Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| dna sequence relationship of the baboon endogenous virus genome to the genomes of other type c and type d retroviruses. | baboon endogenous virus (baev) is a type c retrovirus present in multiple proviral copies in the dna of baboons. although interspecies antigenic determinants present on reverse transcriptase and gag proteins are shared among all mammalian type c viruses, no nucleic acid homology between baev and other type c viruses (except rd-114) has been found in conventional liquid hybridization experiments. in this study, we used restriction fragments of cloned baev dna immobilized on nitrocellulose to test ... | 1982 | 6284972 |
| identification of the rpmi 8226 retrovirus and its dissemination as a significant contaminant of some widely used human and marmoset cell lines. | a retrovirus designated rpmi 8226v, isolated in 1973 from the human myeloma cell line rpmi 8226 has been characterized by competition radioimmunoassay (ria) for the major viral structural protein and by nucleic acid hybridization analysis using cdna of the virus. the virus is highly related to the squirrel monkey type d retrovirus, smrv. in the homologous ria using rabbit anti-rpmi 8226v and 125i-labelled p37 of rpmi 8226v, rpmi 8226v and smrv exhibited competition of 81% and 73% respectively. s ... | 1982 | 6288581 |
| tumor promoter-stimulated synthesis of mason-:pfizer monkey virus. | the tumor promoter 12-0-tetradecanoyl-phorbol-14-acetate (tpa) increases by severalfold the synthesis of mason-pfizer monkey virus (mpmv), a type d retrovirus, when the virus is growing in human embryo kidney (hek) cells. the effect is transient and paralleled by a striking morphological alteration of the cells. the optimal tpa concentration for stimulation is 5 ng. ml-1. contrary to infected hek cells, tpa induces at similar concentrations neither stimulation of mpmv synthesis nor altered morph ... | 1982 | 7061574 |
| effect of monensin on mason-pfizer monkey virus glycoprotein synthesis. | the effect of the monovalent carboxylic ionophore monensin on the biosynthesis, intracellular transport, and surface expression of the glycoproteins of mason-pfizer monkey virus was examined. cells treated with monensin at concentrations of 10(-7) or 10(-6) m continued to synthesize virus particles, which from electron microscopic studies appeared to bud normally from the plasma membrane of the cells. however, the particles released had an altered buoyant density in sucrose gradients and were no ... | 1982 | 7176016 |
| transfection with the proviral dna of a type d retrovirus (mason-pfizer monkey virus). | chromosomal dna was isolated from cmmt cells which were producing mason-pfizer monkey virus (m-pmv), a type d simian retrovirus. human embryonic cells were transfected with the dna. about 2 weeks after transfection, 3 of 7 culture dishes began to produce m-pmv which could be detected by virus-mediated cell fusion in rsb human cells dually transformed by rous sarcoma virus and simian virus 40, reverse transcriptase assay, and electron microscopy. mock-transfected cultures did not produce virus. | 1982 | 6811499 |
| isolation of a unique retrovirus, mnv-1, from macaca nemestrina. | cell cultures established from the spleen of a macaca nemestrina with enzootic retroperitoneal fibromatosis (erf) spontaneously released a unique retrovirus. throughout 14 serial passages, the spleen cell cultures remained fibroblastic and no cytopathic effect was evident. the virus incorporates [3h]uridine, contains an rna-dependent dna polymerase (rddp), has a buoyant density of 1.15 g/cm3 in sucrose, and was designated mnv-1. virion-associated reverse transcriptase showed no preference for ei ... | 1983 | 6868369 |
| in vivo modification of retroviral gag gene-encoded polyproteins by myristic acid. | it has recently been shown by mass spectral analysis (henderson et al., proc. natl. acad. sci. u.s.a. 80:339-343, 1983) that the p15gag protein of murine leukemia viruses contains a novel post-translational modification, an amino-terminal myristyl (tetradecanoyl) amide. in this report we show that p15gag is the only structural protein to contain this fatty acid. in addition, the gag precursor polyproteins of type b, c, and d retroviruses have been examined for the presence of myristic acid by me ... | 1983 | 6302307 |
| sheep pulmonary adenomatosis: demonstration of a protein which cross-reacts with the major core proteins of mason-pfizer monkey virus and mouse mammary tumour virus. | a retrovirus that causes pulmonary adenomatosis, a contagious lung tumour of sheep, contains a 25 000 mol. wt. polypeptide which cross-reacts with the major core protein (p27) of mason-pfizer monkey virus and mouse mammary tumour virus. | 1983 | 6311958 |
| blastogenic response of lymphocytes derived from patients with hematopoietic malignancies to antigens of a type c retrovirus isolated from a burkitt's lymphoma cell line. | cellular immune response to antigens associated with a type c retrovirus derived from burkitt's lymphoma (bl) lymphoblastoid cells was studied in patients with hematopoietic malignancies, noncancer patients and healthy controls. response was determined by lymphocyte blastogenesis assay measuring [3h]-thymidine incorporation, thereby enabling the calculation of stimulation indices (si). positive response (si greater than 2.0) was demonstrated in patients with multiple myeloma (mm), chronic lympho ... | 1983 | 6315444 |
| monoclonal antibodies to three epitopic regions of feline leukemia virus p27 and their use in enzyme-linked immunosorbent assay of p27. | three different monoclonal antibodies were developed against the major core protein (p27) of feline leukemia virus (felv). each antibody was directed against a different epitope of the species-specific portion of felv-p27. the 3 antibodies reacted with 5 different isolates of felv but not with 7 other retroviruses (mulv (rauscher), mulv (akr), mpmv, mmtv, smrv, baev, rd 114). these monoclonal antibodies could readily be adapted to an enzyme-linked immunosorbent assay (elisa) for the specific mea ... | 1983 | 6186744 |
| effect of human interferon on type d retroviruses multiplication in chronically infected cell lines. | a study was made on the effect of human interferon (huifn) on the synthesis and release of type d viruses (mpmv and smrv) by chronically infected human lines. interferon at concentrations of 50 iu/ml lead to an inhibition of the extracellular virus production by about 50%-80% as measured by virus-associated reverse transcriptase activity, by metabolic labeling of the virus with (3h) uridine or (3h) amino acids, or by electron microscopy counting of particles. the profiles of intracellular viral ... | 1983 | 6188793 |
| chemical crosslinking of major structural proteins within type d retroviruses. | the nearest neighbor relationships of major structural proteins within type d retroviruses (smrv, mpmv, pmfv) were investigated by crosslinking with the cleavable bifunctional reagent dimethyl dithiobispropionimidate (dtbpi) or by use of 2-iminothiolane (methyl mercaptobutyrimidate, mbi) and subsequent oxidation by hydrogen peroxide. the crosslinked complexes of proteins were analyzed by two-dimensional diagonal polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. in int ... | 1983 | 6882406 |
| polypeptides of mason-pfizer monkey virus. i. synthesis and processing of the gag-gene products. | mason-pfizer monkey virus (m-pmv), the prototype d-type retrovirus, differs from the mammalian c-type retroviruses by preassembling core structures in the cytoplasm of infected cells during morphogenesis. studies that define the protein composition of m-pmv virions and identify two gag-related polyprotein precursors in m-pmv infected cells are reported. the polyprotein precursor to the internal structural (gag) proteins of m-pmv was identified by immunoprecipitation from lysates of pulse-labeled ... | 1984 | 6333757 |
| a new type d retrovirus isolated from macaques with an immunodeficiency syndrome. | macaque monkeys with the recently described acquired immunodeficiency syndrome show a marked defect in t-lymphocyte function and die with opportunistic infections and lymphoproliferative abnormalities. in the study described here a new type d retrovirus was isolated from two macaca cyclopis with this syndrome. this virus is related to, but distinct from, mason-pfizer monkey virus, a type d retrovirus previously isolated from a mammary tumor of a rhesus monkey (macaca mulatta). | 1984 | 6695172 |
| simian aids: isolation of a type d retrovirus and transmission of the disease. | a type d retrovirus related to but distinct from mason-pfizer monkey virus was isolated in vitro from the blood of two rhesus monkeys (macaca mulatta) with simian acquired immunodeficiency syndrome (saids). three juvenile rhesus monkeys that were injected intravenously with tissue culture fluids containing this virus developed saids after 2 to 4 weeks. | 1984 | 6695196 |
| transmission of simian acquired immunodeficiency syndrome (saids) with type d retrovirus isolated from saliva or urine. | saliva and urine specimens from rhesus monkeys with saids were found to contain a type d retrovirus related to mason-pfizer monkey virus (mpmv) which has been linked etiologically to saids. virus isolates from saliva and urine were shown to have the characteristics of the saids agent by their reverse transcriptase divalent cation preference for synthetic template-primers, production of characteristic cytopathology in raji cells and antigenic relatedness to mpmv as determined by enzyme-linked imm ... | 1984 | 6083568 |
| simian aids--evidence for a retroviral etiology. | this paper reviews the major features of a simian model of acquired immunodeficiency ('saids'), saids occurs endemically in colonies of macaque monkeys in the united states and resembles aids in humans in overall clinical manifestations, pathology, and immune deficiency. an infectious type d retrovirus, related to but distinct from the mason-pfizer monkey virus, has been identified as the primary cause of saids. the relevance of these findings for human aids is discussed. | 1984 | 6090298 |
| experimental infection of rhesus monkeys with type d retrovirus. | the naturally occurring immunodeficiency syndrome of macaque monkeys is an important animal model for the acquired immunodeficiency syndrome in humans. a new type d retrovirus, distinct from mason-pfizer monkey virus, has been isolated from affected animals at the new england regional primate research center. we now report the results of experimental infection of macaques with retrovirus d/new england after 13 months of study. inoculated macaques developed lymphadenopathy without follicular hype ... | 1984 | 6092691 |
| [viral etiologies of aids: facts and hypotheses]. | all the epidemiological features suggest that the acquired immunodeficiency syndrome (aids) is caused by a single transmissible agent and surely a virus. first, cytomegalovirus, epstein-barr virus and hepatitis b virus have been proposed as possible etiological agents of aids. a direct link between ubiquitous viruses and the occurrence of the disease has been discarded. at present time, etiological researches provide evidence that retroviruses are the best candidates for the etiology of aids. th ... | 1984 | 6095408 |
| mason-pfizer monkey virus and simian aids. | 1984 | 6141397 | |
| cross-reactivity of a normal human cell surface antigen with primate retrovirus glycoproteins. | normal human cells express a human-specific antigen, huly-m5 (defined by the e4.3 monoclonal antibody), cross-reactive with determinants of the primate retroviruses, mpmv(mason pfizer monkey virus) and galv (gibbon ape leukemia virus). purified virus preparations of mpmv and galv absorbed e4.3 antibody activity while antisera to these retroviruses blocked the binding of e4.3 antibody to human target cells. sequential immunoprecipitation and two-dimensional gel analysis both indicated that the an ... | 1985 | 3924865 |
| purification and n-terminal amino acid sequence comparisons of structural proteins from retrovirus-d/washington and mason-pfizer monkey virus. | a new d-type retrovirus originally designated saids-d/washington and here referred to as retrovirus-d/washington (r-d/w) was recently isolated at the university of washington primate center, seattle, wash., from a rhesus monkey with an acquired immunodeficiency syndrome and retroperitoneal fibromatosis. to better establish the relationship of this new d-type virus to the prototype d-type virus, mason-pfizer monkey virus (mpmv), we have purified and compared six structural proteins from each viru ... | 1985 | 3927012 |
| retrovirus d/new england and its relation to mason-pfizer monkey virus. | seventeen isolates of retrovirus d/new england have been obtained from three species of macaques at the new england regional primate research center. seven of the isolates were obtained from macaques who subsequently died with the macaque immunodeficiency syndrome; other isolates were obtained from macaques with less severe or other forms of illness. attempts to isolate type d retrovirus from peripheral lymphocytes of 97 apparently healthy macaques have not been successful. cloned dna was prepar ... | 1985 | 3989913 |
| suppression of human lymphocyte mitogen response by retroviruses of type d. ii. non-activity of mason-pfizer monkey virus versus activity of human cell line derived virus pmfv. | in contrast to the human cell line derived type d retrovirus pmfv, the mason-pfizer monkey virus (mpmv) does not suppress the mitogen response of normal human lymphocytes. both viruses have been propagated on the same cell lines and purified by the same methods. mpmv did not contain a factor able to abolish pmfv-induced suppression of the mitogen response. neither could mpmv suppress the mitogen response of lymphocytes from rhesus monkeys or baboons. pmfv however inhibited their reactivity. | 1985 | 4062558 |
| ultrastructural comparison of the retroviruses associated with human and simian acquired immunodeficiency syndromes. | three isolates of human acquired immunodeficiency syndrome (aids) virus (lymphadenopathy-associated virus, human t cell lymphotropic virus strain iii, acquired immunodeficiency syndrome-associated retrovirus) were compared with simian aids virus by thin section transmission electron microscopy. simian aids virus was found to form intracytoplasmic a particles and to bud by both ring forms and crescent shapes. the extracellular mature simian aids virus exhibited a cylindrical nucleoid within a tub ... | 1985 | 2991655 |
| isolation of a new serotype of simian acquired immune deficiency syndrome type d retrovirus from celebes black macaques (macaca nigra) with immune deficiency and retroperitoneal fibromatosis. | a new serotype of simian acquired immune deficiency syndrome (saids) retrovirus (type 2) belonging to the d genus of retroviruses is associated with a saids occurring spontaneously in a colony of celebes macaques (macaca nigra) and rhesus macaques (macaca mulatta) at the oregon regional primate research center. this syndrome resembles saids in m. mulatta at the california primate research center, which is associated with a similar type d retrovirus (type 1). however, at the oregon center, saids ... | 1985 | 2997477 |
| molecular cloning of the mason-pfizer monkey virus genome: characterization and cloning of subgenomic fragments. | the molecular characterization of the proviral dna genome of mason-pfizer monkey virus (m-pmv), the prototype d-type retrovirus, is described. an analysis of unintegrated viral dnas present in acutely infected cells revealed open and closed circular molecules and linear species. the size of the m-pmv linear proviral dna is determined to be 8.1 kbp in length. a preliminary screening of restriction enzymes indicated that many of those commonly used for cloning (ecori, sali, clai, xhoi) did not cut ... | 1985 | 2997984 |
| a rapid screening procedure for the isolation of nonconditional replication mutants of mason-pfizer monkey virus: identification of a mutant defective in pol. | a rapid, sensitive, and reproducible method for the isolation of human cell clones containing nonconditional, replication-defective (rd) mutants of mason-pfizer monkey virus (m-pmv), the prototype of the d-type retroviruses is described. the two mutants, rd1 and rd2, thus far isolated have been analyzed for virus particle production (using radiolabeled precursors and by electron microscopy) and for the status of intracellular viral precursors. thin sections of rd1 and rd2 infected cells showed t ... | 1985 | 2579506 |
| teleocidin, a tumour promoter, stimulates synthesis of primate retroviruses in persistently infected human cells. | the naturally occurring tumour promoter teleocidin produces a pronounced but transient enhancement of the synthesis of extracellular viral particles in human cells chronically infected with simian retroviruses of type c (baboon endogenous virus, simian sarcoma virus) or type d (mason-pfizer monkey virus) or a human cell line-derived type d isolate (pmf virus), respectively. the retrovirus-stimulating activity of teleocidin is very similar to that previously described for the tumour-promoting pho ... | 1985 | 2415081 |
| biochemical and immunological characterization of suncus murinus mammary tumor virus dna polymerase. | enzymological properties of the rna-directed dna polymerase associated with the suncus murinus mammary tumor virus (sm-mtv) was investigated and its antigenic relatedness to other retroviral dna polymerases was examined. the enzyme exhibited higher activity in the presence of mg2+ than in the presence of mn2+ with endogenous rna as well as with almost all of the synthetic template x primers tested. mg2+ was also effective with poly(2'-o-methylcytidylate) x oligodeoxyguanylate which was known to ... | 1986 | 2417416 |
| nucleotide sequence of mason-pfizer monkey virus: an immunosuppressive d-type retrovirus. | the genetic structure of mason-pfizer monkey virus (mpmv), a d-type retrovirus, has been determined. in addition to the viral gag, pol, and env genes is an orf overlapping both gag and pol and that encodes the viral protease. surprisingly, the mpmv env protein is highly homologous to that of the avian c-type virus, reticuloendotheliosis associated virus rev-a. the env sequence encodes an immunosuppressive peptide, which suggests that mpmv, like rev-a, may transiently induce a t-suppressor cell p ... | 1986 | 2421920 |
| polypeptides of mason-pfizer monkey virus. ii. synthesis and processing of the env gene products. | mason-pfizer monkey virus (m-pmv), the prototype d-type retrovirus, encodes two glycosylated virion proteins, gp20 and gp70. the polyprotein precursor to these proteins was identified by immunoprecipitation of pulse labeled m-pmv-infected cells with an antiserum raised against gp70, the major glycoprotein of the virus. the relationship of this precursor to the two viral glycoproteins was verified by tryptic peptide mapping, which demonstrated that gp20 and gp70 were independent products of the e ... | 1986 | 3083581 |
| distribution of type d retrovirus sequences in tissues of macaques with simian acquired immune deficiency and retroperitoneal fibromatosis. | horizontally acquired saids retrovirus type 2 (srv-2), a type d retrovirus related to the mason-pfizer monkey virus, has been associated with the simian acquired immunodeficiency syndrome (saids) including retroperitoneal fibromatosis (rf) in several macaque species at two primate research centers. virus specific gene sequences are present in lymphoid and rf tissues but not in muscle tissue of diseased macaques or in any tissues of uninfected normal monkeys. serologic and restriction endonucleas ... | 1986 | 3006332 |
| molecular cloning of the mason-pfizer monkey virus genome: biological characterization of genome length clones and molecular comparisons to other retroviruses. | the molecular cloning of the dna provirus of mason-pfizer monkey virus (m-pmv) is described. fourteen independent clones of integrated m-pmv proviruses were isolated from a human embryo kidney cell line that had been previously derived from a single cell clone infected with m-pmv. characterization of these clones for size of insert, restriction pattern of flanking dna, and presence of repetitive dna in the flanking sequences revealed that 10 of the isolates were identical while the four remainin ... | 1986 | 3016990 |
| immunodeficiency in rhesus monkeys associated with the original mason-pfizer monkey virus. | the mason-pfizer monkey virus (mpmv) was reisolated from a cryopreserved sample of the original mpmv-containing rhesus breast carcinoma, and complete integrated mpmv provirus was detected in chromosomal dna of this tumor. reanalysis of the in vivo pathogenicity and molecular character of mpmv reisolated from the rhesus breast tumor and analysis of the original mpmv after long-term in vitro propagation in human and rhesus cells show that the original mpmv produces an acquired immunodeficiency sim ... | 1986 | 3020302 |
| isolation and characterization of covalently closed circular proviral dna molecules of several type d retroviruses isolated from human cell lines. | infection of a human lymphoblastoid b cell line (raji cells) with type d retroviruses, originally isolated either from subhuman primates (mpmv, lv) or from permanent human cell lines (pmfv, helav, hep-2v) led to the production of type d retrovirus particles. subsequent cocultivation of uninfected and virus-producing raji cells was employed for the generation of sufficient amounts of covalently closed circular dna molecules (cccdna). highest amounts of cccdna were obtained after cocultivation of ... | 1986 | 3024412 |
| polypeptides of mason-pfizer monkey virus. iii. translational order of proteins on the gag and env gene specified precursor polypeptides. | mason-pfizer monkey virus (m-pmv), the prototype d-type retrovirus, unlike most retroviruses, preassembles core structures in the cytoplasm of infected cells during morphogenesis. we have shown previously (j. bradac and e. hunter, 1984, virology 138, 260-275) that m-pmv virions contain 5 gag-encoded polypeptides. in this report, the translational order of the proteins encoded on the gag and env genes of m-pmv has been determined by pactamycin mapping. the proposed order of the viral proteins on ... | 1986 | 3485855 |
| the localization of a mason-pfizer monkey virus-related antigen in jaagsiekte tumour tissue and cell lines. | mason-pfizer monkey virus-related antigen was detected in 3 out of 5 jaagsiekte lungs examined using a direct immunoperoxidase staining technique with anti-mpmv p27 serum. most of the antigen was localized in the alveolar lumina of the lesions. the reaction was further characterised on immune blots and found to involve a protein with a molecular mass of 29 000 daltons (jsrv p29). jsrv p29 antigen was also detected in 2 jaagsiekte cell lines. | 1986 | 3523361 |
| chemical crosslinking of lipids and proteins within mason-pfizer monkey and squirrel monkey type d retroviruses. | nearest neighborhoods between lipids and proteins were investigated in mason-pfizer monkey virus (mpmv) and squirrel monkey retrovirus (smrv) using the chemical crosslinking reagent dimethyl suberimidate (dms). analysis of dms-induced lipid-protein complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that in both viruses the major internal structural protein, p27 (mpmv) and p35 (smrv), is linked to the lipid bilayer. additionally, in smrv a second protein (p20) was fou ... | 1986 | 3707293 |
| suppression of human lymphocyte mitogen response by proteins of the type-d retrovirus pmfv. | a type-d retrovirus, derived from a human cell line and designated pmfv, which is related to, but distinct from the mason-pfizer monkey virus (mpmv) suppressed the in vitro mitogen response of human lymphocytes. pmfv was suppressive either as intact virus or after disruption by ether or detergents. in kinetic studies, the time course of the interaction between suppressive virus components and lymphocytes was characterized. neither cytotoxicity nor time shifts in optimum 3h-thymidine incorporatio ... | 1986 | 3943925 |
| recombinant human interferons inhibit replication of mason-pfizer monkey virus in primate cells. | pretreatment of mason-pfizer monkey virus-infected human embryonic kidney cells with either of the cloned human interferons, a or a/d, reduces the release of infectious virus particles to the same extent (greater than 97%) as determined by 125i-protein a binding radioimmune assay. while interferon a has no significant effect on the release of infectious viruses from a mason-pfizer monkey virus-infected monkey cell line consistent with the species specificity of this group of compounds, human int ... | 1987 | 3824911 |
| biochemical and immunological characterization of structural proteins from retrovirus-d/new england and comparison to mason-pfizer monkey virus and permanent human fibroblast virus. | biochemical and immunological properties of retrovirus-d/new england (here referred as r-d/ne) recently isolated at the new england regional primate research center, southborough, ma, from a rhesus monkey with acquired immune deficiency syndrome were investigated and compared to the prototype type d retroviruses mason-pfizer monkey virus (mpmv) and permanent human fibroblast virus (pmfv) isolated from a breast carcinoma of a rhesus monkey and a continuous human cell line, respectively. the polyp ... | 1987 | 3579611 |
| trans-activation of long terminal repeat sequence-mediated gene expression is not a property of type d retrovirus replication. | several retroviruses encode trans-acting factors which activate gene expression directed by long terminal repeat (ltr) sequences and play a role in the positive feedback regulation of virus replication. we have examined two mason-pfizer monkey virus (mpmv) strains for their ability to produce and respond to such factors. plasmids with the ltr of either mpmv or type d retrovirus/new england (d/ne) were fused to the bacterial chloramphenicol acetyltransferase (cat) gene. introduction of these plas ... | 1987 | 3612091 |
| myristylation is required for intracellular transport but not for assembly of d-type retrovirus capsids. | the role of myristylation, a fatty acid modification of nascent polypeptides, in the assembly and intracellular transport of d-type retroviral capsids was investigated through the use of oligonucleotide-directed mutagenesis. myristic acid is normally esterified through an amide linkage to a glycine residue at the amino terminus of the mason-pfizer monkey virus gag gene products. mutant pa-1, which has a codon for valine substituted for that of the normally myristylated glycine, is completely non ... | 1987 | 3493352 |
| experimental coinduction of type d retrovirus-associated pulmonary carcinoma and lentivirus-associated lymphoid interstitial pneumonia in lambs. | two retrovirus-associated pulmonary diseases of sheep [ovine pulmonary carcinoma (opc); sheep pulmonary adenomatosis], a bronchoalveolar carcinoma, and lymphoid interstitial pneumonia (lip) were induced simultaneously in 9 of 9 neonatal lambs. the lambs were killed 8-28 weeks after intratracheal injection of lung tumor homogenate or lung fluid derived from sheep with naturally occurring opc and ovine lentivirus (ovlv) infection. the inoculated lambs developed multifocal neoplasms of alveolar typ ... | 1987 | 3474445 |
| morphological changes of an inflammatory myopathy in rhesus monkeys with simian acquired immunodeficiency syndrome. | eleven of 25 rhesus monkeys which died of simian acquired immunodeficiency syndrome (saids) caused by infection with a type d retrovirus related to mason-pfizer monkey virus showed evidence of muscle weakness and atrophy and had elevated levels of muscle enzymes. biopsies of affected muscle studied with enzyme histochemistry showed the characteristic features of polymyositis. inflammatory cells consisting of lymphocytes, macrophages, and large vacuolated bizarre-shaped cells of undetermined type ... | 1987 | 3039516 |
| sequence relationships of type d retroviruses which cause simian acquired immunodeficiency syndrome. | simian acquired immunodeficiency syndrome (saids) in macaque monkeys is caused by type d retroviruses; three independent virus isolates are identified as srv-1 (saids retrovirus-serotype 1), srv-2, and mpmv (mason-pfizer monkey virus). virions from these three isolates have serologically related core antigens, but distinct surface proteins. also, srv-2 is unique since it apparently induces retroperitoneal fibromatosis in addition to saids. the complete dna sequence of molecularly cloned srv-2 is ... | 1987 | 2435057 |
| major structural polypeptides of retrovirus produced by a suncus murinus mammary tumor cell line and type d retrovirus share interspecies antigenic determinants. | constitutive polypeptides of retrovirus produced by a suncus murinus mammary tumor cell line (sm-mtv) were characterized by immunofluorescence and immunoblotting. the major structural polypeptide of sm-mtv, molecular weight 44/43k, immunologically cross reacted with the structural polypeptides of mason-pfizer monkey virus (mpmv) (molecular weights 27k and 12/10k). sm-mtv constitutive polypeptides did not show antigenic relatedness with those of the following mammalian retroviruses: murine mammar ... | 1988 | 2460996 |
| characterization of vero cells. | a cell line used in the production of biologicals should be free of infectious agents, and 'described with respect to cytogenetic characteristics and tumorigenicity'. vero, a continuous cell line derived from a normal african green monkey kidney, was examined for the presence of retroviruses and for tumorigenic potential. we were unable to detect the presence of retroviruses by reverse transcriptase assay, electron microscopy or hybridization of cellular genomic dna with mason-pfizer monkey viru ... | 1988 | 3198660 |
| [antibodies to the structural and nonstructural gag-coded proteins of type-d retroviruses in patients with lymphadenopathy]. | screening of antibodies to structural and nonstructural gag gene-coded proteins in humans with lymphadenopathy and aids was performed by means of radioimmunoprecipitation (rip) and western blotting. pr78gag precursor of gag-coded proteins of type-d retrovirus from hep-2 cells served as an antigen in rip tests. total number of sera (of humans with lymphoadenopathy) under rip analysis was 18 and one sera of aids patient. six of them reacted with pr78gag and one out of one aids serum. over 80 sera ... | 1988 | 3264729 |
| structural and functional analysis of long terminal repeats of suncus murinus mammary tumor virus. | a 2.7-kilobase (kb) cdna sequence complementary to suncus murinus mammary tumor virus (sm-mtv) genomic rna [corrected] was prepared using purified virions produced by the sm-mt cell line, which had been established from a spontaneous mammary tumor of s. murinus. it was found, by using this cdna in southern hybridization experiments, that sm-mtv was endogenous to this animal and that some 50 copies of endogenous provirus were present per haploid cellular genome. in addition, a proviral sm-mtv dna ... | 1988 | 2831384 |
| [presence of antibodies specifically reacting with structural proteins of the mammary cancer virus among antibodies found in circulating immune complexes in patients with breast cancer]. | circulating immune complexes were precipitated from breast cancer patients' sera using 2.5% polyethylene glycol. cic isolated from 70 ml of sera from 15 patients were dissociated and immunoglobulin-containing fraction was prepared by chromatography on sephadex g-200 column. the fraction contained igg specific for mumtv structural proteins, as revealed by elisa. cic preparations from 22 sera of breast cancer patients were digested with pepsin; fab' fragment preparations were also analysed by elis ... | 1988 | 2833956 |
| evaluation of type d retroviruses as diagnostic tools in hiv infections. | a type d retrovirus isolated from a permanent human cell line (pmfv) was employed as diagnostic reagent both in southern transfer hybridization experiments using the cloned genome as a probe and in immunoblot analysis using sds disrupted virus particles. hybridization experiments performed under conditions of different stringencies revealed a close homology of pmfv to saids type d retroviruses of serotype 1 (srv-1, saids retrovirus d/ne), a related homology to the prototype type d virus (mpmv) a ... | 1989 | 2619725 |
| a homologue of retroviral pseudoproteases in the parapoxvirus, orf virus. | the nucleotide sequence of a near-terminal region of orf virus dna was determined. examination of the sequence revealed an open reading frame encoding a peptide with significant amino acid homology to the pseudoprotease domains recently identified in a number of retroviruses including mouse mammary tumor virus, simian mason-pfizer virus, maedi-visna virus, and equine infectious anaemia virus. the orf virus pseudoprotease shares up to 28% amino acid homology with retroviral pseudoproteases and ap ... | 1989 | 2678731 |
| some characteristics of a retrovirus isolated from transformed bovine cells. | a novel retrovirus has been isolated from bovine cells transformed after cocultivation with leukocytes from an animal suffering from sheep-associated bovine malignant catarrhal fever. morphologically and in its morphogenesis the virus resembles the type d mason-pfizer monkey virus (mpmv) as well as the ovine jaagsiekte retrovirus (jsrv). it is also serologically related to these two viruses, whereas a relationship to other known bovine retroviruses was not detected. however, its density of 1.16 ... | 1989 | 2763459 |
| molecular cloning of a type d retrovirus from human cells (pmfv) and its homology to simian acquired immunodeficiency type d retroviruses. | unintegrated circular proviral dna of a type d retrovirus (pmfv) isolated from a permanent human cell line was molecularly cloned in the bacteriophage vector l47.1 and subcloned in the plasmid vector pgem-2. a restriction endonuclease map of pmfv dna was established using 10 different enzymes for single and multiple digestions of closed circular and cloned dna molecules. by restriction endonuclease analysis cloned pmfv dna represented full-length viral dna with one long terminal repeat (ltr). th ... | 1989 | 2815583 |
| the human non-lineage antigen cd46 (huly-m5) and primate retroviral gp70 molecules share protein-defined antigenic determinants. | the cd46 lymphocyte surface antigen of man (until recently called huly-m5), and defined by the e4.3 monoclonal antibody (moab), shares cross-reactive antigenic epitopes with the envelope gp70 glycoproteins of gibbon ape leukaemia virus (galv) and mason pfizer monkey virus (mpmv) primate retroviruses. it is now shown that the cross-reactive antigenic epitope shared by these three molecules is determined solely by the protein portion of these glycoproteins, and that the n-linked and o-linked carbo ... | 1989 | 2482250 |
| [simian aids virus: review]. | the review article on simian aids viruses compiles the presently known facts of aids-related simian retroviruses causing immunodeficiencies or lymphomas in nonhuman primates. they are also compared to the situation in man. simian acquired immunodeficiencies or lymphoproliferative diseases can be caused by infectious (exogenous) oncoviruses (c- or d-type) or by lentiviruses. infectious d-type oncoviruses of simian origin are: mason-pfizer monkey virus (mpmv), simian retrovirus type 1 (srv-1), sim ... | 1989 | 2559560 |
| use of molecular cloned viral genomes for studies into interrelationship between type d retroviruses from monkey and human cells. | type d retroviruses constitute a group of rna tumor viruses so far isolated exclusively from primates. 4 groups of isolates are known to date (mason-pfizer virus, agents of simian acquired immunodeficiency syndrome--saids, endogenous viruses of old world and new world monkeys, and some isolates from cell lines--pmf virus). the members of the latter group are well characterized at protein-chemical and immunological levels. briefly described in this paper are the results of our studies into the mo ... | 1990 | 2129382 |
| a linkage map of endogenous murine leukemia proviruses. | thirty endogenous proviruses belonging to the modified polytropic (mpmv) class of murine leukemia virus (mlv) were identified by proviral-cellular dna junction fragment segregation in several sets of recombinant inbred mice. twenty-six mpmv loci were mapped to chromosomal regions by matching proviral strain distribution patterns to those of previously assigned genes. like other endogenous nonecotropic mlvs, mpmv loci were present on several chromosomes in all strains examined. we pooled recombin ... | 1990 | 2155154 |
| a single amino acid substitution within the matrix protein of a type d retrovirus converts its morphogenesis to that of a type c retrovirus. | two different morphogenic processes of retroviral capsid assembly have been observed: the capsid is either assembled at the plasma membrane during the budding process (type c), or preassembled within the cytoplasm (types b and d). we describe here a gag mutant of mason-pfizer monkey virus, a type d retrovirus, in which a tryptophan substituted for an arginine in the matrix protein results in efficient assembly of capsids at the plasma membrane through a morphogenic process similar to that of typ ... | 1990 | 2170021 |
| detection and quantitation of a type d retrovirus gag protein in ovine pulmonary carcinoma (sheep pulmonary adenomatosis) by means of a competition radioimmunoassay. | a heterologous competition radioimmunoassay (ria) which consisted of 125i-labeled langur retrovirus major gag protein and goat anti-squirrel monkey retrovirus serum was used to detect a type d retrovirus-associated antigen in tumor cell homogenates, lung fluid, and cell culture supernatant fluids of naturally occurring and experimentally-induced ovine pulmonary carcinoma (opc, sheep pulmonary adenomatosis). in this assay, there was no cross reactivity between structural proteins of the type d re ... | 1990 | 2247933 |
| preassembled capsids of type d retroviruses contain a signal sufficient for targeting specifically to the plasma membrane. | the capsids of mason-pfizer monkey virus (m-pmv), an immunosuppressive type d retrovirus, are preassembled in the infected cell cytoplasm and are then transported to the plasma membrane, where they are enveloped in a virus glycoprotein-containing lipid bilayer. the role of viral glycoprotein in intracellular transport of m-pmv capsids was investigated with a spontaneous mutant (5a) of m-pmv, which we show here to be defective in envelope glycoprotein biosynthesis. dna sequence analysis of the en ... | 1990 | 2370682 |
| the use of primers from highly conserved pol regions to identify uncharacterized retroviruses by the polymerase chain reaction. | two degenerate oligonucleotide primers derived from regions of pol conserved among retroviruses have been synthesized. polymerase chain reactions utilizing these primers amplify a 135-bp pol fragment in every retrovirus dna tested to date. the polymerase chain reaction has been linked to a reverse transcriptase step so that a pol-specific dna fragment can be obtained from a moderate amount of a purified retrovirus or viral rna. the identity of an unknown retrovirus can be determined by sequencin ... | 1990 | 1693369 |
| amino acid substitutions within the matrix protein of type d retroviruses affect assembly, transport and membrane association of a capsid. | the functional roles of the matrix (ma) protein in the assembly and maturation of retroviruses was investigated with a series of ma mutants of mason-pfizer monkey virus (m-pmv), an immunosuppressive type d retrovirus. the mutants we describe here were generated by the introduction of random point mutations within the ma coding domain by use of sodium bisulphite mutagenesis. studies of these mutants show that the ma protein plays a critical role in three different, sequential events in the final ... | 1991 | 1705884 |
| enzootic nasal tumour of goats: demonstration of a type d-related retrovirus in nasal fluids and tumours. | nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. the same particle contained a 25,000 mr protein that cross-reacted with the p27 of mason-pfizer monkey virus (mpmv) and with p25 of sheep pulmonary adenomatosis retrovirus. it also contained a low mr protein related to p10-12 of mpmv. | 1991 | 1717643 |
| isolation of a type d retrovirus from b-cell lymphomas of a patient with aids. | an atypical syncytial variant of a high-grade burkitt's-type b-cell lymphoma from a patient with aids who was seropositive for human immunodeficiency virus type 1 was studied. a productive type d retrovirus infection was identified in early-passage cell lines derived from two lymphomas from this patient. nucleotide and amino acid sequence analysis as well as immunologic reactivity indicated that the isolated virus was highly related to mason-pfizer monkey virus (mpmv). mpmv is an immunosuppressi ... | 1991 | 1717707 |
| antibodies to gag gene coded polypeptides of type d retroviruses in healthy people from guinea-bissau. | antibodies to proteins of mason-pfizer monkey virus (m-pmv) were screened in sera from 61 healthy donors living in guinea-bissau (4 hiv-1 and hiv-2 antibody positive hiv = human immunodeficiency virus), from 19 healthy french european blood donors, and from 9 french patients with induced immunodeficiency prior to bone marrow transplantation (all hiv-1 antibody negative). in 30 (49%) of the african sera tested, antibodies reacting against p27 and/or p14 were detected by western blot. some of thes ... | 1991 | 1650766 |
| rna pseudoknots downstream of the frameshift sites of retroviruses. | rna pseudoknot structural motifs could have implications for a wide range of biological processes of rnas. in this study, the potential rna pseudoknots just downstream from the known and suspected retroviral frame-shift sites were predicted in the rous sarcoma virus, primate immunodeficiency viruses (hiv-1, hiv-2, and siv), equine infectious anemia virus, visna virus, bovine leukemia virus, human t-cell leukemia virus (types i and ii), mouse mammary tumor virus, mason-pfizer monkey virus, and si ... | 1991 | 1663382 |
| tightly bound zinc in human immunodeficiency virus type 1, human t-cell leukemia virus type i, and other retroviruses. | human immunodeficiency virus type 1 (hiv-1) and human t-cell leukemia virus type i (htlv-i) were purified by sucrose density gradient centrifugation in the presence of 1 mm edta. pelleted gradient fractions were analyzed for total protein, total gag capsid protein, and total zinc. zinc was found to copurify and concentrate with the virus particles. through successive cycles of resuspending in buffer containing edta and repelleting, the zinc content remained constant at about 1.7 mol of zinc per ... | 1992 | 1731111 |
| retroviral pseudotypes produced by rescue of a moloney murine leukemia virus vector by c-type, but not d-type, retroviruses. | human hos cells containing a moloney murine leukemia virus (mo-mlv) recombinant genome were infected by a panel of retroviruses. the c-type viruses simian sarcoma associated virus, feline leukemia virus subgroup b, and the feline endogenous virus rd114 were able to form pseudotypes with the mo-mlv genome, which transferred a selectable marker gene to target cells; however, human t cell leukemia virus-1 and the d-type viruses mason-pfizer monkey virus and simian retrovirus-1 failed to rescue the ... | 1992 | 1733113 |
| mutational analysis of the major homology region of mason-pfizer monkey virus by use of saturation mutagenesis. | the major capsid (ca) protein of retroviruses possesses a stretch of 20 amino acids, called the major homology region (mhr), which is evolutionarily conserved and invariant in location within the primary sequence of the protein. the function of this region was investigated by examining the effect of random single-amino-acid substitutions within the central 13 positions of the mhr on the life cycle of mason-pfizer monkey virus (m-pmv), an immunosuppressive d-type retrovirus. when these mutants we ... | 1992 | 1279197 |
| mutations within the env gene of mason-pfizer monkey virus: effects on protein transport and su-tm association. | by deletion mutagenesis analyses, we have examined the contribution of the immunosuppressive peptide (isp) region within the transmembrane (tm) protein of mason-pfizer monkey virus to viral maturation and infectivity. deletion of the entire region (mutant d105) results in the production of an env precursor that is transport defective and therefore unable to be processed to mature glycoproteins. this mutation results in the release of noninfectious virions devoid of surface glycoproteins. a secon ... | 1992 | 1316462 |
| protein of macaques against infection with simian type d retrovirus (srv-1) by immunization with recombinant vaccinia virus expressing the envelope glycoproteins of either srv-1 or mason-pfizer monkey virus (srv-3). | rhesus macaques were immunized with live vaccinia virus recombinants expressing the envelope glycoproteins (gp70 and gp22) of simian type d retrovirus (srv), serotype 1 or 3. all of the animals immunized with either the srv-1 env or the srv-3 env vaccinia virus recombinant developed neutralizing antibodies against the homologous srv. in addition, both groups developed cross-reactive antibodies and were protected against an intravenous live-virus challenge with srv-1. the four control animals imm ... | 1992 | 1316495 |
| identification of a generalised packaging sequence for d-type retroviruses and generation of a d-type retroviral vector. | in order to construct vectors based upon d-type, rather than c-type, retroviruses, we have identified a 624-bp fragment of mason-pfizer monkey virus (mpmv) which constitutes a packaging sequence for at least two d-type retroviruses. when this fragment was included in an extensively deleted d-type vector genome, the d-type viruses mpmv and srv-5, but not the c-type viruses mlv-a or mlv-e, rescued the vector rna from hela cells. the recombinant virus stocks have the host range of the rescuing d-ty ... | 1992 | 1322603 |
| investigations into the mechanism by which sulfated polysaccharides inhibit hiv infection in vitro. | sulfated polysaccharides have been shown to inhibit human immunodeficiency virus (hiv) infection in vitro. dextrin sulfate, fucoidan, and dextran sulfate fail to neutralize virions directly, but interact with target cells to inhibit virus entry. ionic interactions of sulfated polyanions with oppositely charged cell surface components, including cd4, have been assumed to be the inhibitory mechanism. it is shown that the sulfated polysaccharides inhibit infection of both cd4+ and cd4- cell lines b ... | 1992 | 1346567 |
| studies on a type d retrovirus isolated from an aids patient lymphoma. | the development of aids-related lymphomas (arl) has been on the rise in recent years. during an analysis of arl from aids patients, one individual developed atypical syncytial variants of high-grade burkitt's-type b-cell lymphomas, which prompted further study. however, the search for a hiv-1 retrovirus, which we hypothesized was infecting these cells, led to the subsequent discovery of a type d retrovirus in two early-passage lymphoma cell lines derived from this patient. nucleotide and amino a ... | 1992 | 1381207 |
| importance of p12 protein in mason-pfizer monkey virus assembly and infectivity. | mason-pfizer monkey virus (m-pmv) represents the prototype type d retrovirus, characterized by the assembly of intracytoplasmic a-type particles within the infected-cell cytoplasm. these immature particles migrate to the plasma membrane, where they are released by budding. the gag gene of m-pmv encodes a novel protein, p12, just 5' of the major capsid protein (ca) p27 on the polyprotein precursor. the function of p12 is not known, but an equivalent protein is found in mouse mammary tumor virus a ... | 1992 | 1433505 |
| a viral protease-mediated cleavage of the transmembrane glycoprotein of mason-pfizer monkey virus can be suppressed by mutations within the matrix protein. | the envelope glycoprotein precursor of retroviruses undergoes proteolytic cleavage in the golgi complex to yield the mature surface and transmembrane (tm) glycoproteins of the virus. we report here that the tm glycoprotein of mason-pfizer monkey virus undergoes a second proteolytic processing event during a late maturation step that can follow virus release and gag polyprotein cleavage. cleavage results in the conversion of the cell-associated tm glycoprotein (gp22) to a virus-associated gp20. p ... | 1992 | 1565636 |
| effect of retroviral proteinase inhibitors on mason-pfizer monkey virus maturation and transmembrane glycoprotein cleavage. | mason-pfizer monkey virus (m-pmv) is the prototype type d retrovirus which preassembles immature intracytoplasmic type a particles within the infected cell cytoplasm. intracytoplasmic type a particles are composed of uncleaved polyprotein precursors which upon release are cleaved by the viral proteinase to their constituent mature proteins. this results in a morphological change in the virion described as maturation. we have investigated the role of the viral proteinase in virus maturation and i ... | 1992 | 1602542 |
| retroviral nucleocapsid proteins possess potent nucleic acid strand renaturation activity. | the nucleocapsid protein (nc) is the major genomic rna binding protein that plays integral roles in the structure and replication of all animal retroviruses. in this report, select biochemical properties of recombinant mason-pfizer monkey virus (mpmv) and hiv-1 ncs are compared. evidence is presented that two types of saturated zn2 nc-polynucleotide complexes can be formed under conditions of low [nacl] that differ in apparent site-size (n = 8 vs. n = 14). the formation of one or the other compl ... | 1993 | 8443601 |
| expression of simian type d retroviral (mason-pfizer monkey virus) capsids in insect cells using recombinant baculovirus. | mason-pfizer monkey virus (m-pmv) is a primate retrovirus that shows type d morphogenesis in mammalian cells. immature intracytoplasmic a type particles (icaps) preassemble in the infected cell cytoplasm migrate to the plasma membrane and are released by budding. this is in contrast to retroviruses that show type c morphogenesis, where assembly and budding occur concurrently at the plasma membrane. we expressed the m-pmv structural genes (gag-pro-pol) in insect cells using a recombinant baculovi ... | 1993 | 8517023 |
| serological survey for type d retroviruses and simian immunodeficiency virus in monkeys living in hungary. | acquired immunodeficiency in non-human primates has been associated with two types of retroviruses: (i) simian retrovirus (srv), a type d virus and (ii) a lentivirus, simian immunodeficiency virus (siv). both types represent a serious health threat to animals living in different primate research centres, zoos, medical institutions and in private homes. the sera of 175 monkeys belonging to different species were tested for the presence of antibodies against type d retroviruses and siv. the mason- ... | 1993 | 8116496 |
| postassembly cleavage of a retroviral glycoprotein cytoplasmic domain removes a necessary incorporation signal and activates fusion activity. | viral protease-mediated cleavage within the cytoplasmic domain of the transmembrane (tm) glycoprotein of the type d retrovirus, mason-pfizer monkey virus, removes approximately 16 amino acids from the carboxy terminus of the protein. to determine the functional significance of this cleavage in the virus life cycle, we introduced premature stop codons into the tm coding domain, resulting in the production of truncated glycoproteins. progressive truncated of the cytoplasmic domain identified the c ... | 1994 | 8207836 |
| continuous propagation of rre(-) and rev(-)rre(-) human immunodeficiency virus type 1 molecular clones containing a cis-acting element of simian retrovirus type 1 in human peripheral blood lymphocytes. | molecular clones of human immunodeficiency virus type 1 that contained either 37 point mutations in the rev-responsive element (rre) that did not affect the overlapping env reading frame or both a mutated rre and two mutations that eliminated rev were constructed. the mutations in the rre were shown to remove both negative and rev-inducible positive effects of the rre on gene expression (g. nasioulas, a. s. zolotukhin, c. tabernero, l. solomin, c. p. cunningham, g. n. pavlakis, and b. k. felber, ... | 1994 | 7966585 |
| mutations within the transmembrane glycoprotein of mason-pfizer monkey virus: loss of su-tm association and effects on infectivity. | we have previously reported that an 11-amino-acid deletion (d33) within the immunosuppressive peptide (isp) region of the mason-pfizer monkey virus transmembrane (tm) glycoprotein, gp22, caused the loss of interaction between tm and the surface (su) glycoprotein, gp70. this resulted in the secretion of large amounts of biologically active su glycoprotein, and we postulated that the isp might represent a point of contact between the two glycoproteins. to further define the amino acids that might ... | 1994 | 8030233 |
| a small element from the mason-pfizer monkey virus genome makes human immunodeficiency virus type 1 expression and replication rev-independent. | replication of human immunodeficiency virus type 1 (hiv-1) is dependent on the viral rev protein. this protein acts in concert with the cis-acting rev-responsive element present in intron-containing rnas to facilitate nuclear export of these rnas. here we show that a cis-acting 219-nucleotide sequence from an unrelated "simple" retrovirus, mason-pfizer monkey virus (mpmv), enables rev-independent hiv-1 replication. this sequence is present in an untranslated region near the 3' end of the mpmv ge ... | 1994 | 8108397 |
| stem cell factor binding to retrovirus primer binding site silencers. | using modified nuclear lysis and binding conditions, we have examined the binding of an embryonal carcinoma (ec) cell factor, binding factor a, to a stem cell-specific silencer which acts at the dna level and overlaps the moloney murine leukemia virus (m-mulv) proline primer binding site (pbs). following our protocol, we found that in vitro binding of factor a correlated with the in vivo activity of the m-mulv silencer. factor a bound specifically to the wild-type silencer element at room temper ... | 1995 | 7529329 |
| production of soluble surface glycoprotein, gp70, of the mason-pfizer monkey virus in cos cells is dependent on the presence of regions of the transmembrane domain. | 1995 | 7672366 | |
| cloning, bacterial expression, and characterization of the mason-pfizer monkey virus proteinase. | we have cloned and expressed the 3' region of the mason-pfizer monkey virus pro gene in escherichia coli. the recombinant 26-kda precursor undergoes rapid self-processing both in e. coli and in vitro at the nh2 terminus, yielding a proteolytically active 17-kda protein, p17. this initial cleavage is followed in vitro by a much slower self-processing that leads to emergence of proteolytically active p12 and a cooh-terminal cleavage product p5. we have found the nh2-terminal processing site of bot ... | 1995 | 7797487 |
| efficient in vivo and in vitro assembly of retroviral capsids from gag precursor proteins expressed in bacteria. | the capsid precursor protein (gag) of mason-pfizer monkey virus, the prototype type d retrovirus, has been expressed to high levels in bacteria under the control of the phage t7 promoter. electron microscopic studies of induced cells revealed the assembly of capsid-like structures within inclusion bodies that formed at the poles of the cells 6 h after induction with isopropyl-beta-d-thiogalactopyranoside (iptg). the inclusion bodies and enclosed capsid-like structures were solubilized completely ... | 1995 | 7815488 |
| characterization of infectious type d retrovirus from baboons. | infectious virus resembling type d simian retrovirus (srv) was isolated from ethiopian baboons (papio cynocephalus) (srv-pc) housed at the university of washington regional primate research center. when baboon peripheral blood mononuclear cells (pbmc) or tissues were cocultured with the h-9 human t-cell line or the raji human b-cell line, large multinucleated syncytia positive for srv-2 antigens were observed microscopically. immunoblot analysis of purified srv-pc from cell culture supernatants ... | 1995 | 7871741 |
| proteolytic processing of particle-associated retroviral polyproteins by homologous and heterologous viral proteinases. | retroviral proteinase(pr)-catalyzed cleavage of the viral gag and gag-pol polyproteins within the nascent virus particle is required for productive viral infection. kinetic characterization and specificity analyses have been reported for several retroviral pr using oligopeptide substrates. in this study, we performed a comparative analysis of pr from avian, bovine, simian and human retroviruses using polyproteins of human immunodeficiency virus (hiv) type 1 or avian leukosis virus as substrates. ... | 1995 | 7883003 |
| secondary structure model of the mason-pfizer monkey virus 5' leader sequence: identification of a structural motif common to a variety of retroviruses. | a stable secondary structure model is presented for the region 3' of the primer-binding site to 130 bases into the gag sequence of the prototype type d retrovirus mason-pfizer monkey virus. using biochemical probing of rna from this region in association with free energy minimization, we have identified a stem-loop structure in the region, which from other studies has been shown to be important for genomic rna encapsidation. the structure involves a highly stable stem of five g-c pairs terminati ... | 1995 | 7884866 |
| development and application of an antibody elisa for the marker protein of ovine pulmonary carcinoma. | ovine pulmonary carcinoma (opc) is a contagious pulmonary neoplasia with a suspected retroviral etiology. the major core protein (p27) of the putative opc virus cross-reacts with antibodies to p27 of the mason-pfizer monkey virus (mpmv), a type-d retrovirus. this serological reactivity serves as the only accepted biological marker for opc. in order to make a useful reagent for the detection of the opc marker for serodiagnosis and epidemiological studies, the mpmv-p27 coding region was cloned and ... | 1995 | 8571550 |
| presence of mason-pfizer monkey virus in some stocks of the human hbl-100 mammary epithelial cell line. | 1996 | 8609647 | |
| synthesis and assembly of retrovirus gag precursors into immature capsids in vitro. | the assembly of retroviral particles is mediated by the product of the gag gene; no other retroviral gene products are necessary for this process. while most retroviruses assemble their capsids at the plasma membrane, viruses of the type d class preassemble immature capsids within the cytoplasm of infected cells. this has allowed us to determine whether immature capsids of the prototypical type d retrovirus, mason-pfizer monkey virus (m-pmv), can assemble in a cell-free protein synthesis system. ... | 1996 | 8648705 |
| the posttranscriptional control element of the simian retrovirus type 1 forms an extensive rna secondary structure necessary for its function. | it was previously shown that a 240-nucleotide (nt) rna element (cis-acting transactivation element [cte]) located between the env gene and the 3' long terminal repeat of simian retrovirus type 1 (srv-1) can functionally replace posttranscriptional activation directed by rev and the rev-responsive element (rre) when inserted into a rev- and rre-deficient molecular clone of human immunodeficiency virus type 1, resulting in efficient virus replication. here, we analyze the molecular and structural ... | 1996 | 8709222 |
| rev/rre-independent mason-pfizer monkey virus constitutive transport element-dependent propagation of sivmac239 vectors using a single round of replication assay. | in a step toward creating live-attenuated or dna subunit vaccines for aids, the replication of simian immunodeficiency virus (siv) was studied independently of the rev and rre (rev-responsive element) regulatory system, over a single round. to accomplish this, the env gene of an siv vector was made defective by the insertion of a sv40 promoter/enhancer hygromycin b phosphotransferase gene cassette. using this vector as the backbone, molecular clones of siv were generated that contained a mutated ... | 1996 | 8806531 |
| role of mason-pfizer monkey virus (mpmv) constitutive transport element (cte) in the propagation of mpmv vectors by genetic complementation using homologous/heterologous env genes. | to study mason-pfizer monkey virus (mpmv) replication over a single round, virus particles were generated that contain a replication-defective vector encoding a dominant selectable marker, the hygromycin b phosphotransferase (hyg) gene. genetic complementation with a homologous mpmv envelope glycoprotein (env-gp) or pseudotyping by several heterologous env-gps from a variety of viruses resulted in infectious mpmv particles containing the replication-defective rna. recently, it has been shown tha ... | 1996 | 8874512 |