| influence of b-haplotype on the relative efficacy of marek's disease vaccines of different serotypes. | to determine if b-haplotype differentially influences vaccinal immunity to very virulent marek's disease (md) virus challenge, chickens of five 15.b-congenic lines were vaccinated with vaccines representing serotypes 1, 2, and 3. b-haplotype differentially influenced vaccinal immunity to very virulent md virus challenge using vaccines of all three serotypes, and different md vaccines were optimal for some b-haplotypes. regarding specific haplotypes, the 15.b-congenic chickens with b2 and b13 dev ... | 1993 | 8383961 |
| alterations in dna sequence and rna transcription of the bam hi-h fragment accompany attenuation of oncogenic marek's disease herpesvirus. | the nucleotide sequences of the bamhi-h fragment of the hprs16 strain of marek's disease virus (mdv) and of its attenuated derivative hprs16/att have been determined. the results show that in addition to the tandem expansion of a 132 bp sequence from two copies in hprs16 virus to eight copies in hprs16/att, nucleotide substitutions, deletions, and insertions were also noted. several potential open reading frames (orfs) were identified. one of these (orf 13) encoded a deduced protein, mol wt 32 k ... | 1993 | 8385839 |
| retroviral insertions into a herpesvirus are clustered at the junctions of the short repeat and short unique sequences. | we previously described the integration of a nonacute retrovirus, reticuloendotheliosis virus (rev), into the genome of a herpesvirus, marek disease virus (mdv), following both long-term and short-term coinfection in cultured fibroblasts. the long-term coinfection occurred in the course of attenuating the oncogenicity of the jm strain of mdv and was sustained for > 100 passages. the short-term coinfection, which spanned only 16 passages, was designed to recreate the insertion phenomenon under co ... | 1993 | 8387199 |
| 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 |
| consistent chromosomal aberration in cell lines transformed with marek's disease herpesvirus: evidence of genomic dna amplification. | a specific chromosomal aberration was observed in 14 of 15 avian lymphoblastoid cell lines transformed with marek's disease herpesvirus. this aberration, designated dup(1p)(p22-p23), appeared as an extra g-positive band and interband on the short arm of one chromosome i homolog. using fluorescent in situ hybridization, we identified amplified genomic dna sequences in this region. this amplification involves sequences linked to an endogenous retrovirus locus and genes in the histone multigene fam ... | 1993 | 8390410 |
| retrovirus insertion into herpesvirus: characterization of a marek's disease virus harboring a solo ltr. | we recently reported the phenomenon of retroviral insertion into a herpesvirus (isfort et al., (1992) proc. natl. acad. sci. usa 89, 991-995). we have now isolated marek's disease virus (mdv) clones that carry retroviral inserts. retroviral ltr insertion has the potential to activate or inactivate herpesvirus genes leading to alterations of the biological properties of the herpesviruses. the structure and the expression pattern of a virus clone carrying a solitary ltr insertion was characterized ... | 1993 | 8390750 |
| marek's disease virus protein kinase gene identified within the short unique region of the viral genome is not essential for viral replication in cell culture and vaccine-induced immunity in chickens. | the open reading frame (orf) of 1206 bp within the short unique region (us) of marek's disease virus type 1 (mdv1) shows significant homology with the herpes simplex virus type 1 us3 gene encoding protein kinase (pk). the lacz gene of escherichia coli was inserted within the orf, designated mdv1-us3, of mdv1 k544 strain dna by homologous recombination. the plaque-purified recombinant mdv1 stably expressed the beta-galactosidase encoded by the inserted lacz gene in infected cells and replicated w ... | 1993 | 8391181 |
| 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 |
| 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 |
| latent marek's disease virus can be activated from its chromosomally integrated state in herpesvirus-transformed lymphoma cells. | marek's disease virus (mdv), a lymphotropic herpesvirus, induces t-cell lymphomas in chicken, its natural host. the lymphoma cells are latently infected with mdv but the viral contribution to the transformed phenotype is not understood. to investigate the virus-cell interaction, we focused on the status of mdv in the transformed cells. by the use of highly sensitive fluorescent in situ hybridization with metaphase chromosomes, we found (i) mdv dna to be randomly integrated at multiple sites in t ... | 1993 | 8393785 |
| characterization of a monoclonal antibody against a nuclear antigen associated with serotype-1 marek's disease virus-infected and transformed cells. | a monoclonal antibody (mab), 2bn90, was characterized on a panel of marek's disease virus (mdv) isolates representing three antigenically related serotypes and lymphoblastoid cell lines established from marek's disease (md) tumors. it was reactive with all serotype 1 isolates, including cv1988, in both enzyme-linked immunosorbent assay (elisa) and immunofluorescence (if) test. the mab immunoprecipitated and immunoblotted a 40-kilodalton protein, which was found to be phosphorylated by metabolic ... | 1993 | 8395807 |
| defective marek's disease virus dna contains a gene encoding a potential nuclear dna binding protein and a hsv a-like sequence. | four rna transcripts from chicken embryo fibroblast cells infected with marek's disease virus (mdv) strain 281ml/1 hybridized to the 4-kbp mdv replicon dna. in an attempt to identify open reading frames coding for the four transcripts, we determined the nucleotide sequences of 4-kbp replicon dna (represents a single monomeric repeat unit of defective mdv genome). computer analysis indicates that the 4-kbp mdv replicon dna contains two intact open reading frames (orfs) with common promoter regula ... | 1993 | 8396799 |
| nucleotide and predicted amino acid sequences of marek's disease virus homologues of herpes simplex virus major tegument proteins. | the dna sequence of an 8.4 kbp bamhi-ecori fragment of marek's disease virus (mdv) strain ga was determined. three of the predicted polypeptides are homologous to ul47, ul48 and ul49 encoding the major tegument proteins of herpes simplex virus type 1 (hsv-1), and four are homologous to hsv-1 ul45, ul46, ul49.5 and ul50. these seven genes are found in the long unique region of the mdv genome and are collinear with homologues in hsv-1 and varicella-zoster virus (vzv). northern blot analysis reveal ... | 1993 | 8397281 |
| 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 |
| isolation of serotype 1 marek's disease viruses from vaccinated australian flocks. | field samples were received for marek's disease virus (mdv) isolation from clinically affected flocks from several regions of eastern australia. lymphocytes were fractionated in ficoll-paque and passaged once or twice in chicken embryo kidney cultures. serotype-specific virus was detected in infected cultures by indirect immunofluorescence with monoclonal antibodies. serotype 1 mdv was isolated from 10 flocks. in samples from 5 of these flocks, serotype 2 and 3 vaccine viruses were isolated from ... | 1995 | 8545959 |
| 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 |
| marek's disease virus (mdv) icp4, pp38, and meq genes are involved in the maintenance of transformation of mdcc-msb1 mdv-transformed lymphoblastoid cells. | an antisense strategy has been used to identify genes important for the maintenance of transformation of mdcc-msb1 (msb1) marek's disease virus-transformed lymphoblastoid cells. oligodeoxynucleotides antisense to the predicted translation initiation regions of icp4 and pp38 mrnas inhibited proliferation of msb1 cells but not mdcc-cu91 (cu91) reticuloendotheliosis virus-transformed cells. control oligodeoxynucleotides having the same base composition but a different sequence did not inhibit msb1 ... | 1996 | 8551572 |
| development of a sustainable chick cell line infected with marek's disease virus. | marek's disease virus (mdv) is a highly infectious and cell-associated avian herpesvirus. fully productive infections with mdv are restricted to feather follicle epithelium of afflicted birds. in culture, mdv infection of primary chick (cef) and duck embryo fibroblast cells is semiproductive. passage of mdv and production of mdv vaccines is limited to these primary cell-associated systems. the finite life span of primary avian cell cultures has hampered efforts to use positive selection in gener ... | 1995 | 8553556 |
| preparation of monoclonal antibodies against marek's disease virus serotype 1 glycoprotein d expressed by a recombinant baculovirus. | a recombinant baculovirus, the genome of which contains dna encoding marek's disease virus serotype 1 (mdv1) homolog of glycoprotein d (gd) of herpes simplex virus under the polyhedrin promoter was constructed and designated racmdv1gd. five monoclonal antibodies (mabs) which recognize the mdv1 homolog of gd (mdv1 gd) in spodoptera frugiperda cells infected with racmdv1gd were prepared. the mabs reacted with proteins ranging from 52 to 49 kda in racmdv1gd-infected cell lysates by immunoblot analy ... | 1995 | 8578860 |
| molecular interactions between retroviruses and herpesviruses. | human and animal herpesviruses are able to stimulate gene expression of various human and animal retroviruses and the activation appears to be a common theme. it is of interest why the retroviruses can be commonly activated by herpesviruses despite clear diversities in each mechanism for retrovirus gene expression. in this review, three typical examples of the interactions; human immunodeficiency virus and human herpesviruses, avian retroviruses and marek's disease virus, and feline immunodefici ... | 1995 | 8593284 |
| kinetic analysis of t cells and antibody production in chickens infected with marek's disease virus. | in chickens inoculated with a marek's disease (md) vaccine and subsequently with virulent md virus (mdv), cd4+ t cell population was drastically decreased following a transient increase at 21 days after hatching (16 days after mdv infection). to elucidate the immune response after the decrease of cd4+ t cell population, the antibody production against sheep red blood cells (srbc) was examined in these chickens. chickens challenged with a virulent mdv after md vaccination produced lower titers, o ... | 1995 | 8593309 |
| stages of marek's disease virus latency defined by variable sensitivity to interferon modulation of viral antigen expression. | cytokines in conditioned medium can suppress expression of viral internal antigens (via) in lymphocytes latently infected with marek's disease virus. in the present study, conditioned media produced by spleen cells stimulated with concanavalin a or by mixed-lymphocyte reaction had significantly greater (p < 0.05) via-suppressive activity with lymphocytes harvested from birds at 14 days post infection than with those collected at 7 days. this finding defines two stages during the latent period in ... | 1995 | 8604560 |
| retroviral insertional activation in a herpesvirus: transcriptional activation of us genes by an integrated long terminal repeat in a marek's disease virus clone. | insertional activation of host proto-oncogenes has been recognized as a basic mechanism by which nonacute retroviruses induce cancer. our previous work has demonstrated that retroviruses can efficiently integrate into dna virus genomes. specifically, coinfection of cultured fibroblasts with a chicken herpesvirus, marek's disease virus (mdv), and a chicken retrovirus results in frequent stable retroviral insertions into the herpesvirus genome. such insertions could alter the expression of herpesv ... | 1996 | 8642673 |
| sequence and expression of a bovine herpesvirus-1 gene homologous to the glycoprotein k-encoding gene of herpes simplex virus-1. | in the bovine herpes virus-1 (bhv-1) genome, a gene equivalent to the glycoprotein k (gk)-encoding gene of other herpesviruses was identified and sequenced. the primary translation product is predicted to comprise 338 amino acids (aa) and to exhibit a molecular mass of 37.5 kda. it possesses characteristics typical for membrane glycoproteins including a potential cleavable signal sequence, three transmembrane domains and two potential n-linked glycosylation sites. comparison to the gk proteins o ... | 1996 | 8654942 |
| isolation and characterization of marek's disease virus (mdv) cdnas from a mdv-transformed lymphoblastoid cell line: identification of an open reading frame antisense to the mdv eco-q protein (meq). | two marek's disease virus (mdv) cdnas of 852 and 1168 bp, which map to the right end of the bamhi-i2 fragment of the mdv genome, were isolated from a cdna library derived from the mdv transformed lymphoblastoid cell line mkt-1. these cdnas hybridized to relatively abundant leftward mrna transcripts in mkt-1 cells and cells lytically infected with mdv. the transcriptional initiation site for these transcripts was located in the adjacent bamhi-q2 fragment, as determined by rnase protection and pri ... | 1996 | 8661449 |
| use of the polymerase chain reaction for the detection of reticuloendotheliosis virus in marek's disease vaccines and chicken tissues. | reticuloendotheliosis virus (rev) proviral dna appears to be a frequent contaminant in marek's disease (md) vaccines. a polymerase chain reaction (pcr) was established and evaluated for its ability to detect rev proviral dna in infected cell cultures and chicken tissues. deoxynucleotide primers were selected from the highly conserved gag region of the rev genome. the amplification products were identified by electrophoresis, nested pcr and by hybridization with a digoxigenine-labelled oligonucle ... | 1996 | 8693845 |
| interferon modulation of marek's disease virus genome expression in chicken cell lines. | lines of chicken lymphoblastoid cells were established from local lesions induced by simultaneous injection of marek's disease virus and various stimulants of t-cell activation. lines developed with regular medium had relatively high mean rates of spontaneous expression of viral internal antigen (6.2%). in contrast, lines developed and maintained with conditioned medium generated by mixed-lymphocyte reaction had a 62-fold reduction in the mean rate of viral internal antigen expression (0.1%). th ... | 1996 | 8713052 |
| 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 |
| detection of contamination of vaccines with the reticuloendotheliosis virus by reverse transcriptase polymerase chain reaction (rt-pcr). | the reverse transcriptase polymerase chain reaction (rt-pcr) was applied to detect contamination of marek's disease (md) vaccine with reticuloendotheliosis virus (rev). the env primers were used for the 1st rt-pcr to amplify the dna fragments of rev-a and -t. the rel and env primers were used for nested-pcr to confirm the sites deleted from rev-t and rev-a. specific amplification products were detected in the 1st rt-pcr with these primers. by nested pcr with the env and the rel primer pairs, the ... | 1996 | 8725107 |
| asymmetric deletion of the junction between the short unique region and the inverted repeat does not affect viral growth in culture and vaccine-induced immunity against marek's disease. | to construct an effective recombinant marek's disease virus type 1 (mdv1), we localized a stable insertion site for expression of the escherichia coli lacz gene near or within the short inverted repeats of mdv1 strain k554 dna. a stable recombinant mdv1 was obtained by deleting the junction region between the short unique sequence (us) and the internal short inverted repeat (irs). the recombinant mdv1 replicated in cultured cells as well as the parental viral dna. antibodies against both mdv1 an ... | 1996 | 8744553 |
| association between the rfp-y haplotype and the incidence of marek's disease in chickens. | certain haplotypes at the major histocompatibility (b) complex (mhc) of the chicken provide an easily demonstrated influence on tumor formation following infections with marek's disease virus (mdv). recognition that there is a second histocompatibility complex of genes in the chicken, rfp-y, comprised of mhc class i and class ii genes, some of which are at least transcribed, evokes the question of whether this gene complex might also influence the outcome of mdv infections. to test this hypothes ... | 1996 | 8753853 |
| occupational exposure to poultry and prevalence of antibodies against marek's disease virus and avian leukosis retroviruses. | to compare the prevalence of antibodies against marek's disease herpes virus (mdv) and against avian leukosis viruses type c (alv) in groups of workers exposed to poultry and in unexposed groups. | 1996 | 8758036 |
| 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 |
| 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 |
| novel dna binding specificities of a putative herpesvirus bzip oncoprotein. | marek's disease virus is a highly oncogenic herpesvirus that can cause t lymphomas and peripheral nerve demyelination in chickens. meq, a candidate oncogene of marek's disease virus, encodes a basic leucine zipper (bzip) transcription factor which contains a large proline-rich domain in its c terminus. on the basis of its bzip structural homology, meq is perhaps the only member of the jun-fos gene family completely viral in origin. we previously showed that meq's c-terminal domain has potent tra ... | 1996 | 8794363 |
| syngeneic marek's disease virus (mdv)-specific cell-mediated immune responses against immediate early, late, and unique mdv proteins. | marek's disease (md) infection has been controlled effectively by vaccination using nononcogenic and/or attenuated oncogenic marek's disease virus (mdv) vaccines. thus far, there is little knowledge on the role of cell-mediated immune (cmi) responses during mdv infection or vaccination. to elucidate the importance of mdv proteins in cmi responses, the pp38, meq, icp4, or icp22 genes of an oncogenic strain, ga and the gb, orf a, a41, or l1 genes of a highly oncogenic strain, rb1b were stably tran ... | 1996 | 8806490 |
| immunomodulation of peripheral t cells in chickens infected with marek's disease virus: involvement in immunosuppression. | marek's disease virus (mdv) causes t cell immunosuppression in chickens during latent infection. morphological changes specific to apoptosis were demonstrated in peripheral blood mononuclear cells (pbmc) of mdv-infected chickens at 2-3 weeks post-inoculation (p.i.). analysis of dna fragmentation in t cell subsets in the peripheral blood revealed that cd4+ t cells but not cd8+ t cells underwent apoptosis after mdv infection. the proportion of cd4+ t cells, but not that of cd8+ t cells, in the per ... | 1995 | 8847503 |
| enhancement of gene expression by marek's disease virus homologue of the herpes simplex virus-1 icp4. | | 1996 | 8870396 |
| detection of marek's disease virus serotype 1 (mdv1) glycoprotein d in mdv1-infected chick embryo fibroblasts. | chick embryo fibroblasts (cefs) infected with three strains of marek's disease virus serotype 1 (mdv1), ga, md5 and jm, were subjected to indirect immunofluorescence assay with monoclonal antibodies (mabs) against mdv1 homolog of glycoprotein d (mdv1 gd) of herpes simplex virus. by the mabs, a number of mdv1 gd-positive cells were detected in cefs infected with ga, whereas only a few and no positive cells were detected in cefs infected with md5 and jm, respectively. the mdv1 gd in ga-infected ce ... | 1996 | 8877978 |
| 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 |
| influence of marek's disease virus strain ac-1 on cellular immunity in birds carrying endogenous viral genes. | the effects of marek's disease virus (mdv) strain ac-1 on humoral and cellular immune responses were investigated in two lines of chickens segregating for the endogenous viral (ev) genes ev-6 and ev-12. all birds were vaccinated at 14 days of age against newcastle disease virus (ndv). at 3 wk of age, 48 birds per line received an intraperitoneal injection of mdv (ac-1 isolate), and 24 were injected with saline. birds of each group were killed on days 5, 7, 12, and 14 postinfection. data were fir ... | 1996 | 8883796 |
| retroviral insertional activation of the c-myb proto-oncogene in a marek's disease t-lymphoma cell line. | marek's disease virus (mdv) is an avian herpesvirus that causes, in chickens, a lymphoproliferative disease characterized by malignant transformation of t lymphocytes. the rapid onset of polyclonal tumors indicates the existence of mdv-encoded oncogenic products. however, the molecular basis of mdv-induced lymphoproliferative disease and latency remains largely unclear. several lines of evidence suggest that mdv and rous-associated virus (rav) might cooperate in the development of b-cell lymphom ... | 1996 | 8892859 |
| expression of the endogenous marek's disease virus icp4 homolog (mdv icp4) gene is enhanced in latently infected cells by transient transfection with the recombinant mdv icp4 gene. | the icp4 homolog of marek's disease virus (mdv icp4) is a possible candidate for the transactivator of the early genes. we transfected mdcc-msb-1 (msb-1) tumor cells with plasmid including a coding region of mdv icp4 using cationic liposome. as carriers for intranuclear transport, high mobility group -1 and -2 proteins were bound to the plasmid dna before forming liposomes. we detected transcripts from the plasmid 2 hr after transfection by quantitative reverse-transcriptase polymerase chain rea ... | 1995 | 8901028 |
| detection of transcripts of marek's disease virus serotype 1 icp4 homologue (mdv1 icp4) by in situ hybridization. | homologues of herpes simplex virus icp4 are important genes for the activation of many herpesviruses. we detected transcripts of the marek's disease virus serotype 1 homologue of icp4 (mdv1 icp4) by in situ hybridization (ish). using a digoxigenin-labeled-rna (dig-rna) probe, mdv1 icp4 transcripts were detected in c.a. 90% of mdv1-infected chicken embryo fibroblasts (cef) cells when cytopathic effect was reached to 90% of the cef cells and in 0.35% of mdcc-msb-1 (msb-1) cells, at a frequency sim ... | 1996 | 8915996 |
| first isolation and characterization of very virulent marek's disease virus in taiwan. | isolation of very virulent marek's disease virus (vvmdv) was carried out by inoculating blood and spleen samples of marek's disease (md) chickens onto chicken embryo fibroblast cell cultures and into the peritoneal cavity of one-day-old chicks. seven isolates of mdv were isolated in this experiment. by the results of cytopathic effect and fluorescent antibody tests, the 7 isolates were divided into 3 serotypes: serotype 1 of strains ltb-1, -2, -3, lts-1, and -2; serotype 2 of strain ltb-4; and s ... | 1996 | 8916003 |
| 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 |
| characterization of the protein product encoded by a splicing variant of the marek's disease virus eco-q gene (meq). | in the present study, we report the characterization of a 212-amino-acid polypeptide encoded by a splicing variant of the marek's disease virus eco-q gene (meq). this protein, referred to as meq-sp, contains the n-terminal 100 amino acids of meq, which include part of meq's dna binding/dimerization domain, but lacks the transactivation domain of meq. thus, meq-sp was examined for its ability to bind to dna and act as a transactivator. results indicated that while meq and meq-sp could both bind t ... | 1996 | 8941324 |
| intimal lipid accretion and elevated serum cholesterol in marek's disease virus-inoculated chickens. | in our previous studies of the early pathogenesis of the marek's disease virus (mdv)-associated model of atherosclerosis, the brachiocephalic arteries and ascending aortas of mdv-inoculated chickens failed to develop lipid accretion and intimal/medial proliferation consistent with atherosclerotic lesions, as described in the original reports of this model. the role of cholesterol supplementation in the formation of mdv-associated atherosclerotic lesions was reexamined. at 3 days of age, 40 chick ... | 1996 | 8952031 |
| marek's disease virus serotype 2 glycoprotein i gene: nucleotide sequence and expression by a recombinant baculovirus. | in the marek's disease virus (mdv) serotype 2 (mdv2) genome, a gene equivalent to the glycoprotein i (gi) of other alphaherpesviruses was identified and sequenced. the primary translation product comprises 355 amino acids with a m(r) of 38.4 kda. the predicted amino acid sequence possesses several characteristics typical of membrane glycoproteins, including a n-terminal hydrophobic signal sequence, c-terminal transmembrane and cytoplasmic domains, and extra-cellular region containing three poten ... | 1996 | 8959652 |
| cloning and sequence analysis of a marek's disease virus origin binding protein (obp) reveals strict conservation of structural motifs among obps of divergent alphaherpesviruses. | marek's disease virus (mdv) is a highly cell-associated avian herpesvirus. in its natural host, mdv induces marek's disease (md), a lethal condition characterized by malignant lymphoma of t cells. although symptoms of md may be prevented by vaccination, no practical pharmacological method of control has been widely accepted. viral replication represents a point at which pharmacological control of herpesvirus infection may be most successful. however, this requires detailed knowledge of viral rep ... | 1996 | 8972568 |
| 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 |
| apoptosis and cd8-down-regulation in the thymus of chickens infected with marek's disease virus. | marek's disease virus (mdv)-infected chickens show thymic atrophy during the acute phase of infection. we examined whether the thymic atrophy by mdv-infection was mediated by apoptosis. apoptosis-specific dna ladderings were clearly observed in thymocytes one week after mdv-infection. histological and flow cytometry studies revealed that immature cd4+ cd8+ thymocytes underwent apototic cell death. in addition, the expression level of cd8 molecules on both cd4(-)cd8+ and cd4+ cd8+ thymocyte popul ... | 1996 | 8973538 |
| from essential to beneficial: glycoprotein d loses importance for replication of bovine herpesvirus 1 in cell culture. | glycoprotein d (gd) of bovine herpesvirus 1 (bhv-1) has been shown to be an essential component of virions involved in virus entry. gd expression in infected cells is also required for direct cell-to-cell spread. therefore, bhv-1 gd functions are identical in these aspects to those of herpes simplex virus 1 (hsv-1) gd. in contrast, the gd homolog of pseudorabies virus (prv), although essential for penetration, is not necessary for direct cell-to-cell spread. cocultivation of cells infected with ... | 1997 | 8985319 |
| marek's disease virus latency-associated transcripts belong to a family of spliced rnas that are antisense to the icp4 homolog gene. | marek's disease virus (mdv) latency-associated transcripts include at least two mdv small rnas (msrs) and a 10-kb rna which map antisense to the icp4 homolog gene and are relatively abundant in mdv-transformed lymphoblastoid cells. this report further describes the biological and structural properties of these rnas. first, these rnas were detected in primary lymphomas isolated from chickens infected with several oncogenic mdv strains. second, the msrs are nonpolyadenylated, whereas, the 10-kb rn ... | 1997 | 8995659 |
| [cloning and sequencing of genes coding the glycoproteins of antigens a and b of oncogenic strain jm of marek disease virus (mdv)]. | the genes encoding the precursors of secretory glycoprotein gp57-65 (a antigen) and glycoprotein complex gp100, gp60, gp48 (b antigen) of virulent strain jm of marek's disease virus (mdv) have been cloned using pcr of viral dna. nucleotide sequences of both genes have been determined and amino acid sequence of the precursor peptides predicted, and compared with the corresponding sequences of other mdv strains. the results will be used for developing methods for the diagnosis of marek's disease a ... | 1996 | 8999319 |
| marek's disease vaccination of chickens. | | 1996 | 9006866 |
| 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 |
| nucleolar and nuclear localization properties of a herpesvirus bzip oncoprotein, meq. | marek's disease virus (mdv) is one of the most oncogenic herpesviruses and induces t lymphomas in chickens within weeks after infection. only a limited number of viral transcripts are detected in mdv tumor samples and cell lines. one of the major transcripts encodes meq, a 339-amino-acid bzip protein which is homologous to the jun/fos family of transcription factors. the c-terminal half of meq contains proline-rich repeats and, when fused to the dna-binding domain of a yeast transcription factor ... | 1997 | 9060682 |
| 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 |
| evidence that marek's disease virus exists in a latent state in a sustainable fibroblast cell line. | previously, we reported the development of two fibroblastic cell lines (mdv ou2.1 and ou2.2) infected with marek's disease virus (mdv). the two cell lines, in nonconfluent continuous cultures, displayed characteristics consistent with mdv existing in a latent state. however, presence of distinct plaques in confluent cell monolayers and the ability to transfer cytolytic infection to susceptible birds and primary chick embryo fibroblasts, suggest that, if latent, the virus is easily reactivated fr ... | 1997 | 9126245 |
| quantification of marek's disease virus in chicken lymphocytes using the polymerase chain reaction with fluorescence detection. | a quantitative assay was developed for marek's disease virus (mdv). the assay determines the numbers of viral genomes present in samples by polymerase chain reaction (pcr) amplification of a portion of the viral genome for a restricted number of cycles. fluorescent-tagged primers are used for the pcr amplification which allows quantification of the fluorescent product. previously, quantitation of marek's disease virus has required plaque assays, which are laborious and potentially error-prone, a ... | 1997 | 9128864 |
| characterization and expression of the marek's disease virus serotype 2 glycoprotein e in recombinant baculovirus-infected cells: initial analysis of its dna sequence and antigenic properties. | in marek's disease virus (mdv) serotype 2 (mdv2) genome, a gene equivalent to the glycoprotein e (ge) of other alphaherpesviruses was identified and sequenced. the primary translation product comprises 488 amino acids with a m(r) of 54.3 kda. the predicted amino acid sequence possesses several characteristics typical of membrane glycoproteins, including a n-terminal hydrophobic signal sequence, c-terminal transmembrane and cytoplasmic domains, and extra-cellular region containing four potential ... | 1997 | 9175249 |
| characterization of marek's disease herpesvirus-specific cytotoxic t lymphocytes in chickens inoculated with a non-oncogenic vaccine strain of mdv. | previously we have reported that reticuloendotheliosis virus (rev)-transformed cell lines expressing marek's disease virus (mdv) genes pp38, meq or gb were lysed by syngeneic mdv-specific splenocytes from major histocompatibility complex (mhc):b9b19 and mhc:b1b21 chickens. in contrast, rev-transformed cell lines expressing the mdv gene icp4 were only lysed by syngeneic mdv-specific splenocytes from mhc:b21b21 chickens. in this study we report that this syngeneic cell-mediated immune response is ... | 1997 | 9176112 |
| retroviral insertional mutagenesis of a herpesvirus: a marek's disease virus mutant attenuated for oncogenicity but not for immunosuppression or in vivo replication. | our earlier studies have shown that retrovirus insertion into herpesvirus is an efficient process that engenders recombinant herpesviruses with altered biological properties. the rm1 clone is derived from the jm strain of marek's disease virus (mdv) through retrovirus insertional mutagenesis and contains sequences of reticuloendotheliosis virus inserted at the junction of the internal repeat and unique short regions of the genome. in previous studies, the rm1 clone appeared attenuated for oncoge ... | 1997 | 9201407 |
| 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 |
| avian leukemias and lymphomas: interplay between retroviruses and herpesviruses. | avian leukemias and lymphomas are caused primarily by retroviruses and herpesviruses. the protooncogenes activated by avian retroviral insertions in b & t-cell lymphomas will be summarized, with discussion on a new common insertion site, bravo, associated with rav-o ltr insertion. two novel interactions between avian retroviruses and marek's disease herpesvirus (mdv) will be described: one involves direct interactions between putative viral oncoproteins and the other integrative recombination be ... | 1997 | 9209335 |
| apoptosis in peripheral cd4+t cells and thymocytes by marek's disease virus-infection. | histological study revealed that marek's disease virus (mdv) can cause apoptosis in peripheral blood lymphocytes (pbl) in latently infected chickens. analysis of dna fragmentation indicated that cd4+t cells but not cd8+t cells underwent apoptosis. these apoptotic changes were also observed in the thymus during the acute phase of the infection. flow cytometry analysis showed the drastic decrease of cd4+cd8+ thymocytes, indicating that mdv can induce apoptosis in cd4+cd8+ immature thymocytes in ac ... | 1997 | 9209342 |
| insertion of tandem direct repeats consisting of avian leukosis virus ltr sequences into the inverted repeat region of marek's disease virus type 1 dna. | the bc-1 strain dna of marek's disease virus type 1 (mdv1) at high-passage in culture was found to contain tandem direct repeats of the complete long terminal repeat (ltr) sequence of avian leukosis virus rav0 strain as the repeat unit within the short inverted repeats of the mdv1 dna. since the attenuated bc-1 strain grows well in cultured cells, the insertion site for retroviral dna sequence within the short inverted repeat of mdv1 dna is not essential for viral growth in culture. | 1997 | 9237356 |
| 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 |
| viral diseases of the immune system and strategies to control infectious bursal disease by vaccination. | viral infections which are immunosuppressive can affect the economics of poultry production, often as a result of the chicken's increased susceptibility to secondary infections and sub-optimal response to vaccinations. the mechanism of this immunosuppression has been studied in detail for certain chicken viruses. the replicating virus can have both direct and indirect effects on the cells of the immune system. the special role of the bursa of fabricius, as a lympho-epithelial organ, will be ment ... | 1997 | 9276986 |
| avian tumor viruses: persistent and evolving pathogens. | most neoplasias of lymphoid and other hematopoietic cells in commercial poultry are caused by viruses which belong to one of four distinct groups. marek's disease virus (mdv) is an oncogenic herpesvirus. avian leukosis virus (alv), reticuloendotheliosis virus (rev) and lymphoproliferative disease virus (lpdv) are oncogenic retroviruses. each group is distinguished by nucleic acid type, molecular structure, antigenicity, epidemiology, host range and other characteristics. however, most of these v ... | 1997 | 9276987 |
| marek's disease virus ecori-q gene (meq) and a small rna antisense to icp4 are abundantly expressed in cd4+ cells and cells carrying a novel lymphoid marker, av37, in marek's disease lymphomas. | mature lymphomas produced in rhode island red (rir) chickens infected with the rb1b strain of marek's disease virus (mdv) were examined for the presence of viral dna and rna and expression of viral antigens. in situ hybridization showed that all tumours examined contained viral dna in areas of lymphoid infiltration. in 3/5 tumours, there was a correlation between the number and distribution of cells expressing the marek's disease ecori-q gene (meq) and those that carried the lymphoid cell marker ... | 1997 | 9292006 |
| identification and dna sequence analysis of the marek's disease virus serotype 2 gene homologous to the herpes simplex virus type 1 glycoprotein h. | marek's disease virus (mdv) serotype 2 (mdv2) gene homologous to the glycoprotein h (gh) gene of herpes simplex virus type 1 was identified and sequenced. the predicted region encoding for the mdv2 gh gene was 2436 nucleotide and the primary translation product was 812 amino acids with a molecular weight of 89.4 kda. the protein encoded by mdv2 gh gene has a number of features characteristic of a membrane-associated glycoprotein. first, there are 9 potential n-linked glycosylation sites and 11 c ... | 1997 | 9300357 |
| 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 |
| non-association between rfp-y major histocompatibility complex-like genes and susceptibility to marek's disease virus-induced tumours in 6(3) x 7(2) f2 intercross chickens. | marek's disease (md) is a lymphoproliferative disease caused by a member of the herpesvirus family, and the best understood genetic resistance to md involves the chicken major histocompatibility complex (mhc) b-complex. preliminary observations have suggested that mhc-like rfp-y genes might also influence the incidence of md. this study describes the differentiation and definition of unique rfp-y genes in inbred lines 6(3) and 7(2), lines that possess identical b-complex genes, but that are resi ... | 1997 | 9363593 |
| transforming potential of the herpesvirus oncoprotein meq: morphological transformation, serum-independent growth, and inhibition of apoptosis. | marek's disease virus (mdv) induces the rapid development of overwhelming t-cell lymphomas in chickens. one of its candidate oncogenes, meq (mdv eco q) which encodes a bzip protein, has been biochemically characterized as a transcription factor. interestingly, meq proteins are expressed not only in the nucleoplasm but also in the coiled bodies and the nucleolus. its novel subcellular localization suggests that meq may be involved in other functions beyond its transcriptional potential. in this r ... | 1998 | 9420237 |
| the "minimal essential mhc" revisited: both peptide-binding and cell surface expression level of mhc molecules are polymorphisms selected by pathogens in chickens. | birds, like mammals, have a highly polymorphic mhc that determines strong allograft rejection. however, in contrast to mammals, there are a number of viral diseases for which resistance and susceptibility are determined by particular chicken mhc haplotypes. we have found that certain common chicken mhc haplotypes express only one class i molecule at high levels. the selection on a single mhc gene should be strong, in contrast to the situation in mammals. we have determined the peptide motifs for ... | 1997 | 9420472 |
| transformation of primary chick embryo fibroblasts by marek's disease virus. | marek's disease virus (mdv) is an alphaherpesvirus, which can mediate the malignant transformation of lymphocytes to form lymphomas in chickens. in this study, we demonstrate that mdv can transform primary chick embryo fibroblasts (cef). the cell line derived from primary cef infected with the ga strain of mdv was called cem(mdv). the fibroblast nature of cem(mdv) was verified by absence of cytokeratin type ii. the cem(mdv) phenotype differed from either primary cef or mdv-infected cef. cem(mdv) ... | 1997 | 9426443 |
| the leeuwenhoek lecture, 1997. marek's disease herpesvirus: oncogenesis and prevention. | there are a number of neoplasias for which a herpesvirus is an essential part of the aetiology. of these, marek's disease is the most common and provides excellent opportunities for the study of a herpesvirus-induced tumour both experimentally and under natural conditions in the field. marek's disease is caused by an alpha herpesvirus; it differs from the other oncogenic herpesviruses which are gamma herpesviruses. it is a ubiquitous virus in poultry populations of the world and is highly cell-a ... | 1997 | 9451743 |
| 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 |
| genetic mapping of quantitative trait loci affecting susceptibility to marek's disease virus induced tumors in f2 intercross chickens. | marek's disease (md) is a lymphoproliferative disease caused by the md virus (mdv), which costs the poultry industry nearly $1 billion annually. to identify quantitative trait loci (qtl) affecting md susceptibility, the inbred lines 6(3) (md resistant) and 7(2) (md susceptible) were mated to create more than 300 f2 chickens. the f2 chickens were challenged with mdv jm strain, moderately virulent) at 1 wk of age and assessed for md susceptibility. the qtl analysis was divided into three stages. i ... | 1998 | 9475745 |
| protection of chickens with or without maternal antibodies against both marek's and newcastle diseases by one-time vaccination with recombinant vaccine of marek's disease virus type 1. | we constructed a stable recombinant marek's disease virus type 1 (rmdv1) expressing the fusion protein (f) of newcastle disease virus (ndv) by inserting the coding sequence within the us10 gene of mdv1 by homologous recombination and designated this as rmdv1-us10l(f). the ndv-f protein was significantly expressed under control of the sv40 late promoter in cultured cells infected with the rmdv1. to examine the protective efficacy of the rmdv1, specific pathogen-free (spf) chickens were vaccinated ... | 1998 | 9491501 |
| rapid induction of lymphoid leukosis and ascites by avian leukosis virus from a lymphoid leukosis cell line. | to examine whether a lymphoid leukosis (ll) cell line releases an ll-specific avian leukosis virus (alv) or not, two viral materials, culture fluid and a concentrated viral material from an ll-cell line, were inoculated into a total of 74 day-old chicks of line 15i in 5 experiments. spectrum of diseases induced, their incidence and incubation periods to onset were examined. fifteen chicks were inoculated with the culture fluid and 9 (60%) developed ascites [59-119 days post inoculation (dpi); ge ... | 1998 | 9492364 |
| the glycoprotein d (us6) homolog is not essential for oncogenicity or horizontal transmission of marek's disease virus. | rb1bus6lacgpt, a marek's disease virus (mdv) mutant having a disrupted glycoprotein d (gd) homolog gene, established infection and induced tumors in chickens exposed to it by inoculation or by contact. lymphoblastoid cell lines derived from rb1bus6lacgpt-induced tumors harbored only the mutant virus. these results provide strong evidence that an intact gd homolog gene is not essential for oncogenicity or horizontal transmission of mdv. | 1998 | 9499123 |
| isolation of serotype 2 marek's disease virus from a cell line of avian lymphoid leukosis. | to determine a serotype of marek's disease virus (mdv) persistently infected in a lymphoid leukosis (ll)-cell line, lscc-bk3, clone a (bk3a), and to examine the pathogenicity of the virus, an attempt was made to isolate mdv from culture fluid of the ll-cell line, using chick embryo fibroblast cultures resistant to infection with subgroup a avian leukosis virus (alv) to eliminate subgroup a alv. the mdv isolate, serologically identified as serotype 2 mdv and designated as the 2h strain, was free ... | 1998 | 9524935 |
| retroviral sequence located in border region of short unique region and short terminal repeat of md5 strain of marek's disease virus type 1. | a 246-base pair (bp) retroviral sequence, which was homologous to a long terminal repeat of avian erythroblastosis virus (aev), was detected and cloned from md5 strain (md5) of marek's disease virus type 1 (mdv1) by representational difference analysis (rda). the retroviral sequence was thought to be located in the border region of short unique region (u(s) and short terminal repeat (trs), but did not exist in the border region of u(s) and the inverted short repeat (irs) of the md5 genome. a clo ... | 1998 | 9524948 |
| relationship between the immunosuppressive potential and the pathotype of marek's disease virus isolates. | isolates of marek's disease virus (mdv) representing three pathotypes of differing virulence were compared for relative immunosuppressive properties in genetically susceptible p2a-strain and genetically resistant n2a-strain chickens. criteria of immunosuppression were 1) persistence of early cytolytic infection (i.e., a delay or failure to enter latency) in lymphoid organs, 2) atrophy of the bursa of fabricius and thymus as measured by organ weight proportional to body weight at 8 and 14 days po ... | 1998 | 9533089 |
| spontaneous cell-mediated cytotoxicity (scmc) in various mammalian species and chickens: selective reaction pattern and different mechanisms. | cultured cell lines derived from donors of various species served as 75se- or 51cr-labelled targets in microcytotoxicity assays. as in human donors, considerable spontaneous cell-mediated cytotoxicity (scmc) was exhibited by peripheral blood lymphoid effector cells from healthy chickens, mink, swine, cattle, horses and tigers. although all target lines tested could be lysed in scmc, there was no 'general scmc target' for all species or all individuals of one species. the selectivity, the kinetic ... | 1980 | 9537048 |
| further characterization of the latency-associated transcription unit of marek's disease virus. | previous studies have identified a large (l) and a small (s) rna transcript antisense to the mdv homologue of the icp4 gene of herpes simplex virus (hsv) in cells infected with marek's disease virus (mdv) and in lymphoblastoid cell lines. in this study the 5' and 3' ends of the l rna and of the sense icp4 transcript of mdv were mapped by northern hybridization and rnase protection assays. the results showed that l rna is approximately 10.6 kb and that the icp4 sense transcript is initiated in th ... | 1998 | 9541614 |
| rfp-y region polymorphism and marek's disease resistance in multitrait immunocompetence-selected chicken lines. | although the influence of the chicken classical mhc in resistance to many diseases is well established, the role of the recently identified, genetically independent, mhc-like region known as rfp-y is unclear. the objectives of this study were to analyze the frequencies of dna polymorphisms of the rfp-y region in white leghorn lines, which were divergently selected in replicate for multitrait immunocompetence, and to determine the association of these polymorphisms with marek's disease (md) resis ... | 1998 | 9565235 |
| association of endogenous viral genes with quantitative traits in chickens selected for high egg production and susceptibility or resistance to marek's disease. | 1. the association of endogenous viral (ev) genes with quantitative traits in 2 genetically distinct sets of white leghorn strains were investigated. strain s had been selected for susceptibility to marek's disease (md) whereas strain k had been selected for resistance to md and high egg production and egg weight. 2. in all, 8 ev genes were typed. ev10, ev19 and 'newb' occurred exclusively in strain s, 'newa' occurred only in strain k, and ev1, ev3, ev6 and ev8 occurred in both strains. 3. where ... | 1998 | 9568296 |
| open reading frame l1 of marek's disease herpesvirus is not essential for in vitro and in vivo virus replication and establishment of latency. | two mutant cv1988 marek's disease virus (mdv) strains were developed in which a part of orf l1 was replaced by lacz with the sv40 early promoter. these mutant strains, cvil1lacz-a and -b, were inoculated into chickens to test the hypothesis that orf l1 is involved in the induction and/or maintenance of latency. mutant virus could be reisolated from lymphocytes obtained from chickens during both the lytic and latent phase of infection, indicating that orf l1 is not essential for the induction and ... | 1998 | 9568980 |
| cytotoxic t lymphocyte response in chickens immunized with a recombinant fowlpox virus expressing marek's disease herpesvirus glycoprotein b. | previously, we demonstrated that cytotoxic t lymphocytes (ctls) from mhc: b19b19 and mhc: b21b21 chickens inoculated with a non-oncogenic marek's disease virus (mdv) vaccine strain, sb-1/12 can lyse syngeneic reticuloendotheliosis virus (rev)-transformed cell lines expressing mdv pp38 or gb genes. in this study, we report the characterization of mdv gb-specific ctls in chickens immunized with recombinant fowlpox virus expressing mdv gb gene (rfpv-gb). spleen cells from rfpv-gb inoculated chicken ... | 1998 | 9618870 |
| atherosclerosis in marek's disease virus infected hypercholesterolemic roosters is reduced by hmgcoa reductase and ace inhibitor therapy. | accelerated atherosclerosis is associated with herpesviral infection both in transplant patients and after balloon angioplasty. marek's disease virus (mdv) is a herpesvirus that induces accelerated atherosclerosis associated with the development of an invasive lymphoma in hyperlipemic roosters. we have examined the effects of pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme a (hmgcoa) reductase inhibitor and quinapril, an angiotensin converting enzyme (ace) inhibitor, on atherosclerosis develo ... | 1998 | 9683927 |
| lack of evidence for marek's disease virus genomic sequences in leukocyte dna from multiple sclerosis patients in germany. | herpes viruses have repeatedly been associated with the etiology of multiple sclerosis (ms). in the course of investigations on a cluster of ms patients in key west, florida, it was suggested that marek's disease virus (mdv), a cell-associated avian herpes virus, might be involved in the pathogenesis of the disease. the aim of our study was to investigate 107 well-defined ms patients with regard to latent mdv infection. using a highly-sensitive polymerase chain reaction technique, we did not fin ... | 1998 | 9697938 |
| control strategies for marek's disease: a perspective for the future. | marek's disease virus is an evolving pathogen, acquiring virulence in response to increasingly effective vaccines. although vaccine efficacy is generally good, industry has placed a high priority on more effective products. the search for better vaccines has been conducted mainly in the arena of molecular biology, and has been thus far disappointing. various conditions prevail that currently limit the potential to develop suitable long-term solutions. a new paradigm based on reduction of early e ... | 1998 | 9706090 |
| transcriptional analysis of marek's disease virus (mdv) genes in mdv-transformed lymphoblastoid cell lines without mdv-activated cells. | spontaneously activated mdv is rarely included in mdv-transformed cells, while it may influence the results of transcriptional analysis. a population consisting of 10(3) mdv-transformed cells probably did not include spontaneously activated mdv, since the estimated frequency of mdv-transformed cells including activated mdv was below 0.01% according to limiting-dilution polymerase chain reaction (pcr) and the presence of the major early antigen pp38 in 6 transformed cell lines. reverse transcript ... | 1998 | 9713810 |
| cytology of feather pulp lesions from marek's disease (md) virus-infected chickens and its application for diagnosis and prediction of md. | cytological changes of feather pulp lesions (fpl) sampled chronologically from the same specific-pathogen free chickens inoculated with marek's disease virus serotype 1 (mdv) were examined, comparing with their histological changes. the birds having marek's disease (md) lymphomas or nerve lesions exhibited the characteristic lesion changes on the cytological smears of fpl; the initial non-suppurative inflammatory to the late lymphomatous fpl. the birds having neither the md visceral lymphomas no ... | 1998 | 9713813 |
| identification and transcriptional analysis of the homologues of the herpes simplex virus type 1 ul41 to ul51 genes in the genome of nononcogenic marek's disease virus serotype 2. | studies on marek's disease virus serotype 2 (mdv2) are important for understanding the natural nonpathogenic phenotypes of mdv. we determined the 16770 bp nucleotide sequence of the mdv2 genome located in the right part the of unique long region. the analysis revealed 12 complete open reading frames (orfs) with high amino acid sequence identities to the gene products of other alphaherpesviruses. the mdv2 orfs were arranged collinearly with the prototype sequence of herpes simplex virus type 1 ra ... | 1998 | 9714249 |
| differential susceptibility to marek's disease is associated with differences in number, but not phenotype or location, of pp38+ lymphocytes. | flow cytometric and immunocytochemical techniques were used to quantify, identify and locate marek's disease herpesvirus (mdv)-infected lymphocytes in lymphoid organs of infected chickens, by expression of the virus antigen pp38. two closely related lines of chicken, one susceptible to marek's disease (line 7(2)) and another resistant (line 6(1)), were infected at 2 weeks of age and compared at 10 sampling times between 0 and 50 days post-infection. in both lines 6(1) and 7(2), pp38+ lymphocytes ... | 1998 | 9820156 |