| resistance to marek's disease herpesvirus-induced lymphoma is multiphasic and dependent on host genotype. | genotype-dependent differences in marek's disease (md) susceptibility were identified using 14-day-old line n and 6(1) (resistant) and 151 and 7(2) (susceptible) inbred chickens infected with hprs-16 md virus (mdv). all line 72 chickens developed progressive md. line 15i had fluctuating md-specific clinical signs and individuals recovered. a novel histologic scoring system enabled indices to be calculated for lymphocyte infiltration into nonlymphoid organs. all genotypes had increased mean lesio ... | 2001 | 11280369 |
| the genome of herpesvirus of turkeys: comparative analysis with marek's disease viruses. | the complete coding sequence of the herpesvirus of turkeys (hvt) unique long (u(l)) region along with the internal repeat regions has been determined. this allows completion of the hvt nucleotide sequence by linkage to the sequence of the unique short (u(s)) region. the genome is approximately 160 kbp and shows extensive similarity in organization to the genomes of marek's disease virus serotypes 1 and 2 (mdv-1, mdv-2) and other alphaherpesviruses. the hvt genome contains 75 orfs, with three orf ... | 2001 | 11297687 |
| historical background. | the persisting ancient view of cancer as a contagious disease ended with 19th century scientific investigations which seemed to show it was not. the resulting dogma against an infectious cause for cancer produced great prejudice in the scientific community against the first report of an oncogenic virus by rous early in the 20th century and, even in the 1950s, against gross's finding of a murine leukaemia virus and a murine virus causing solid tumours. the lucké frog renal carcinoma virus was the ... | 2001 | 11313002 |
| in vivo events of retroviral long terminal repeat integration into marek's disease virus in commercial poultry: detection of chimeric molecules as a marker. | the present study demonstrated, for the first time, that not only in vitro, but also in vivo, coinfections with marek's disease virus (mdv) and each of the three avian retroviruses (reticuloendotheliosis virus [rev], avian lymphoid leukosis virus [alv], and alv-j) lead to retroviral long terminal repeat (ltr) integration into mdv. a total of 306 chicken and 59 turkey commercial flocks, submitted for differential avian oncogenic virus diagnosis, served to evaluate the flock mixed virus infection ... | 2001 | 11332471 |
| safety and efficacy of in ovo administration of infectious bursal disease viral vaccines. | in ovo vaccination against marek's disease virus and infectious bursal disease virus (ibdv) in commercial broilers in the united states is common. little information exists as to the safety and efficacy of intermediate ibdv vaccines given in ovo. experiments were initiated to determine the safety and efficacy of three commercially available live intermediate ibdv vaccines by in ovo route. commonly used vaccines were given at 18 days of embryonation to specific-pathogen-free (spf) broiler embryos ... | 2001 | 11332475 |
| coinfection of specific-pathogen-free chickens with marek's disease virus (mdv) and chicken infectious anemia virus: effect of mdv pathotype. | both marek's disease virus (mdv) and chicken infectious anemia virus (ciav) infections are prevalent in chickens throughout the world. in the past decade, mdv strains with increased virulence (very virulent plus mdv pathotype [vv+mdv]) have been isolated. the purpose of this experiment was to determine the effects of coinfection of chickens with ciav and a vv+mdv isolate. specific-pathogen-free chickens were inoculated at 1 day posthatch with rb1b (very virulent mdv pathotype [vvmdv]) only, 584a ... | 2001 | 11332504 |
| marek's disease virus (mdv) encodes an interleukin-8 homolog (vil-8): characterization of the vil-8 protein and a vil-8 deletion mutant mdv. | chemokines induce chemotaxis, cell migration, and inflammatory responses. we report the identification of an interleukin-8 (il-8) homolog, termed vil-8, encoded within the genome of marek's disease virus (mdv). the 134-amino-acid vil-8 shares closest homology to mammalian and avian il-8, molecules representing the prototype cxc chemokine. the gene for vil-8 consists of three exons which map to the bamhi-l fragment within the repeats flanking the unique long region of the mdv genome. a 0.7-kb tra ... | 2001 | 11333897 |
| heparin inhibits plaque formation by cell-free marek's disease viruses in vitro. | the mechanisms of marek's disease virus (mdv) entry to host cells have not yet been analyzed. heparan sulfate (hs) on the cell surface serves as a receptor for several herpesviruses in mammalian species. in this study, we demonstrated that plaque formation by cell-free mdv is inhibited by the addition of soluble heparin to the cell culture. moreover, pretreatment of susceptible cells, chicken embryo fibroblasts, with heparinase, partially reduced infectivity of the cell-free mdv. from these resu ... | 2001 | 11346178 |
| histological evaluation of immune organs in chicken embryos inoculated with marek's disease virus and lymphokines. | the aim of the present study was to evaluate the presence of lymphocytes and granulocytes in different stages of embryonic development and on the first posthatching day. the lymphocytes present in the bursa of fabricius and thymus were evaluated by histological analysis of the yolk sac, bursa of fabricius, thymus, liver and bone marrow of 100 chicken embryos divided into groups and treated with: (i) marek's disease vaccine as viral antigen, (ii) marek's disease vaccine plus lymphokines, (iii) ly ... | 2001 | 11402644 |
| cellular responses in chickens treated with ifn-alpha orally or inoculated with recombinant marek's disease virus expressing ifn-alpha. | mammalian type i interferons (ifn-alpha/beta) are potent mediators of innate antiviral immune responses, in particular through enhancement of natural killer (nk) cell cytotoxicity. recently, chicken ifn-alpha (chifn-alpha) has been identified and shown to ameliorate newcastle disease virus (ndv) infection when given to chickens at relatively high concentrations in the drinking water. in this report, the effect of recombinant chifn-alpha (rchifn-alpha) on nk cell cytotoxicity was examined using ( ... | 2001 | 11429159 |
| glycoproteins h and l of marek's disease virus form a hetero-oligomer essential for translocation and cell surface expression. | glycoproteins h and l form a hetero-oligomeric complex (gh-l) which plays an important role in virus entry to host cells and cell-to-cell infection in herpesviruses. interaction of gh and gl is considered to be critical for the biological function of these two glycoproteins. to investigate the interaction of mdv gh and gl, both gh and gl were expressed in in vitro cell culture systems using indirect immunofluorescence assay with gh and gl antibodies. the results suggested that co-expression of g ... | 2001 | 11448035 |
| growth hormone interacts with the marek's disease virus sorf2 protein and is associated with disease resistance in chicken. | marek's disease (md) is a lymphoproliferative disease of chickens induced by a herpesvirus, the md virus (mdv). because md is a significant economic problem to the poultry industry, there is great interest in enhancing genetic resistance, which is controlled by multiple genes. the influence of the mhc has been clearly demonstrated, and several relevant quantitative trait loci have been mapped; however, no single gene influencing md resistance has been identified. transcription of sorf2 is pertur ... | 2001 | 11470922 |
| resistance to marek's disease virus in white leghorn chickens: effects of avian leukosis virus infection genotype, reciprocal mating, and major histocompatibility complex. | genetic improvement for resistance to marek's disease (md) in chickens continues to be of interest to the poultry industry. the aims of this study were to identify effects of the mhc on the molecular level and of avian leukosis virus (alv) resistance status on md mortality in two noninbred white leghorn chicken lines that differ in b blood group type. previously, within each of the chicken lines, sublines had been selected for resistance or susceptibility to alv infection with subgroups a and b. ... | 2001 | 11495456 |
| attenuation of marek's disease virus and study of its properties in two different cell cultures. | | 1970 | 11515447 |
| early posthatch protection against marek's disease in chickens vaccinated in ovo with a cvi988 serotype 1 vaccine. | cvi988, a serotype 1 marek's disease virus (mdv), was used as an in ovo vaccine in specific-pathogen-free chickens to determine if this virus induces early posthatch protection against marek's disease as has been shown previously for turkey herpesvirus. mdv cvi988 was injected at embryonation day (ed) 17 (group 1) or at hatch (group 2). a third group (group 3) was left unvaccinated. at 1, 2, 3, 4, 5, and 7 days of age, chickens from each group were sampled and examined as follows: a) single-cell ... | 2001 | 11569737 |
| marek's disease virus infection in the brain: virus replication, cellular infiltration, and major histocompatibility complex antigen expression. | marek's disease virus (mdv) infection in the brain was studied chronologically after inoculating 3-week-old chickens of two genetic lines with two strains of serotype i mdv representing two pathotypes (v and vv+). viral replication in the brain was strongly associated with the development of lesions. three viral antigens (pp38, gb, and meq) were detected in the brain of infected chickens. marked differences between v and vv+ pathotypes of mdv were identified for level of virus replication, time ... | 2001 | 11572556 |
| lack of contact transmission of recombinant marek's disease virus type 1 expressing the fusion protein of newcastle disease virus. | to clarify the level of excretion of a recombinant marek's disease virus type 1 (rmdv1) that confers good protection in chickens against both marek's and newcastle diseases, even in the presence of maternal antibodies, contact transmission tests were conducted. naïve chickens kept in the same cage or room with chickens inoculated with rmdv1 did not produce antibodies against mdv1 or the fusion protein of newcastle disease virus. moreover, the rmdv1 was not isolated from the dander of chickens in ... | 2001 | 11672913 |
| glycoproteins e and i of marek's disease virus serotype 1 are essential for virus growth in cultured cells. | the role of glycoprotein e (ge) and gi of marek's disease virus serotype 1 (mdv-1) for growth in cultured cells was investigated. mdv-1 mutants lacking either ge (20deltage), gi (20deltagi), or both ge and gi (20deltagei) were constructed by rece/t-mediated mutagenesis of a recently established infectious bacterial artificial chromosome (bac) clone of mdv-1 (d. schumacher, b. k. tischer, w. fuchs, and n. osterrieder, j. virol. 74:11088-11098, 2000). deletion of either ge or gi, which form a comp ... | 2001 | 11689611 |
| increased virulence of marek's disease virus type 1 vaccine strain cv1988 after adaptation to qt35 cells. | cvi988/rispens strain of marek's disease virus type i (mdv-1) is widely used as efficient vaccine to control marek's disease (md) in chicken flocks. similarly to other live md vaccine viruses it is propagated in freshly prepared chicken embryo fibroblasts (cef). in this study, mdv-1 cvi988/rispens strain was adapted to qt35 cells. the adapted virus, designated qt-cvi, exhibited similar cytopathic effect (cpe) in vitro to that of parental virus propagated in cee in contrast, qt-cvi induced md sym ... | 2001 | 11719980 |
| functional characterization of marek's disease virus (mdv) origin-binding protein (obp): analysis of its origin-binding properties. | in previous studies, we identified a marek's disease virus (mdv) origin-binding protein (obp) gene that is highly homologous to the herpes simplex virus type 1 ul9 gene that encodes an obp and functions as an initiator protein for viral dna replication. in this study, a protein of 95 kda was produced in coupled in vitro transcription-translation reaction with the plasmid containing the wild type mdv obp gene. the in vitro synthesized protein was detected by immunoprecipitation with a penta-histi ... | 2001 | 11724278 |
| a strategy to identify positional candidate genes conferring marek's disease resistance by integrating dna microarrays and genetic mapping. | marker-assisted selection (mas) to enhance genetic resistance to marek's disease (md), a herpesvirus-induced t cell cancer in chicken, is an attractive alternative to augment control with vaccines. our earlier studies indicate that there are many quantitative trait loci (qtl) containing one or more genes that confer genetic resistance to md. unfortunately, it is difficult to sufficiently resolve these qtl to identify the causative gene and generate tightly linked markers. one possible solution i ... | 2001 | 11736805 |
| protective effect of avian myelomonocytic growth factor in infection with marek's disease virus. | marek's disease virus (mdv) is a herpesvirus that induces t lymphomas in chickens. the aim of this study was to assess the role of the macrophage activator chicken myelomonocytic growth factor (cmgf) in controlling mdv infection. b13/b13 chickens, which are highly susceptible to md, were either treated with cmgf delivered via a live fowlpox virus (fp/cmgf) or treated with the parent vector (fp/m3) or were left as untreated controls. seven days later, when challenged with the very virulent rb-1b ... | 2002 | 11773382 |
| characterization of marek's disease virus serotype 1 (mdv-1) deletion mutants that lack ul46 to ul49 genes: mdv-1 ul49, encoding vp22, is indispensable for virus growth. | experiments were conducted to investigate the roles of marek's disease virus serotype 1 (mdv-1) major tegument proteins vp11/12, vp13/14, vp16, and vp22 in viral growth in cultured cells. based on a bacterial artificial chromosome clone of mdv-1 (bac20), mutant viruses were constructed in which the mdv-1 homologs of ul46, ul47, ul48, or ul49 were deleted alone and in various combinations. it could be demonstrated that the ul46, ul47, and ul48 genes are dispensable for mdv-1 growth in chicken emb ... | 2002 | 11799190 |
| marek's disease virus genome separation from feather tip extracts by pulsed field gel electrophoresis. | marek's disease virus is an oncogenic herpes virus of poultry that is highly cell associated. in the infected tissues and tumors the virus replicates in a low copy number. the propagation and dissemination of the virus takes place at the feather follicle epithelium, where the viral genome is produced in high copy number. as the viral genome is a large circular dna molecule (200 kbp), pulsed field gel electrophoresis was used for separation of the viral genome directly from the infected chicken. ... | 2002 | 11849695 |
| identification and characterization of marek's disease virus serotype 1 (mdv1) icp22 gene product: mdv1 icp22 transactivates the mdv1 icp27 promoter synergistically with mdv1 icp4. | a previous report [virus genes 6 (1992) 365-378] has shown that the us1 gene of marek's disease virus serotype 1 (mdv1) encodes a homologue of herpes simplex virus type 1 infected cell protein no. 22 (icp22). in the present study, we expressed and identified a product of the mdv1 us1 gene in chicken embryo fibroblasts (cefs) with the aid of a recombinant baculovirus expressing a flag epitope-tagged mdv1 us1 gene, under control of the sralpha promoter (composed of the enhancer region of the simia ... | 2002 | 11856580 |
| improving dna vaccine potency by linking marek's disease virus type 1 vp22 to an antigen. | we have previously employed an intercellular spreading strategy using herpes simplex virus type 1 (hsv-1) vp22 protein to enhance dna vaccine potency because dna vaccines lack the intrinsic ability to amplify in cells. recently, studies have demonstrated that the protein encoded by ul49 of marek's disease virus type 1 (mdv-1) exhibits some degree of homology to the hsv-1 vp22 protein and features the property of intercellular transport. we therefore generated a dna vaccine encoding mdv-1 vp22 li ... | 2002 | 11861834 |
| herpesvirus and multiple sclerosis. | evidence suggests that multiple sclerosis (ms) is caused by host genetic factors in association with one or more environmental agents. the clinical and pathological features of ms implicate viral infections as either cofactors in its aetiology or triggers of relapses, although no specific environmental factors have been identified. in particular, several herpesviruses have attracted interest because their ability to cause latent infections that periodically reactivate has some familiarity with t ... | 2001 | 11867021 |
| marek's disease virus vp22: subcellular localization and characterization of carboxyl terminal deletion mutations. | marek's disease virus (mdv) is an alphaherpesvirus that causes t cell lymphoma and severe immunosuppression in chickens. the mdv ul49 gene, which encodes the tegument viral protein 22 (vp22), has been expressed as a green fluorescent protein (gfp) fusion protein in chicken embryonic fibroblasts to examine its subcellular localization. as with both human herpesvirus 1 and bovine herpesvirus 1vp22-gfp fusion proteins, the mdv vp22-gfp product binds to microtubules and heterochromatin. in addition, ... | 2002 | 11878926 |
| resistance and susceptibility to marek's disease: nitric oxide synthase/arginase activity balance. | the metabolic no pathway, catalyzed by the enzyme no synthase in macrophages, is a key defense element against viruses and tumors. however, arginase is an other enzyme able to metabolize the substrate l-arginine, and the two enzymes are alternatively regulated by th1 and th2 cytokines in murine macrophages. marek's disease is characterized by strong immunosuppression and development of t-cell lymphomas in chickens. inoculation of the very virulent strain of mdv rb-1b induced strong and long-last ... | 2002 | 11900957 |
| antiviral activity of ovotransferrin discloses an evolutionary strategy for the defensive activities of lactoferrin. | ovotransferrin (formerly conalbumin) is an iron-binding protein present in birds. it belongs to the transferrin family and shows about 50% sequence homology with mammalian serum transferrin and lactoferrin. this protein has been demonstrated to be capable of delivering iron to cells and of inhibiting bacterial multiplication. however, no antiviral activity has been reported for ovotransferrin, although the antiviral activity of human and bovine lactoferrins against several viruses, including hum ... | 2002 | 11908636 |
| the products of the ul10 (gm) and the ul49.5 genes of marek's disease virus serotype 1 are essential for virus growth in cultured cells. | the role of the products of the ul10 and the ul49.5 homologous genes of marek's disease virus serotype 1 (mdv-1) in virus replication was investigated. deletion of either open reading frame in an infectious bacterial artificial chromosome clone (bac20) of mdv-1 resulted in progeny viruses that were unable to spread from cell to cell. after transfection of ul10- or ul49.5-negative bac20 dna into chicken or quail cells, only single infected cells were observed by indirect immunofluorescence analys ... | 2002 | 11961253 |
| complete, long-lasting protection against lethal infectious bursal disease virus challenge by a single vaccination with an avian herpesvirus vector expressing vp2 antigens. | marek's disease herpesvirus is a vaccine vector of great promise for chickens; however, complete protection against foreign infectious diseases has not been achieved. in this study, two herpesvirus of turkey recombinants (rhvts) expressing large amounts of infectious bursal disease virus (ibdv) vp2 antigen under the control of a human cytomegalovirus (cmv) promoter or cmv/beta-actin chimera promoter (pec promoter) (rhvt-cmvvp2 and rhvt-pecvp2) were constructed. rhvt-pecvp2, which expressed the v ... | 2002 | 11991992 |
| rescue of a pathogenic marek's disease virus with overlapping cosmid dnas: use of a pp38 mutant to validate the technology for the study of gene function. | marek's disease virus (mdv) genetics has lagged behind that of other herpesviruses because of the lack of tools for the introduction of site-specific mutations into the genome of highly cell-associated oncogenic strains. overlapping cosmid clones have been successfully used for the introduction of mutations in other highly cell-associated herpesviruses. here we describe the development of overlapping cosmid dna clones from a very virulent oncogenic strain of mdv. transfection of these cosmid clo ... | 2002 | 11997455 |
| molecular identification of the marek's disease virus vaccine strain cvi988 in vaccinated chickens. | the study describes three polymerase chain reaction (pcr) systems for the cvi988 vaccine virus: the meq gene, the mdv bamhi-d/h 132 bp tandem repeat fragment and the mdv-gb gene. whereas the pcr product of virulent mdv strains and of the cvi988 virus strain with the meq and the 132 bp primer sets differed for the two templates, the mdv-gb pcr products were similar. the sensitivity of the three pcrs was determined for the two templates: the cvi988 dna was detected up to 2.48 plaque forming units, ... | 2002 | 12002424 |
| molecular indications for in vivo integration of the avian leukosis virus, subgroup j-long terminal repeat into the marek's disease virus in experimentally dually-infected chickens. | marek's disease virus, a herpesvirus, and avian leukosis virus, subgroup j, a retrovirus, are oncogenic viruses of poultry. both viruses may infect the same flock, the same bird and the same cell. in a double-infected cell, the retroviral dna can integrate into the cellular or the marek's disease virus (mdv) genome. the retroviral-long terminal repeat (ltr) integration into mdv was first described by isfort et al., (proc natl acad sci 89, 991-995, 1992) following tissue culture co-infection. the ... | 2002 | 12018709 |
| effect of in ovo vaccine delivery route on herpesvirus of turkeys/sb-1 efficacy and viremia. | a study was designed to ascertain the influence of in ovo site of inoculation and embryonic fluid type on the development of marek's disease (md) vaccine viremia and efficacy against md challenge. the experiments were divided into in vitro and in vivo phases. in the in vitro phase, herpesvirus of turkeys/sb-1 vaccine was combined with basal medium eagle (bme) medium (control), amniotic fluid, or allantoic fluid and subsequently titrated on secondary chick embryo fibroblast cultures. there were n ... | 2002 | 12061635 |
| marek's disease in turkeys. i. a seven-year survey of commercial flocks and experimental infection using two field isolates. | marek's disease virus (mdv) causes immunosuppression and tumors in chickens, but the turkey is an unusual host for the virus, and tumors caused by mdv in turkeys are unique. we describe the prevalence of turkey tumors in israel between 1993 and 2000, their molecular diagnosis by polymerase chain reaction (pcr), and the natural distribution of herpesvirus of turkeys (hvt). most clinical cases with tumors in commercial turkeys were diagnosed as mdv. the reproduction of marek's disease (md) in turk ... | 2002 | 12061640 |
| marek's disease in turkeys. ii. characterization of the viral glycoprotein b gene and antigen of a turkey strain of marek's disease virus. | marek's disease virus (mdv) causes immunosuppression and tumors in chickens. as sporadic cases of marek's disease (md) were recorded in turkeys, the antigenic and genomic characteristics of the mdv glycoprotein b (gb) gene and antigen of turkeys were compared to the chicken mdv gb. the whole chicken and turkey gb genes were sequenced and found identical. by immunoblotting of infected-cell culture lysates using chicken convalescent and gb monoclonal antibodies, the antigenic epitopes of the chick ... | 2002 | 12061641 |
| the detection of the meq gene in chicken infected with marek's disease virus serotype 1. | in the genome of strains of very virulent marek's disease virus serotype 1(vvmdv1), such as md5 and rb1b, the meq open reading frame (orf) encoding a 339-amino-acid bzip protein, is present, while a slightly longer meq orf, termed as l-meq, in which a 180-bp sequence is inserted into the meq orf is found in other strains of mdv1, such as cv1988/r6 and attenuated jm. when chickens were infected with vvmdv1 strains and the meq gene was amplified by nested polymerase chain reaction (pcr), the meq g ... | 2002 | 12069073 |
| identification of the neoplastically transformed cells in marek's disease herpesvirus-induced lymphomas: recognition by the monoclonal antibody av37. | understanding the interactions between herpesviruses and their host cells and also the interactions between neoplastically transformed cells and the host immune system is fundamental to understanding the mechanisms of herpesvirus oncology. however, this has been difficult as no animal models of herpesvirus-induced oncogenesis in the natural host exist in which neoplastically transformed cells are also definitively identified and may be studied in vivo. marek's disease (md) herpesvirus (mdv) of p ... | 2002 | 12072527 |
| [the selecting experiment of resistance to marek's disease of chicken]. | the marek's disease is an acute infectious disease in poultry production. the selecting experiment through blood-group gene inspection of adult parents and attack-test by using of marek's disease virus (mdv) for offspring chicks was carried out. the results showed as follows: (1) the rates of positive reaction by no. 614 blood-group gene inspection of adult parents in four generations were increased due to generation increase, as f0-68.8%, f1-77.3%, f2-81.8% and f3-90.5%. (2) in the attack-test ... | 2002 | 12096624 |
| generation of a permanent cell line that supports efficient growth of marek's disease virus (mdv) by constitutive expression of mdv glycoprotein e. | a recombinant cell line (soge) was established, which was derived from the permanent quail muscle cell line qm7 and constitutively expressed the glycoprotein e (ge) gene of marek's disease virus serotype 1 (mdv-1). the soge cell line supported growth of virulent (rb-1b) and vaccine (cvi988, 584ap80c) mdv-1 strains at a level comparable with that of primary chicken embryo cells (cec). the soge cell line was used to produce a vaccine against marek's disease. chickens were immunized at 1 day old wi ... | 2002 | 12124462 |
| alterations of the mdv oncogenic regions in an mdv transformed lymphoblastoid cell line. | lymphoblastoid cell lines derived from marek's disease virus (mdv) induced tumours have served as models of mdv latency and transformation. they are stable and can be cultured with no detectable mdv genomic alterations upon repeated passaging. an mdv transformed lymphoblastoid t cell line (t9 cell line) has been reported to contain a disrupted mdv bamhi-h fragment and a rous associated virus insertional activation of the c-myb protooncogene. in an attempt to define the respective participation o ... | 2002 | 12147717 |
| derivation, safety and efficacy of a marek's disease vaccine developed from an australian isolate of very virulent marek's disease virus. | to develop a serotype 1 marek's disease (md) vaccine from a very virulent mdv (vvmdv) pathotype and demonstrate safety and efficacy against early challenge with very virulent field strains in the presence of maternal antibody. | 2002 | 12180882 |
| a dna vaccine containing an infectious marek's disease virus genome can confer protection against tumorigenic marek's disease in chickens. | a dna vaccine containing the infectious bac20 clone of serotype 1 marek's disease virus (mdv) was tested for its potential to protect against marek's disease (md). chickens were immunized at 1 day old with bac20 dna suspended either in pbs, as calcium phosphate precipitates, incorporated into chitosan nanoparticles, in escherichia coli dh10b cells, or bound to gold particles for gene-gun delivery. challenge infection with mdv strain eu1 was performed at 12 days old, and four out of seven birds i ... | 2002 | 12237417 |
| field trial in commercial broilers with a multivalent in ovo vaccine comprising a mixture of live viral vaccines against marek's disease, infectious bursal disease, newcastle disease, and fowl pox. | a multivalent in ovo vaccine (miv) was tested for safety and efficacy in a commercial broiler complex. the miv comprised five replicating live viruses including serotypes 1, 2, and 3 of marek's disease virus (mdv), an intermediate infectious bursal disease virus (ibdv) and a recombinant fowl poxvirus (fpv) vector vaccine containing hn and f genes of newcastle disease virus (ndv). the performance of miv-vaccinated broilers was compared with that of hatchmates that received turkey herpesvirus (hvt ... | 2002 | 12243525 |
| influence of genetic resistance of the chicken and virulence of marek's disease virus (mdv) on nitric oxide responses after mdv infection. | nitric oxide (no), a free radical produced by the enzyme no synthase (nos), is a potent antiviral agent in addition to having immune regulating functions. recently, it was reported that chickens resistant (n2a, mhc: b21b21) to the development of marek's disease (md) had a greater potential to produce no than md-susceptible chickens (p2a, mhc: b19b19). this difference was shown by measuring no levels in chick embryo fibroblast cultures obtained from these chickens after treatment with lipopolysac ... | 2002 | 12243528 |
| two nonconsensus sites in the epstein-barr virus oncoprotein ebna3a cooperate to bind the co-repressor carboxyl-terminal-binding protein (ctbp). | ctbp (carboxyl-terminal binding protein) has been shown to be a highly conserved co-repressor of transcription that is important in development, cell cycle regulation, and transformation. viral proteins e1a and ebna3c and all the various drosophila and vertebrate transcription factors to which ctbp has been reported to bind contain a conserved "pxdls" ctbp-interaction domain. here we show that ebna3a binds ctbp both in vitro and in vivo but that this interaction does not require a near consensus ... | 2002 | 12372828 |
| the feather tips of commercial chickens are a favorable source of dna for the amplification of marek's disease virus and avian leukosis virus, subgroup j. | marek's disease virus (mdv), a herpesvirus, and avian leukosis virus, subgroup j (alv-j), a retrovirus, are oncogenic viruses of poultry. the present report describes a case-report study aimed at examining the efficacy of amplifying mdv and/or alv-j from feather-tip dna as compared with dna purified from liver and spleen. we show that the polymerase chain reaction for mdv and alv-j env using dna from feather tips was more effective for diagnosis of naturally infected commercial chickens than usi ... | 2002 | 12396346 |
| identification of new herpesvirus gene homologs in the human genome. | viruses are intracellular parasites that use many cellular pathways during their replication. large dna viruses, such as herpesviruses, have captured a repertoire of cellular genes to block or mimic host immune responses, apoptosis regulation, and cell-cycle control mechanisms. we have conducted a systematic search for all homologs of herpesvirus proteins in the human genome using position-specific scoring matrices representing herpesvirus protein sequence domains, and pair-wise sequence compari ... | 2002 | 12421761 |
| immunosuppressive effects of marek's disease virus (mdv) and herpesvirus of turkeys (hvt) in broiler chickens and the protective effect of hvt vaccination against mdv challenge. | much of the impact of marek's disease in broiler chickens is considered to be due to immunosuppression induced by marek's disease virus (mdv). the present study evaluates the effects of an australian isolate of pathogenic mdv (strain mpf 57) and a non-pathogenic vaccinal strain of herpesvirus of turkeys (hvt) (strain fc 126) on the immune system of commercial broiler chickens for 35 days following challenge at days 0 or 3 of age. it also investigates the extent of protection provided by hvt vacc ... | 2002 | 12427339 |
| antiviral and antitumoral effects of recombinant chicken myelomonocytic growth factor in virally induced lymphoma. | chicken myelomonocytic growth factor (cmgf) is a 27-kda glycoprotein that stimulates the growth and activation of cells from the monocyte/macrophage lineage. recombinant cmgf was produced in a prokaryotic (escherichia coli) expression system and purified via a c-terminal his-tag. treatment of 2-week-old histocompatible b(13)/b(13) chickens highly susceptible to marek's disease (md) with rcmgf (two daily injections of 50 microg rcmgf per chicken) enhanced background and lps-inducible systemic no ... | 2002 | 12433057 |
| cytotoxic t lymphocyte responses to marek's disease herpesvirus-encoded glycoproteins. | cell-mediated immune responses are important for protective immunity to marek's disease (md), especially because md herpesvirus (mdv) infection is strictly cell-associated in chickens with the exception of the feather follicle epithelium. a system previously developed using reticuloendotheliosis (rev)-transformed cell lines stably expressing individual mdv genes allows the determination of relevant mdv proteins for the induction of cytotoxic t lymphocyte (ctl) responses. to examine the importanc ... | 2002 | 12459161 |
| differential cytokine responses following marek's disease virus infection of chickens differing in resistance to marek's disease. | the production of cytokine mrnas, in addition to viral dna, was quantified by real-time quantitative reverse transcription-pcr (rt-pcr) (cytokines) or pcr (virus) in splenocytes during the course of marek's disease virus (mdv) infection in four inbred chicken lines: two resistant (lines 6(1) and n) and two susceptible (lines 7(2) and p). virus loads were only different after 10 days postinfection (dpi), increasing in susceptible lines and decreasing in resistant lines. gamma interferon (ifn-gamm ... | 2003 | 12477883 |
| neuropathotyping: a new system to classify marek's disease virus. | a statistical approach was used to establish a new classification system of marek's disease virus (mdv) on the basis of neurologic responses. to develop the system, neurologic response data from 15x7 chickens inoculated with 30 strains of serotype 1 mdv were statistically analyzed by a cluster analysis. the goal was to identify a statistical system that would verify if three neurovirulence groups correlated with the three pathotypes previously described. the system was also validated in two addi ... | 2002 | 12495052 |
| induction of strong protection by vaccination with partially attenuated serotype 1 marek's disease viruses. | studies were conducted to better understand the relationship among marcek's disease (md) vaccine strains between induction of protective immunity and the degree of attenuation (or virulence). to obtain viruses at different stages of attenuation, very virulent plus md strains 584a and 648a and selected clones of these strains were serially passaged in chicken and duck cells. these viruses were considered fully attenuated after passage for 70-100 times in chicken embryo cell cultures until they no ... | 2002 | 12495054 |
| suppression of transcription activity of the meq protein of oncogenic marek's disease virus serotype 1 (mdv1) by l-meq of non-oncogenic mdv1. | meq is one of the candidate oncogenes in the mdv1 genome. we previously reported a difference in the meq open reading frame (orf) between oncogenic and non-oncogenic mdv1: l-meq, in which a 180-bp sequence is inserted into the meq orf, is detected in non-oncogenic mdv1. to study the functions of a gene product of l-meq (l-meq), transactivation by l-meq was analyzed by dual luciferase assay using a reporter gene under the control of long (-1--873 bp) and short (-1 - -355 bp) meq promoter (lmp and ... | 2002 | 12520099 |
| diversity (polymorphism) of the meq gene in the attenuated marek's disease virus (mdv) serotype 1 and mdv-transformed cell lines. | the meq gene encoding a 339-amino-acid bzip transactivator protein has been identified as a candidate oncogene of marek's disease virus serotype 1 (mdv1), which induces malignant lymphomas in chickens. we have previously reported that, in addition to meq, l-meq, in which a 180-bp sequence is inserted into the region encoding the transactivation domain of meq, is also detected in chickens experimentally infected with mdv. to further analyze the diversity in meq, pcr was performed using a primer s ... | 2002 | 12520100 |
| [the clone and comparison of very virulent plus marek's disease virus(vv+ dmv)648 strain glycoprotein e(ge) gene]. | the glycoprotein e(ge) gene of very virulent plus marek's disease (vv+ mdv) 648 strain was amplified by polymerase chain reaction (pcr) and cloned into puc18 vector. the ge sequence was determined and analysed. the whole length of 648 strain ge gene is 1494 base pairs. the protein encoded by ge gene has several features characteristic of a membrane-associated glycoprotein. it contains eight potential glycosylation sites, a markedly hydrophobic region at the n terminus that could function as a si ... | 2001 | 12549019 |
| [studies on in vitro expression for gi gene of marek's disease in e. coli by pgex vector]. | glycoprotein i gene(gi) was amplified from genomic dna of marek's disease virus (mdv) 648 strain by polymerase chain reaction(pcr). pcr product was cloned into pgex-6p-1 according to the right open reading frame(orf). the expression of gst-gi fusion protein was studied in detail on many factors including temperature, timing and iptg. the curve for od600 and the growing time of the recombinant bacteria is also established., which is helpful to find the optimal inducing time. gst-gi fusion protein ... | 2001 | 12552804 |
| [cloning of glycoprotein b gene from strain rispens of marek's disease virus and construction of recombinant fowlpox virus]. | purified dnas from chicken embryo fibroblast (cef) cultures infected with mdv strain rispens were used as templates. specific fragment with the size of about 2.9 kb was successfully amplified through polymerase chain reaction(pcr) and identified to be gb gene of mdv by dot blot hybridization with a digoxigenin-labelled mdv gb specific oligonucleotide probe. the gb gene from strain rispens was cloned into puc19 and fpv insertion vector pfg1175-1 to construct plasmid pmgb and pfgbr1775-1 respectiv ... | 1999 | 12555423 |
| major histocompatibility complex class i is downregulated in marek's disease virus infected chicken embryo fibroblasts and corrected by chicken interferon. | the major histocompatibility complex (mhc) is a part of the immune system which presents epitopes of intracellular antigens on the cell surface. mhc molecules have receptor-ligand binding affinities with t lymphocytes, permitting the latter to detect foreign intracellular infectious agents. some pathogens, such as herpesviruses, have developed strategies of evading the host response by mhc. this pressure on the immune system brought, in turn, improvements in the antigen-presenting pathway, for e ... | 2003 | 12581748 |
| immunological tolerance in chickens hatching from eggs injected with cell-associated herpesvirus of turkey (hvt). | cell-associated herpesvirus of turkeys (hvt) was inoculated in ovo at various stages of incubation. chickens hatching from these eggs were tested for anti-hvt antibodies by several serologic procedures including enzyme-linked immunosorbent assay, indirect immunofluorescence assays, and western blot. viremic chickens that remained free of detectable antibodies were considered tolerant to hvt. chickens exposed to hvt at embryonation day 14 or earlier had 6-33% incidence of tolerance. tolerant chic ... | 2003 | 12631525 |
| the rna subunit of telomerase is encoded by marek's disease virus. | marek's disease virus (mdv) is a herpesvirus of chickens that induces t lymphomas and tumors within 4 to 5 weeks of infection. although the ability of mdv to induce tumors was demonstrated many years ago and although a number of viral oncogenic proteins have been identified, the mechanism by which the mdv is implicated in tumorigenesis is still unknown. we report the identification of a virus-encoded rna telomerase subunit (vtr) within the genome of mdv. this gene is found in the genomic dna of ... | 2003 | 12719590 |
| the immunologists' debt to the chicken. | the immune system of the chicken is an invaluable model for studying basic immunology and has made seminal contributions to fundamental immunological principles. graft versus host responses and the key role of lymphocytes in adaptive immunity were first described in work with chicken embryos and chickens. 2. most notably, the bursa of fabricius provided the first substantive evidence that there are two major lineages of lymphocytes. bursa-derived lymphocytes, or b cells, make antibodies while th ... | 2003 | 12737220 |
| monocytosis is associated with the onset of leukocyte and viral infiltration of the brain in chickens infected with the very virulent marek's disease virus strain c12/130. | marek's disease (mdv) virus is mainly known for the induction of visceral lymphomas and lymphoid infiltration of peripheral nerves. recently, additional tropism for the central nervous system has been recognised as a distinct feature of disease induced by very virulent mdv isolates. during the analysis of changes in the peripheral blood leukocyte subpopulations in chickens infected with either a virulent (hprs-16) or a very virulent (c12/130) strain of mdv, we observed a marked monocytosis in ch ... | 2003 | 12745364 |
| infection with chicken anaemia virus impairs the generation of pathogen-specific cytotoxic t lymphocytes. | infection with chicken anaemia virus (cav), a circovirus, can result in immunosuppression and subsequent increased susceptibility to secondary infections. this is the first report of impairment of pathogen-specific cytotoxic t lymphocytes (ctl) after natural and experimental infection of chickens with cav and marek's disease virus (mdv) or reticuloendotheliosis virus (rev). mdv- and rev-specific ctl were generated at 7 days post infection by 9-30-day-old-chickens that were positive for maternal ... | 2003 | 12757624 |
| detection of marek's disease virus dna in chicken but not in human plasma. | marek's disease virus (mdv) causes a common lymphomatous and neuropathic disease in domestic chickens and, less commonly, turkeys and quail. it is a member of the alpha-herpesviruses and until now was considered to be strongly cell associated. in 1991, mdv was suggested to be the causative infectious agent of multiple sclerosis (ms) in humans. in a previous study, we investigated the leukocytes of 107 well-defined ms patients for the presence of mdv dna but were unable to confirm a role for mdv ... | 2003 | 12791859 |
| marek's disease virus reactivation from latency: changes in gene expression at the origin of replication. | marek's disease is a contagious lymphoma of chickens caused by marek's disease virus (mdv). mdv replicates in chicken lymphocytes and establishes latency within and transforms chicken cd4+ t-cells. transformed t-cells are seen as skin leukosis or as lymphomas in visceral organs. a major focus of our laboratory is the functional study of genes flanking the origin of replication. this origin (orilyt) is contained within the repeats flanking the unique long (ul) region of the genome (irl and trl). ... | 2003 | 12817443 |
| impact of deletions within the bam hi-l fragment of attenuated marek's disease virus on vil-8 expression and the newly identified transcript of open reading frame lorf4. | marek's disease (md) in chickens is caused by md herpesvirus (mdv), which induces t cell lymphomas. the early pathogenesis of mdv infection is characterized by a primary infection in b lymphocytes followed by infection of activated t lymphocytes. it has been speculated that a mdv-encoded homologue of interleukin-8 (vil-8) may be important to attract activated t lymphocytes to infected b lymphocytes. recently, more virulent strains of mdv have emerged, named very virulent plus (vv+)mdv, that caus ... | 2003 | 12876454 |
| replication-competent bacterial artificial chromosomes of marek's disease virus: novel tools for generation of molecularly defined herpesvirus vaccines. | marek's disease (md), a highly infectious disease caused by an oncogenic herpesvirus, is one of the few herpesvirus diseases against which live attenuated vaccines are used as the main strategy for control. we have constructed bacterial artificial chromosomes (bacs) of the cvi988 (rispens) strain of the virus, the most widely used and effective vaccine against md. viruses derived from the bac clones were stable after in vitro and in vivo passages and showed characteristics and growth kinetics si ... | 2003 | 12885890 |
| persistence of chicken herpesvirus and retroviral chimeric molecules upon in vivo passage. | mareks disease virus (mdv), a herpesvirus, and avian leucosis virus subgroup j (alv-j), a retrovirus, were used for experimental coinfection of chickens. chimeric molecules having sequences of both viruses were detected by the hotspot-combined polymerase chain reaction (hs-cpcr) system. the detection of chimeric molecules provided evidence for avian retroviral inserts in the herpesvirus genome. the persistence of chimeric molecules on in vivo passage served to indicate the infectivity of the rec ... | 2003 | 12887189 |
| early cell-mediated immune responses to marek's disease virus in two chicken lines with defined major histocompatibility complex antigens. | n2a and p2a chickens, resistant and susceptible to marek's disease (md), respectively, were used to examine relationships between major histocompatibility complex (mhc)-restricted cytotoxic t lymphocytes (ctl) and natural killer (nk)-like cell activity with resistance to infection with marek's disease virus (mdv). ten-day-old chickens were infected with mdv and euthanatized at selected times to evaluate for nk cell and mhc-restricted cytotoxicity. the n2a mdv-infected chickens had an early cell- ... | 2003 | 12963275 |
| infection of macrophages by a lymphotropic herpesvirus: a new tropism for marek's disease virus. | marek's disease virus (mdv) is classified as an oncogenic lymphotropic herpesvirus of chickens. mdv productively and cytolytically infects b, alphabetat and gammadeltat lymphocytes and latently infects t-helper lymphocytes. the aims of this study were to identify whether mdv infects macrophages in vivo and, if so, whether quantitative differences in macrophage infection are associated with mdv strain virulence. chickens were infected with either virulent mdv (hprs-16) or 'hypervirulent' mdv (c12 ... | 2003 | 13679597 |
| characterization of a spontaneously transformed chicken mononuclear cell line. | we describe the characterization of a spontaneously transformed chicken monocytic cell line that developed as a single colony of cells in a heterophil culture that was inadvertently left in the incubator over a period of 25 days. these cells, hitherto named htc, grow efficiently at both 37 or 41 degrees c in culture medium containing either 5% fbs or 2% chicken serum. the htc cells are acid phosphatase positive, show expressions of both class i and class ii major histocompatibility complex (mhc) ... | 2003 | 14522138 |
| novel applications of feather tip extracts from mdv-infected chickens; diagnosis of commercial broilers, whole genome separation by pfge and synchronic mucosal infection. | marek's disease virus (mdv) productive replication occurs in the feather follicle epithelium and the feather tips are valuable both for research and disease diagnosis. three novel applications of feather tip extracts are described now: (a). as a source of dna for amplifying either mdv and/or alv-j. in two clinical situations a marked advantage was obtained compared to blood and organs; in broiler breeder flocks with a mixed mdv and alv-j infection, and in young broilers with neurological marek's ... | 2003 | 14522455 |
| [establishment and use of infectious bacterial artificial chromosome (bac) dna clones of animal herpesviruses]. | since the first description of the cloning und mutagenesis of a herpesviral genome in 1997, a number of herpesviral dna's have been cloned as bacterial artificial chromosomes (bacs). herpesvirus bac's are established by introduction of a mini f origin of replication into the viral genome, which can as such be maintained und manipulated in escherichia coli as a single copy extrachromosomal dna. herpesvirus dna's cloned as bac's are accessible to the dna repair und mutagenesis apparatus encoded by ... | 2003 | 14526467 |
| protection and synergism by recombinant fowl pox vaccines expressing multiple genes from marek's disease virus. | recombinant fowl poxviruses (rfpvs) were constructed to express genes from serotype 1 marek's disease virus (mdv) coding for glycoproteins b, e, i, h, and ul32 (gb1, ge, gi, gh, and ul32). an additional rfpv was constructed to contain four mdv genes (gb1, ge, gi, and ul32). these rfpvs were evaluated for their ability to protect maternal antibody-positive chickens against challenge with highly virulent mdv isolates. the protection induced by a single rfpv/gb1 (42%) confirmed our previous finding ... | 2003 | 14562881 |
| characterization of the chromosomal binding sites and dimerization partners of the viral oncoprotein meq in marek's disease virus-transformed t cells. | marek's disease virus (mdv) is an acute transforming alphaherpesvirus that causes t-cell lymphomas in chickens. we previously reported the identification of a putative oncogene, meq, that is encoded only by the oncogenic serotype of mdv. the gene product, meq, is a latent protein that is consistently expressed in mdv-transformed lymphoblastoid cells and tumor cells. meq has a bzip (basic leucine zipper) structure resembling the family of jun/fos. the mechanism whereby meq transforms t cells rema ... | 2003 | 14610205 |
| marek's disease virus latent protein meq: delineation of an epitope in the br1 domain involved in nuclear localization. | marek's disease virus latent protein meq (mdv eco q) is abundantly expressed and consistently detected in mdv-induced tumors and cell lines. deletion mutants were constructed to study the domain structure of meq. four deletion mutants were obtained in the basic regions of meq, namely basic region 1 (deltabr1), basic region 2 (deltabr2), basic regions 1 and 2 (deltabr1 and 2), and the c-terminal (bzip) domain. the br1 and br2 are nuclear localization signals and either is sufficient to cause tran ... | 2003 | 14618081 |
| biocharacteristics shared by highly protective vaccines against marek's disease. | attenuated serotype 1 marek's disease virus strains vary widely in their protection properties. this study was conducted to elucidate which biocharacteristics of serotype 1 mdv strains are related with protection. three pairs of vaccines, each one including a higher protective (hp) vaccine and a lower protective (lp) vaccine originating from the same mdv strain, were studied. two other highly protective vaccines (rm1 and cvi988/bp5) were also included in the study. comparison within pairs of vac ... | 2004 | 14681069 |
| effects of cyclosporin a treatment on the pathogenesis of avian leukosis virus subgroup j infection in broiler chickens with marek's disease virus exposure. | in this study, we investigated the effects of t-cell suppression on the pathogenesis of subgroup j avian leukosis virus (alv-j). chickens were treated with cyclosporin a (csp) 50 mg/kg body weight or a corresponding volume of olive oil per every three days after hatching until the end of experiment. some of the chickens from each treatment group were infected with an isolate of alv-j, adol-7501, at 2 weeks of age. the effects of viral infection were compared to uninfected birds in same treatment ... | 2003 | 14685030 |
| expansion of a unique region in the marek's disease virus genome occurs concomitantly with attenuation but is not sufficient to cause attenuation. | pathogenic marek's disease viruses (mdvs) have two head-to-tail copies of a 132-bp repeat. as mdv is serially passaged in cell culture, the virus becomes attenuated and the number of copies of the 132-bp repeat increases from 2 to often more than 20 copies. to determine the role of the repeats in attenuation, we used five overlapping cosmid clones that spanned the mdv genome to reconstitute infectious virus (rmd5). by mutating the appropriate cosmids, we generated clones of infectious mdvs that ... | 2004 | 14694105 |
| influence of a reovirus-antibody complex vaccine on efficacy of marek's disease vaccine administered in ovo. | two experiments determined the influence of an experimental reovirus-antibody complex vaccine on mareks disease virus (mdv) vaccine when used in ovo. designs were the same except that specific-pathogen-free (spf) broiler eggs were used in experiment 1 and commercial broiler eggs with maternal antibodies against reovirus were used in experiment 2. at 18 days of incubation, embryos were separated into four groups and inoculated with either diluent, mdv vaccine, reovirus-antibody complex vaccine, o ... | 2003 | 14708983 |
| interferon-containing supernatants increase marek's disease herpesvirus genomes and gene transcription levels, but not virion replication in vitro. | viruses encounter the innate immune system immediately after infection of the host; specifically, soluble molecules that are both directly lethal and that initiate acquired immunity. using the oncogenic marek's disease alpha-herpesvirus (mdv) model, we quantified the effect of a interferon-containing supernatants (ics), on mdv replication, gene transcription and antigen expression kinetics. we used an established cell culture system and a well-defined virulent mdv (rb-1b). rb-1b was cultured wit ... | 2003 | 14733737 |
| identification of chicken lymphocyte antigen 6 complex, locus e (ly6e, alias sca2) as a putative marek's disease resistance gene via a virus-host protein interaction screen. | marek's disease virus (mdv) is a naturally occurring oncogenic avian herpesvirus that causes neurological disorders and t cell lymphoma disease in domestic chickens. identification and functional characterization of the individual factors involved in marek's disease (md) resistance or pathogenesis will enhance our understanding of mdv pathogenesis and further genetic improvement of chickens. to study the genetic basis for resistance to md, a strategy that combined protein-protein interaction scr ... | 2003 | 14970721 |
| the chicken telomerase rna gene: conservation of sequence, regulatory elements and synteny among viral, avian and mammalian genomes. | telomerase rna (tr) is essential for telomerase activity and the maintenance of telomere length in proliferating cell populations. the objective of the present research was to define the cytogenetic and molecular genomic organization of chicken tr (chtr). the chtr exists as a single copy gene (terc, alias tr), mapping to chromosome 9 (gga9). the loci on the q arm of gga9 map to three chromosomes in human with five of the nine gga9q loci mapping to hsa3q. sequencing of the chterc locus (3,763 bp) ... | 2003 | 14970722 |
| herpesvirus of turkeys: microarray analysis of host gene responses to infection. | herpesvirus of turkeys (hvt) provides an economically important live vaccine for prevention of marek's disease (md) of chickens. md, characterized by both immunosuppression and t-cell lymphoma, is caused by another herpesvirus termed marek's disease virus (mdv). microarrays were used to investigate the response of chicken embryonic fibroblasts (cef) to infection with hvt. genes responding to hvt infection include several induced by interferon along with others modulating signal transduction, tra ... | 2004 | 14972539 |
| detection and localization of avian alphaherpesviruses in embryonic tissues following in ovo exposure. | we investigated whether chicken embryonic tissues are susceptible to infection with virulent marek's disease virus (mdv). groups of embryonic day (ed) 17 chicken embryos and 1-day-old chicks were compared for tissue sites of viral persistence of mdv and herpesvirus of turkeys (hvt) in lungs, thymuses, bursae of fabricius and spleens. mdv dna was detectable in the lungs and thymuses of embryos at 3 days post-inoculation (dpi) by in situ hybridization, while hvt dna was only present in embryonic l ... | 2004 | 15019243 |
| the effects of cyclophosphamide treatment on the pathogenesis of subgroup j avian leukosis virus (alv-j) infection in broiler chickens with marek's disease virus exposure. | studies were performed to determine the effects of bcell suppression on the pathogenesis of subgroup j avian leukosis virus (alv-j) in broiler chickens. neonatal chickens were treated with cyclophosphamide (cy) or pbs, and then infected with alv-j (adol-7501) at 2 weeks of age. cy treatment induced b cell specific immunosuppression throughout the experiment confirmed by decreased bursal weight, intact lymphocyte mitogenetic activity stimulated by con a and increased relative subpopulation of cd3 ... | 2004 | 15028885 |
| an enzyme-linked immunosorbent assay (elisa) for detection of marek's disease virus-specific antibodies and its application in an experimental vaccine trial. | an enzyme-linked immunosorbent assay (elisa) for the detection of marek's disease virus (mdv)-specific antibodies was developed. chicken embryo cells (cec) or chicken kidney cells (ckc) were infected with mdv vaccine strain cvi988/rispens, and infected-cell lysates were prepared at day 5 post-infection by freeze-thawing. uninfected-cell lysates served as negative controls. sera were used at a 1 : 100 dilution and were added in parallel to wells containing the infected and uninfected cell lysates ... | 2004 | 15030602 |
| assembly of marek's disease virus (mdv) capsids using recombinant baculoviruses expressing mdv capsid proteins. | the genes ul18, ul19, ul26, ul26.5, ul35 and ul38 of marek's disease virus 1 (mdv-1) strain rb1b, encoding the homologues of herpes simplex virus type 1 (hsv-1) capsid proteins vp23, vp5, vp21-vp24, prevp22a, vp26 and vp19c, were identified and sequenced. recombinant baculoviruses were used to express the six capsid genes in insect cells. coexpression of the six genes or of ul18, ul19, ul26.5 and ul38 in insect cells resulted in the formation of capsids with a large core. in addition, electron m ... | 2004 | 15039519 |
| pathogenesis of a marek's disease virus mutant lacking vil-8 in resistant and susceptible chickens. | a homologue of interleukin-8, viral interleukin-8 (vil-8) has been identified in the genome of marek's disease virus (mdv). this protein attracts peripheral blood mononuclear cells in vitro although its role in the pathogenesis of marek's disease (md) is not known. p chickens, genetically susceptible to md, and n chickens, genetically resistant to the disease, were inoculated with either rb1b mdvor rb1bvil-8smgfp, a vil8 knockout rb1b mdv, to assess the role of vil8 in the pathogenesis of md. th ... | 2004 | 15077797 |
| the efficacy of recombinant fowlpox vaccine protection against marek's disease: its dependence on chicken line and b haplotype. | earlier studies have shown that the b haplotype has a significant influence on the protective efficacy of vaccines against marek's disease (md) and that the level of protection varies dependent on the serotype of md virus (mdv) used in the vaccine. to determine if the protective glycoprotein gene gb is a basis for this association, we compared recombinant fowlpox virus (rfpv) containing a single gb gene from three serotypes of mdv. the rfpv were used to vaccinate 15.b congenic lines. nonvaccinat ... | 2004 | 15077806 |
| relationship of campylobacter isolated from poultry and from darkling beetles in new zealand. | campylobacter, a foodborne pathogen closely associated with poultry, is considered to be an important agent of human gastroenteritis in new zealand. the pathways involved in the contamination of poultry flocks remain unclear; however, many vectors, such as insects, rodents, and wild birds, have been implicated. infestation of poultry houses by insects, particularly darkling beetles (alphitobius diaperinus), is difficult to control. furthermore, darkling beetles are known vectors for a variety of ... | 2004 | 15077807 |
| marek's disease virus-encoded vil-8 gene is involved in early cytolytic infection but dispensable for establishment of latency. | marek's disease, a lymphoproliferative disease of chickens, is caused by an alphaherpesvirus, marek's disease virus (mdv). this virus encodes a virokine, vil-8, with general homology to cellular cxc chemokines such as interleukin-8 (il-8) and gro-alpha. to study the function of vil-8 gene, we deleted both copies of vil-8 residing in the terminal repeat long and internal repeat long region of the viral genome and generated a mutant virus with vil-8 deleted, rmd5/deltavil-8. growth kinetics study ... | 2004 | 15078957 |
| field evaluations of safety and efficacy of an australian marek's disease vaccine. | to demonstrate the safety and efficacy of the marek's disease virus-1 vaccine (strain bh 16) from field studies in comparison with the cvi 988 rispens vaccine currently available in australia. | 2003 | 15080446 |
| serial cultivation of chicken keratinocytes, a composite cell type that accumulates lipids and synthesizes a novel beta-keratin. | the epidermis of birds differs from that of mammals by the presence of intracellular lipid droplets and the absence of sebaceous glands. we describe here the cultivation of chicken epidermal keratinocytes; these cells cannot be grown in medium supplemented with the usual fetal bovine serum even in the presence of supporting 3t3 cells, but they can grow from single cells in the presence of supporting 3t3 cells and 10% chicken serum. as revealed by their cell structure, their protein composition, ... | 2004 | 15157236 |
| differential amplification and quantitation of marek's disease viruses using real-time polymerase chain reaction. | quantitative real-time pcr (qpcr) assays for the three serotypes of marek's disease virus (mdv) have been developed. an internal control qpcr assay that detects chicken alpha2 (vi) collagen gene was also developed to allow quantitation of mdv. to reduce costs and time, the assays for mdv1 and the internal control were combined into a duplex assay. the sensitivity, specificity, precision, and reproducibility of each assay are reported. the mdv qpcr assays were specific to their target gene when c ... | 2004 | 15158591 |
| single-nucleotide polymorphisms in two marek's disease virus genes (meq and gd): application to a retrospective molecular epidemiology study (1982-1999) in france. | marek's disease virus (mdv) is a herpesvirus that causes a lymphoproliferative disease in chickens. vaccines against mdv are available, but the virus is gradually becoming more virulent. a molecular epidemiology study of mdv was carried out by assessing nucleotide variation in two different genes, meq and gd, in 68 french field isolates circulating from 1982 to 1999, compared with reference strains. viral dna was amplified by nested pcr and sequenced directly. comparison of the nucleotide sequen ... | 2004 | 15166420 |