Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| transactivation of latent marek's disease herpesvirus genes in qt35, a quail fibroblast cell line, by herpesvirus of turkeys. | the qt35 cell line was established from a methylcholanthrene-induced tumor in japanese quail (coturnix coturnix japonica) (c. moscovici, m. g. moscovici, h. jimenez, m. m. lai, m. j. hayman, and p. k. vogt, cell 11:95-103, 1977). two independently maintained sublines of qt35 were found to be positive for marek's disease virus (mdv)-like genes by southern blotting and pcr assays. sequence analysis of fragments of the icp4, icp22, icp27, vp16, meq, pp14, pp38, open reading frame (orf) l1, and glyc ... | 2000 | 11024146 |
| a recombinant fowlpox virus vaccine expressing glycoprotein b gene from cvi988/rispens strain of mdv: protection studies in different chickens. | recombinant fowlpox virus (rfpv) was constructed to express glycoprotein b (gb) gene from cvi988/rispens strain of marek's disease virus (mdv). the rfpv-gb/r alone and in combination with herpesvirus of turkey (hvt) preparations were evaluated for their protective efficacy against challenge with very virulent mdv strains md5 and rb1b in different chickens. the rfpv-gb/r alone induced protection comparable to that by hvt vaccines in both ab- spf chickens and ab+ production chickens. significant p ... | 1999 | 10696446 |
| non-essential loci in the bamhi-i and -f fragments of the hvt fc126 genome. | the sequence of bamhi-i fragment of the herpesvirus of turkeys (hvt) fc126 strain dna was analyzed for the presence of potential open reading frames (orfs). four complete (orfs 2 to 5) and 2 partial orfs (orfs 1 and 6) were detected. orfs 2 and 3 were homologous to the hsv-1 ul55 and the ehv-1 gene 3, respectively. the orf 6 was already partially sequenced by smith et al. (virology 207, 205-216, 1995), and was homologous to a marek's disease virus (mdv) orf located in a similar position (orf 21; ... | 1999 | 10696442 |
| effect of native chicken interferon on mdv replication. | marek's disease virus (mdv) is an oncogenic alphaherpesvirus. its specific phosphorylated protein, pp38 has been implicated in mdv oncogenesis. in order to check whether the known anti-viral or anti-proliferative actions of interferon (ifn) are of importance in marek's disease (md), chicken embryo fibroblasts (cefs) were infected with attenuated serotype-1 mdv strain cvi988, or with herpesvirus of turkeys (hvt). different concentrations of native chicken ifn were added to the cell cultures, prio ... | 1999 | 10696431 |
| evidence for marek's disease in turkeys in germany: detection of mdv-1 using the polymerase chain reaction. | since 1994 tumorous lesions have been monitored in turkeys on three farms in germany. on one of these farms, chickens also had tumorous lesions. affected turkeys were retarded in growth, apathic, pale and almost unable to move. the older the animals got, the more indistinct the clinical signs became. mortality started at an age of 5 weeks and reached between 20% and 60% by the end of the fattening period of about 20 weeks. the aetiological differential diagnosis includes reticuloendotheliosis (r ... | 1999 | 10696435 |
| tissue-specific restriction of latent turkey hvt transcription. | using in situ hybridization, latent turkey herpesvirus (hvt) transcription was examined in lymphoid and/or nonlymphoid tissues. blood samples were taken for virus isolation from chickens at 7 and 240 days post infection (pi) representing time points for productive and latent turkey herpesvirus infections, respectively. spleen, thymus, sciatic and brachial nerves from infected chickens were analyzed for latent hvt transcription and hvt glycoprotein b (gb) expression at 240 days pi. using indirect ... | 1999 | 10696436 |
| efficacy of a combination vaccine containing mdv cvi 988 strain and hvt against challenge with very virulent mdv. | with the emergence of very virulent marek's disease virus (mdv) strains, vaccines based on herpesvirus of turkeys (hvt) appear to be not powerful enough to confer full protection, whereas in chicken flocks vaccinated with mdv cvi 988 strain protective immunity sometimes is generated not early enough for full protection. for this reason combination vaccines containing hvt as well as cvi 988 have been developed. in this paper the beneficial effect of combining both types of virus strains in one va ... | 1999 | 10696445 |
| vaccination of broilers with hvt expressing an eimeria acervulina antigen improves performance after challenge with eimeria. | the sequence encoding part of the 100 kda refractile body protein (ea1a) from eimeria acervulina was cloned into the us10 locus of herpesvirus of turkeys (hvt) downstream of ltr promoter. expression of the fusion protein was shown in vitro. recombinant hvt showed a delayed and slightly reduced level of viremia compared to the parent strain in spf chickens as well as in broilers. effect on the performance of broilers vaccinated with recombinant or parent hvt was measured by challenge at day 24 wi ... | 1999 | 10696444 |
| enhancement of spontaneous bursal lymphoma frequency by serotype 2 marek's disease vaccine, sb-1, in transgenic and non-transgenic line 0 white leghorn chickens. | a significant incidence of bursal lymphomas with long latencies was noted in transgenic breeders carrying a benign defective subgroup a avian leukosis provirus, alva6, in their germline and maintained free of exposure to avian retroviruses. serotype 2 marek's disease (md) vaccine virus, strain sb-1, a component of the bivalent md vaccine used to vaccinate the breeders, was suspected as a contributory factor in the increased bursal lymphoma incidence. although these bursal lymphomas had several c ... | 1999 | 26911501 |
| response of embryonic chicken lymphocytes to in ovo exposure to lymphotropic viruses. | to examine effects of virus exposure on embryonic lymphoid organ structure, apoptosis, and lymphoid cell subpopulations. | 1999 | 10451200 |
| atherosclerosis induced by infection with marek's disease herpesvirus in chickens. | this research was suggested after crystals that we observed in herpesvirus-infected cell cultures were identified as cholesterol. other reports and the development of defined reagents led us to select the use of marek's disease herpesvirus (mdv) infection of chickens to demonstrate a potential role of herpesviruses in the pathogenesis of atherosclerosis. available for our use were a clone-purified strain of mdv of known virulence, genetically selected, specific pathogen-free chickens, and approp ... | 1999 | 10539849 |
| an acute form of transient paralysis induced by highly virulent strains of marek's disease virus. | a novel syndrome was observed after inoculation of 3-wk-old chickens with highly virulent marek's disease virus (mdv) strains. this syndrome was characterized by the acute onset of neurologic signs including flaccid paralysis of neck and limbs 9-10 days postinoculation, typically resulting in death 1-3 days after the onset of clinical signs. most affected birds died, and spontaneous recovery was rare. few if any gross tissue changes were found. histologic brain lesions included acute vasculitis ... | 1999 | 10611987 |
| pathogenesis of marek's disease (md) and possible mechanisms of immunity induced by md vaccine. | marek's disease (md) is a lymphoproliferative disease of chicken, which is characterized by malignant t cell-lymphoma formation. this disease can be effectively prevented by vaccination with attenuated md virus (mdv), apathogenic mdv or herpesvirus of turkey. md vaccines are ones of a few vaccines which can prevent virus-induced tumor among mammalian and avian species. to determine the roles of t cell subsets in the protection mechanism, chickens vaccinated with an attenuated mdv (cvi988) were d ... | 1998 | 9492353 |
| latent turkey herpesvirus infection in lymphoid, nervous, and feather tissues of chickens. | in earlier studies, we found that a late gene product, glycoprotein b (gb) was highly expressed in lymphoid tissues of chickens inoculated with turkey herpesvirus (hvt). the objectives of the present study were twofold. first, we wanted to expand on our previous research and determine if gb expression declines or disappears during later time periods of hvt infection. second, we wanted to correlate gb expression with presence of hvt, i.e. if gb expression is absent, can hvt still be detected? fif ... | 1998 | 9645320 |
| the genetic organization and transcriptional analysis of the short unique region in the genome of nononcogenic marek's disease virus serotype 2. | studies on the marek's disease virus (mdv) serotype 2 (mdv2) genome may be important for understanding the naturally nononcogenic nature of the virus. to determine the complete dna sequence of mdv2 unique short (us) region, genomic bamhi fragments f, m1 and r were sequenced. the mdv2 us region is 12109 bp long and contains 12 potential open reading frames (orfs) likely to encode for proteins. seven of them exhibit homologies to herpes simplex virus type 1 (hsv-1) us1 (icp22), us2, us3 (protein k ... | 1998 | 9879770 |
| serological characteristics of a membrane glycoprotein gp82 of marek's disease virus. | marek's disease virus (mdv) is a cell-associated herpesvirus of gallinaceous fowl. glycoproteins of herpesviruses have been reported to be important in stimulating humoral and cell-mediated immune responses against viral infection. at least eight glycoproteins of mdv have been identified, and glycoprotein b (gb) has been reported to produce protective immunity. in addition to glycoproteins, other cell membrane proteins may also be important for engendering immunity. in an attempt to determine wh ... | 1997 | 9454915 |
| recombinant fowlpox virus vaccines against australian virulent marek's disease virus: gene sequence analysis and comparison of vaccine efficacy in specific pathogen free and production chickens. | we have cloned and sequenced the glycoprotein genes gb, gc and gd of the australian virulent marek's disease virus (mdv) isolate woodlands no. 1. the glycoprotein gb and gc sequences were identical to the homologs of other virulent mdv type 1 strains, and the glycoprotein gd sequence contained only one unique amino acid substitution. recombinant fowlpox viruses (rfpvs) expressing the mdv glycoprotein genes were constructed and their efficacy as vaccines was evaluated in specific pathogen free (s ... | 1997 | 9255932 |
| herpesvirus of turkeys homologue of hsv vp16 is structurally related to varicella zoster virus trans-inducing protein encoded by orf 10. | expression of the immediate-early genes of alpha-herpesviruses is stimulated by a family of trans-inducing factors represented by vp16 of hsv-1 and orf10 gene product of vzv. we have identified and determined the nucleotide sequence of the ul48 gene encoding the herpesvirus of turkeys (hvt) homologue of hsv vp16. the gene maps to the bamhi-j fragment and appears to be expressed in a form of bicistronic transcript together with ul49. the deduced amino acid sequence of the protein encoded by hvt u ... | 1997 | 9354269 |
| increased virulence of marek's disease virus field isolates. | the continuation of an apparent evolutionary trend of marek's disease virus (mdv) towards greater virulence may explain recent increased losses from marek's disease (md) in vaccinated flocks. to address this question, the virulence of 31 isolates of serotype 1 mdv obtained from layer or broiler flocks between 1987 and 1995 were characterized. each isolate was cultured in duck embryo fibroblasts for four to six passages, and ascertained to be free from contamination with avian retroviruses, chick ... | 1997 | 9087332 |
| efficacy of inovoject egg injection system for delivering marek's disease vaccine under hatchery conditions. | the ability of the inovoject egg injection system to effectively deliver the appropriate titer of herpesvirus of turkeys (hvt) vaccine during normal hatchery operation was evaluated. the inovoject machines configured for the jamesway and chickmaster commercial hatchers both maintained the integrity of the hvt vaccine without an appreciable loss in titer from the diluted vaccine to the egg. | 1997 | 9201414 |
| identification and dna sequence analysis of the marek's disease virus serotype 2 genes homologous to the thymidine kinase and ul24 genes of herpes simplex virus type 1. | the thymidine kinase (tk) gene has been used as a safe and convenient locus for expression of heterologous proteins in some alphaherpesviruses including herpesvirus of turkeys (hvt) antigenically related to marek's disease virus (mdv) serotypes 1 (mdv1) and 2 (mdv2). in mdv2 strain hprs 24 genome, genes equivalent to the tk and ul24 homologues of herpes simplex virus type 1 were identified and sequenced. the mdv2 ul24 gene overlaps the 5' end of the tk gene in a head-to-head orientation. the pre ... | 1997 | 9208458 |
| comparison of the genomes of 15 avian herpes-virus isolates by restriction endonuclease analysis. | differentiation of herpesvirus isolates has been performed mostly on the basis of biological properties and serology. in this study, 15 herpesvirus isolates from different species of birds were compared by restriction endonuclease analysis of genomic dna. all herpesviruses were isolated in europe or are used as vaccine viruses there. the isolates could be differentiated into seven groups based on restriction patterns. the largest group contains isolates from passeriform and psittacine birds and ... | 1997 | 18483909 |
| a simple immunoperoxidase plaque assay to detect and quantitate marek's disease virus plaques. | we report an immunoperoxidase-based staining technique that can be used to rapidly and accurately detect and quantitate marek's disease virus (mdv) plaques. monolayer cultures were fixed and incubated with a monoclonal antibody specific for mdv. after washing, a second antibody of horseradish peroxidase-conjugated goat anti-mouse igg was applied, incubated for 1 hr, and washed with phosphate-buffered saline. after the cultures were incubated with diaminobenzidine, cocl2, and h2o2, the plaques ap ... | 1997 | 9356696 |
| influence of chicken genotype on protection against marek's disease by a herpesvirus of turkeys recombinant expressing the glycoprotein b (gb) of marek's disease virus. | two inbred lines of white leghorn chickens which differ in b-haplotype were immunized at 2 days of age with a thymidine kinase negative (tk-ve) herpesvirus of turkeys (hvt) recombinant expressing the glycoprotein b (gb) gene of marek's disease virus (mdv) and were challenged 6 days later with 1000 p.f.u. of the highly virulent rb1b strain of mdv. mock-vaccinated chickens and chickens immunized with a spontaneous tk-ve hvt mutant served as controls. genetically resistant b21 chickens were protect ... | 1996 | 8920698 |
| protective efficacy of a recombinant herpesvirus of turkeys as an in ovo vaccine against newcastle and marek's diseases in specific-pathogen-free chickens. | we investigated the potential of a herpesvirus of turkey (hvt)-based recombinant virus (rhvt) as an in ovo vaccine to protect specific-pathogen-free chickens against newcastle disease (nd) and marek's disease (md). the rhvt, designed to express fusion (f) and hemagglutinin-neuraminidase (hn) glycoproteins of the lentogenic hitchner b1 strain of nd virus (ndv), as well as glycoproteins a and b of the ga strain of serotype 1 md virus (mdv) was efficacious in protecting chickens against nd and md. ... | 1996 | 8782342 |
| onset of protective immunity in chicks after vaccination with a recombinant herpesvirus of turkeys vaccine expressing newcastle disease virus fusion and hemagglutinin-neuraminidase antigens. | the onset of protective immunity from lethal newcastle disease virus (ndv) challenge of chicks was determined after vaccination with a recombinant herpes virus of turkeys (hvt) expressing the fusion and hemagglutinin-neuraminidase proteins of ndv. one-day-old specific-pathogen-free chicks devoid of maternal antibodies to ndv were vaccinated with 130 to 3300 plaque forming units of hvt (depending on the trial) and then challenged at 4, 7, 10, and 14 days postvaccination (dpv) with a neurotropic v ... | 1996 | 8980804 |
| antigen-specific lymphoproliferative responses to tetanus toxoid: a means for the evaluation of marek's disease virus-induced immunosuppression in chickens. | antigen-specific lymphoproliferative responses were examined in chickens following immunization with tetanus toxoid (ttx). the immune competence of chickens was assessed by mitogen assay utilizing phytohemagglutinin (pha)-stimulation and ttx-specific antigen proliferation assay (ttx-apa). immune spleen cells but not peripheral blood leucocytes demonstrated specific proliferation following stimulation in vitro in a ttx-apa. in this study, we examined firstly the effects of marek's disease (md)-as ... | 1996 | 9032901 |
| enhancement of reticuloendotheliosis virus-induced bursal lymphomas by serotype 2 marek's disease virus. | the effect of serotype 2 and 3 marek's disease virus (mdv) vaccines on the pathogenesis of reticuloendotheliosis virus (rev)-induced bursal and non-bursal lymphomas was examined in chickens of rprl lines 15i(5) x 7(1) and 6(3) x 0, respectively. at hatch, chickens were vaccinated with strain 301b/1 of serotype 2 mdv or strain fc126 of turkey herpesvirus (hvt), a serotype 3 mdv and inoculated with spleen necrosis virus (snv), a non-defective strain of rev. in another experiment, bursas from 14-we ... | 1996 | 18645839 |
| protection and synergism by recombinant fowl pox vaccines expressing genes from marek's disease virus. | recombinant fowl poxviruses (rfpv) were constructed to express genes from serotype 1 marek's disease virus (mdv) coding for glycoproteins b (gb1), c (gc), and d (gd) and tegument proteins ul47 and ul48, as well as genes from serotypes 2 and 3 mdv coding for glycoprotein b (gb2 and gb3). these rfpvs, alone and in various combinations, including combinations of fowl poxvirus (fpv)/gbs with turkey herpesvirus (hvt), were evaluated for ability to protect maternal antibody-positive (ab+) and -negativ ... | 1996 | 8790888 |
| genetic susceptibility to marek's disease virus of local chickens in taiwan. | marek's disease is a contagious disease in chickens caused by marek's disease virus (mdv) infection. invasion of very virulent mdv (vvmdv) was considered to be a major cause of vaccine break, resulting in a large economic loss in the poultry industry. two strains of the vvmdv (strains ltb-1 and lts-1) have been reported in taiwan, causing early mortality and formation of lymphoid tumors in broilers and layers. in this study, we report the susceptibility of local chickens in taiwan to inoculation ... | 1996 | 8883787 |
| identification of a potential marek's disease virus serotype 2 glycoprotein d gene with homology to herpes simplex virus glycoprotein d. | the gene of marek's disease virus (mdv) serotype 2 (mdv2) homologous to glycoprotein d (gd) of herpes simplex virus (hsv) was identified and characterized by its nucleotide and predicted amino acid sequences. the mdv2 gd homologous gene contains an open reading frame capable of specifying a polypeptide of 385 amino acids, which include n- and c-terminal hydrophobic domains consistent with signal and anchor regions, respectively, and two potential n-linked glycosylation sites, one of which was lo ... | 1996 | 8973534 |
| a comparative study of histological conditions suitable for both immunofluorescence and in situ hybridization in the detection of herpesvirus and its antigens in chicken tissues. | our objective was to identify an optimal single set of conditions for use in both indirect immunofluorescence assays (ifa) and in situ hybridization (ish) to detect viral proteins and nucleic acids in avian lymphoid and neural tissues. various fixatives were evaluated for use with ifa to detect turkey herpesvirus (hvt) glycoprotein b (gb) and ish to identify hvt mrna in chicken tissues. a precipitating fixative (acetone) was compared to crosslinking fixatives [buffered glutaraldehyde-picric acid ... | 1996 | 8648086 |
| characteristics of cvi988/rispens and r2/23, two prototype vaccine strains of serotype 1 marek's disease virus. | studies were focused on two attenuated serotype 1 marek's disease (md) vaccine viruses, cvi988/rispens (passage 42) and r2/23 (passage 105). both serotype 1 vaccine viruses provided much higher levels of protection than the prototype md vaccine, turkey herpesvirus (hvt); the best protection was generally provided by cvi988/rispens when compared with other vaccines. the efficacy of neither serotype 1 vaccine was improved by mixture with viruses of other serotypes (synergism). no differences betwe ... | 1995 | 7677647 |
| field safety and efficacy of in ovo administration of hvt + sb-1 bivalent marek's disease vaccine in commercial broilers. | the field safety and efficacy of a bivalent marek's disease (md) vaccine (herpesvirus of turkeys + strain sb-1) administered in ovo were evaluated. the vaccine was administered to commercial broiler chicken eggs using embrex's inovoject automated egg-injection system. comparisons were made with a conventional method of vaccination, in which the vaccine was administered subcutaneously to chicks at hatching. in ovo administration of the vaccine at day 17.5-18.5 of incubation significantly reduced ... | 1995 | 7677641 |
| effect of serotype 2 and 3 marek's disease vaccines on the development of avian leukosis virus-induced pre-neoplastic bursal follicles. | the effect of serotype 2 and 3 marek's disease virus (mdv) vaccines on the development of pre-neoplastic bursal lesions induced by two strains of subgroup a avian leukosis virus (alv) was studied. chickens of line 15i5 x 7(1) susceptible to alv-induced lymphoma were inoculated at hatch with rous-associated virus-1 (rav-1) or strain rpl-40 of subgroup a alv. all chickens, except for negative controls, were also inoculated at hatch with strain 301b/1 of serotype 2 mdv or strain fc126 of turkey her ... | 1995 | 8719208 |
| molecular evolution of infectious laryngotracheitis virus (iltv; gallid herpesvirus 1): an ancient example of the alphaherpesviridae? | an analysis of two essential genes of infectious laryngotracheitis virus (iltv), glycoprotein d (gd) and the immediate early gene, herpes simplex virus homologue icp27, was performed with the equivalent gene homologues from several alphaherpesviruses. amino acid (aa) sequence analysis revealed that these iltv genes shared limited homology to other alphaherpesvirus equivalents and were distinct from the two other avian herpesviruses, marek's disease virus (mdv) and herpesvirus of turkeys (hvt). s ... | 1995 | 8545960 |
| sequence characteristics of a gene in infectious laryngotracheitis virus homologous to glycoprotein d of herpes simplex virus. | an infectious laryngotracheitis virus (iltv, gallid herpesvirus 1) gene homologous to glycoprotein d of herpes simplex virus (hsv) was identified and characterized by its nucleotide and derived amino acid sequence. the iltv gd gene is located in the unique short region (u(s)) and contains an open reading frame capable of specifying a polypeptide of 380 amino acids, including n- and c- terminal hydrophobic domains consistent with signal and anchor regions respectively, and no potential sites for ... | 1995 | 7612933 |
| herpesvirus of turkey recombinant viruses expressing infectious bursal disease virus (ibdv) vp2 immunogen induce protection against an ibdv virulent challenge in chickens. | two recombinant herpesviruses of turkey (hvt) expressing the vp2 protein of infectious bursal disease virus (ibdv or gumboro disease virus) have been constructed: vhvt001 and vhvt002. the vp2 open reading frame was inserted at the locus of the small subunit of ribonucleotide reductase gene (hsv-1 ul40 homolog) without any exogenous promoter in vhvt001 and at the locus of gl gene (hsv-1 us7 homolog) under the control of the human cytomegalovirus immediate-early promoter in vhvt002. the isolation ... | 1995 | 7645252 |
| gene organization in herpesvirus of turkeys: identification of a novel open reading frame in the long unique region and a truncated homologue of pp38 in the internal repeat. | the dna sequence of a 4.792-kb fragment comprising 3.176 kb of the long unique region (ul) and 1.605 kb of the internal repeat (irl) flanking ul of herpesvirus of turkeys (hvt) was determined. three potential open reading frames (orfs) and an origin of replication have been identified. orf 1, which maps entirely within ul, has the capacity to code for an 82k protein, 731 amino acids long, which has a counterpart in marek's disease virus (mdv) but not in other herpesviruses. orf 2 has the potenti ... | 1995 | 7871728 |
| structure and properties of a herpesvirus of turkeys recombinant in which us1, us10 and sorf3 genes have been replaced by a lacz expression cassette. | in the process of generating an insertional mutant of herpesvirus of turkeys (hvt) expressing lacz at the protein kinase (pk) locus, we isolated a recombinant which contained an intact pk gene but the short unique regions us1, us10 and sorf3 had been deleted and replaced by the lacz cassette. moreover, the virus contained duplicate copies of gd, gi and ge in an opposite orientation flanking lacz, us2 and pk which were contiguous. these results are of interest in relation to the flexibility of th ... | 1995 | 7595402 |
| marek's disease and new approaches to its control. | marek's disease (md) is a lymphoproliferative disorder induced by a herpesvirus. several factors, including those virus-encoded and host-dependent, affect the course of the disease. existing vaccination program is based on the use of attenuated strains of md virus (mdv) serotype 1 and on strains of non-oncogenic serotype 2 (mdv2) and serotype 3 (herpesvirus of turkey-hvt) viruses. failures resulting in disease progress have been reported and indicate need for production of new, more effective va ... | 1995 | 7572471 |
| virus-neutralization domains on the oligomeric (230 kda) forms of antigen b of herpesvirus of turkeys and marek's disease virus differ in cross-serotypic activity. | herpesvirus of turkeys (hvt) is frequently used to protect chickens against marek's disease (md). the hvt and mdv native antigen b complex shares common epitopes. to determine whether these oligomers present virus-neutralizing domains, monospecific antibodies to the hvt and mdv native 230 kda oligomers were produced. the monospecific antibody immunopurified from an anti-hvt avian serum neutralized the in vitro infectivity of the oncogenic isolate mdv-b and the vaccine strains cvi988, sb1 and hvt ... | 1995 | 7483903 |
| identification and localization of glycoprotein b expression in lymphoid tissues of chickens infected with turkey herpesvirus. | one-day-old chickens were inoculated with turkey herpesvirus (hvt). using an indirect immunofluorescence assay with a monoclonal antibody against hvt glycoprotein b (gb), we determined the course of productive hvt infection in peripheral blood mononuclear cells (pbmcs), spleen, thymus, and bursa. pbmcs were examined from days 4 through 35 postinfection (pi). the spleen, thymus, and bursa were examined from 21 through 70 days pi. although productive infection in pbmcs was detected at 4 to 12 days ... | 1994 | 7832696 |
| partial inhibition by turkey herpesvirus of serotype 2 marek's disease virus plaque formation and in vivo infectivity. | the increased use of serotype 2 marek's disease virus (mdv) and serotype 3 turkey herpesvirus (hvt) as components of effective bivalent vaccines against marek's disease (md) prompted studies on the possible interactions of these two viruses in vitro and in vivo. the replication of the sb-1 strain of mdv was compared with replication of the fc126/2 strain of hvt in chickens and cell cultures infected with one or both viruses. replication of mdv was reduced in the presence of hvt in both in vitro ... | 1994 | 7702514 |
| cosmid cloning and restriction endonuclease mapping of the herpesvirus of turkeys (hvt) genome. | the genomic libraries of the herpesvirus of turkeys (hvt) presented to date do not include the entire genome. to construct a complete genomic library, hvt dna was partially digested with sau3a and inserted into the double cos site vector pcos2embl. the psti maps derived from the partial sau3a library demonstrate that the left region of the genome compared to the right area is overrepresented. similar to the libraries of the hvt genome established earlier, a defined portion of the middle genomic ... | 1994 | 8198443 |
| integration of multiple chicken retroviruses into multiple chicken herpesviruses: herpesviral gd as a common target of integration. | integration of two different avian retroviruses, reticuloendotheliosis virus (rev) and avian leukosis virus (alv), into the genome of two different avian herpesviruses, the herpesvirus of turkeys (hvt) and marek's disease virus (mdv), was investigated. integration events occurred by the fourth and sixth in vitro passage of cells coinfected with rev/hvt and alv/mdv, respectively. in order to further characterize the integration events, integrated proviruses and surrounding herpesviral genetic mat ... | 1994 | 8030268 |
| syngeneic lysis of reticuloendotheliosis virus-transformed cell lines transfected with marek's disease virus genes by virus-specific cytotoxic t cells. | cell-mediated immune responses against marek's disease virus (mdv) antigens were examined using reticuloendotheliosis virus (rev)-transformed cell lines of two haplotypes (b19b19 and b13b13). these cell lines were stably transfected with cloned fragments of mdv dna resulting in the expression of the mdv-specific phosphoprotein pp38. effector cells were obtained from p2a (b19b19) and s13 (b13b13) chickens at 7 days post inoculation with rev, oncogenic or attenuated serotype 1 mdv (jm-16/o and jm- ... | 1994 | 7725630 |
| characterization of proteins encoded by the short unique region of herpesvirus of turkeys by in vitro expression. | nine open reading frames mapping in the short unique (us) region of the genome of herpesvirus of turkeys (hvt) were expressed by in vitro transcription and translation. the observed m(r)s of us10, sorf3 and us2 were as predicted from the sequence but there were discrepancies between the observed and predicted m(r)s of us1, protein kinase, gi, gd and ge. these could be accounted for in most cases by post-translational and co-translational processing. analysis of the synthesized products at differ ... | 1994 | 7931161 |
| expression of a novel marek's disease virus type 1 (mdv1)-specific protein p40 in insect cells by a baculovirus vector and in chick embryo fibroblasts infected with mdv1. | we found that the open reading frame of 1053 nucleotides within the short unique sequence of marek's disease virus (mdv) type 1 (mdv1) expresses a 40 kda protein, using a baculovirus vector in insect cells. mouse antisera against the 40 kda protein reacted with a 40 kda protein in mdv1-infected cells. a cross-reactive polypeptide of 37 kda was also detected in cells infected with herpesvirus of turkey. | 1994 | 7979993 |
| b haplotype influence on the relative efficacy of marek's disease vaccines in commercial chickens. | the objectives were to investigate whether or not b haplotypes influence vaccinal immunity against marek's disease (md) in commercial chickens and to evaluate whether retrospective analysis would detect the influence. this method involved evaluating the b haplotypes of turkey herpesvirus (hvt)-vaccinated sick vs normal chickens from a flock afflicted with md symptoms. an analysis of the retrospective data disclosed that md symptoms were present in a higher proportion of b2b19 than b2b21 chickens ... | 1994 | 8202426 |
| 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 ... | 1993 | 8383172 |
| 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 ... | 1993 | 8383385 |
| identification and sequence analysis of the homologues of the herpes simplex virus type 1 glycoprotein h in marek's disease virus and the herpesvirus of turkeys. | the glycoprotein h (gh) genes of two avian herpesviruses, marek's disease virus and the herpesvirus of turkeys, have been cloned and sequenced and the coding regions found to be of 2439 and 2424 nucleotides respectively. the predicted primary polypeptide products of these open reading frames are 813 and 808 amino acids and correspond to mrs of 90,800 and 91,100. both amino acid sequences exhibit characteristic glycoprotein features such as hydrophobic signal and anchor sequences and potential si ... | 1993 | 8389802 |
| development of pcr method specific for marek's disease virus. | a rapid polymerase chain reaction (pcr) assay specific for marek's disease virus (mdv) was developed. this assay was able to detect mdv in inoculated chick kidney cells at dilutions of 10(-5). negative pcr results were obtained using uninoculated chick cells, marek's disease vaccine (sb), herpesvirus of turkeys (hvt) and fowl laryngotracheitis vaccine (lt). bursae, feathers and kidneys from mdv infected chickens were positive in the pcr assay. the same tissues from normal chickens were negative. ... | 1993 | 8391640 |
| efficacy in chickens of a herpesvirus of turkeys recombinant vaccine containing the fusion gene of newcastle disease virus: onset of protection and effect of maternal antibodies. | the onset of protection against newcastle disease and the effect of maternal antibodies to newcastle disease virus (ndv) and marek's disease virus (mdv) on vaccine efficacy were determined following vaccination of chickens with a recombinant herpesvirus of turkeys (hvt) vaccine expressing the fusion (f) glycoprotein gene of ndv. onset of protection following intra-abdominal administration of the recombinant hvt/f vaccine at 1 day of age and subsequent ocular challenge with the neurotropic veloge ... | 1993 | 8141730 |
| the complete sequence and gene organization of the short unique region of herpesvirus of turkeys. | the dna sequence of the whole of the short unique region (u(s)) and that of part of the short terminal repeat (trs) of herpesvirus of turkeys (hvt) were determined. hvt u(s) is 8.6 kbp long and contains eight potential open reading frames (orfs). seven of these have counterparts in the u(s) of herpes simplex virus type 1 (hsv-1). the homologous proteins include us1, us2, us10, protein kinase (us3) and the glycoproteins gd, gi and ge. in addition, hvt contains one orf which has a counterpart in t ... | 1993 | 8409940 |
| selection of marek's disease virus recombinants expressing the escherichia coli gpt gene. | we developed a positive selection method for recovering marek's disease virus (mdv) recombinants. the escherichia coli xanthine-guanine phosphoribosyltransferase gene (gpt), under the control of the major immediate-early promoter from cytomegalovirus, was inserted into the inverted repeats flanking the unique long (ul) region of a non-pathogenic serotype 2 mdv strain 281mi/1. in a second demonstration of the usefulness of the positive selection system, the gpt gene was inserted into the inverted ... | 1993 | 8393240 |
| identification of genomic regions of the herpesvirus of turkeys (hvt) with helper activity for avian adeno-associated virus (aaav). | herpesvirus of turkeys (hvt) is a potent helper for the defective parvovirus avian adeno-associated virus (aaav). to study the helper mechanism at the molecular level, we established a complete cosmid library of hvt dna in a set of seven overlapping clones and transiently cotransfected secondary chicken embryo fibroblast (cef) cells with aaav dna and recombinant cosmids (cbl) (individual as well as in different combinations). using an aaav-specific indirect immunofluorescence assay, we identifie ... | 1993 | 8382409 |
| 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 ... | 1993 | 8117828 |
| cosmid library of the turkey herpesvirus genome constructed from nanogram quantities of viral dna associated with an excess of cellular dna. | a protocol was designed for the rapid and efficient construction of cosmid libraries from cell-associated viral genomes available in very low quantities. purification of viral dna from cellular dna was unnecessary. the vast excess of cellular dna compensated for the limited amount of available viral dna, enabling titration of the restriction endonuclease partial digest. a cosmid library of the turkey herpesvirus dna genome was constructed from 1.5 micrograms of cellular dna containing approximat ... | 1993 | 8097201 |
| 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 ... | 1993 | 18671041 |
| 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 ... | 1992 | 1310755 |
| 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 ... | 1992 | 1316798 |
| 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 ... | 1992 | 1318409 |
| 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 ... | 1992 | 1320867 |
| 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 ... | 1992 | 1329711 |
| 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 ... | 1992 | 1333751 |
| [pathologic changes in the organs in chickens after infection with the turkey herpesvirus thv-bio-i]. | the objective of our work was to investigate the dynamics of pathological lesions of chicken organs after infection with high doses of turkey herpesvirus thv-bio-i. this virus strain is commonly used in form of the marvak vaccine against marek's disease of poultry in czechoslovakia. high doses of the vaccine are used in practice with respect to the epizootological situation. the incidence of pathological lesions in the organs of brown leghorn chickens was investigated in a five-week experiment. ... | 1992 | 1336236 |
| 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 ... | 1992 | 1485872 |
| 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 ... | 1991 | 1659363 |
| 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 ... | 1991 | 1664721 |
| establishment and characterization of a thymidine kinase deficient avian fibroblast cell line derived from a japanese quail cell line, qt35. | an avian thymidine kinase deficient (tk-) fibroblast cell line (qttk-) was established from a japanese quail cell line, qt35, and characterized the biological properties. qttk- could grow in the presence of 5-bromo-2'-deoxyuridine (budr, 100 micrograms/ml) and not in the growth medium with hypoxanthine-aminopterin-thymidine. compared to qt35 cells, the 3h-thymidine incorporation of the qttk- cells and the tk activity of the cell extract significantly decreased to 0.3% and 0.5%, respectively. in ... | 1991 | 1832032 |
| 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 ... | 1991 | 1910199 |
| 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 ... | 1991 | 1722930 |
| 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 ... | 1991 | 18679997 |
| 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 ... | 1991 | 18680042 |
| isolation of serotype 2 marek's disease virus from birds belonging to genus gallus in japan. | serotype 2 of marek's disease virus (mdv) was isolated from apparently healthy birds belonging to genus gallus that had no history of vaccination with mdv or herpesvirus of turkeys (hvt). buffy-coat cells from these birds were inoculated onto chicken embryo fibroblast (cef) cultures for primary isolation. thirteen isolates from one golden pheasant and three white silky fowls, three black silky fowls, three japanese long crowers, and three japanese bantams produced herpes-like cytopathic effects ... | 1990 | 2164389 |
| characterization of the gene encoding herpesvirus of turkeys gp57-65: comparison to marek's disease virus gp57-65 and herpes simplex virus glycoprotein c. | a gene encoding herpesvirus of turkeys (hvt) strain fc 126 gp57-65 has been mapped to the viral genome and sequenced. the hvt (fc 126) gp57-65 gene maps to bamhi fragments k1 and m, colinear with the gene from marek's disease virus (mdv) strain ga. hvt gp57-65 gene sequences were compared to the mdv strain ga gp57-65 gene that we sequenced previously. overall, the two sequences are 66% identical, with greater similarity in the 3' proximal two thirds of the genes. hvt gp57-65 gene sequences have ... | 1990 | 2161583 |
| identification of the cross-reactive antigens between marek's disease virus and pseudorabies virus by monoclonal antibodies. | among the 33 monoclonal antibodies (mabs) against pseudorabies virus (prv) examined, three mabs (24-17, 74-26, and 8) were found to react with cells infected with marek's disease virus (mdv)-related viruses by immunofluorescence test. two of the mabs (24-17 and 74-26) reacted with the nuclei of cells infected with mdv serotype 1 (mdv1), mdv serotype 2 (mdv2), and herpesvirus of turkeys (hvt), whereas mab 8 reacted with the cytoplasm of mdv2- and hvt-infected cells. however, none of the mabs agai ... | 1990 | 2164393 |
| isolation of very virulent marek's disease viruses from vaccinated chickens in australia. | very virulent marek's disease viruses (vvmdv), defined as isolates against which the herpesvirus of turkey (hvt) vaccine provide poor protection, have been isolated from poultry flocks in both the united states and europe. twenty-one samples from vaccinated australian flocks, experiencing problems with excessive marek's disease (md), were tested for the presence of transmissible md viruses (mdv). of the 16 samples which contained a transmissible agent, 14 were pathogenic in chickens, based on th ... | 1990 | 2171476 |
| nucleotide sequence and characterization of the marek's disease virus homologue of glycoprotein b of herpes simplex virus. | the marek's disease virus (mdv) homologue of the herpes simplex virus (hsv) gene encoding glycoprotein b (gb) has been identified within bamhi fragments i3 and k3 of the 'highly oncogenic' strain rb1b of mdv. the entire nucleotide sequence of the gene has been determined and its predicted amino acid sequence shown to share gross overall structural features with the gb genes of hsv, varicella-zoster virus (vzv) and other mammalian herpesviruses. in particular, all 10 cysteine residues were conser ... | 1989 | 2544666 |
| the role of the reticuloendothelial system in the immunopathology of marek's disease. | the role of macrophages in immunity against marek's disease (md) was studied. chickens of one group were subjected to depletion of macrophages using repeated doses of francil amorphous silica and those of another group were subjected to activation of macrophages using repeated doses of brewer's thioglycollate broth. chickens of a third group were vaccinated with herpesvirus of turkeys fc 126 vaccine followed by depletion of macrophages. chickens of these three groups, as well as groups of health ... | 1989 | 2549684 |
| identification of virus-specific polypeptides by monoclonal antibodies against serotype 2 marek's disease virus. | a total of 41 antibody-secreting hybridoma cells against the hprs24 strain of marek's disease virus (mdv) type 2 (mdv2) have been isolated. of these monoclonal antibodies (mabs), 24 were found by immunofluorescence tests to react specifically with mdv2-infected cells, but not mdv type 1 (mdv1)- or herpesvirus of turkeys (hvt)-infected cells, while eight reacted with mdv1- or mdv2-infected cells and nine with mdv1-, mdv2- or hvt-infected cells. by using these mabs, seven classes of mdv type-speci ... | 1989 | 2552003 |
| studies on the pathology of marek's disease following challenge in chicks vaccinated with three different vaccines. | the pathology of marek's disease (md) was studied in chickens vaccinated separately with three different vaccines, namely herpesvirus of turkeys (hvt), inactivated marek's disease virus (imdv) and a bivalent vaccine. the md-specific mortality following challenge was significantly lower (2.0 per cent) in bivalent vaccinated birds than in those vaccinated with either hvt (5.9 per cent) or imdv (13.7 per cent) alone. the occurrence, extent and severity of gross lymphomas and lymphoproliferative les ... | 1989 | 2555401 |
| a comparative analysis of the sequence of the thymidine kinase gene of a gammaherpesvirus, herpesvirus saimiri. | we present the nucleotide sequence of a region from the genome of the a + t-rich gammaherpesvirus, herpesvirus saimiri (hvs), which includes the coding sequences for the viral thymidine kinase (tk) gene. the organization of genes in this region resembles the homologous region of the epstein-barr virus (ebv) genome and is very compact, using overlapping coding sequences and with nucleotides shared by initiation and termination codons of neighbouring reading frames. the hvs tk is predicted to cont ... | 1989 | 2555434 |
| nucleotide and predicted amino acid sequences of the marek's disease virus and turkey herpesvirus thymidine kinase genes; comparison with thymidine kinase genes of other herpesviruses. | in this paper we present the nucleotide sequences of the thymidine kinase (tk) genes of two avian herpesviruses: a highly oncogenic strain of marek's disease virus (mdv strain rb1b) and its serologically related vaccine virus, the herpesvirus of turkeys (hvt strain fc-126). the predicted coding regions of the two genes are 1029 and 1050 nucleotides respectively, corresponding to polypeptides of 343 and 350 amino acids in length. putative nucleotide- and nucleoside-binding sites have been identif ... | 1989 | 2555435 |
| homologies between herpesvirus of turkey and marek's disease virus type-1 dnas within two co-linearly arranged open reading frames, one encoding glycoprotein a. | the genomes of two avian herpesviruses, marek's disease virus type 1 (mdv1) and herpesvirus of turkey (hvt), share close homology only within certain dna regions. one such homologous region of hvt dna was cloned and sequenced. two open reading frames (orfs) were found in the long unique region, orf1 encoding the glycoprotein a (ga), and orf2 encoding a still unidentified protein. these two hvt-orfs are located at almost the same positions as the homologous mdv1-orfs. the nucleotide sequence homo ... | 1989 | 2558972 |
| genetic and biochemical characterization of the thymidine kinase gene from herpesvirus of turkeys. | the thymidine kinase gene encoded by herpesvirus of turkeys has been identified and characterized. a viral mutant (atr0) resistant to 1-beta-d-arabinofuranosylthymine was isolated. this mutant was also resistant to 1-(2-fluoro-2-deoxy-beta-d-arabinofuronosyl)-5-methyluracil and was unable to incorporate [125i]deoxycytidine into dna. the mutant phenotype was rescued by a cloned region of the turkey herpesvirus genome whose dna sequence was found to contain an open reading frame similar to that fo ... | 1989 | 2724415 |
| characterization of a highly transcribed dna region of herpesvirus of turkeys. | a highly transcribed dna region of turkey herpesvirus (hvt) codes for multiple species of rna. although the rna is transcribed from both strands of dna, no overlapping complementary transcripts have been detected. the complete nucleotide sequence corresponding to the cdna of one of the hvt transcripts was determined. this sequence is highly homologous to the nucleotide sequence of marek's disease virus antigen gp57-65-coding gene and appears to represent the corresponding hvt-coding gene. | 1989 | 2792768 |
| genomic difference of herpesvirus of turkeys at low and high passage levels in culture of o1 and fc126 strains. | serial passages in culture of herpesvirus of turkeys resulted in structural genomic changes at the regions common to two virus strains with loss of their protective ability against marek's disease. | 1989 | 2615678 |
| augmentation of retrovirus-induced lymphoid leukosis by marek's disease herpesviruses in white leghorn chickens. | our objective was to determine whether the cell-associated herpesvirus vaccines used in chickens to control marek's disease tumors can augment development of lymphoid leukosis (ll) induced by exogenous avian leukosis virus (alv). various single or mixed marek's disease vaccines were inoculated at day 1, and alv was injected at 1 to 10 days, with chickens of several experimental or commercial strains. development of ll was monitored at 16 to 48 weeks in various experiments. in several strains of ... | 1989 | 2536088 |
| in situ production of interferon in tissues of chickens exposed as embryos to turkey herpesvirus and marek's disease virus. | chicken eggs at embryonation day (ed) 18 or newly hatched chicks were inoculated with turkey herpesvirus (hvt), marek's disease virus (mdv), or virus-free diluent and, at intervals after inoculation, tissue homogenates of virus-exposed and virus-free chickens or chicken embryos were examined for interferon (ifn) activity. homogenates of lung, thymus and spleen specimens from chickens given hvt at ed 18 had ifn activity. activity of ifn in the lungs was studied further. homogenates of lung specim ... | 1989 | 2475045 |
| further characterisation of a variant type of turkey herpesvirus which releases large quantities of cell-free viruses into culture medium. | a variant type of turkey herpesvirus (hvt/vt) which releases large quantities of cell-free virus into its culture medium was compared with the prototype of the fc 126 strain of hvt (hvt/wt) as to the biological and serological characteristics. the lack of replication-defective hvt/vt in chickens was considered to be due to the inability of the virus to infect and replicate in lymphocytes and not to temperature-sensitive defects at 41 degrees c. no obvious antigenic differences were found between ... | 1989 | 18679841 |
| depression of vaccinal immunity to marek's disease by infection with chicken anaemia agent. | chicken anaemia agent (caa) depressed protective vaccinal immunity against marek's disease (md) when vaccinated chicks were inoculated with caa at 1 to 14 days of age. in chicks inoculated with caa alone, a typical caa infection as manifested by early mortality, decrease in haematocrit value, severe lymphoid depletion in the lymphoid organs, and aplasia of the bone marrow occurred only when one-day-old chicks were inoculated. when both turkey herpesvirus (hvt) and caa were inoculated, a typical ... | 1988 | 18766691 |
| presence of natural suppressor cells in the chicken embryo spleen and the effect of virus infection of the embryo on suppressor cell activity. | spleen cells but not the thymus or the bursa cells of chicken embryos suppressed the in vitro mitogenesis of spleen cells of adult syngeneic or allogeneic chickens. the natural suppressor cell activity of embryo spleen was present at embryonation day 16, reached peak levels at embryonation day 18 and disappeared at hatch. the embryo spleen cells did not by themselves respond to phytohemagglutinin stimulation in vitro. the suppressive effect of embryonic spleen cells on adult spleen cells was pre ... | 1988 | 2845637 |
| gene sequence and mapping data from marek's disease virus and herpesvirus of turkeys: implications for herpesvirus classification. | purified dnas from marek's disease virus (mdv) and the herpesvirus of turkeys (hvt) were randomly sheared and cloned into the m13 bacteriophage. two-hundred and ten mdv and 130 hvt clones were sequenced to give representative samples of the genome sequences. the predicted amino acid sequences from these gammaherpes-viruses were compared to known sequences from other herpesviruses using computer analysis. thirty-five mdv and 24 hvt genes were identified by comparison with varicella-zoster virus ( ... | 1988 | 2841415 |
| antigen a gene of marek's disease virus (mdv) detects two mrna species (3.7 and 2.1 kb) in mdv- and hvt-infected cells. | the gene of glycoprotein a of marek's disease virus (mdv) detected to mrna species (3.7 and 2.1 kb) by northern blot hybridization. these two mrna species were also detected in rna extracted from herpesvirus of turkeys (hvt)-infected chick embryo fibroblasts (cef) and from the msb-1 cell line. | 1988 | 3245131 |
| the effect of substrate on the production of infectious virus by cells in culture. | herpes simplex virus type i (hsv-1), infectious bovine rhinotracheitis virus (ibr) and turkey herpesvirus were examined for growth in cells cultured on three different substrates. the substrates were glass, deae-dextran and collagen gel. with two of the viruses, hsv-1 and ibr, there were no apparent differences in production as a function of substrate. in contrast, the amount of the turkey herpesvirus which was recovered varied greatly with the substrate. titers were highest on glass, followed b ... | 1988 | 2848844 |
| turkey herpesvirus. vii. the evolution of marek's disease in chickens vaccinated at one day of age and challenged at different periods of time after vaccination. | the single comb white leghorn, the cornell s strain chickens vaccinated at one day of age with cell free herpesvirus of turkey (hvt) 100 and 1000 focus forming-units (ffu) per bird were raised in isolatores. at different periods of time the vaccinated and control chickens were reared together with chickens with clinical symptoms of marek's disease previously inoculated with jm-strain of marek's disease virus (mdv) in a separate isolation room throughout the experiment. the specific protective ef ... | 1988 | 2837003 |
| immune response of chicks inoculated with chicken anemia agent alone or in combination with marek's disease virus or turkey herpesvirus. | 1988 | 2848964 |