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production of marek's disease vaccine.marek's disease (md) is one of the viral infections that attack poultry and are widespread throughout the world. vaccination is widely used for the protection of chickens against outbreaks of md, and commercial vaccines have been used since 1970. there are vaccines derived from three avian herpesvirus serotypes which are propagated in cef or def cell cultures. most of them are used successfully for vaccination against mdv and are effective and safe. in problem areas where the monovalent vaccine ...19902171556
transactivation of the rous sarcoma virus long terminal repeat promoter by marek's disease virus.transient expression of chloramphenicol acetyltransferase (cat) was used to study marek's diseases virus (mdv)-mediated transactivation of the rous sarcoma virus long terminal repeat (rsv-ltr) promoter. cotransfection experiments in primary avian cells were conducted using mdv high-molecular-weight dna and plasmid prsvcat. increased cat activity, relative to controls, was consistently observed in the presence of mdv. enhanced cat activity, expressed via the rsv-ltr promoter, was strictly depende ...19902173259
replicating marek's disease virus (mdv) serotype 2 dna with inserted mdv serotype 1 dna sequences in a marek's disease lymphoblastoid cell line msb1-41c.we characterized the properties of herpes-type viruses which grew well in a marek's disease lymphoblastoid cell line, msb1-41c, inducing cytopathic effect characterized by the formation of syncytial giant cells. examination of the infectious virus by field inversion gel electrophoresis revealed the presence of dna of about 180 kbp in both the culture fluid and cell fractions of the infected msb-41c cells. the dna was found to consist of marek's disease virus (mdv) serotype 2 (mdv2) and mdv serot ...19902173523
[viruses and atherosclerosis].our understanding of the pathogenesis and aetiology of atherosclerosis remains incomplete. an infection by herpesviruses is among the plausible hypotheses. in chicken, inoculation with marek's disease virus provokes arterial lesions closely resembling atherosclerotic plaques. experiments done on cultured arterial cells have shown that herpesviruses might enhance atherogenesis. herpesviruses molecules (proteins, messenger ribonucleic acid, deoxyribonucleic acid) are commonly found in the human ar ...19902175447
establishment and characterization of a chicken mononuclear cell line.a new chicken mononuclear cell line (mq-ncsu) has been established. the starting material used to initiate this cell line was a transformed spleen from a female dekalb xl chicken which had been experimentally challenged with the jm/102w strain of the marek's disease virus. after homogenization, a single cell suspension of splenic cells was cultured using l.m. hahn medium supplemented with 10 microm 2-mercaptoethanol. under these culture conditions, a rapidly proliferating cell was observed and t ...19902176014
identification of virus-specific antigens in cultured cells infected with marek's disease virus serotype 2 and cvi-988 strain.for the identification of serotype-specific antigens of marek's disease virus (mdv) serotype 1 (mdv1) or serotype 2 (mdv2), a total of 24 hybridoma clones, secreting monoclonal antibodies (mabs) against cvi-988 (mdv1) or hprs-24 (mdv2) strain, were established and characterized by immunofluorescence assay, virus neutralization and immunoprecipitation analysis. based upon the molecular weights (mol. wt.) of the immunoprecipitated polypeptides, the mabs were subdivided into 7 groups. among them, t ...19902177808
biological diversity among serotype 2 marek's disease viruses.selected biological characteristics were determined for 14 low-passage serotype 2 marek's disease virus (mdv) isolates. four of these isolates were also tested after extensive serial passage in chicken embryo fibroblast cultures. observations were made on replication in vitro and in vivo, pathogenicity by in ovo inoculation, antigenicity, and protection against virulent mdv challenge. among the low-passage isolates, there were some differences in pathogenicity after in ovo inoculation but relati ...19902177978
identification of protein complexes containing the c-rel proto-oncogene product in avian hematopoietic cells.the c-rel proto-oncogene product has been identified as a 75 kda protein expressed in lymphoid cells transformed by rev-t and marek's disease virus. a 4.0 kb c-rel transcript is expressed in the bursa, spleen and thymus of chickens with highest levels of expression at 10 days post hatch. using antiserum specific for the v-rel oncogene product, p75c-rel has been precipitated from [35s]methionine-labeled extracts of bursal, splenic and thymic lymphocytes. additionally, proteins with the molecular ...19902202947
the effect of serologically defined major histocompatibility complex haplotypes on marek's disease resistance in commercially bred white leghorn chickens.in commercial pure white leghorn lines, a, b, and c, the effects on resistance against a virulent strain of marek's disease virus were assessed for b19 and b21 haplotypes of the chicken major histocompatibility complex. b haplotypes were identified by direct hemagglutination using alloantisera raised against erythrocyte antigens. in homozygous b21 female chicks from lines a and b, mortality upon challenge with virus was 16% and 9%, respectively; in b19 chicks, mortality was 42% and 60%, respecti ...19902282011
isolation of marek's disease virus from japanese quail with lymphoproliferative disease.sixty-one japanese quail from eight flocks with problems of recurring outbreaks of lymphoproliferative diseases resembling marek's disease (md), were examined aetiologically. gross lymphomatous lesions were seen in 17 of the quail and 11 out of 56 quail had md virus (mdv) feather tips antigens. mdv antibody was detectable in only one of 22 quail. none of 9 quail had antibodies against reticuloendotheliosis virus (rev). no mdv was isolated from the total 42 materials of quail using cell culture t ...199018679919
replication of marek's disease virus in chicken feather tips containing vaccinal turkey herpesvirus dna.the presence of herpesvirus of turkeys (hvt) dna in the feather tips of chickens vaccinated with hvt was assessed by dot blot hybridisation with a probe specific for hvt and lacking homology to mdv dna. only small amounts of hvt dna were detected in the feather tips of chickens that were vaccinated or left in contact with hvt vaccinated chickens. however when chickens were challenged with virulent mdv, hvt dna was detected in the feather tips of vaccinated chickens and the largest amount was det ...199118679997
comparative studies on pathogenical, virological and serological properties of marek's disease virus isolated from japanese quail and chicken.the qm-1 strain of marek's disease virus (mdv) isolated from japanese quail (jq) induced higher mortality (96%) with md lesions in quail than the jm strain of mdv isolated from chickens (c) (21%). in contrast both viruses induced md in 90% of chickens. pathological changes produced in quail inoculated with jq-mdv or c-mdv were similar. however, the incidence of tumour lesions in the duodenum of quail inoculated with jq-mdv was significantly higher. neither virus induced tumour lesions in the duo ...199118679999
marek's disease virus isolates with unusual tropism and virulence for ocular tissues: clinical findings, challenge studies and pathological features.outbreaks of marek's disease (md) were diagnosed in two flocks from the same company. clinical signs, mainly blindness (>90%), but also depression, mild paralysis, and 11 to 12% mortality by 20 weeks of age were observed. md virus, serotype 1 was isolated. the isolates were designated nc-1 (flock 1) and nc-2 (flock 2). challenge experiments were conducted with these isolates and with two reference md virus strains (jm/102w and md5) in unvaccinated, turkey herpesvirus- (hvt) vaccinated and bivale ...199118680042
analysis of marek's disease tumor-associated surface antigen on mdcc-msb1-clo.18 cells.the physico-chemical nature of marek's disease tumor-associated surface antigen (matsa) on marek's disease (md) lymphoblastoid tumor cell line (mdcc-msb1-clo.18) was examined by the cellular enzyme-linked immunosorbent assay (celisa) and the sandwich enzyme-linked immunosorbent assay (elisa) using an anti-matsa immune serum or a monoclonal antibody (mab) 2b9 developed against matsa. our results indicate that matsa is a glycoprotein and 2b9 recognizes an antigenic site in the protein moiety of ma ...19911703127
identification of viral proteins encoded by two dna fragments of herpesvirus of turkeys (hvt).herpesvirus of turkeys (hvt) vaccine is used worldwide to immunize chickens against marek's disease (md). polyclonal antiserum directed against one virus cross-reacts with proteins of the other, while only 5% homology at the dna level was demonstrated between the two viruses. a partial library of hvt dna fragments ranging from 1.5 to 13.5 kbp in size was constructed in pbr 322. under stringent conditions of hybridization (low salt concentration, 10% dextran sulfate at 68 degrees c), two of the c ...19911722930
transformation of t-lymphocyte subsets by marek's disease herpesvirus.marek's disease herpesvirus (mdv)-transformed lymphoblastoid tumor cell lines were characterized for the presence of the surface markers. monoclonal antibodies were used for cd3 (t-cell receptor [tcr] complex), tcr1, tcr2, and tcr3, cd4, cd8, and ia antigen by indirect fluorescence staining followed by microscopic examination or flow cytometry. the lymphoblastoid cell lines were obtained from tumors from chickens infected with mdv (n = 44) or from local lesions induced by inoculation of allogene ...19911847460
isolation of a marek's disease virus (mdv) recombinant containing the lacz gene of escherichia coli stably inserted within the mdv us2 gene.we have isolated a stable, recombinant marek's disease virus (mdv) containing the lacz gene of escherichia coli inserted into the unique short region of the genome. the nucleotide sequence of the insertion site indicates that it lies within a sequence homologous to the us2 gene of herpes simplex virus. stable insertion of the lacz gene into the mdv us2 gene indicates that the site is nonessential for mdv growth in cell culture.19911847475
properties and evolutionary relationships of the marek's disease virus homologues of protein kinase, glycoprotein d and glycoprotein i of herpes simplex virus.the deduced amino acid sequences of the open reading frames (orfs) mapping in the short unique segment (us) of marek's disease virus (mdv) reported in the accompanying paper have been analysed using computer programs to determine their relationships to herpesvirus proteins. analysis of the catalytic domains of protein kinases showed that the mdv kinase (mdv pk) was closely related to the alphaherpesvirus protein kinase mapping in us. the results also showed that the mdv pk was more closely relat ...19911849976
dna sequence and organization of genes in a 5.5 kbp ecori fragment mapping in the short unique segment of marek's disease virus (strain rb1b).the dna sequence of a 5.5 kbp ecori fragment located in the short unique region (us) of the 'highly oncogenic' strain rb1b of marek's disease virus (mdv) was determined. the sequence contained six open reading frames (orfs), four of which were homologous to proteins mapping in the us region of herpes simplex virus type 1 (hsv-1). these include the homologues of hsv-1 protein kinase, glycoprotein d (gd), glycoprotein i (gi) and us2 which is of unknown function. the mdv orfs had a marked bias for ...19911849977
multiple bidirectional initiations and terminations of transcription in the marek's disease virus long repeat regions.marek's disease is an oncogenic disease of chickens caused by a herpesvirus, marek's disease virus (mdv). serial in vitro passage of pathogenic mdv results in amplification of a 132-bp direct repeat in the mdv genome's trl and irl repeat regions and loss of tumorigenicity. this led to the hypothesis that upon such expansion, one or more tumor-inducing genes fail to be expressed. in this report a group of cdnas mapping in the expanded regions were isolated from a pathogenic mdv strain in which th ...19911850022
efficacy of coarse-spray administration of a reovirus vaccine in young chickens.coarse-spray (cs) administration of a commercial s1133 reovirus vaccine in chickens for prevention of clinical viral tenosynovitis (vt) infection was evaluated. in expt. 1, one-day-old specific-pathogen-free (spf) white leghorns were vaccinated with a combination of reovirus, newcastle disease (nd), and infectious bronchitis (ib) vaccines by cs and infectious bursal disease vaccine by the subcutaneous (sq) route. in expt. 2, one-day-old commercial broilers were vaccinated by cs with reovirus vac ...19911851416
inhibition of marek's disease virus dna transfection by a sequence containing an alphaherpesvirus origin of replication and flanking transcriptional regulatory elements.a co-transfection method was used to identify regions of the marek's disease virus (mdv) genome that inhibit plaque formation when introduced along with total dna from mdv-infected chicken embryo fibroblasts into secondary chicken embryo fibroblasts. co-transfections involving mdv plasmids containing the bamhi-d or bamhi-h regions of the genome inhibited plaque formation more than 10-fold. the inhibitory region was localized to a 222-base-pair region that contains a sequence homologous to the co ...19911851421
expression of the a antigen (gp57-65) of marek's disease virus by a recombinant baculovirus.a recombinant baculovirus expressing the a antigen (a ag) of marek's disease virus (mdv) was constructed. in spodoptera fruiperda (sf) cells infected with the recombinant virus, a ag expression was localized to the cell surface. only a small amount of recombinant a ag was detected in the culture supernatant of infected sf cells, but authentic a ag is mainly secreted into the culture supernatant of mdv-infected chicken embryo fibroblasts. cell surface-associated recombinant a ag seemed to be slig ...19911851809
the inhibitory effects of oligonucleotides, complementary to marek's disease virus mrna transcribed from the bamhi-h region, on the proliferation of transformed lymphoblastoid cells, mdcc-msb1.an oligonucleotide complementary to the splice donor sequence of the 1.8 kb gene family produced from the bamhi-h region of marek's disease virus (mdv) dna inhibited the proliferation of the mdv-derived lymphoblastoid cell line, mdcc-msb1 (msb-1), but not that of the avian lymphoid leukosis-derived lymphoblastoid cell line, lscc-bk3. colony formation in soft agar was also inhibited by treatment of msb-1 cells with the antisense oligonucleotide. it is hypothesized that expression of the 1.8 kb ge ...19911851810
inverted repeat regions of marek's disease virus dna possess a structure similar to that of the a sequence of herpes simplex virus dna and contain host cell telomere sequences.the genomic structure of marek's disease virus (mdv) is similar to those of the alphaherpesviruses herpes simplex virus (hsv) types 1 and 2. sequence analysis of the junction region between the long component (l) and the short component (s) revealed the existence of an a-like sequence, similar in structure to the a sequence of hsv-1. further study revealed that the mdv genome contains five copies of the a-like sequence within the long terminal repeat region as well as in the short terminal repea ...19911851854
transforming potential is detectable in arteriosclerotic plaques of young animals.the carcinogen-treated cockerel is a model for studying the early stages of arteriosclerotic plaque development. carcinogen administration accelerates arteriosclerotic plaque development in cockerels, and transforming elements are present in dna from advanced human plaques. in this study, we asked whether transforming elements could also be detected at early stages of plaque development in cockerels. nih3t3 cells were transfected with dna from plaques isolated from carcinogen-treated cockerels a ...19911905951
effect of aflatoxin b1 on the efficacy of turkey herpesvirus vaccine against marek's disease.the effect of feeding aflatoxin b1 (afb1) (0.5 ppm) was studied in young chicks. the frequency and the severity of gross and microscopic lesions of marek's disease were significantly higher in those birds which had been vaccinated with turkey herpesvirus (hvi) and birds challenged with marek's disease virus which had been given afb1 in the feed than in those given normal feed. the protective efficacy of hvt vaccine, as judged on the basis of gross and histopathological lesions, was 86.1 and 77.3 ...19911910199
immunopathology of marek's disease in quails: presence of antinuclear antibody and immune complex.antinuclear antibody (ana), a marker for autoimmune reactions, was detected in the sera of quails with marek's disease (md). the autoantibody was detected 3 weeks after infection in quails infected with chicken marek's disease virus and 4 weeks after infection in quails infected with quail marek's disease virus. the ana titers were low and ranged from 10 to 40. a speckled type of nuclear fluorescence was the characteristic staining feature. in addition to the presence of ana, immune complexes (i ...19911647066
importance of cell-mediated immunity in marek's disease and other viral tumor diseases.cell-mediated immune (cmi) responses to viral tumor diseases are often used as examples of the importance of antiviral and antitumor immunity in chickens. especially, reticuloendotheliosis virus (rev) and marek's disease herpesvirus (mdv) are used as models to study the development of cytotoxic t-lymphocytes against viral and tumor antigens and activation of natural killer (nk) cells. major histocompatibility complex class i-restricted, antiviral cytotoxic t-lymphocytes expressing cd4-/cd8+ mark ...19911649464
the early pathogenesis in chicken inoculated with non-pathogenic serotype 2 marek's disease virus.a newly cloned serotype 2 marek's disease virus (mdv), strain ml-6, was inoculated via the nasal cavity in specific-pathogen-free chicks to examine early virus replication and the expression of marek's disease (md)-related antigens. following inoculation, viral intracellular antigens (vias) were detected in lymphoid organs (bursas and spleens) between 5 and 14 days post inoculation (pi), in feather follicles between 14 and 30 days pi, and in lungs at 3 days pi by the immunohistopathological stai ...19911650601
cloning, sequencing, and functional analysis of a marek's disease virus origin of dna replication.previously, we isolated a replicon from a defective marek's disease virus (mdv), analogous to defective herpes simplex viruses (amplicons). defective viruses contain cis-acting elements required for dna synthesis and virus propagation such as an origin of dna replication and a packaging-cleavage signal site. in this report, the mdv replicon was utilized to locate an origin of mdv dna replication. a comparison of mdv replicon sequences with other herpesvirus replication origin sequences revealed ...19911656099
identification of a novel transcription factor, acf, in cultured avian fibroblast cells that interacts with a marek's disease virus late gene promoter.interactions between factors in duck and chick embryo fibroblast (def and cef, respectively) nuclear extracts and the marek's disease virus (mdv) gp57-65 gene promoter were investigated. results of in vitro transcription and gel mobility-shift assays indicated that multiple cellular factors interact with 5'-flanking sequences of the mdv gp57-65 gene. one sequence-specific dna binding activity (termed acf for avian cell factor(s)) was identified by interaction of def and cef nuclear extract prote ...19911656607
structural analysis and transcriptional mapping of the marek's disease virus gene encoding pp38, an antigen associated with transformed cells.the gene encoding a marek's disease virus (mdv) pp38 phosphoprotein has been identified, sequenced, and localized to the bamhi h fragment to the left of the putative mdv origin of replication. the open reading frame was defined by sequencing of a lacz-pp38 fusion protein gene from a lambda gt11 expression library. the entire open reading frame is 290 amino acids long and codes for a protein with a calculated molecular weight of 31,169, compared with the size of 38 kda of the phosphorylated form ...19911658357
antibody directed against marek's disease-associated tumor surface antigen can be eluted from marek's disease tumor cells.antibody directed against marek's disease-associated tumor surface antigen (matsa) was eluted from tumor cells of lymphomas and peripheral blood lymphocytes that were isolated from marek's disease virus-infected chickens. feather follicular marek's disease virus (mdv) antigen could not be demonstrated with this antibody by indirect immunofluorescent (if) staining. monoclonal antibody directed against matsa could completely block the activity of eluted antibody and vice versa. by indirect if stai ...19911659032
humoral immune responses to inactivated oil-emulsified marek's disease vaccine.when inactivated md11/75c vaccine was inoculated into 1-day-old chickens, it stimulated antibodies detectable by enzyme-linked immunosorbent assay (at a titer of 6400) and indirect fluorescent antibody test (at a titer of 640), but lacking virus-neutralizing activity. chickens passively inoculated with these antibodies were protected against bursal atrophy, weight loss, and early mortality when challenged with the virulent md5 strain of marek's disease virus (mdv). that led to the conclusion tha ...19911659363
restriction endonuclease analysis of marek's disease virus dna: differentiation of viral strains and determination of passage history.the restriction endonuclease (re) patterns of dna from serotype 1 marek's disease viruses (mdvs) are unique to serotype 1 viruses and can also be used to differentiate between low and high cell-culture-passaged viruses. we compared the re patterns of dna from seven serotype 2 and 3 mdvs before and after serial in vitro passage. passage of four serotype 2 strains resulted in a variety of changes in the re pattern. individual strains within a serotype exhibited unique restriction patterns that all ...19911659367
purification and characterization of infectious marek's disease virus genomes using pulsed field electrophoresis.marek's disease virus (mdv) is an acutely oncogenic avian herpesvirus. the tightly cell-associated in vitro growth characteristics of mdv present unique problems when attempting to purify, analyze, and manipulate mdv genomes. to facilitate molecular characterization of mdv, contour-clamped homogeneous electric fields electrophoresis (chef) was used to purify infectious mdv genomes. chef techniques were optimized for evaluation of total genome size and alterations in structure which occur during ...19911660199
nucleosomal structure of marek's disease virus genome in transformed lymphoblastoid cell lines, mdcc-msb1 and mdcc-rp1.the latent mdv (marek's disease virus) genomes are folded into nucleosomal structures in both virus-productive and -nonproductive lymphoblastoid cell lines, mdcc-msb1 (msb-1) and -rp1 (rp-1), respectively. there was no difference between transcriptionally active and inactive regions of mdv genome with regard to nucleosomal patterns. in order to investigate whether nucleosomal structure is correlated with the repression of the transcription of mdv genome in lymphoblastoid cells, we examined the d ...19911661363
monospecific antibodies to marek's disease virus antigen b dimer (200 kda) and monomer (130 and 60 kda) glycoproteins neutralize virus infectivity and detect the antigen b proteins in infected cell membranes.monospecific antibodies were prepared by nitrocellulose blot immunoaffinity to 3 polypeptide components of the host-membrane associated b antigen of marek's disease herpesvirus (mdv) and to its soluble a antigen. the b antigen comprised a 200 kda dimer which is 2-mercaptoethanol (2-me) labile, a monomer of 130 kda and a 60 kda protein, both of which are 2-me resistant. cross-immunoblotting studies showed that the anti-dimer antibody recognized the dimer protein as well as the 130 and 60 kda comp ...19911662035
proliferation of chicken lymphoblastoid cells after in vitro infection with marek's disease virus.activated, thymus-derived (t) lymphoblasts were exposed to marek's disease virus and cultivated in attempts to induce in vitro transformation. after 9 to 15 days, colonies or small clusters of proliferating lymphoblasts were observed in cultures from three of a total of 122 attempts. these developed into proliferating cell cultures that resembled conventional marek's disease (md) lymphoblastoid cell lines in terms of growth characteristics and morphology. all proliferative cultures were unusual ...19911664718
attenuated revertant serotype 1 marek's disease viruses: safety and protective efficacy.in earlier studies, a revertant serotype 1 marek's disease virus (mdv), clone md11/75c/r2, was found to be a highly protective vaccine virus but was mildly pathogenic for susceptible chickens. the term "revertant" indicates that the virus, after attenuation, gained virulence following backpassage in chickens. the present study is an attempt to develop a more attenuated but still protective vaccine virus from md11/75c/r2. forty-two derivative viruses or clones from md11/75c/r2 were evaluated. two ...19911664721
deletion within the cyp17 gene together with insertion of foreign dna is the cause of combined complete 17 alpha-hydroxylase/17,20-lyase deficiency in an italian patient.the molecular basis of 17 alpha-hydroxylase/17,20-lyase deficiency syndrome in a 14-yr-old 46,xy italian patient was investigated by amplification, subcloning, and sequencing of specific exonic sequences from genomic dna samples. a homozygous mutation, consisting of a 518-basepair (bp) deletion combined with a 469-bp insertion, was identified in the cyp17 gene of the patient. the deletion spans much of exon ii, the whole intron 2, and a portion of exon iii. a part (156 bp) of the inserted sequen ...19911665206
vaccination against herpesvirus, fiction or reality?against herpes simplex type 1 (hsv-1) there are commercially available vaccines which may induce protection against symptoms of primary infections, but not against establishment of latency. effective animal vaccines have been developed against herpes simplex-like viruses, for example pseudorabies vaccine for pigs, and an experimental vaccine can protect cattle against infection with infectious bovine rhinotracheitis (ibr) virus. there are also commercially available effective live vaccines again ...19911666442
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
isolation and characterization of cdnas from bamhi-h gene family rnas associated with the tumorigenicity of marek's disease virus.it has been reported that loss of the tumorigenic potential of attenuated marek's disease virus (mdv) is strongly associated with amplification of the 132-bp repeat sequences found within the bamhi-d and bamhi-h fragments contained within the long terminal repeat and the long internal repeat, respectively. the expansion of this region results in loss of transcripts that are 3.8, 3.0, and 1.8 kbp long that are produced by tumorigenic strains of mdv. this evidence suggests that production of one o ...19921279201
sequence determination and genetic content of an 8.9-kb restriction fragment in the short unique region and the internal inverted repeat of marek's disease virus type 1 dna.the dna sequence (8.9 kb) covering about 70% of the short unique region (us) and part of the short inverted repeat of the marek's disease virus type 1 ga strain was determined. computer analysis of the sequence showed the presence of nine potential open reading frames (orfs), consisting of more than 300 nucleotides in the us region. of these orfs, four were found to be homologous to us10 (minor virion protein), us3 (protein kinase), us2, and us6 (gd) in the us region of alpha-herpesvirus herpes ...19921282282
isolation of chicken anaemia virus from broiler chickens.chicken anaemia virus (cav) infection was demonstrated, by both serology and virus isolation, in 1- to 6-week-old broiler chickens originated from various parent flocks in hungary. total losses in the broiler flocks were estimated at 7 to 8% and about 25% of the chickens failed to reach target body mass by the 7th week of life. the clinical signs, postmortem lesions and histopathological changes of the affected chickens were similar to those of naturally occurring cav-induced infectious anaemia ...19921298167
identification of a unique marek's disease virus gene which encodes a 38-kilodalton phosphoprotein and is expressed in both lytically infected cells and latently infected lymphoblastoid tumor cells.the identification of unique marek's disease (md) virus (mdv) antigens expressed not only in lytically infected cells but also in latently infected md lymphoblastoid tumor cell lines is important in understanding the molecular mechanisms of latency and transformation by mdv, an oncogenic lymphotropic herpesvirus of chickens. through cdna and nucleotide sequence analysis, an open reading frame (designated the pp38 orf) which encodes a predicted polypeptide of 290 amino acids was identified in bam ...19921309266
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
recombinant fowlpox viruses expressing the glycoprotein b homolog and the pp38 gene of marek's disease virus.two marek's disease virus (mdv) genes, one homologous to the glycoprotein b gene of herpes simplex virus and encoding the b antigen complex and the other encoding a 38-kda phosphorylated protein (pp38), were inserted into the fowlpox virus (fpv) genome under the control of poxvirus promoters. randomly selected nonessential regions of fpv were used for insertion, and the vaccinia virus 7.5 kda polypeptide gene promoter or a poxvirus synthetic promoter was used for expression of mdv genes. gene ex ...19921310754
protection against marek's disease by a fowlpox virus recombinant expressing the glycoprotein b of marek's disease virus.fowlpox virus (fpv) recombinants expressing the glycoprotein b and the phosphorylated protein (pp38) of the ga strain of marek's disease virus (mdv) were assayed for their ability to protect chickens against challenge with virulent mdv. the recombinant fpv expressing the glycoprotein b gene elicited neutralizing antibodies against mdv, significantly reduced the level of cell-associated viremia, and, similar to the conventional herpesvirus of turkeys, protected chickens against challenge with the ...19921310755
sequence determination of cdna clones of transcripts from the tumor-associated region of the marek's disease virus genome.the number of 132-bp tandem direct repeats within the long inverted repeat region of the marek's disease virus type 1 (mdv1) genome increases concomitantly with the loss of oncogenicity during serial passages in cultured cells. twelve clones carrying the 132-bp sequence were isolated from a cdna library constructed from chicken embryo fibroblasts infected with the mdv1 md5 strain. through sequence analysis of a cdna clone and primer extension analysis, the corresponding mrna was found to be a li ...19921312278
investigations of environmental conditions during cluster indicate probable vectors of unknown exogenous agent(s) of multiple sclerosis.during the tail-end of an active cluster several environmental investigations indicated that wildbirds were very probably the vectors of the unknown exogenous agent of ms. canine distemper and genetic-autoimmune theories were very definitely eliminated because of the unusual pattern of the cluster. studies of several avian pathogens unveiled marek's (mdv) and/or ibd (gumboro) as the most likely candidates for exogenous agent of ms.19921312422
expression of the marek's disease virus (mdv) homolog of glycoprotein b of herpes simplex virus by a recombinant baculovirus and its identification as the b antigen (gp100, gp60, gp49) of mdv.a gene encoding a homolog of glycoprotein b of herpes simplex virus (gb homolog) has been identified on the marek's disease virus (mdv) genome (l. j. n. ross, m. sanderson, s. d. scott, m. m. binns, t. doel, and b. milne, j. gen. virol. 70:1789-1804, 1989); however, the molecular and immunological characteristics of the gene product(s) are still not clear. in the present study, the gb homolog of mdv was expressed in insect cells by a recombinant baculovirus, and it was characterized to determine ...19921313890
marek disease virus encodes a basic-leucine zipper gene resembling the fos/jun oncogenes that is highly expressed in lymphoblastoid tumors.marek disease virus (mdv) is a herpesvirus of chickens that induces t lymphomas within 3 weeks of infection. the short latency and polyclonal nature of mdv-induced tumors have suggested that the virus may encode one or more direct-acting oncogenes. to date, however, no mdv-specific tumor antigens or candidate transforming genes have been demonstrated. in this paper, we report the identification of a mdv gene encoding a protein with homology to the leucine-zipper class of nuclear oncogenes. it al ...19921315048
comparison of indirect immunofluorescence (if) test with enzyme-linked immunosorbent assay (elisa) in screening of hybridomas to very virulent marek's disease virus.for identifying virus-specific antigens of marek's disease virus (mdv), monoclonal antibodies (mabs) against strain md5 of serotype 1, which is known to be a very virulent mdv (vvmdv), were isolated. fifty-eight hybridoma clones that secreted mabs against vvmdv were obtained. of these mabs, 36 gave positive reactions in an immunofluorescence (if) test, and 22 gave positive reactions on enzyme-linked immunosorbent assay (elisa). none of these mabs gave positive reactions in both the if test and e ...19921316535
search for the origin of multiple sclerosis by first identifying the vector.by intensive study of environmental conditions during the final stages in an active cluster area, an attempt is made to crack the enigmatic deadlock concerning the origin and etiological cause of multiple sclerosis (ms). previous investigations of other cluster areas have emphasized the probability that the outbreaks of ms were most likely caused by an unknown exogenous environmental agent, but unfortunately, the studies were conducted several years after the epidemics had occurred, making it vi ...19921316536
detection of infectious laryngotracheitis virus infected cells with cloned dna probes.a genomic library of infectious laryngotracheitis virus (iltv) dna bamh1 fragments was prepared and two cloned fragments were evaluated for their potential as probes for the detection of iltv infected cells. the virus was purified by a modified sucrose density gradient procedure for the isolation of pure iltv dna. a genomic library was constructed using bamh1-digested iltv dna and pgem7 as a vector. a 1.1 kb cloned bamh1 fragment of iltv dna was tested in a slot or dot blot assay for the detecti ...19921316798
expression of the marek's disease virus homolog of herpes simplex virus glycoprotein b in escherichia coli and its identification as b antigen.marek's disease (md) is an oncogenic disease of chickens caused by md virus (mdv). among the major glycoproteins found in mdv-infected cells are gp100, gp60, and gp49, detected by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis with antisera previously shown to be reactive with b antigen in immunodiffusion analysis. following treatment with tunicamycin (tm), an inhibitor of n-linked glycosylation, the same sera were reported to detect two molecules call ...19921318409
suppression mediated in vitro by marek's disease virus-transformed t-lymphoblastoid cell lines: effect on lymphoproliferation.marek's disease virus (mdv)-transformed lymphoblastoid cells (mdcc-msb1, -pa9 and -rp1) added to chicken splenic lymphocytes after treatment with mitomycin, suppress the lymphoproliferative response to t-cell mitogens (concanavalin a or phytohemagglutinin) by 40-70%. this suppressive activity was observed in syngeneic as well as in allogeneic combinations of cell lines and responder lymphocytes. the suppressive effect disappeared when the addition of md-transformed cell lines to the responder cu ...19921318599
influence of turkey herpesvirus vaccination on the b-haplotype effect on marek's disease resistance in 15.b-congenic chickens.eight recently developed 15.b congenic lines of chickens were tested for marek's disease (md) resistance by intra-abdominal injection of cell-associated preparations of md virus of a virulent strain (jm), a very virulent strain (md5), or md5 after vaccination with turkey herpesvirus (hvt) strain fc126. chickens of the 15.n congenic line (b15b21 or b21b21) were very resistant to jm-induced md, in contrast to chickens homozygous for the b-haplotypes 2, 5, 12, 13, 15, or 19. after md5 infection, mo ...19921320867
complete nucleotide sequence of the marek's disease virus icp4 gene.the marek's disease virus (mdv) gene encoding a homologue to the icp4 protein of herpes simplex virus has been mapped to bamhl fragment a based on the physical map of the mdv genome (fukuchi et al., 1984). the gene lies completely within the inverted repeat flanking the unique short region of the genome. the complete nucleotide sequence of the mdv icp4 gene has been determined. the coding region is 4245 nucleotides long and has an overall g+c content of 52%. the mdv icp4 protein is predicted to ...19921322594
persistence of marek's disease virus in a subpopulation of b cells that is transformed by avian leukosis virus, but not in normal bursal b cells.previous studies have described an augmentation of avian leukosis virus (alv)-induced lymphoid leukosis in chickens that were coinfected with a serotype 2 marek's disease virus (mdv) strain, sb-1. as a first step toward understanding the mechanism of this augmentation, we have analyzed the tropism of the mdv for the alv-transformed b cell. after hatching, chickens were coinfected with alv and a nonpathogenic strain of mdv, sb-1. seventy primary and metastatic alv-induced lymphomas that developed ...19921326647
disulfide bond structure of glycoprotein d of herpes simplex virus types 1 and 2.glycoprotein d (gd) is a structural component of the herpes simplex virus envelope which is essential for virus penetration. the function of this protein is highly dependent on its structure, and its structure is dependent on maintenance of three intact disulfide bonds. gd contains six cysteines in its ectodomain whose spacing is conserved among all its homologs in other alphaherpesviruses as well as marek's disease virus. for other proteins, conservation of cysteine spacing correlates with cons ...19921328685
the restriction endonuclease map of marek's disease virus (mdv) serotype 2 and collinear relationship among three serotypes of mdv.a bamhi, ecori, and xhoi restriction endonuclease map of marek's disease virus (mdv) serotype 2 (mdv2) dna was constructed by double-digest analyses of 28 cloned bamhi and 11 cloned ecori fragments of mdv2 dna, followed by hybridization tests of these cloned bamhi dna fragments with electrophoretically separated digests of mdv2-infected cell dna. on this map, mdv2 genome consisted of two segments which have unique regions inserted between two inverted repeat regions as observed in mdv serotype 1 ...19921329331
[resistance to viral-induced tumors in the chicken]. 19921329605
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
differentiation of oncogenic and nononcogenic strains of marek's disease virus type 1 by using polymerase chain reaction dna amplification.differentiation of oncogenic and nononcogenic strains of marek's disease virus type 1 (mdv1) was attempted by polymerase chain reaction (pcr) using the primers chosen from the sequence within the long inverted repeats of mdv1 dna. pcr of the dnas extracted from oncogenic-strain-infected cells and marek's disease tumor cell lines produced a major product containing two or three copies of 132-base-pair (bp) repeat units, whereas pcrs of the dnas extracted from nononcogenic-strain-infected cells yi ...19921329711
chicken anemia virus causes apoptosis of thymocytes after in vivo infection and of cell lines after in vitro infection.after infection of 1-day-old chickens, chicken anemia virus (cav) causes a complete depletion of the thymic cortex by day 14. since cell death can be caused either by necrosis or by apoptosis, we investigated which type of cell death occurs after in vivo and in vitro infections with cav. using electron microscopy and biochemical methods, we demonstrated that cav induces apoptosis of cortical thymocytes after in vivo infection and of lymphoblastoid cell lines after in vitro infection. at day 13 a ...19921331529
[gene expression of marek's disease virus--in relation to tumor induction and vaccination]. 19921332123
marek's disease virus-transformed chicken t-cell lines respond to lymphokines.current assays for chicken interleukin-2 (il-2) utilize mitogen-activated lymphocytes. however, very high inter-assay variability and sporadic high background proliferation limit their usefulness. in view of the above, several marek's disease virus (mdv)-transformed t-cell lines (which grow well in a serum-supplemented medium) were tested for a response to chicken il-2 when grown in serum-free media. five of six lines examined showed a dose-dependent proliferative response to chicken t-cell cond ...19921332253
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
plasmid-associated effects on test gene expression and marek's disease virus plaque formation during recombination trials.marek's disease virus (mdv), a herpesvirus of avian origin, is being examined for suitability as a vector for expressing foreign genes. we observed that plasmids encoding the lacz gene of e. coli under the control of either the herpes simplex virus alpha 4 immediate-early promoter or the cytomegalovirus major immediate-early promoter inhibited mdv plaque formation. plaque numbers were decreased by one-third, and transient expression of the beta-galactosidase reporter gene was increased by up to ...19921333474
antigen b of the vaccine strains of marek's disease virus and herpesvirus of turkeys presents heat-labile group and serotype specific epitopes.antigen b of marek's disease virus (mdv) vaccine strains cvi988 and sb1 (serotypes 1 and 2) and herpesvirus of turkeys (hvt) (serotype 3) is formed of oligomeric molecules that are detergent-stable and heat-labile. immunoblots of native membranal extracts of hvt- and mdv-infected chick embryo fibroblasts (cef) probed with avian monoserotypic antisera, murine monoclonal antibodies (mab) to the three serotypes and mab to antigen b showed two distinct patterns of high molecular weight oligomeric an ...19921333751
polymerase chain reaction for differentiation between pathogenic and non-pathogenic serotype 1 marek's disease viruses (mdv) and vaccine viruses of mdv-serotypes 2 and 3.a polymerase chain reaction (pcr) test based on primers flanking the 132 bp tandem repeat in pathogenic mdv-1 dna was developed. these primers amplify a dimer or a trimer 132 bp repeat in pathogenic mdv-1 dna from blood and organs of commercial chickens with marek's disease (md) symptoms. using the same primers in a radioactive pcr test, it was possible to distinguish between vvmdv-1 and the non-pathogenic mdv-1 cvi-988 vaccine in which the 132 bp repeats in the dna were increased up to 9 repeat ...19921335457
use of a soluble tetrazolium/formazan assay for chicken cells.we evaluated a soluble tetrazolium/formazan assay using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl ]-2h- tetrazolium hydroxide (xtt) for chicken cell growth. fifty microliter of solution containing 1 mg/ml of xtt and 0.025 mm phenazine methosulfate was added to the cells in a well of 96-well microplate. after 4 hr incubation at 37 degrees c, the absorbance was measured at 490 nm. under this condition, absorbances were well correlated with cell number of marek's disease tu ...19921335760
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
[isolation and study of biological properties of non-oncogenic marek's disease herpesviruses in chickens. 1. characterization in vitro].the present paper deals with isolation of nonpathogenic chicken herpesviruses of marek's disease (md) and their in vitro characterization. two strains of herpesviruses (denoted as vub-m and -k isolates) were isolated from leucocytes separated from the blood of fattening chickens without clinical and pathomorphological symptoms of marek's disease and from the blood of laying hens of a laboratory nonvaccinated flock without clinical symptoms, but with almost 100% incidence of precipitating md anti ...19921337955
[isolation and study of biological properties of non-oncogenic marek's disease herpesviruses in chickens. 2. characterization in vivo].in a previous paper (jurajda and halouzka, 1992) the in vitro isolation of two chicken herpesviruses of marek's disease (m and k strains) was described and results of their characterization were presented. the present paper deals with the in vivo characterization of both isolates: pathogenicity and immunosuppressive characteristics of isolates were observed in a five-week test period, along with the development and production dynamics of antibodies and viral antigen in the feathers of experiment ...19921337956
marek's disease virus-mediated enhancement of avian leukosis virus gene expression and virus production.direct interaction between two viruses in coinfected cells may promote replication and pathogenesis of one or both virus types. synergism between herpesviruses and retroviruses is an important factor in diagnosis, treatment, and prevention of animal and human diseases. in birds, marek's disease virus (mdv) may be an important cofactor in avian leukosis virus induced disease. infection of susceptible cells with non-oncogenic serotype 2 mdv, an avian herpesvirus, and rous-associated virus type 2 ( ...19921370125
protection of chickens from newcastle and marek's diseases with a recombinant herpesvirus of turkeys vaccine expressing the newcastle disease virus fusion protein.recombinant strains of herpesvirus of turkeys (hvt) were constructed that contain either the fusion protein gene or the hemagglutinin-neuraminidase gene of newcastle disease virus (ndv) inserted into a nonessential gene of hvt. expression of the ndv antigens was regulated from a strong promoter element derived from the rous sarcoma virus long terminal repeat. recombinant hvt strains were stable and fully infectious in cell culture and in chickens. chickens receiving a single intra-abdominal inoc ...19921485872
characterization of very virulent marek's disease viruses isolated in japan.pathogenicity of two isolates of marek's disease virus (mdv), ms1 and ms2, from chickens was examined in two genetically different strains of chickens, md-susceptible p-2 chickens and less susceptible pdl-1 chickens. the isolates induced an early mortality syndrome unassociated with lymphoproliferative lesions in p-2 chickens. there were no significant differences in pathogenicity between our isolates and the md/5 strain of very virulent mdv (vvmdv) in both p-2 and pdl-1 chickens. protective ind ...199218670921
jmv-1 stimulation of avian natural killer cell activity.the phenotypic characterization of the non-productive, marek's disease virus-transformed, lymphoblastoid cell line, jmv-1 and the immunological effects of its cell-free culture supernatant were examined. it was verified that the jmv-1 cell line is an activated t-helper cell line that bears antigens indicative of t-cell activation, and it is not a natural killer or cytotoxic t-cell line. furthermore, the jmv-1 cell line was shown to be unique among marek's disease-transformed cell lines in that j ...199218670936
cytopathology caused by the ac-1 isolate of marek's disease virus in the feather follicle epidermis.the ac-1 strain of marek's disease herpesvirus (mdv), recently isolated from an outbreak of marek's disease in vaccinated chickens, was used for intraperitoneal inoculation of one-day-old single comb white leghorns. chicks were necropsied 12 to 32 days post inoculation and skin was collected for electron microscopic studies. this paper focuses on early stages of mdhv development in feather follicle epithelial cells and on cytoplasmic changes that occur in formation and release of virus particles ...199318671018
detection of reticuloendotheliosis virus infection using the polymerase chain reaction.the polymerase chain reaction (pcr) was shown to be a sensitive and useful method for detection of infection by members of the group of avian reticuloendotheliosis virus (rev). genomic dna extracted from chick embryo fibroblasts (cefs), blood and tumours of chickens experimentally infected with the spleen necrosis virus (snv) strain of rev was used as the target for chain elongation. deoxyoligonucleotide primers that encompass a portion of the unique 3', repeat and unique 5' region of the long t ...199318671039
effects of age at infection with serotype 2 marek's disease virus on enhancement of avian leukosis virus-induced lymphomas.inoculation of susceptible, 15i5 x 7i chickens with serotype 2 marek's disease virus (mdv) at various ages had no influence on the development of avian leukosis virus (alv)-induced viraemia or antibody in chickens infected with alv and turkey herpesvirus (hvt) at hatch. however, the incidence of alv-induced lymphoma (ll) was significantly higher in chickens infected with alv and hvt at hatch and inoculated with serotype 2 mdv up to 6 weeks of age than in chickens receiving serotype 2 mdv at 8 to ...199318671041
latency and reactivation of marek's disease virus in b lymphocytes transformed by avian leukosis virus.the physical and biological state of the marek's disease virus (mdv) genome in avian leukosis virus (alv)-transformed cells is characterized using cell lines established from alv tumours co-infected with the sb-1 strain of mdv. the mdv genome within the alv-transformed cells was found to be methylated at 5' cpg 3' dinucleotides. less than 2% of the tumour cells expressed mdv antigen and only one virus plaque that was characteristic of an mdv infection was noted when tumour cells were cocultured ...19937691987
complex role of gamma-herpesviruses in multiple sclerosis and infectious mononucleosis.various researchers over the past few years have demonstrated higher titers and higher incidence rates of epstein-barr virus (ebv) antibodies in multiple sclerosis (ms) patients compared to controls. these findings were tentatively attributed to immunoregulation abnormalities of ms or perhaps to some other relationship with the ms syndrome yet to be determined. meanwhile, an intensive environmental investigation of the key west cluster just before it ended and for two years afterwards produced t ...19937907407
[the isolation of the herpes virus from the white crane and a study of its properties].isolation of a virus agent from sick white cranes in national oka preserve is described. the results of virological and serological studies on specimens from the sick birds permitted a conclusion that the infection in the cranes could be induced by avian herpes virus.19938073746
the 132 bp repeats are present in rna transcripts from 1.8 kb gene family of marek disease virus-transformed cells.marek's disease virus (mdv) is an oncogenic, lymphotropic herpesvirus of chickens: loss of its tumourigenic potential is believed to be associated with amplification of the 132 bp repeats from bamhi-d and bamhi-h fragments. we prepared cdna libraries from rpl1 and msb1 cell line and from the latter we identified a clone which spanned the 132 bp repeats within the bamhi-h fragment. by sequencing and northern blot analysis we confirmed the presence of the 132 bp repeats. the analysis by pcr made o ...19938105666
assembly pathway of avian infectious laryngotracheitis virus.infectious laryngotracheitis virus (iltv) is the causative agent of a highly contagious upper respiratory tract infection in chickens. at present, iltv vaccines are not satisfactory because of development of a latent carrier status in vaccinated birds. development of recombinant virus vaccines has been hampered by the limited information available on the molecular level and organization of this virus. we isolated 3 assembly intermediates, designated a, b, and c from iltv-infected cells. analysis ...19938116934
nucleotide sequence of the glycoprotein c (gc) homologous gene of marek's disease virus (mdv) serotype 2 and comparison of gc homologous genes among three serotypes of mdv.the sequence analysis of the genomic region of marek's disease virus (mdv) serotype 2 (mdv2) which had homology with the gene encoding mdv serotype 1 (mdv1) homologue of glycoprotein c (gc) of herpes simplex virus revealed that there was a single open reading frame (orf) capable of encoding 479 amino acids. the predicted protein from this orf had strong hydrophobic regions in both the amino and carboxyl termini and several potential n-linked glycosylation sites, as seen in those from the orfs of ...19938117828
c-fos proto-oncogene transient transcription is negatively affected in the ela4-2 transformed rat cell line.to study the effects of the regulatory phosphoprotein icp4 of the herpes simplex virus, (hsv), a dna tumor virus, on the induction of gene expression by the epidermal growth factor (egf), we have constructed a cell line, ela4-2, which constitutively expresses the a-4 gene product. the ela4-2 cells are derived from the rat fibroblast el2, in which egf induces a marked c-fos and c-myc proto-oncogene transcription. here we report that in ela4-2 cells, the gene expression induced by egf was negative ...19938297495
status of marek's disease virus in established lymphoma cell lines: herpesvirus integration is common.six cell lines derived from marek's disease lymphomas of chickens and turkeys were investigated for the status of marek's disease virus (mdv) dna. in the transformed t- and b-cell lines, viral dna could be detected by conventional southern blot hybridization, by gardella gel electrophoresis, and by in situ hybridization of metaphase and interphase chromosomes. integration of viral dna into the host cell chromosome was observed in all cell lines. two to 12 integration sites of viral dna could be ...19938380099
the number of copies of an a-like region in the serotype-3 marek's disease virus dna genome is variable.a 1.2-kilobase-pair dna region (a-like) in the serotype-3 marek's disease virus was directly repeated at the ends of the long (l) and short (s) components of the genome and repeated in the opposite orientation at the junction between the l and s components. four variants from plaque-purified virus that varied in the number of copies of the a-like region were identified. the predominant variant contained one copy at both ends of the genome and at the l-s junction. two other variants contained eit ...19938382396
a double-cos-site vector containing a multiple cloning site flanked by t7 and t3 rna polymerase promoters.a double-cos-site cosmid vector, c2xmcs, contains a multiple cloning site (mcs) with fifteen restriction sites flanked by phage t7 and t3 rna polymerase promoters. the two cos sites in the cosmid vector enable the construction of cosmid libraries from unfractionated partial digests of genomic dna. this simple construct combines the efficiency of a double-cos-site cosmid with the versatility provided by the mcs from pbluescript.19938382653
construction and properties of a turkey herpesvirus recombinant expressing the marek's disease virus homologue of glycoprotein b of herpes simplex virus.a herpesvirus of turkeys (hvt) recombinant containing a 3.9 kbp fragment of marek's disease virus (mdv) dna encoding mdv glycoprotein b (gb), stably integrated into the thymidine kinase (tk) gene of hvt, has been constructed. the replication of the recombinant in chick embryo fibroblasts (cef) was comparable to that of wild-type hvt. the recombinant expressed authentic mdv gb and its processed forms (110k, 65k and 48k) in cef as shown by immunoblotting using an mdv-specific anti-peptide serum. n ...19938383172
avian herpesvirus as a live viral vector for the expression of heterologous antigens.control of marek's disease in the poultry industry has been successfully achieved for several decades by large-scale vaccination of day-old chickens with live herpesvirus of turkeys (hvt) strains. several features of this virus including lack of pathogenicity and long-term immune protection due to a persistent viraemic infection made us decide to use hvt as a live viral vector for the expression of foreign antigens. potential sites for the integration of foreign dna in the unique short region of ...19938383385
influence of b-haplotype on the relative efficacy of marek's disease vaccines of different serotypes.to determine if b-haplotype differentially influences vaccinal immunity to very virulent marek's disease (md) virus challenge, chickens of five 15.b-congenic lines were vaccinated with vaccines representing serotypes 1, 2, and 3. b-haplotype differentially influenced vaccinal immunity to very virulent md virus challenge using vaccines of all three serotypes, and different md vaccines were optimal for some b-haplotypes. regarding specific haplotypes, the 15.b-congenic chickens with b2 and b13 dev ...19938383961
alterations in dna sequence and rna transcription of the bam hi-h fragment accompany attenuation of oncogenic marek's disease herpesvirus.the nucleotide sequences of the bamhi-h fragment of the hprs16 strain of marek's disease virus (mdv) and of its attenuated derivative hprs16/att have been determined. the results show that in addition to the tandem expansion of a 132 bp sequence from two copies in hprs16 virus to eight copies in hprs16/att, nucleotide substitutions, deletions, and insertions were also noted. several potential open reading frames (orfs) were identified. one of these (orf 13) encoded a deduced protein, mol wt 32 k ...19938385839
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