l-specific cdna clone obtained from a marek's disease lymphoblastoid cell line.two marek's disease (md) virus bamhi-l-specific cdna clones were isolated from a cdna library constructed from poly(a)+ rna fractions of an md lymphoblastoid cell line, mdcc-cu41 (cu41). these clones were mapped to the region corresponding to the bamhi-q2 and l-regions. these clones hybridized with 2.5-, 0.8-, and 0.6-kb transcripts prepared from cu41. the transcriptional unit of the 0.6-kb transcript was determined by rnase protection assays. an open reading frame encoding a 107-amino-acid poly ...19948289349
a survey of an antibody to reticuloendotheliosis virus in sera of chickens and other avian species in japan.an examination of antibody to reticuloendotheliosis virus (rev) in sera of chickens and other avian species collected from various districts in japan was carried out. agar gel immunodiffusion test (agid) to the chicken sera revealed positive results in 25.9% of the 54 farms, 21.4% of the 126 flocks and 14.3% of the 1,892 individual chickens. all the agid positive sera also were positive in indirect immunofluorescence and/or virus neutralization tests. in avian species other than chickens, peking ...19938286554
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
flow cytometric analysis of the neutralizing immune response against infectious bursal disease virus using reticuloendotheliosis virus-transformed lymphoblastoid cell lines.infectious bursal disease virus (ibdv) is a lymphotropic virus with cytocidal effect on b lymphocytes of the bursa of fabricius. we investigated the susceptibility of clonal populations of reticuloendotheliosis virus-transformed chicken b lymphocytes of both spleen and bursal origin to ibdv infection. the infected cells were metabolically-labelled and the viral polypeptides were analyzed by immunoprecipitation using monoclonal antibodies (mabs). virus adsorption and the effects of neutralizing c ...19938263113
v-rel induces expression of three avian immunoregulatory surface receptors more efficiently than c-rel.the c-rel gene is a member of nf-kappa b/rel family of transcription factors that regulate expression of a variety of immunoregulatory molecules. the viral oncogene, v-rel, is a truncated and mutated form of the turkey c-rel gene expressed by reticuloendotheliosis virus, strain t. in this study, we demonstrated that three avian immunoregulatory receptors, major histocompatibility (mhc) antigens class i and class ii as well as the interleukin-2 receptor (il-2r), were induced on the surface of spl ...19948254742
thymocyte apoptosis induced by elevated endogenous corticosterone levels.a well-known model of apoptosis is induction in thymocytes by injection of pharmacological doses of exogenous steroids. the aim of this study was to investigate whether this process also occurs under physiological conditions, i.e. by stimulation of endogenous glucocorticoid release, using the chicken as an experimental model. endogenous glucocorticoid levels can be elevated by immunization with exogenous antigens or by injection of conditioned medium, e.g. supernatant of mitogen-stimulated splee ...19948181522
poultry oncogenic retroviruses and humans.viruses of the avian leukosis/sarcoma group (alsv) and reticuloendotheliosis viruses (rev) are highly prevalent in chickens and turkeys and naturally cause tumors in them. commercial chickens are positive for antibodies, and a proportion actually carry infectious virus. virus may be present in chicken products and in eggs, thus human exposure is virtually universal. the viruses show little potential for producing infectious viral particles in mammalian cells; nevertheless, they have the capacity ...19948162609
in vivo evolution of c-rel oncogenic potential.the c-rel proto-oncogene belongs to the nf-kappa b/rel and i kappa b gene families, which regulate several inducible processes, including self-defense/repair and embryogenesis. transduction of the c-rel transcription factor by the avian retrovirus resulted in the formation of a highly oncogenic virus, reticuloendotheliosis virus strain t (rev-t), that encodes the oncogene v-rel. to examine the oncogenic potential of c-rel, we inserted it into a rev-t-based retroviral vector, rescued virus [rev-c ...19948139023
identification of latency-associated transcripts that map antisense to the icp4 homolog gene of marek's disease virus.two small rnas (0.9 and 0.75 kb), named marek's disease virus (mdv) small rnas (msrs) and a 10-kb rna, all of which map antisense to the mdv icp4 homolog gene, have been readily detected in mdcc-msb1 mdv-transformed t-lymphoblastoid cells. these rnas were not detectable in reticuloendotheliosis virus-transformed t cells. when mdv was reactivated by treatment of lymphoblastoid cells with 25 micrograms of iododeoxyuridine per ml, the relative levels of the transcripts decreased. these rnas were no ...19948083968
integration of multiple chicken retroviruses into multiple chicken herpesviruses: herpesviral gd as a common target of integration.integration of two different avian retroviruses, reticuloendotheliosis virus (rev) and avian leukosis virus (alv), into the genome of two different avian herpesviruses, the herpesvirus of turkeys (hvt) and marek's disease virus (mdv), was investigated. integration events occurred by the fourth and sixth in vitro passage of cells coinfected with rev/hvt and alv/mdv, respectively. in order to further characterize the integration events, integrated proviruses and surrounding herpesviral genetic mat ...19948030268
structural genes, not the ltrs, are the primary determinants of reticuloendotheliosis virus a-induced runting and bursal atrophy.reticuloendotheliosis virus strain a (rev-a) and chicken syncytial virus (csv), two replication competent avian retroviruses, differ in the extent to which they induce a runting syndrome that includes anemia, lymphoid organ atrophy, and reduced body size. we have isolated an infectious clone of csv, the less pathogenic of the two viruses, and compared it to rev-a. partial dna sequence analysis suggests that it differs from rev-a by no more than 1 to 2% at the nucleotide level. analysis of viral ...19948009826
an immunoperoxidase plaque assay for reticuloendotheliosis virus and its application to a sensitive serum neutralization assay.a rapid assay for the enumeration of reticuloendotheliosis virus (rev) is described. chicken embryo fibroblast monolayer cultures were infected with rev and incubated 6 days under an agar overlay. after removal of the overlay, cells were fixed with acetone/ethanol. foci of infection (hereafter referred to as plaques) were detected using either an anti-rev envelope monoclonal antibody or convalescent chicken serum as the primary antibody; the secondary antibody was either horseradish peroxidase-c ...19948002888
pseudotyped rev/srv retroviruses reveal restrictions to infection and host range within members of the same receptor interference group.the reticuloendotheliosis virus (rev) group of retroviruses and type d simian retroviruses (srv) belong to the same receptor interference group. the cellular receptor for these viruses has not yet been identified. in order to study the distribution of the receptor and to identify a receptor negative cell line, vector viral pseudotypes between rev and srv were made. using these viral pseudotypes, susceptibility to infection was examined in some rodent and marsupial cell lines. infectivity assays ...19947975230
cell-mediated immune effector functions in chickens.cell-mediated immune responses form an important part of the protection against intracellular pathogens. the mhc class i and class ii antigens are important for the proper presentation of degraded proteins to cytotoxic t lymphocytes (ctl) and helper t cells, respectively. recent developments in the knowledge of the molecular structure of the mhc in relation to antigen presentation are discussed. although ctl are important, there is a paucity of information concerning their relevance for the cont ...19947937468
the v-rel oncoprotein complexes with new rel- and rela-related proteins in transformed cells.the v-rel oncoprotein of the rev-t retrovirus interacts with a number of cellular proteins in transformed chicken spleen cells including p40/i kappa b alpha, p68c-rel, hsc70, and the p124 and p115 precursors for the p50 and p52 subunits of nf kappa b. here we report that v-rel associates with at least three other cellular proteins of 75-85 kda in these cells, as well as with a protein related to human rela. western blot analysis of v-rel immune complexes showed cross-reactivity between all of th ...19957886940
mutations of conserved cysteine residues in the cwlc motif of the oncoretrovirus su protein affect maturation and translocation.the envelope glycoprotein complex is composed of two polypeptides, an external heavily glycosylated polypeptide (su) and a membrane-spanning protein (tm). together they form a heterodimer on the surface of the virion. these proteins are synthesized in the form of a polyprotein precursor which is glycosylated and proteolytically processed during its maturation in the secretory pathway. a highly conserved stretch of four amino acids, cwlc, has been identified in most known oncoretroviral su protei ...19957856101
diseases and management of backyard chicken flocks in chitungwiza, zimbabwe.to 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
a serosurvey using enzyme-linked immunosorbent assay for antibodies against poultry pathogens in ostriches (struthio camelus) from zimbabwe.horseradish peroxidase-conjugated goat anti-ostrich igg was raised and used in commercial enzyme-linked immunosorbent assay kits to detect antibodies reactive with 11 poultry pathogens in sera from 149 ostriches from nine farms around zimbabwe. antibodies were detected to turkey rhinotracheitis virus (99%), newcastle disease virus (23%), avian reovirus (19%), infectious bursal disease virus (15%), avian encephalomyelitis virus (15%), mycoplasma gallisepticum and/or m. synoviae (11%), reticuloend ...19947832718
mapping of receptor binding domains in the envelope protein of spleen necrosis virus.spleen necrosis virus (snv) is an amphotropic retrovirus originally isolated from a duck. although of avian origin, it also replicates on some mammalian cells. snv-derived retroviral vectors work with high efficiency and have a high potential for various gene transfer applications. however, little is known about the envelope-receptor interactions of this virus. we constructed a series of recombinant envelope proteins to characterize the su peptide of snv. we found that, in contrast to the envelo ...19957769695
mutations in the dna-binding and dimerization domains of v-rel are responsible for altered kappa b dna-binding complexes in transformed cells.the c-rel proto-oncogene encodes a member of the rel/nf-kappa b family of transcription factors. the oncogenic viral form, v-rel, transduced by avian reticuloendotheliosis virus t, induces lymphoid tumors. v-rel transformation may be mediated directly by binding of v-rel to cognate dna sites, resulting in altered gene expression, and/or indirectly by releasing rel/nf-kappa b transcription factors from cytoplasmic retention molecules, resulting in their translocation to the nucleus and the inappr ...19957745683
syngeneic lysis of reticuloendotheliosis virus-transformed cell lines transfected with marek's disease virus genes by virus-specific cytotoxic t cells.cell-mediated immune responses against marek's disease virus (mdv) antigens were examined using reticuloendotheliosis virus (rev)-transformed cell lines of two haplotypes (b19b19 and b13b13). these cell lines were stably transfected with cloned fragments of mdv dna resulting in the expression of the mdv-specific phosphoprotein pp38. effector cells were obtained from p2a (b19b19) and s13 (b13b13) chickens at 7 days post inoculation with rev, oncogenic or attenuated serotype 1 mdv (jm-16/o and jm- ...19947725630
reticuloendotheliosis viruses and derived vectors.in most human gene therapy trials, the tools of gene delivery are retroviral vectors. all current vectors are derived from murine leukemia virus (mlv). although this system is suitable for delivering a large variety of genes into different tissues, it also has its limitations and is not adequate for all potential applications of human gene therapy. thus, attempts are underway in many laboratories to develop other gene delivery tools. potential agents range from non-viral based gene delivery syst ...19957671105
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
uses of flow cytometry in virology.this article reviews some of the published applications of flow cytometry for in vitro and in vivo detection and enumeration of virus-infected cells. sample preparation, fixation, and permeabilization techniques for a number of virus-cell systems are evaluated. the use of flow cytometry for multiparameter analysis of virus-cell interactions for simian virus 40, herpes simplex viruses, human cytomegalovirus, and human immunodeficiency virus and its use for determining the effect of antiviral comp ...19947530594
surface antigens on marek's disease lymphoblastoid tumor cell lines.a total of 32 marek's disease virus (mdv)-induced cell lines, 1 avian leukosis virus-induced cell line, and 1 reticuloendotheliosis virus (rev)-induced lymphoblastoid cell line were investigated for the presence of fc receptors, surface igm, and ia-like antigen. surface igm and fc receptors could not be demonstrated on any of the cell lines. ia-like antigen was detected on all mdv-induced cell lines and on the 1 rev-induced cell line. ia-like antigen was unrelated to other antigens reported to b ...19826955560
spontaneous changes in nucleotide sequence in proviruses of spleen necrosis virus, an avian retrovirus.we determined the nucleotide sequence of about 1 kilobase of dna 3' to the 5' long terminal repeat of three noninfectious ad one infectious proviral dna clones of spleen necrosis virus, an avian retrovirus, to determine if the types of nucleic acid changes involved in retrovirus mutation shed light on special features of retrovirus replication. an open reading frame was found starting 411 base pairs from the end of the long terminal repeat. it contained sequences coding for the 36 amino acids at ...19826951170
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
improved focus assay of reticuloendotheliosis virus in a quail fibroblast cell line (qt35).reticuloendotheliosis virus (rev) strains t and cs consistently induced focus formation in a quail fibroblast cell line designated qt35 that was maintained under agarose overlay following inoculation of rev. the foci were more distinct and better circumscribed than those that developed in qt35 cultures under fluid medium. the focus formation in qt35 cultures under agarose overlay was inhibited by rev antiserum, and there were a highly significant correlation (r = 0.966, p less than 0.005) and a ...19846721800
a survey of disease in five commercial flocks of meat breeder chickens.causes of sickness and death in approximately 30,000 chickens in 5 meat breeder flocks were investigated between may 1979 and april 1980. approximately 23% of disease was due to neoplasms; 81% of these were marek's disease despite vaccination against this infection. other frequent diagnoses included cellulitis (15%), respiratory disease (14%), lesions of the reproductive tract (11%) and tenosynovitis/arthritis (9%). antibodies to mycoplasma gallisepticium, avian adenovirus, infectious bursal dis ...19846704066
basolateral maturation of retroviruses in polarized epithelial cells.we have investigated the maturation sites of avian and mammalian c-type retroviruses in polarized epithelial cells. examination of thin sections of madin darby canine kidney cells infected with rd114 or avian reticuloendotheliosis virus revealed that these viruses mature from the basolateral membrane domains. similar results were obtained with a continuous line of mouse mammary epithelial cells infected with friend, moloney, rauscher, or kirsten murine leukemia viruses, or friend virus-related o ...19836339737
influence of reticuloendotheliosis on the severity of eimeria tenella infection in broiler chickens.broiler chickens free of maternal immunity to reticuloendotheliosis virus (rev) were used in the experiment. two groups of 25 chickens were inoculated with rev at one day of age. one of these groups and another group of 25 chickens were inoculated with eimeria tenella sporulated oocysts at 7 days of age. chickens inoculated with e. tenella showed bloody diarrhoea from 12 to 14 days of age. six out of 25 chickens died (p less than 0.05) at 13 and 14 days of age in the dual infected group. at 14 d ...19846328737
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
construction of a helper cell line for avian reticuloendotheliosis virus cloning vectors.we wished to construct cell lines that supply the gene products of gag, pol, and env for the growth of replication-defective reticuloendotheliosis retrovirus vectors without production of the helper virus. to do this, first we located by s1 mapping the donor and acceptor splice sites of reticuloendotheliosis virus strain a. the donor splice site is ca. 850 base pairs from the 5' end of proviral dna. it is close to or overlaps the encapsidation sequences for viral rna. the splice acceptor site is ...19836318091
pathogenesis of reticuloendotheliosis virus infection in ducks.a new isolate of reticuloendotheliosis virus (rev) from ducks, ru-1, was used to experimentally infect white pekin ducks. embryonal or neonatal infection usually resulted in persistent viremias, no rev antibody development, and inability to mount antibody responses against bovine serum albumin (bsa) or sheep red blood cells (srbc). in contrast, infection at 21 days of age resulted in transient viremias, which terminated coincident with rev antibody development. these ducks remained persistently ...19836316895
avian lymphoproliferative diseases and their virus associations. 19836316767
the pathogenesis of oncogenic avian retroviruses. 19836312780
nucleotide sequence of v-rel: the oncogene of reticuloendotheliosis virus.the nucleotide sequence of v-rel, the oncogene carried by reticuloendotheliosis virus (rev), has been determined. the defective transforming genome rev arose through the insertion of v-rel (1,415 nucleotides) into the env gene of the helper virus rev-a. the predicted rel protein (503 amino acids) employs the rev-a env initiator and terminates within the p20e region of env. because there are no natural antisera that detect the rev transforming protein, this nucleotide sequence provides the first ...19836312449
relative efficiency of techniques for detecting avian reticuloendotheliosis virus as a vaccine contaminant.three techniques were compared for sensitivity in detecting reticuloendotheliosis virus (rev) in a deliberately contaminated marek's disease vaccine. the most sensitive and rapid test was the indirect fluorescent antibody test (fat). the indirect immunoperoxidase test, although simple to perform and only marginally less sensitive than the fat, was difficult to interpret at low levels of rev. using immunoelectron microscopy, virions were seen only after three subcultures and then not to the same ...19836308736
isolation and characterization of genomic mouse dna clones containing sequences homologous to trnas and 5s rrna.we have cloned and characterized three fragments of balb/c mouse dna which hybridize to mouse cell trnas. fractionation of the trnas which hybridize to these clones reveals that two of the clones, lambda mt-4a and lambda mt-6a hybridize to only one or two trnas, while one clone, lambda mt-4b, hybridizes to at least seven trnas. two of the trnas were identified as trnaproccg and trnaglygga, and others have been identified as trnas which are selectively encapsidated into virions of murine leukemia ...19836308561
the organization of c-rel in chicken and turkey dnas.the process of transduction of a proto-oncogene involves the loss of intervening sequences, the loss of 3' mrna terminal sequences, and possible base changes. it is not possible to know how similar the c-rel sequences we studied are to sequences from which v-rel arose. if one of the alleles we studied is identical to progenitor sequences of v-rel, then base changes must have occurred during the process of transduction. alternatively, there may exist an allele of c-rel which did not need to under ...19836306690
effect of reticuloendotheliosis virus on the response of chickens to salmonella typhimurium infection.groups of 25 chickens free of maternal antibody to reticuloendotheliosis virus (rev) were inoculated with either third or seventh passage rev at either one or seven days of age. some of the birds inoculated at day 1 with rev were inoculated with salmonella typhimurium either concurrently or six or 13 days later while some of those inoculated with rev at day 7 were inoculated concurrently with s typhimurium. at day old, infection with s typhimurium alone caused the death of 12 of 25 chicks wherea ...19836304835
reticuloendotheliosis virus-transformed cells contain infectious and noninfectious proviral sequences in different chromosomes.the integration site of reticuloendotheliosis virus proviral dna in the dna from a cloned reticuloendotheliosis virus-transformed bone marrow cell line was studied. these reticuloendotheliosis virus-transformed bone marrow cells produce a replication-defective transforming virus (rev-t) and a nontransforming helper virus, designated reticuloendotheliosis-associated virus (rev-at). the dna from this rev-t transformed bone marrow cell line was hybridized with 3h-labeled in vitro synthesized dna co ...19836303538
studies of reticuloendotheliosis virus-induced lymphomagenesis in chickens.seventy-three percent of chickens inoculated with the chick syncytial strain of reticuloendotheliosis virus (rev) at hatching developed lymphomas by 39 weeks of age. neonatal treatment with cyclophosphamide or surgical bursectomy at 2, 4, 8, or 12 weeks of age significantly (p less than 0.01) reduced lymphoma development. in a further experiment, surgical bursectomy of rev-infected chickens followed by intravenous inoculation of the chickens with a single cell suspension of their own bursa cells ...19836303293
cytopathic effects and focus formation by reticuloendotheliosis viruses in a quail fibroblast cell line.the t and cs (chick syncytial) strains of reticuloendotheliosis virus (rev) induced focus formation and cytonecrotic changes in a japanese quail fibroblast cell line designated qt35. the focus was distinctive and readily discernible, consisting of rounded refractile and larger dark-appearing (syncytia) cells usually aggregated along the periphery of a hole within a focus. the foci and cytopathic effects induced by the two strains of rev were morphologically indistinguishable. the focus formation ...19836303292
detection of antibodies against reticuloendotheliosis viruses by an enzyme-linked immunosorbent assay.a microplate indirect enzyme-linked immunosorbent assay (elisa) for antibodies against reticuloendotheliosis virus (rev) was consistently more sensitive than indirect immunofluorescent-antibody tests. limits of antibody detection were comparable to those obtained in virus neutralizations. detection of rev-infected chickens long after infection and after immunofluorescent antibody has waned makes elisa especially suitable for screening chicken flocks.19836303290
high-efficiency ligation and recombination of dna fragments by vertebrate cells.dna-mediated gene transfer (transfection) is used to introduce specific genes into vertebrate cells. events soon after transfection were quantitatively analyzed by determining the infectivity of the dna from an avian retrovirus and of mixtures of subgenomic fragments of this dna. the limiting step of transfection with two dna molecules is the uptake by a single cell of both dna's in a biologically active state. transfected cells mediate ligation and recombination of physically unlinked dna's at ...19836301012
substitution of 5' helper virus sequences into non-rel portion of reticuloendotheliosis virus strain t suppresses transformation of chicken spleen cells.the genome of the highly oncogenic avian retrovirus reticuloendotheliosis virus strain t (rev-t) differs from that of the helper virus reticuloendotheliosis virus strain a by a substitution (rel and a large deletion. further deletions, constructed in vitro, within the helper-virus-related sequences of rev-t have little effect on the ability of the virus to transform chicken spleen cells in vitro. however, deletions that extend into rel abolish transformation. substitution of helper-virus-related ...19826297744
structure and expression of c-rel, the cellular homolog to the oncogene of reticuloendotheliosis virus strain t.the cellular homolog of the onc sequences in the avian retrovirus reticuloendotheliosis virus strain t (v-rel) was studied by molecular cloning and nucleic acid hybridization. in contrast to v-rel sequences, which are 1.4 kilobase pairs long, the cellular homolog, c-rel, from line 15b chickens is at least 25 kilobase pairs long, with multiple apparent introns. a 4.0-kilobase polyadenylic acid-containing rna transcript is the primary species of c-rel rna present in uninfected chicken cells. seque ...19836296425
establishment of a chicken lymphoblastoid cell line infected with reticuloendotheliosis virus. 19826296206
a monoclonal antibody reactive with marek's disease tumor-associated surface antigen.an antibody-secreting hybridoma, rph-6, to marek's disease tumor-associated surface antigen (matsa) was produced by somatic-cell hybridization between the mouse myeloma sp2/o-ag/14 and spleen cells from msb1 immunized mice. the antibody reacted with 95 to 100% of the cells from eight of 10 chicken md cell lines and one of two turkey md cell lines. it did not react with chicken md cell lines rp1 and sk3, turkey md cell line rp19, lymphoid leukosis (ll) cell lines, rp9 and rp12, and reticuloendoth ...19836294177
in situ hybridization: general infectivity assay for retroviruses.we have devised a general infectivity assay for retroviruses. a virus-specific [32p]dna probe is hybridized in situ to a monolayer culture, and foci of infected cells in the monolayer are detected by exposure of the hybridized culture to x-ray films. the method is quantitative, in that it gives the same titer for moloney murine leukemia virus as does the standard uv-xc test. the specificity of the assay is indicated by the fact that murine leukemia virus and baboon endogenous virus do not cross ...19826292448
effect of endogenous leukosis virus genes on response to infection with avian leukosis and reticuloendotheliosis viruses.we examined the effect of the presence or absence of endogenous viral gene (ev) 3, which controls expression of group-specific viral and envelope antigens (gs+chf+ phenotype), and ev2, which controls the production of a complete subgroup e virus (v-e+ phenotype), on the response of chickens to rav-1, an exogenous avian leukosis virus (alv) with an antigenic relationship to endogenous virus. after inoculation at one day of age, the chickens lacking either ev gene expression had a lower frequency ...19826285878
dna sequence relationship of the baboon endogenous virus genome to the genomes of other type c and type d retroviruses.baboon endogenous virus (baev) is a type c retrovirus present in multiple proviral copies in the dna of baboons. although interspecies antigenic determinants present on reverse transcriptase and gag proteins are shared among all mammalian type c viruses, no nucleic acid homology between baev and other type c viruses (except rd-114) has been found in conventional liquid hybridization experiments. in this study, we used restriction fragments of cloned baev dna immobilized on nitrocellulose to test ...19826284972
genome of reticuloendotheliosis virus: characterization by use of cloned proviral dna.reticuloendotheliosis virus is an avian type c retrovirus that is capable of transforming fibroblasts and hematopoietic cells both in vivo and in vitro. this virus is highly related to the three other members of the reticuloendotheliosis virus group, including spleen necrosis virus, but it is apparently unrelated to the avian leukosis-sarcoma virus family. previous studies have shown that it consists of a replication-competent helper virus (designated rev-a) and a defective component (designated ...19826283142
morphological, immunological, and biochemical analyses of chicken spleen cells transformed in vitro by reticuloendotheliosis virus strain t.reticuloendotheliosis virus strain t (rev-t) is a highly oncogenic avian retrovirus which causes a rapid neoplastic disease of the lymphoreticular system. we derived six cell lines (1-3, 1-5, 2-10, 2-14, 2-16, and 2-20) from chicken spleen cells infected with rev-t. these cells can produce both the rev-t and its associated reticuloendotheliosis helper virus, rev-a. histochemical analyses of these cells indicate that, while they are not stained by benzidine, peroxidase, beta-glucuronidase or acid ...19826282448
helper viruses associated with avian acute leukemia viruses inhibit the cellular immune response. 19826278717
an igm-producing b lymphoblastoid cell line established from lymphomas induced by a non-defective reticuloendotheliosis virus.chick syncytial virus (csv), a strain of avian reticuloendotheliosis virus (rev) causes lymphoid tumours in chickens after a prolonged incubation period. a number of csv-induced tumours were examined for cell surface antigen and were found to be of the b cell type and to produce immunoglobulin. attempts were made to grow in vitro cell lines from csv-induced tumours and a lymphoblastoid cell line was established from a liver tumour of a chicken that was inoculated with csv via the yolk sac in emb ...19826278061
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
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
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
characterization of reticuloendotheliosis virus strain t dna and isolation of a novel variant of reticuloendotheliosis virus strain t by molecular cloning.reticuloendotheliosis virus strain t (rev-t) is a highly oncogenic avian retrovirus which causes a rapid neoplastic disease of the lymphoreticular system. upon infection, this virus gives rise to two species of unintegrated linear viral dna, which are 8.3 and 5.5 kilobase pairs long and represent the helper virus (rev-a) and the oncogenic component (rev-t), respectively. restriction endonuclease cleavage maps of these two dna components indicate that rev-t dna has a large portion of the genome d ...19816275117
staphylococcal protein-a agglutination assay for avian viruses.protein-a rich staphylococci were used to develop an agglutination assay for the detection and quantitation of avian reticuloendotheliosis virus (rev) and herpes virus of turkeys (hvt). rabbit anti-rev or anti-hvt were used to coat the staphylococci and these reagents were mixed with rev or various other viral antigen preparations. an agglutination titer was determined for antigen preparations of varying purity and the results indicated that in addition to being rapid, this assay allows the dete ...19816274147
hematopoietic cells transformed in vitro by revt avian reticuloendotheliosis virus express characteristics of very immature lymphoid cells. 19816274086
specific integration of rev proviruses in avian bursal lymphomas. 19816273749
avian reticuloendotheliosis virus: identification of the hematopoietic target cell for transformation.non-virus-producing hematopoietic cells transformed in vitro by reticuloendotheliosis virus (rev-t) induce lethal "reticuloendotheliosis" when inoculated into histocompatible chickens. this is the first direct demonstration that an in vivo target cell of an avian acute leukemia virus can be transformed in vitro. the tumorigenic, rev-t-transformed non-virus-producing cells fail to express helper-virus-coded proteins. rev-t transformed tumorigenic cells therefore do not require helper-virus functi ...19816269747
nucleic acid homology between avian and mammalian type c viruses: relatedness of reticuloendotheliosis virus cdna to cloned proviral dna of the endogenous colobus virus cpc-1. 19816269291
a survey of non-specific cross-protective immunities induced by avian retroviruses.reticuloendotheliosis virus strain t (rev-t) induced immunity in chicks to challenge by representative subgroup members of the avian leukosis-sarcoma virus (alsv) complex. immunity levels were compared to determine the extent of antigenic relation between rev-t and the alsv complex. reciprocal studies using alsv subgroup members and pheasant viruses as immunogens and rev-t as challenge were also performed. it was concluded that reciprocity of immunity is not equal between the viruses studied, no ...19806268039
characterization of transformation- and replication-specific sequences of reticuloendotheliosis virus. 19816267804
secretion of a virus-regulated factor by clonal variants of reticuloendotheliosis virus-transformed hematopoietic cells. 19816267788
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
modification of low virulent newcastle disease virus infection in chickens infected with reticuloendotheliosis virus.one-day-old spf chicks were inoculated with reticuloendotheliosis virus (rev) which had been isolated from contaminated marek's disease vaccine. then they were subjected to super infection with the b1 or tcnd strain of newcastle disease virus (ndv) and examined for virus recovery, antibody response and the appearance of symptoms. regardless of the time, from 0 to 8 weeks, of inoculation with the ndv-b1 strain after the rev infection, the antibody response was suppressed and the duration of the n ...19816264326
avian reticuloendotheliosis virus contains a new class of oncogene of turkey origin. 19816263007
avian reticuloendotheliosis virus: characterization of genome structure by heteroduplex mapping.the genome structure of defective, oncogenic avian reticuloendotheliosis virus (rev) was studied by heteroduplex mapping between the full-length complementary dna of the helper virus rev-t1 and the 30s rev rna. the rev genome (5.5 kilobases) had a deletion of 3.69 kilobases in the gag-pol region, confirming the genetic defectiveness of rev. in addition, rev lacked the sequences corresponding to the env gene but contained, instead, a contiguous stretch (1.6 to 1.9 kilobases) of the specific seque ...19816262534
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