| influence of reticuloendotheliosis on the severity of eimeria tenella infection in broiler chickens. | broiler chickens free of maternal immunity to reticuloendotheliosis virus (rev) were used in the experiment. two groups of 25 chickens were inoculated with rev at one day of age. one of these groups and another group of 25 chickens were inoculated with eimeria tenella sporulated oocysts at 7 days of age. chickens inoculated with e. tenella showed bloody diarrhoea from 12 to 14 days of age. six out of 25 chickens died (p less than 0.05) at 13 and 14 days of age in the dual infected group. at 14 d ... | 1984 | 6328737 |
| basolateral maturation of retroviruses in polarized epithelial cells. | we have investigated the maturation sites of avian and mammalian c-type retroviruses in polarized epithelial cells. examination of thin sections of madin darby canine kidney cells infected with rd114 or avian reticuloendotheliosis virus revealed that these viruses mature from the basolateral membrane domains. similar results were obtained with a continuous line of mouse mammary epithelial cells infected with friend, moloney, rauscher, or kirsten murine leukemia viruses, or friend virus-related o ... | 1983 | 6339737 |
| a survey of disease in five commercial flocks of meat breeder chickens. | causes of sickness and death in approximately 30,000 chickens in 5 meat breeder flocks were investigated between may 1979 and april 1980. approximately 23% of disease was due to neoplasms; 81% of these were marek's disease despite vaccination against this infection. other frequent diagnoses included cellulitis (15%), respiratory disease (14%), lesions of the reproductive tract (11%) and tenosynovitis/arthritis (9%). antibodies to mycoplasma gallisepticium, avian adenovirus, infectious bursal dis ... | 1984 | 6704066 |
| improved focus assay of reticuloendotheliosis virus in a quail fibroblast cell line (qt35). | reticuloendotheliosis virus (rev) strains t and cs consistently induced focus formation in a quail fibroblast cell line designated qt35 that was maintained under agarose overlay following inoculation of rev. the foci were more distinct and better circumscribed than those that developed in qt35 cultures under fluid medium. the focus formation in qt35 cultures under agarose overlay was inhibited by rev antiserum, and there were a highly significant correlation (r = 0.966, p less than 0.005) and a ... | 1984 | 6721800 |
| spontaneous changes in nucleotide sequence in proviruses of spleen necrosis virus, an avian retrovirus. | we determined the nucleotide sequence of about 1 kilobase of dna 3' to the 5' long terminal repeat of three noninfectious ad one infectious proviral dna clones of spleen necrosis virus, an avian retrovirus, to determine if the types of nucleic acid changes involved in retrovirus mutation shed light on special features of retrovirus replication. an open reading frame was found starting 411 base pairs from the end of the long terminal repeat. it contained sequences coding for the 36 amino acids at ... | 1982 | 6951170 |
| fowlpox virus recombinants expressing the envelope glycoprotein of an avian reticuloendotheliosis retrovirus induce neutralizing antibodies and reduce viremia in chickens. | eight stable fowlpox virus (fpv) recombinants which express the envelope glycoprotein of the spleen necrosis virus (snv) strain of reticuloendotheliosis virus (rev), an avian retrovirus, were constructed. these recombinants differ in the genomic location of the inserted genes, in the orientation of the insert relative to flanking viral sequences, and in the promoter used to drive expression of the env gene. of these variables, promoter strength seems to be the most crucial. the p7.5 promoter of ... | 1993 | 8388488 |
| alteration of location of dimer linkage sequence in retroviral rna: little effect on replication or homologous recombination. | retrovirus particles contain a dimer of retroviral genomic rna. a defined region of the retrovirus genome has previously been shown to be important for both dimerization and encapsidation. to study the importance of the position of this encapsidation and dimerization signal for retroviral replication and homologous recombination, we used a previously described spleen necrosis virus-based helper cell system. this system allows retroviral vectors with multiple genetic markers to be studied after a ... | 1993 | 8388494 |
| 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 |
| the matrix region is responsible for the differential ability of two retroviruses to function as helpers for vector propagation. | we have investigated the ability of two related reticuloendotheliosis viruses to propagate a spleen necrosis virus (snv) based retroviral vector in canine osticosarcoma (d17) cells. reticuloendotheliosis virus strain a (rev-a) consistently propagated the vector more efficiently than snv in cell culture. to identify the area of the viral genome responsible for the superior helper function of rev-a, we constructed chimeric viruses between snv and rev-a. analysis of helper function indicated that a ... | 1993 | 8421894 |
| structure and regulation of the gene encoding avian inhibitor of nuclear factor kappa b-alpha. | the rel/nf-kappa b family of transcription factors exist in the cytoplasm as inactive complexes in association with an inhibitory protein called i kappa b-alpha. we have isolated a clone containing the avian i kappa b-alpha gene from a chicken genomic library. avian i kappa b-alpha is devoid of any recognizable promoter elements, i.e., tata and caat boxes; however, the 5'-utr of the gene contains the initiator elements frequently found in tata-less genes. avian i kappa b-alpha contains seven put ... | 1995 | 8543172 |
| uses of flow cytometry in virology. | this article reviews some of the published applications of flow cytometry for in vitro and in vivo detection and enumeration of virus-infected cells. sample preparation, fixation, and permeabilization techniques for a number of virus-cell systems are evaluated. the use of flow cytometry for multiparameter analysis of virus-cell interactions for simian virus 40, herpes simplex viruses, human cytomegalovirus, and human immunodeficiency virus and its use for determining the effect of antiviral comp ... | 1994 | 7530594 |
| rrr-alpha-tocopheryl succinate inhibits dna synthesis and enhances the production and secretion of biologically active transforming growth factor-beta by avian retrovirus-transformed lymphoid cells. | the rrr-alpha-tocopheryl succinate form of vitamin e, referred to as vitamin e succinate (ves), inhibits the proliferation of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells in a dose-dependent manner in vitro. analyses of conditioned medium (cm) from ves growth-inhibited cells revealed a potent antiproliferative activity. characterization of the antiproliferative activity as transforming growth factor-beta (tgf-beta) was established by 1) growth inhibition ... | 1995 | 8584453 |
| detection of antibodies to avian leukosis/sarcoma viruses (alsv) and reticuloendotheliosis viruses (rev) in humans by elisa. | we used a modified commercial elisa kit to test for antibodies to avian leukosis/sarcoma and reticuloendotheliosis viral antigens in the sera of 45 poultry workers and their matched controls. we found that 42% of sera from poultry workers had anti-avian leukosis sarcoma viruses (anti-alsv) and 20% had anti-reticuloendotheliosis viruses (anti-rev), antibody titers that were higher than the highest titer recorded in control subjects, and hence were regarded as positive. to determine the specificit ... | 1995 | 7585725 |
| 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 |
| mutations in the dna-binding and dimerization domains of v-rel are responsible for altered kappa b dna-binding complexes in transformed cells. | the c-rel proto-oncogene encodes a member of the rel/nf-kappa b family of transcription factors. the oncogenic viral form, v-rel, transduced by avian reticuloendotheliosis virus t, induces lymphoid tumors. v-rel transformation may be mediated directly by binding of v-rel to cognate dna sites, resulting in altered gene expression, and/or indirectly by releasing rel/nf-kappa b transcription factors from cytoplasmic retention molecules, resulting in their translocation to the nucleus and the inappr ... | 1995 | 7745683 |
| mapping of receptor binding domains in the envelope protein of spleen necrosis virus. | spleen necrosis virus (snv) is an amphotropic retrovirus originally isolated from a duck. although of avian origin, it also replicates on some mammalian cells. snv-derived retroviral vectors work with high efficiency and have a high potential for various gene transfer applications. however, little is known about the envelope-receptor interactions of this virus. we constructed a series of recombinant envelope proteins to characterize the su peptide of snv. we found that, in contrast to the envelo ... | 1995 | 7769695 |
| lymphoid leukosis viruses, their recognition as 'persistent' viruses and comparisons with certain other retroviruses of veterinary importance. | diseases caused by lymphoid leukosis virus (llv), a retrovirus, take a long time after infection to develop and have a wide variety of pathological manifestations. this long latent period is characteristic of 'persistent virus infections'. disease produced by llv infection and its underlying mechanisms is compared with 'persistent' infections caused by other retroviruses in birds and mammals of veterinary importance. the diseases considered for comparison are those caused by reticuloendotheliosi ... | 1996 | 8693704 |
| 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 |
| 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 |
| mutations of conserved cysteine residues in the cwlc motif of the oncoretrovirus su protein affect maturation and translocation. | the envelope glycoprotein complex is composed of two polypeptides, an external heavily glycosylated polypeptide (su) and a membrane-spanning protein (tm). together they form a heterodimer on the surface of the virion. these proteins are synthesized in the form of a polyprotein precursor which is glycosylated and proteolytically processed during its maturation in the secretory pathway. a highly conserved stretch of four amino acids, cwlc, has been identified in most known oncoretroviral su protei ... | 1995 | 7856101 |
| the immunodominant proteins of reticuloendotheliosis virus. | the antigenic profiles of three rev prototype strains, csv, snv and rev-t and eight israeli isolates were analysed by sds-page and immunoblotting with convalescent chicken serum, three mabs, 11a25, 11c237 and 11c100, a rabbit antiserum to rev-t whole virus (cui et al., 1986) and a rabbit antiserum to rev-a p30 gag protein (tsai et al., 1985). under both reducing (+dtt) and non-reducing conditions of sds-page, a major immunodominant 75-100 kda band was shared by all strains examined. in contrast ... | 1996 | 8734645 |
| the v-rel oncoprotein complexes with new rel- and rela-related proteins in transformed cells. | the v-rel oncoprotein of the rev-t retrovirus interacts with a number of cellular proteins in transformed chicken spleen cells including p40/i kappa b alpha, p68c-rel, hsc70, and the p124 and p115 precursors for the p50 and p52 subunits of nf kappa b. here we report that v-rel associates with at least three other cellular proteins of 75-85 kda in these cells, as well as with a protein related to human rela. western blot analysis of v-rel immune complexes showed cross-reactivity between all of th ... | 1995 | 7886940 |
| cell-mediated immune effector functions in chickens. | cell-mediated immune responses form an important part of the protection against intracellular pathogens. the mhc class i and class ii antigens are important for the proper presentation of degraded proteins to cytotoxic t lymphocytes (ctl) and helper t cells, respectively. recent developments in the knowledge of the molecular structure of the mhc in relation to antigen presentation are discussed. although ctl are important, there is a paucity of information concerning their relevance for the cont ... | 1994 | 7937468 |
| rrr-alpha-tocopheryl succinate induces apoptosis in avian retrovirus-transformed lymphoid cells. | the rrr-alpha-tocopheryl succinate form of vitamin e [vitamin e succinate (ves)] inhibits the proliferation of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells in a dose-dependent manner, blocks the cells in the g2/m cell cycle phase, and induces the cells to undergo apoptosis. apoptosis was documented by demonstrating changes that are characteristic of this type of cell death, including morphological analyses of chromatin condensation by 4',6-diamidine-2'-ph ... | 1996 | 8837858 |
| pseudotyped rev/srv retroviruses reveal restrictions to infection and host range within members of the same receptor interference group. | the reticuloendotheliosis virus (rev) group of retroviruses and type d simian retroviruses (srv) belong to the same receptor interference group. the cellular receptor for these viruses has not yet been identified. in order to study the distribution of the receptor and to identify a receptor negative cell line, vector viral pseudotypes between rev and srv were made. using these viral pseudotypes, susceptibility to infection was examined in some rodent and marsupial cell lines. infectivity assays ... | 1994 | 7975230 |
| an immunoperoxidase plaque assay for reticuloendotheliosis virus and its application to a sensitive serum neutralization assay. | a rapid assay for the enumeration of reticuloendotheliosis virus (rev) is described. chicken embryo fibroblast monolayer cultures were infected with rev and incubated 6 days under an agar overlay. after removal of the overlay, cells were fixed with acetone/ethanol. foci of infection (hereafter referred to as plaques) were detected using either an anti-rev envelope monoclonal antibody or convalescent chicken serum as the primary antibody; the secondary antibody was either horseradish peroxidase-c ... | 1994 | 8002888 |
| reverse transcriptase activity in vaccines derived from chick cells. | | 1996 | 8978928 |
| structural genes, not the ltrs, are the primary determinants of reticuloendotheliosis virus a-induced runting and bursal atrophy. | reticuloendotheliosis virus strain a (rev-a) and chicken syncytial virus (csv), two replication competent avian retroviruses, differ in the extent to which they induce a runting syndrome that includes anemia, lymphoid organ atrophy, and reduced body size. we have isolated an infectious clone of csv, the less pathogenic of the two viruses, and compared it to rev-a. partial dna sequence analysis suggests that it differs from rev-a by no more than 1 to 2% at the nucleotide level. analysis of viral ... | 1994 | 8009826 |
| identification of latency-associated transcripts that map antisense to the icp4 homolog gene of marek's disease virus. | two small rnas (0.9 and 0.75 kb), named marek's disease virus (mdv) small rnas (msrs) and a 10-kb rna, all of which map antisense to the mdv icp4 homolog gene, have been readily detected in mdcc-msb1 mdv-transformed t-lymphoblastoid cells. these rnas were not detectable in reticuloendotheliosis virus-transformed t cells. when mdv was reactivated by treatment of lymphoblastoid cells with 25 micrograms of iododeoxyuridine per ml, the relative levels of the transcripts decreased. these rnas were no ... | 1994 | 8083968 |
| 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 |
| poultry oncogenic retroviruses and humans. | viruses of the avian leukosis/sarcoma group (alsv) and reticuloendotheliosis viruses (rev) are highly prevalent in chickens and turkeys and naturally cause tumors in them. commercial chickens are positive for antibodies, and a proportion actually carry infectious virus. virus may be present in chicken products and in eggs, thus human exposure is virtually universal. the viruses show little potential for producing infectious viral particles in mammalian cells; nevertheless, they have the capacity ... | 1994 | 8162609 |
| thymocyte apoptosis induced by elevated endogenous corticosterone levels. | a well-known model of apoptosis is induction in thymocytes by injection of pharmacological doses of exogenous steroids. the aim of this study was to investigate whether this process also occurs under physiological conditions, i.e. by stimulation of endogenous glucocorticoid release, using the chicken as an experimental model. endogenous glucocorticoid levels can be elevated by immunization with exogenous antigens or by injection of conditioned medium, e.g. supernatant of mitogen-stimulated splee ... | 1994 | 8181522 |
| v-rel induces expression of three avian immunoregulatory surface receptors more efficiently than c-rel. | the c-rel gene is a member of nf-kappa b/rel family of transcription factors that regulate expression of a variety of immunoregulatory molecules. the viral oncogene, v-rel, is a truncated and mutated form of the turkey c-rel gene expressed by reticuloendotheliosis virus, strain t. in this study, we demonstrated that three avian immunoregulatory receptors, major histocompatibility (mhc) antigens class i and class ii as well as the interleukin-2 receptor (il-2r), were induced on the surface of spl ... | 1994 | 8254742 |
| 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 |
| in vivo evolution of c-rel oncogenic potential. | the c-rel proto-oncogene belongs to the nf-kappa b/rel and i kappa b gene families, which regulate several inducible processes, including self-defense/repair and embryogenesis. transduction of the c-rel transcription factor by the avian retrovirus resulted in the formation of a highly oncogenic virus, reticuloendotheliosis virus strain t (rev-t), that encodes the oncogene v-rel. to examine the oncogenic potential of c-rel, we inserted it into a rev-t-based retroviral vector, rescued virus [rev-c ... | 1994 | 8139023 |
| 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 |
| retroviral techniques for studying organogenesis with a focus on heart development. | the study of development has been revolutionized by the application of molecular techniques, which make it possible to identify factors involved in the developmental process. however, in order to correctly assess the contribution of these growth factors, transcription factors, receptors or signaling molecules, it is necessary to study them in the animal as a whole; it is not enough to conclude that they must be important based on their expression patterns. | 1997 | 9278229 |
| antibody response elicited against empty reticuloendotheliosis virus particles in two inbred lines of chicken. | immunisation of houghton white leghorn line 15i and 6(1) chickens with empty reticuloendotheliosis virus particles elicited a primary antibody response which is probably directed against the viral envelope glycoproteins gp73/71 and gp22. antibodies in line 15i birds were shown to be non-neutralising and did not protect against the tumourigenic effects of reticuloendotheliosis virus, strain t. however, immunised line 6(1) chicks did not exhibit the runting syndrome associated with reticuloendothe ... | 1993 | 8273276 |
| comparative evaluation of in vitro and in vivo assays for the detection of reticuloendotheliosis virus as a contaminant in a live virus vaccine of poultry. | indirect immunofluorescence (ifa), polymerase chain reaction (pcr), and enzyme-linked immunosorbent assay (elisa) were used for detection of reticuloendotheliosis virus (rev) as a contaminant in a live virus fowl pox (fp) vaccine of poultry. a fp vaccine known to be contaminated with rev was tested by in vitro and in vivo assays in chicken embryo fibroblasts (cefs) and day-old specific-pathogen-free (spf) chicks, respectively. using in vitro assays, ifa and pcr were more sensitive than elisa in ... | 1997 | 9356718 |
| characterization of an internal ribosomal entry segment within the 5' leader of avian reticuloendotheliosis virus type a rna and development of novel mlv-rev-based retroviral vectors. | the murine leukemia virus (mlv)-related type c viruses constitute a major class of retroviruses that includes numerous endogenous and exogenous mammalian viruses and the related avian spleen necrosis virus (snv). the mlv-related viruses possess a long and multifunctional 5' untranslated leader involved in key steps of the viral life cycle--splicing, translation, rna dimerization, encapsidation, and reverse transcription. recent studies have shown that the 5' leader of friend murine leukemia viru ... | 1997 | 9382952 |
| 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 |
| a survey of an antibody to reticuloendotheliosis virus in sera of chickens and other avian species in japan. | an examination of antibody to reticuloendotheliosis virus (rev) in sera of chickens and other avian species collected from various districts in japan was carried out. agar gel immunodiffusion test (agid) to the chicken sera revealed positive results in 25.9% of the 54 farms, 21.4% of the 126 flocks and 14.3% of the 1,892 individual chickens. all the agid positive sera also were positive in indirect immunofluorescence and/or virus neutralization tests. in avian species other than chickens, peking ... | 1993 | 8286554 |
| characterization of a marek's disease virus bamhi-l-specific cdna clone obtained from a marek's disease lymphoblastoid cell line. | two marek's disease (md) virus bamhi-l-specific cdna clones were isolated from a cdna library constructed from poly(a)+ rna fractions of an md lymphoblastoid cell line, mdcc-cu41 (cu41). these clones were mapped to the region corresponding to the bamhi-q2 and l-regions. these clones hybridized with 2.5-, 0.8-, and 0.6-kb transcripts prepared from cu41. the transcriptional unit of the 0.6-kb transcript was determined by rnase protection assays. an open reading frame encoding a 107-amino-acid poly ... | 1994 | 8289349 |
| 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 |
| retrovirus-induced disease in poultry. | three species of avian retrovirus cause disease in poultry: the avian leukosis/sarcoma virus (alsv), reticuloendotheliosis virus (rev), and lymphoproliferative disease virus (lpdv) of turkeys. the alsv can be classified as slowly transforming viruses, which lack a viral oncogene, and acutely transforming viruses, which possess a viral oncogene. slowly transforming viruses induce late onset leukoses of the b cell lymphoid, erythroid, and myeloid cell lineages, and other tumors, by viral promoter ... | 1998 | 9706091 |
| orbital lymphosarcoma associated with reticuloendotheliosis virus in a peafowl. | lymphosarcoma associated with infection by avian reticuloendotheliosis virus was diagnosed in an indian peafowl with exophthalmia and exposure keratitis. exenteration of the orbit was complicated by a profound oculocardiac reflex and extensive hemorrhage during surgery. orbital bleeding was controlled by direct pressure, electrocautery, topical administration of bovine thrombin, and application of sterile gelatin sponges and oxidized regenerated cellulose. a blood transfusion was also performed. ... | 1998 | 9702227 |
| a double hairpin structure is necessary for the efficient encapsidation of spleen necrosis virus retroviral rna. | we conducted a mutational analysis within the previously defined encapsidation sequence (e) for spleen necrosis virus (snv), an avian retrovirus. we found that two regions are necessary for efficient snv replication. the first region is a double hairpin structure as proposed by konings et al. (1992, j. virol., 66, 632-640); the second region is located downstream of the hairpins. we showed further that the double hairpin structure is required for efficient snv rna encapsidation. our work is the ... | 1994 | 8313915 |
| retroviral transformation in vitro of chicken t cells expressing either alpha/beta or gamma/delta t cell receptors by reticuloendotheliosis virus strain t. | exposure of normal juvenile chicken bone marrow cells to the replication defective avian reticuloendotheliosis virus strain t (rev-t) (chicken syncytial virus [csv]) in vitro resulted in the generation of transformed cell lines containing t cells. the transformed t cells derived from bone marrow included cells expressing either alpha/beta or gamma/delta t cell receptors (tcrs) in proportions roughly equivalent to the proportions of tcr-alpha/beta and tcr-gamma/delta t cells found in the normal b ... | 1993 | 8382253 |
| efficient insertion from an internal long terminal repeat (ltr)-ltr sequence on a reticuloendotheliosis virus vector is imprecise and cell specific. | to examine the fidelity and efficiency of integration from a covalently closed long terminal repeat (ltr)-ltr sequence in vivo, we isolated individual spleen necrosis virus proviruses that arose following infection of chicken embryo fibroblasts (cefs) and sequenced the provirus-cell dna junctions. some but not all cef preparations allowed efficient insertion from the internal sequence. moreover, in contrast to integration from the normal ends of the viral dna, which occurs with precision with re ... | 1993 | 8382311 |
| a sodium-dependent neutral-amino-acid transporter mediates infections of feline and baboon endogenous retroviruses and simian type d retroviruses. | the type d simian retroviruses cause immunosuppression in macaques and have been reported as a presumptive opportunistic infection in a patient with aids. previous evidence based on viral interference has strongly suggested that the type d simian viruses share a common but unknown cell surface receptor with three type c viruses: feline endogenous virus (rd114), baboon endogenous virus, and avian reticuloendotheliosis virus. furthermore, the receptor gene for these viruses has been mapped to huma ... | 1999 | 10196349 |
| 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 |
| 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 |
| 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 |
| [effect of internal sequences in the moloney murine leukemia virus genome on replication]. | construction and using of retrovirus vectors derived from the moloney murine leukemia virus (momulv) are described. these vectors, designated minimal vectors, contain the left and right long terminal repeats (ltrs), a binding site for proline trna, a polypurine tract (ppt), and a dominant marker for selective introduction of vectors into a packaging cell line, but lack the internal sequences of the virus genome. the experiments showed that the minimal vectors can be replicated and that their tit ... | 1995 | 8666218 |
| selective activation of the proto-oncogene c-jun promoter by the transforming protein v-rel. | the transcription factor v-rel is a transforming protein of the reticuloendotheliosis virus. we found that v-rel activates the promoter of the proto-oncogene c-jun. two elements in the c-jun promoter were required for the activation by v-rel. one was a kb-site (v-rel binding site), and the other was a c-jun promoter region between -52 and +148 (c-jun promoter (-52/+148)). two promoters with the kb-site(s), those of human immunodeficiency virus (hiv) and sv40, were not activated by v-rel, but the ... | 1996 | 8668346 |
| the v-rel oncogene promotes malignant t-cell leukemia/lymphoma in transgenic mice. | the oncogene product from the avian reticuloendotheliosis virus strain t, v-rel, is a member of the rel/ nf-kappa b family of transcription factors. the mechanism by which v-rel induces oncogenic transformation remains unclear. several attempts to transform mammalian cells with v-rel have failed, suggesting that v-rel transformation may be a species-specific event. however, here we demonstrate that v-rel, but not a truncated c-rel, expressed under the control of the lck promoter, efficiently ind ... | 1996 | 8670867 |
| oncogenic retroviruses of cattle, chickens and turkeys: potential infectivity and oncogenicity for humans. | reticuloendotheliosis virus naturally infects and cause lymphoid leukosis in chickens and turkeys. we investigated whether it can infect/transfect a variety of human cells in vitro. successful infection and transfection were achieved with limited replication of virus. these findings, together with the knowledge that other oncogenic retroviruses of chickens and cattle, viz. the avian leukosis/sarcoma viruses and bovine leukemia virus show similar infectivity/oncogencity in vitro for humans, and t ... | 1996 | 8733164 |
| a non-radioactive method for identifying enzyme-amplified products of the reticuloendotheliosis proviral env and ltr genes using psoralen-biotin labelled probes. | a novel polymerase chain reaction (pcr) system based on the env gene of reticuloendotheliosis virus (rev) strain rev-a for the detection of proviral dna is described. the designed pcr product of 807 bp was identified using an internal probe of 278 bp produced by nested pcr from rev-infected dna cef. the env-gene pcr was then compared with the previously described pcr for proviral rev-long terminal repeat and the pcr product served also as the probe. the probes were labelled with the psoralen-bio ... | 1996 | 8793837 |
| 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 |
| detection of antibodies to avian leukosis/sarcoma viruses and reticuloendotheliosis viruses in humans by western blot assay. | serologic evidence of antibodies in humans to avian leukosis/sarcoma viruses (alsv) and reticuloendotheliosis viruses (rev) has in general been negative. because of the difficulty in infecting mammalian cells in vitro with these viruses, it is generally held that they do not infect humans. we first provided presumptive evidence of serologic response to these viruses in human sera of workers in poultry slaughtering plants, using an elisa. we now provide confirmatory evidence using western blot as ... | 1995 | 8925516 |
| reduction of type v collagen using a dominant-negative strategy alters the regulation of fibrillogenesis and results in the loss of corneal-specific fibril morphology. | a number of factors have been implicated in the regulation of tissue-specific collagen fibril diameter. previous data suggest that assembly of heterotypic fibrils composed of two different fibrillar collagens represents a general mechanism regulating fibril diameter. specifically, we hypothesize that type v collagen is required for the assembly of the small diameter fibrils observed in the cornea. to test this, we used a dominant-negative retroviral strategy to decrease the levels of type v coll ... | 1996 | 8947562 |
| tricistronic and tetracistronic retroviral vectors for gene transfer. | we have combined the picornavirus foot-and-mouth disease virus (fmdv) 2a sequence and the internal ribosome entry sites (ireses) from encephalomyocarditis virus (ecmv) and avian reticuloendotheliosis virus type a (rev-a) to construct tricistronic and tetracistronic vectors. all the polycistronic constructs show high titers and expression of the genes inserted. clones have been obtained in which cells simultaneously express the three or four genes carried by the polycistronic vectors. | 2000 | 10986564 |
| avian retroviruses. | avian leukosis virus (alv) and reticuloendotheliosis virus (rev) are the most common naturally occurring avian retroviruses associated with neoplastic disease conditions in domesticated poultry. avian leukosis virus infects primarily chickens, whereas rev infects chickens, turkeys, and other avian species. in addition to causing tumors, both alv and rev can reduce productivity and induce immunosuppression and other production problems in affected flocks. | 1997 | 9071747 |
| rous sarcoma virus translation revisited: characterization of an internal ribosome entry segment in the 5' leader of the genomic rna. | the 5' leader of rous sarcoma virus (rsv) genomic rna and of retroviruses in general is long and contains stable secondary structures that are critical in the early and late steps of virus replication such as rna dimerization and packaging and in the process of reverse transcription. the initiation of rsv gag translation has been reported to be 5' cap dependent and controlled by three short open reading frames located in the 380-nucleotide leader upstream of the gag start codon. translation of r ... | 2000 | 11090156 |
| the antiretrovirus drug 3'-azido-3'-deoxythymidine increases the retrovirus mutation rate. | it was previously observed that the nucleoside analog 5-azacytidine increased the spleen necrosis virus (snv) mutation rate 13-fold in one cycle of retrovirus replication (v. k. pathak and h. m. temin, j. virol. 66:3093-3100, 1992). based on this observation, we hypothesized that nucleoside analogs used as antiviral drugs may also increase retrovirus mutation rates. we sought to determine if 3'-azido-3'-deoxythymidine (azt), the primary treatment for human immunodeficiency virus type 1 (hiv-1) i ... | 1997 | 9151812 |
| differences in kappab dna-binding properties of v-rel and c-rel are the result of oncogenic mutations in three distinct functional regions of the rel protein. | the oncogene v-rel of reticuloendotheliosis virus, strain t, is derived from an avian c-rel proto-oncogene. c-rel encodes a member of the rel/nf-kappab family of transcription factors. the highly oncogenic v-rel differs from c-rel which has low transforming potential by the acquisition of numerous mutations. in this manuscript, we demonstrate that the oncogenic mutations in v-rel directly alter the ability of this protein to bind to dna. electrophoretic mobility shift analysis with rel proteins ... | 1997 | 9205096 |
| v-rel activates the proto-oncogene c-jun promoter: a correlation with its transforming activity. | v-rel is a transforming protein of the reticuloendotheliosis virus, and is a transcription factor regulating various cellular genes. we found that v-rel activates the promoter of the proto-oncogene c-jun in a transient transfection assay system. moreover, the expression of endogenous c-jun was augmented in cells expressing exogenous v-rel, but not c-rel. the transcriptional activities of v-rel to the tested promoters containing the kb-site are lower than that of c-rel, but that to the c-jun prom ... | 1997 | 9209405 |
| c-jun involvement in vitamin e succinate induced apoptosis of reticuloendotheliosis virus transformed avian lymphoid cells. | previous studies have shown that treatment of avian reticuloendotheliosis virus-transformed recc-utc4-1 (c4-1) lymphoblastoid cells with 10 microg/ml (18.8 microm) of rrr-alpha-tocopheryl succinate (vitamin e succinate, ves) for 3 days induced approximately 50% of the cells to undergo apoptosis. elevated and prolonged expression of c-jun mrna and protein was temporally correlated with ves-induced cell death. data presented in this paper show that the elevated and prolonged expression of c-jun me ... | 1997 | 9244357 |
| 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 |
| serological investigations on reticuloendotheliosis in turkey flocks. | four meat turkey and one turkey breeding flocks were surveyed for antibodies against reticuloendotheliosis virus (rev) at different intervals using commercial enzyme-linked immunosorbent assays. in addition, serum samples collected from 18 flocks at different ages were also tested for antibodies against rev. no antibodies were detected in any of the four meat turkey flocks that were surveyed. in the breeder flock, 20%) of tested samples from 1-day-old poults were positive. between the fourth and ... | 2001 | 11666037 |
| 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 |
| field and vaccine strains of fowlpox virus carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus. | for baculoviruses and herpesviruses, integration of transposons or retroviruses into the virus genome has been documented. we report here that field and vaccine strains of fowlpox virus (fpv) carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus (rev). using pcr and hybridization analysis we observed that vaccine and field strains of fpv carry rev sequences integrated into a previously uncharacterized region of the right 1/3 of the fpv genome. long-range pcr, hybridiz ... | 1997 | 9281517 |
| 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 |
| the secondary structure of the r region of a murine leukemia virus is important for stimulation of long terminal repeat-driven gene expression. | in addition to their role in reverse transcription, the r-region sequences of some retroviruses affect viral transcription. the first 28 nucleotides of the r region within the long terminal repeat (ltr) of the murine type c retrovirus sl3 were predicted to form a stem-loop structure. we tested whether this structure affected the transcriptional activity of the viral ltr. mutations that altered either side of the stem and thus disrupted base pairing were generated. these decreased the level of ex ... | 1998 | 9733816 |
| isolation and characterization of chicken interleukin-17 cdna. | interleukin-17 (il-17) is a proinflammatory cytokine produced by activated t cells. a 917-bp cdna encoding the il-17 gene was isolated from our est cdna library prepared from intestinal intraepithelial lymphocytes (iels) of eimeria-infected chickens. it contained a 507-bp open reading frame (orf) predicted to encode a protein of 169 amino acids (aa) with a molecular mass of 18.9 kda, a 27-residue nh(2)-terminal signal peptide, a single potential n-linked glycosylation site, and 6 cysteine residu ... | 2002 | 12513911 |
| infectious disease survey of rio grande wild turkeys in the edwards plateau of texas. | state wildlife agencies have translocated thousands of wild turkeys (meleagris gallopavo) since the 1930s to reestablish this species. because of threats to the domestic poultry industry and wild birds, screening for selected infectious agents has become routine since the early 1980s. one of the principal sources for rio grande wild turkeys (m. gallopavo intermedia) for translocation purposes was the edwards plateau of texas (usa). unfortunately, turkey abundance has declined in the southern edw ... | 2002 | 12528453 |
| infectious disease survey of lesser prairie chickens in north texas. | lesser prairie chicken (tympanuchus pallidicinctus) abundance, like that of most grassland birds, has declined rangewide for decades. although habitat loss and degradation are likely ultimate causes for this decline, infectious agents, particularly microparasites, could be proximate contributors. no surveys of pathogenic bacteria or viruses have been published for this species. we surveyed 24 free-living lesser prairie chickens from hemphill county, texas (usa), for evidence of exposure to salmo ... | 2002 | 12528454 |
| reticuloendotheliosis viruses and derived vectors for human gene therapy. | the reticuloendotheliosis viruses (rev) spleen necrosis virus (snv) and reticuloendotheliosis virus strain-a (rev-a) are amphotropic retroviruses which infect a large variety of cells of avian and some mammalian species. they normally do not infect primate or rodent cells. however, they efficiently infect and integrate their genome into that of human cells when they are pseudotyped with the envelope protein of other mammalian retroviruses or the g protein of vesicular stomatitis virus (vsv) or r ... | 2003 | 12700113 |
| differential regulation of the inhibitor of apoptosis ch-iap1 by v-rel and the proto-oncogene c-rel. | the v-rel oncogene encoded by reticuloendotheliosis virus is the acutely transforming member of the rel/nf-kappab family of transcription factors. v-rel is a truncated and mutated form of c-rel and transforms cells by inducing the aberrant expression of genes regulated by rel/nf-kappab proteins. the expression of ch-iap1, a member of the inhibitor-of-apoptosis family, is highly elevated in cells expressing v-rel and contributes to the immortalization of cells transformed by this oncoprotein. in ... | 2002 | 12414938 |
| resistance to salmonella enteritidis organ invasion in day-old turkeys and chickens by transformed t-cell line-produced lymphokines. | we previously reported an increased resistance to salmonella enteritidis (se) organ invasion in chicks and turkey poults injected prophylactically with se-immune lymphokines (ilk). in the present study, concanavalin a (con-a)-activated splenic t cells isolated from se-hyperimmunized hens were transformed in vitro with reticuloendotheliosis virus strain t (rev-t) (chicken syncitial virus). these transformed t cells were then maintained as a long-term (> 1 yr) cell line for the harvest of immune l ... | 1998 | 9777155 |
| reticuloendotheliosis in captive greater and attwater's prairie chickens. | reticuloendotheliosis in captive greater (tympanuchus cupido pinnatus) and attwater's (t. cupido attwateri) prairie chickens is reported for the first time. between september 1993 and august 1994, two adult female wild-caught greater prairie chickens housed at texas a&m university (college station, texas, usa) were observed with multiple subcutaneous nodules. both birds were euthanatized. complete necropsy examinations revealed lesions limited to the skin of each bird. histopathologic examinatio ... | 1998 | 9813849 |
| molecular characterization of reticuloendotheliosis virus insertions in the genome of field and vaccine strains of fowl poxvirus. | evidence of the widespread occurrence of reticuloendotheliosis virus (rev) sequence insertions in fowl poxvirus (fpv) genome of field isolates and vaccine strains has increased in recent years. however, only those strains carrying a near intact rev provirus are more likely to cause problems in the field. detection of the intact provirus or rev protein expression from fpv stocks has proven to be technically difficult. the objective of the present study was to evaluate current and newly developed ... | 2003 | 12887193 |
| pulmonary sarcomas in a young chicken. | both lungs of a 5-wk-old broiler chicken contained miliary, round, white tumors. microscopically, these masses were composed of compactly arranged cells with round to oval nuclei and indistinct cytoplasmic borders. immunohistochemically, tumor cells were positive for vimentin but negative for cytokeratin, s-100 protein, neuron-specific enolase, smooth muscle actin, and muscle-specific actin. ultrastructurally, tumor cells were separated by collagen bands and some contained collagen fibrils. thes ... | 1998 | 9876857 |
| mechanisms of the eimeria tenella growth inhibitory activity induced by concanavalin a and reticuloendotheliosis virus supernatants with interferon gamma activity in chicken macrophages and fibroblasts. | pretreatment of chicken bone marrow macrophages and embryo fibroblasts with supernatants containing chicken interferon gamma (ifn-gamma) for 24 hr prior to inoculation inhibited intracellular eimeria tenella replication, measured by [3h] uracil incorporation. the supernatants (sns) were obtained from culture of lymphoblastoid cells transformed by a reticuloendotheliosis virus (rev) and chicken splenocytes stimulated with concanavalin a (con a). the mechanisms of the e. tenella growth inhibitory ... | 1999 | 10216761 |
| identification of an internal ribosome entry segment in the 5' region of the mouse vl30 retrotransposon and its use in the development of retroviral vectors. | mouse virus-like 30s rnas (vl30m) constitute a family of retrotransposons, present at 100 to 200 copies, dispersed in the mouse genome. they display little sequence homology to moloney murine leukemia virus (momlv), do not encode virus-like proteins, and have not been implicated in retroviral carcinogenesis. however, vl30 rnas are efficiently packaged into mlv particles that are propagated in cell culture. in this study, we addressed whether the 5' region of vl30m could replace the 5' leader of ... | 1999 | 10482590 |
| the nucleocapsid domain is responsible for the ability of spleen necrosis virus (snv) gag polyprotein to package both snv and murine leukemia virus rna. | murine leukemia virus (mlv)-based vector rna can be packaged and propagated by the proteins of spleen necrosis virus (snv). we recently demonstrated that mlv proteins cannot support the replication of an snv-based vector; rna analysis revealed that mlv proteins cannot efficiently package snv-based vector rna. the domain in gag responsible for the specificity of rna packaging was identified using chimeric gag-pol expression constructs. a competitive packaging system was established by generating ... | 1999 | 10516024 |
| avian reticuloendotheliosis virus strain a and spleen necrosis virus do not infect human cells. | spleen necrosis virus (snv) and reticuloendotheliosis virus strain a (rev-a) belong to the family of reticuloendotheliosis viruses and are 90% sequence related. snv-derived retroviral vectors produced by the rev-a-based d17.2g packaging cell line were shown to infect human cells (h.-m. koo, a. m. c. brown, y. ron, and j. p. dougherty, j. virol. 65:4769-4776, 1991), while similar vectors produced by another snv-based packaging cell line, dsh134g, are not infectious in human cells (reviewed by r. ... | 2000 | 10590142 |
| a monoclonal antibody to icp4 of mdv recognizing icp4 of serotype 1 and 3 mdv strains. | monoclonal antibodies (mabs) were prepared against icp4 of marek's disease virus (mdv). mice were inoculated with icp4 obtained from high-five insect cells infected with a recombinant baculovirus expressing icp4. mabs were selected by enzyme-linked immunosorbent assay (elisa) using mdv-infected and control chick kidney cells as antigens. one of the mabs, 5h8, recognized an epitope toward the carboxyl terminus of icp4 based on staining of reticuloendotheliosis virus-transformed cells transfected ... | 1999 | 10696430 |
| inhibition of apoptosis by marek's disease viruses. | strains of marek's disease virus (mdv), a herpesvirus, have been shown to augment the development of lymphoid leukosis induced by retroviruses, the avian leukosis virus (alv) or the reticuloendotheliosis virus. in this study we explored the possibility that the ability to augment lymphoid leukosis may be correlated with the ability of different strains of mdv to block apoptosis. subclones of the alv-transformed b cell line, dt40, which was free of mdv dna were infected with either r2/23 strain o ... | 1999 | 10696433 |
| multiple infection of chickens and turkeys with avian oncogenic viruses: prevalence and molecular analysis. | the avian herpesvirus, marek's disease virus (mdv) and several retroviruses, reticuloendotheliosis virus (rev), avian leukosis virus (alv) (chickens) and lymphoproliferative disease virus (turkeys) are oncogenic and immunosuppressive agents. these viruses were detected either alone, or in various combinations in blood and tumor dnas of commercial birds using pcr. we present a 5-year retrospective study that included 207 chicken and 52 turkey flocks. of these, 32 chicken and 18 turkey flocks were ... | 1999 | 10696434 |
| the complete unique long sequence and the overall genomic organization of the ga strain of marek's disease virus. | we have determined the dna sequence of the unique long (ul) region and the repeat long (rl) region in the genome of serotype 1 ga strain of marek's disease virus (mdv), a member of the alpha-herpesvirus family. with this information, the complete nucleotide sequence of ga-mdv is now known. the entire ga-mdv genome is predicted to be about 174 kbp in size, with an organization of trl-ul-irl-irs-us-trs, typical of a alpha-herpesvirus. the ul sequence contains 113,508 bp and has a base composition ... | 2000 | 10823954 |
| development of the hot spot-combined pcr assay for detection of retroviral insertions into marek's disease virus. | a two-step pcr, the hot spot-combined pcr assay, was developed for the identification and characterization of recombinant viruses in marek's disease (herpes) and retrovirus co-infections. in the first pcr the herpesvirus genomic fragment, that was recognized in previous studies as a hot spot site for retroviral integration was amplified [reviewed in bronovskis, p., kung, h.-j., 1996. retrotransposition and herpesvirus evolution. virus genes 11, 259-270]. the products served for a second amplific ... | 1999 | 10894628 |
| neoplastic diseases: marek's disease, avian leukosis and reticuloendotheliosis. | the commercially important neoplastic diseases of poultry are marek's disease, which is caused by a herpesvirus, and the avian leukoses and reticuloendotheliosis, which are caused by retroviruses. these diseases are responsible for economic loss due to both mortality and depressed performance. marek's disease virus (mdv) and avian leukosis viruses (alvs) are prevalent throughout the world, and new strains which arise in particular locations may spread across borders, thereby undermining national ... | 2000 | 10935279 |
| inhibition of eimeria tenella replication after recombinant ifn-gamma activation in chicken macrophages, fibroblasts and epithelial cells. | we have previously shown that activation of primary cultures of chicken bone-marrow macrophages and embryo fibroblasts with supernatants of concanavaline a-stimulated or reticuloendotheliosis virus (rev)-transformed chicken spleen cells as source of ifn-gamma significantly decreases eimeria tenella growth in vitro. in the present study, we used various chicken cell lines, hd11 macrophages and du24 fibroblasts, both virally transformed, chcc-ou2 fibroblasts and lmh hepatic epithelial cells, both ... | 2000 | 10936544 |
| defence mechanisms against viral infection in poultry: a review. | defence against viral infections in poultry consists of innate and adaptive mechanisms. the innate defence is mainly formed by natural killer cells, granulocytes, and macrophages and their secreted products, such as nitric oxide and various cytokines. the innate defence is of crucial importance early in viral infections. natural killer cell activity can be routinely determined in chickens of 4 weeks and older using the rp9 tumour cell line. in vitro assays to determine the phagocytosis and killi ... | 2000 | 11087131 |
| reticuloendotheliosis virus (rev) long terminal repeats incorporated in the genomes of commercial fowl poxvirus vaccines and pigeon poxviruses without indication of the presence of infectious rev. | because of reticuloendotheliosis virus (rev) contamination in commercial poultry vaccines, polymerase chain reaction (pcr) assays have been described to increase the sensitivity of biological assays used to detect rev in vaccines. the pcr assay designed to amplify the long terminal repeat (ltr) region of rev identified rev ltrs in many of the commercial fowl poxvirus (fpv) vaccines evaluated. these commercial vaccines were not thought to be contaminated with replicating rev because of the lack o ... | 2000 | 11195637 |
| in vivo events of retroviral long terminal repeat integration into marek's disease virus in commercial poultry: detection of chimeric molecules as a marker. | the present study demonstrated, for the first time, that not only in vitro, but also in vivo, coinfections with marek's disease virus (mdv) and each of the three avian retroviruses (reticuloendotheliosis virus [rev], avian lymphoid leukosis virus [alv], and alv-j) lead to retroviral long terminal repeat (ltr) integration into mdv. a total of 306 chicken and 59 turkey commercial flocks, submitted for differential avian oncogenic virus diagnosis, served to evaluate the flock mixed virus infection ... | 2001 | 11332471 |
| growth hormone interacts with the marek's disease virus sorf2 protein and is associated with disease resistance in chicken. | marek's disease (md) is a lymphoproliferative disease of chickens induced by a herpesvirus, the md virus (mdv). because md is a significant economic problem to the poultry industry, there is great interest in enhancing genetic resistance, which is controlled by multiple genes. the influence of the mhc has been clearly demonstrated, and several relevant quantitative trait loci have been mapped; however, no single gene influencing md resistance has been identified. transcription of sorf2 is pertur ... | 2001 | 11470922 |
| efficient gene transfer in mouse neural precursors with a bicistronic retroviral vector. | gene transfer into neural precursors is a powerful approach to study the function of specific gene products during nervous system development. here we describe a retrovirus-based methodology to transduce foreign genes into mouse neural precursors. we used a high-titer bicistronic retroviral vector that encodes a marker gene, placental alkaline phosphatase (plap), and a selection gene, neomycin phosphotransferase ii (neor), under the translational control of two retroviral internal ribosome entry ... | 2001 | 11494355 |