Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| murine xenotropic type c viruses. iv. replication and pathogenesis of ducks. | the xenotropic (x-tropic) mouse type c virus (mulv) and its pseudotype of murine sarcoma virus (msv) were inoculated into several fertilized developing pekin duck eggs. the development of the duck embryos was substantially reduced in those receiving the x-tropic viruses compared to eggs inoculated only with tissue culture medium. infections virus was isolated from some of the adult animals; in others, evidence for integrated virus sequences in the tissues was noted. no specific pathology was fou ... | 1982 | 6288852 |
| characterization of xenotropic and dual-tropic type c retroviruses isolated from abelson tumour. | tumours induced in balb/c mice by abelson virus complex were found to contain a xenotropic virus (a-x-mulv) and an nb-tropic, dual-tropic virus (nbx), in addition to the moloney leukaemia virus (m-mulv) and the defective, transforming abelson virus genome. both a-x-mulv and nbx virus were presumably present in a genomically masked form and could be recovered only by co-cultivation of tumour cells with permissive cells. only about 0.87% and 0.13% of the viruses in the co-culture supernatant repre ... | 1982 | 6292337 |
| fbj murine osteosarcoma virus: identification and molecular cloning of biologically active proviral dna. | a 12.0-kilobase ecori restriction fragment containing fbj murine osteosarcoma virus (fbj-msv) proviral dna was identified in fbj-msv-transformed nonproducer rat cells and molecularly cloned in bacteriophage charon 30 (lambda fbj-1). a 5.8-kb hindiii fragment containing the entire fbj-msv proviral dna was isolated from lambda fbj-1 and subsequently subcloned in plasmid pbr322 (pfbj-2). the dna from recombinant plasmid pfbj-2 was able to induce morphological transformation of rat fibroblasts in ti ... | 1982 | 6292525 |
| transformation of mmc-e epithelial cells by acute 3611-msv: inhibition of collagen synthesis and induction of novel polypeptides. | mouse embryo epithelial cells mmc-e were transformed by novel fibrosarcoma-inducing murine sarcoma virus 3611-msv. the cells were analyzed for the production and deposition of pericellular glycoproteins by immunofluorescence and by radioactive metabolic and cell surface labeling techniques followed by analysis in polyacrylamide gels and fluorography. the pericellular fibronectin matrix was lost, but unlike in virus-transformed fibroblastic cells, the production of fibronectin was not affected. t ... | 1982 | 6302114 |
| molecularly cloned c-mos(rat) is biologically active. | a unique rat cellular gene, c-mos(rat), homologous to the transforming sequences, v-mos, of moloney murine sarcoma virus (m-msv) was detected by hybridization to a v-mos specific probe. the c-mos(rat) gene was cloned together with its flanking sequences in an 11-kbp ecori dna fragment inserted in vector charon 4a. two probes were used to investigate the position and orientation of c-mos(rat) in the clone examined ( d3e ), namely pmsv -31 which contains the sequences specific for the transforming ... | 1982 | 6327263 |
| t cell tolerance in moloney-murine leukemia virus (m-mulv) carrier mice: low cytotoxic t lymphocyte precursor frequency and absence of suppressor t cells in carrier mice with moloney-murine sarcoma (m-msv)-induced tumors. | 1982 | 6459385 | |
| potential identification of chemical carcinogens in a viral transformation system. | chemical carcinogens from several diverse chemical classes i.e.; aromatic amines, polycyclic hydrocarbons, nitrosamines, hormonal derivatives, metals and direct alkylating agents cause a 6.2-60.5-fold increase in the frequency of murine sarcoma virus (msv)-induced transformation in a normal rat kidney (nrk) cell system. exogenous metabolic activation with a rat liver s-9 homogenate is required for expression of this activity by procarcinogens. non-carcinogenic analogs of these compounds fail to ... | 1982 | 7055852 |
| isolation of a transformation-defective deletion mutant of moloney murine sarcoma virus. | a transformation-defective (td) deletion mutant of moloney murine sarcoma virus (td mo-msv) and a transforming component termed mo-msv 3 were cloned from a stock of clone 3 mo-msv. to define the defect of the transforming function, the rna of td mo-msv was compared with those of mo-msv 3 and of another transforming variant termed mo-msv 124 and with helper moloney murine leukemia virus (mo-mulv). the rna monomers of td mo-msv and mo-msv 3 comigrated on polyacrylamide gels and were estimated to b ... | 1982 | 7077752 |
| anti-tumor immunity in b-lymphocyte-deprived mice. iii. immunity to primary moloney sarcoma virus-induced tumors. | tumor induction and immunity to tumors were studied following the injection of moloney sarcoma virus (msv) into mice whose b-lymphocyte functions had been suppressed by the chronic administration of anti-igm antibodies. two preparations of msv were used; one which gives rise to tumors which uniformly regress in normal adult mice, and another which elicits progressively growing tumors in the majority of recipients. the tumor incidence, mean tumor size, and tempo of regression were not modified by ... | 1982 | 6978293 |
| specific chromosome changes associated with viral transformation of rat glial cells. | karyotypes of three malignant cell lines derived from wistar and wka/mk fetal rat glioblasts, transformed by murine sarcoma virus (msv-m-os) as well as those of four cell lines derived from c6 glioma cells of wistar origin, retransformed by msv-m-os, were analyzed in early culture passages. the c6 line had a modal number of 42 chromosomes with a normal male karyotype, and only a minor population of cells with 43 chromosomes. the modal chromosome number in every transformed glial cell line shifte ... | 1982 | 7141743 |
| persistence of one species of oncovirus in mixed infection after antiserum treatment or transspecies rescue. | attempts were made to change the envelope of murine sarcoma virus (msv) from b-mux (a xenotropic murine leukaemia virus isolate) to feline leukaemia virus (felv) by infecting cat cells with msv(b-mux), adding excess felv as helper and using mouse serum oncovirus-inactivating factor or anti-b-mux serum. in several attempts, virus from single foci of msv initially contained only msv(felv) but on passage each showed a minimal persistence of b-mux. to eliminate the b-mux component, msv(b-mux) was su ... | 1982 | 7142977 |
| immunotoxicology studies on lead: effects of exposure on tumor growth and cell-mediated tumor immunity after syngeneic or allogeneic stimulation. | chronic exposure of c57bl/6 mice to lead acetate in the drinking water enhanced the growth of primary moloney sarcoma virus (msv)-induced tumors. regression of msv-induced tumors was not prevented by lead exposure and lead-treated animals were more resistant to late sarcoma development following primary tumor regression. the primary cell-mediated cytotoxic response in the spleen or lymph nodes of msv-tumor bearing mice was significantly augmented by lead exposure. this augmentation appeared to r ... | 1982 | 6980867 |
| repeated isolation of unique qa2+ ia+ clonally derived cell lines from qa2- mice. | qa2+ tumor cell lines were previously isolated from individual balb/cby (qa2-) splenic lymphomas induced by murine sarcoma virus-murine leukemia virus-moloney (msv-mulv-m). two clonally derived cell lines, ora i-a and thorbly, and one noncloned cell line, boms, expressed qa2, but neither ly-1 nor ly-2 were detected. in order to determine whether eight cloned and two noncloned tumor cell lines all represented a unique population of transformed cells, the presence of a series of surface differenti ... | 1982 | 6979571 |
| the possible role of cellular genes related to retroviruses in the process of chemical and radiation carcinogenesis. | chemical carcinogens, radiation, and tumor promoters can not introduce new genetic information into cells. they must, therefore, call upon genes already present in the target cell. we have recently explored the possibility that these host genes share homology with specific nucleic acid sequences present in some of the known retroviruses. in one set of experiments we used a cloned dna probe prepared from the oncogene (v-mos) of moloney murine sarcoma virus (mo-msv) to examine the state of integra ... | 1982 | 6897728 |
| specific immunotherapy combined with whole body irradiation of balb/c mice bearing moloney murine sarcoma virus-induced primary tumors. | adoptive transfer of lymphocytes was performed into mice bearing progressor moloney murine sarcoma virus (m-msv)-induced primary tumors. lymphocytes from mice immunized against m-msv (designated as immune lymphocytes, il) inhibited tumor growth when transferred before the virus injection. however, the same lymphocytes were ineffective against tumors consisting of a solid mass when transferred after the virus inoculation. when il was transferred shortly after 500 rad whole-body irradiation of the ... | 1982 | 6751920 |
| in vitro methylation of specific regions of the cloned moloney sarcoma virus genome inhibits its transforming activity. | the transforming activity of cloned moloney sarcoma virus (msv) proviral dna was inhibited by in vitro methylation of the dna at cytosine residues, using hpaii and hhai methylases before transfection into nih 3t3 cells. the inhibition of transforming activity due to hpaii methylation was reversed by treatment of the transfected cells with 5-azacytidine, a specific inhibitor of methylation. analysis of the genomic dna from the transformed cells which resulted from the transfection of methylated m ... | 1983 | 6843547 |
| proteoglycans from the substratum adhesion sites of msv-transformed balb/c 3t3 cells. | kirsten murine sarcoma virus-transformed balb/c 3t3 cells (kimsv) are highly tumorigenic and metastatic in the appropriate murine host, are loosely adherent to the tissue culture substratum, and can be readily detached from the substratum by ethylene glycol bis(beta-aminoethyl ether) n,n'-tetraacetic acid treatment leaving their adhesion sites as substratum-attached material. both long-term culture-generated adhesion sites (l-sam) of kimsv cells and newly formed adhesion sites of reattaching cel ... | 1983 | 6838200 |
| immunocytochemical localization in normal and transformed human cells in tissue culture using a monoclonal antibody to the src protein of the harvey strain of murine sarcoma virus. | using a rat monoclonal antibody directed against the p21 src protein of the harvey strain of murine sarcoma virus (msv), we have examined the reactivity of human cells in tissue culture using immunofluorescence and electron microscopy. qualitative results indicated that untransformed mouse and human fibroblastic cells have undetectable amounts of p21; these levels were greatly increased after transformation with harvey msv. a group of human tumor cell lines adapted to tissue culture were examine ... | 1983 | 6357812 |
| rat mutant cells showing temperature sensitivity for transformation by wild-type moloney murine sarcoma virus. | to clarify the cellular target(s) of onc gene products of moloney murine sarcoma virus (mo-msv), we isolated seven mutant cells that exhibit temperature sensitivity for transformation by wild-type mo-msv from fischer rat cell line. five strains of these mutant cells showed normal virus production at the nonpermissive temperature when infected with mo-msv, suggesting that viral replication is not affected by these cellular mutations. four of these mutants were also temperature sensitive (ts) for ... | 1983 | 6829165 |
| in vitro growth control phenotypes of transformed rodent cells prior to and following tumorigenesis. | a number of virus and chemical carcinogen-transformed cell lines were generated in tissue culture and analyzed for growth control phenotypes prior to and following tumorigenesis in appropriate hosts. the cell lines include those of mouse, rat, human, and syrian hamster, transformed by papovaviruses and adenoviruses (dna) or murine (rna) tumor viruses. cell lines were assayed for: (a) multinucleation or uncontrolled nuclear division (und+) and uncontrolled dna synthesis in cytochalasin b (cb) med ... | 1983 | 6848175 |
| [cellular factors participating in cell transformation]. | to clarify the cellular target(s) of onc gene products of moloney murine sarcoma virus (mo-msv), we isolated eight mutant cells that exhibit temperature-sensitivity for transformation by wild type mo-msv from f2408 (fischer rat cell line). these mutant cells showed normal growth and normal mo-msv production at the nonpermissive temperature, suggesting that cellular and viral replication are not affected by these cellular mutations. these mutant cells are divided into 3 classes on the bases of te ... | 1983 | 6881989 |
| new mammalian transforming retrovirus: demonstration of a polyprotein gene product. | a new acute transforming type c retrovirus was isolated from mice inoculated with a virus stock obtained by iododeoxyuridine induction of methylcholanthrene-transformed c3h/10t1/2 mouse cells. this virus, designated 3611-msv, transforms embryo fibroblasts and epithelial cells in culture and induces fibrosarcomas in vivo. 3611-msv is replication defective, requiring a type c helper virus for propagation both in vitro and in vivo. by using endpoint transmission of 3611-msv to mmce c17 mouse and fr ... | 1983 | 6300462 |
| adoptive t cell immunotherapy of msv-induced tumours in nude mice. part i. biology of tumour regression and recurrence. | the induction of immunity to progressively growing murine sarcoma virus (msv) tumours in nude (nu/nu) mice by reconstitution with immune t cells from syngeneic (+/+) donors has been studied. whole spleen cell preparations served as the source of immune t cells. transfer of immune, but not of normal, spleen cells resulted in partial or apparently complete regression of primary tumours and a related moderate to considerable extension of survival time. the dose, the time in days between immunizatio ... | 1983 | 6100803 |
| adoptive t cell immunotherapy of msv-induced tumours in nude mice. part ii. sequential analysis of serum immune complexes and blocking activity in reconstituted mice in relation to tumour biology. | in seven separate experiments, nude (nu/nu) mice carrying established murine sarcoma virus (msv) tumours were reconstituted with syngeneic (+/+) immune splenic t cells. these immune protected mice were randomly divided to provide smaller groups for serial exsanguination. at various time points mice were individually bled and cic concentration and blocking activity of each individual serum was determined. control sera were obtained from nu/nu and adult +/+ mice inoculated with tumour cells only, ... | 1983 | 6100804 |
| high-level expression of oncogenes in escherichia coli. | a plasmid, pjl6, was constructed that contains a unique cla i site 12 codons beyond the bacteriophage lambda cii gene initiation codon, as well as an adjacent unique hind iii site. these sites allowed us to fuse the sequences from the avian myelocytomatosis virus (mc29) v-myc gene, the avian myeloblastosis virus (amv) v-myb gene, and the harvey murine sarcoma virus (ha-musv) v-ras gene to the amino-terminal portion of the cii gene. transcription of the hybrid genes is controlled from the lambda ... | 1983 | 6101025 |
| stimulation of secondary anti-msv cytolytic t lymphocytes with mbl-2 reconstituted membranes. | membranes and solubilized, reconstituted membranes from moloney-infected tumors mbl-2 have been used to stimulate in vitro secondary cytolytic t lymphocytes (ctl) in c57bl/6 mice primed and moloney murine sarcoma virus. membranes are shown to stimulate the generation of moloney-specific and h-2 restricted ctl. stimulation with solubilized, reconstituted membranes required the presence of rat lymphocyte con a supernatant (containing interleukin 2) during the culture. reconstituted membranes made ... | 1983 | 6600194 |
| natural history of m-msv tumors in mice carrying endogenized moloney leukemia virus. | 1983 | 6602736 | |
| expression of h-2 and viral antigens and resistance to the antitumor lysis of tunicamycin-treated mbl-2 lymphoma cells. | the role of protein glycosylation in the tumor lysis mediated by effector cells derived from moloney-sarcoma-virus(msv)-immune mice was studied. treatment of the moloney-virus-induced h-2b lymphoma target cells, mbl-2, with tunicamycin (tm), an inhibitor of the protein-n-linked glycosilation, was found to cause a loss of susceptibility to lysis by msv-immune syngeneic effectors cells, while the same target cells remained fully sensitive to the lytic action of anti-h-2b-immune lymphocytes. examin ... | 1983 | 6605298 |
| cytotoxic t lymphocyte recognition of transfected cells expressing a cloned retroviral gene. | the lysis of murine sarcoma virus-murine leukaemia virus (msv-mulv)-induced tumour cells by cytotoxic t lymphocytes (ctl) appears to require that an antigen specified by msv-mulv, or induced by the infection, be presented in association with class i major histocompatibility complex antigens. the viral proteins of the tumorigenic mulv seem to be a part of the antigens recognized by these dually restricted anti-mulv ctl, but the precise nature of the putative viral antigen(s) recognized by ctl is ... | 1983 | 6605480 |
| stimulation of cell proliferation by vitamin a derivatives on murine sarcoma virus-transformed mouse cells in serum-free culture. | the effect of retinoids (rds) on cell proliferation was studied in serum-free culture condition, using non-transformed and transformed derivatives of balb 3t3. cell proliferation of an sv40-transformed line was inhibited significantly by rd treatment. however, proliferation of two cell lines that were transformed by a kirsten and moloney strain of murine sarcoma virus (msv) and produced growth factor into culture medium, was remarkably stimulated by rds. addition of serum masked both the inhibit ... | 1983 | 6303821 |
| structure of the fbj murine osteosarcoma virus genome: molecular cloning of its associated helper virus and the cellular homolog of the v-fos gene from mouse and human cells. | the 8.2-kilobase (kb) unintegrated circular dna form of the fbj murine leukemia virus (fbj-mlv) was linearized by cleavage at the single hindiii site, molecularly cloned into bacteriophage charon 30, and subsequently subcloned into pbr322 (pfbj-mlv-1). both fbj-mlv virion rna and pfbj-mlv-1 dna were used to investigate the arrangement of helper virus sequences in the fbj murine osteosarcoma virus genome (fbj-msv) by heteroduplex formation with cloned fbj-msv proviral dna. the results showed that ... | 1983 | 6306448 |
| conservation patterns of mouse "virus-like" (vl30) dna sequences. | vl30 sequences are a murine dispersed multigene family with several "retrovirus-like" characteristics. notably, they share basic structural features with retrovirus proviruses and 30s rna transcripts of these genes are capable of efficient packaging in c-type virions and may be subsequently transmitted to other cells. it is not known whether vl30 information is genetically related to endogenous proviruses or to cellular elements. we extended our studies concerning evolutionary conservation and g ... | 1983 | 6306915 |
| leukocyte adherence inhibition response to murine sarcoma virus-induced tumors. ii. requirement for t-cell subpopulations and macrophages. | murine sarcoma virus (msv)-immune t cells from c57bl/6 mice respond to intact rbl-5 tumor cells with the production of leukocyte adherence inhibition factor (laif), which mediates an adherence inhibition response of macrophages. laif is elaborated by isolated lyt-2+ cells incubated with rbl-5 cells, whereas lyt-1+ cells elaborate a substance that enhances macrophage adherence. spleen macrophages or peritoneal exudate macrophages from msv-immune mice when present at concentrations of 0.1% changed ... | 1983 | 6307531 |
| structure and biological activity of v-raf, a unique oncogene transduced by a retrovirus. | we have molecularly cloned a unique acutely transforming replication-defective mouse type c virus (3611-msv) and characterized its acquired oncogene. the viral genome closely resembles moloney (m) murine leukemia virus (mulv), except for a substitution in m-mulv in the middle of p30 and the middle of the polymerase gene (pol). heteroduplex analysis revealed that 2.4 kilobases of m-mulv dna were replaced by 1.2 kilobases of cellular dna. the junctions between viral and cellular sequences were det ... | 1983 | 6308607 |
| induction of rat brain tumor with xenotropic pseudotype murine sarcoma virus. | the oncogenicity of xenotropic pseudotype kirsten murine sarcoma virus (msv) was investigated in sprague-dawley rats. when fetal or newborn rats were inoculated intracerebrally with xenotropic pseudotype msv, brain tumors developed after about one month. tumors were induced both in the cerebrum and the cerebellum. histologically, the tumors were predominantly glioblastoma multiforme and hemangioendotheliomas. in cerebellar lesions, malignant transformation of vascular endothelial cells, polycyst ... | 1983 | 6308962 |
| differential effects of 2-deoxy-d-glucose on surface glycoproteins of normal and transformed cells. | sarcoma virus transformed rat kidney cells, nrk[msv-mlv] cells, and their non-transformed counterparts, nrk cells, were repeatedly subcultured in medium supplemented with 1 mm 2-deoxy-d-glucose (dglc). these dglc-grown cells exhibited alterations in glycosylation of surface proteins. gel filtration analyses of pronase-treated, trypsin-sensitive, surface fucopeptides indicated a reduction in the average size of the fucopeptides from both dglc-grown nrk and nrk[msv-mlv] cells. when the cells were ... | 1983 | 6309366 |
| restriction of host range of xenotropic pseudotype murine sarcoma virus by helper leukemia virus. | we investigated the restriction of the host range to infectivity of msv by helper leukemia virus in vivo. when newborn sd-rats were inoculated intracerebrally, subcutaneously, intraperitoneally or intramuscularly with xenotropic pseudotype kirsten msv, ki-msv(bv2), either brain tumors or myogenic sarcomas were induced, depending upon the route of inoculation. however, no tumors developed in sw-icr mice inoculated with ki-msv(bv2) either intracerebrally or intramuscularly at birth. ecotropic ki-m ... | 1983 | 6312766 |
| glucocorticoids enhance viral transformation of mammalian cells. | the effect of glucocorticoids on the replication of murine sarcoma virus (msv) in mammalian cells were examined. glucocorticoids, hydrocortisone (1 to 10 micrograms/ml) and dexamethasone (5 micrograms/ml), enhance transformation induced by the kirsten strain of msv (ki-msv) in normal rat kidney and human cells 10- to 30-fold. the enhancing effect was much more pronounced in normal human colonic mucosal epithelial-like cells. on the other hand, the hormones estradiol, testosterone, and progestero ... | 1983 | 6314344 |
| expression of fbj-msv oncogene (fos) product in bacteria. | the protein predicted from the dna sequence of the fbj murine osteosarcoma virus (fbj-msv) onc gene (v-fos) was expressed in escherichia coli under the control of the tryptophan operon regulatory region. the 381-amino acid protein was identified by synthesis in minicells isolated from bacteria containing the expression vector plasmid. a 52,000-da protein was made in these minicells, along with the proteins encoded by the beta-lactamase gene present on the expression vector plasmid. synthesis of ... | 1983 | 6318437 |
| role of accessory cells in the induction of a secondary cytotoxic response to moloney murine sarcoma virus-induced tumors. | the role of ia-positive accessory cells in the generation of a secondary cytotoxic response to tumor-associated antigens induced by moloney murine sarcoma virus (m-msv) was evaluated. spleen cells from m-msv-immune a.tl mice, depleted of accessory cells by anti-iak serum plus c treatment and stimulated in secondary mixed leukocyte tumor cell culture (mltc) with syngeneic ia-negative a6atl moloney leukemic cells, failed to generate virus-specific cytotoxic t lymphocytes (ctl). ctl generation in i ... | 1983 | 6185589 |
| [role of interferon in the phenotypic reversion of transformed cells: loss of malignancy]. | transformation of cells by oncogenic rna viruses is related to a number of significant changes in cell morphology and functions. the most common features of transformed cells are essentially the decrease of cell adhesiveness and the loss of contact inhibition. these changes are probably associated with an alteration of the cytoskeleton together with a marked modification in the number and distribution of membrane and extracellular matrix components. balb/c embryonic fibroblasts transformed by mu ... | 1983 | 6190122 |
| the mechanism of interferon effect on cell transformation by murine sarcoma virus. | mouse interferon (ifn) was found to inhibit murine sarcoma virus (msv)-induced neoplastic transformation of normal rat kidney (nrk) cells. this effect was observed upon examining the formation of foci of morphologically altered cells and colonies of anchorage-independent cells. ifn had no cytotoxic effect on msv-transformed nrk cells, nor on their focus or colony-forming ability. it was therefore apparent that its inhibitory effect was directed against the viral role in cell transformation. in a ... | 1983 | 6190765 |
| hormonal-like modulation of growth of moloney virus-induced tumors by interferon and platelet-derived growth factor. | continued intramuscular (i.m.) administration of highly purified preparations of mouse interferon (muifn) and/or bovine platelet-derived growth factor (pdgf) to the moloney sarcoma virus (msv) infected balb/c mice resulted in a hormonal-like modulation of growth of tumors. large dose muifn treatment (10(5) units per mouse daily, for 14 days) inhibited the msv-induced tumors. on the other hand, small-dose muifn treatment (100 units per mouse daily, for 14 days or 10(4) units per mouse, every seco ... | 1983 | 6197039 |
| selective failure of accessory cell function in moloney murine leukemia virus-tolerant mice. | accessory cell activity of spleen cells from m-mulv neonatally injected (tolerant) mice was studied to evaluate their ability to take part in in vitro ctl generation against tumor-associated antigens induced by m-msv. in contrast with accessory cell activity in normal spleen cells, spleen cells from m-mulv-tolerant mice are unable to reconstitute the in vitro virus-specific ctl generation of m-msv immune, ia-depleted spleen cells. a selective defect seems to characterize m-mulv-tolerant mice as ... | 1983 | 6223070 |
| sequence relationships between kirsten retrovirus genomes and the genomes of other murine retroviruses. | rna sequence relationships between the genomes of the kirsten murine sarcoma virus (msv-k) complex, the kirsten murine leukemia virus (mulv-k) complex, the gross murine leukemia virus (mulv-g), and the moloney murine leukemia virus (mulv-m) were investigated. sedimentation analyses revealed the expected 30 and 34 s rna subunits in the msv-k complex and a previously undetected 30 s rna subunit accompanying the 34 s rna subunit in the mulv-k complex. nucleic acid hybridization data indicated that ... | 1983 | 6302979 |
| construction and characterization of moloney murine leukemia virus mutants unable to synthesize glycosylated gag polyprotein. | murine leukemia virus (mulv) encodes two independent pathways for expression of the gag gene. one pathway results in processing and cleavage of the precursor pr65gag to yield the internal capsid proteins of the virion and is analogous to gag polyprotein precursors for all classes of retroviruses. the other pathway, which is not encoded by several other classes of retroviruses, begins with a glycosylated polyprotein gpr80gag . gpr80gag is synthesized independently of pr65gag; it contains pr65gag ... | 1983 | 6310608 |
| recombinational junctions of variants of moloney murine sarcoma virus: generation and divergence of a mammalian transforming gene. | different variants of moloney murine sarcoma virus (msv) were examined by nucleotide sequencing to compare the junctions between the acquired cellular sequence, v-mos, and the adjacent virus-derived sequences. these variants included 124-msv, m1-msv, and ht1-msv and also the purportedly independent isolate gazdar msv. these four strains have an identical 5' junction between the murine leukemia virus env gene and the v-mos gene. this junction lies within the sixth codon of the chimeric env-mos co ... | 1983 | 6300424 |
| microfilaments and intermediate filaments in epithelial cells transformed by murine sarcoma or leukemia viruses. | the murine epithelial cell line mmc-e was used to study changes in the cytoskeletal organization associated with viral transformation of epithelial cells by two different viruses. the cells were transformed with moloney mouse sarcoma virus (msv) or murine leukemia virus (mulv). the expression of actin, myosin and of intermediate filament proteins in the cells was then studied. in mmc-e cells actin and myosin were organized as belt-like structures at the edges of the border cells of the cell isla ... | 1983 | 11596492 |
| immunity against moloney sarcoma virus in h-2db mutant bm14 mice. unimpaired tumor immunity despite absence of a virus-specific cytotoxic t-cell response. | it was shown previously that b6.c-h-2bm14 (bm14) mice, carrying a mutation in the h-2db locus, are unable to generate cytotoxic t cells (ctl) against moloney murine sarcoma virus (m-msv). we now report an analysis of tumor induction and regression kinetics and of immunity to the virus, following the injection of graded doses of m-msv into c57bl/6 (b6) and bm14 mice. contrary to expectation, bm14 mice showed slightly less tumors than wildtype b6 mice. moreover, all bm14 mice that developed a tumo ... | 1984 | 6319305 |
| fbr murine osteosarcoma virus. i. molecular analysis and characterization of a 75,000-da gag-fos fusion product. | the fbr murine osteosarcoma virus complex induces bone tumors with a similar latency and pathology to those induced by the fbj virus complex. fbr murine sarcoma virus ( fbr -msv) has been isolated from its helper virus(es) by the establishment of transformed nonproducer cells. these cells were found to express a 75,000-da protein (p75) which was antigenically related to the p55 oncogene product of the fbj murine osteosarcoma virus ( fbj -msv). p75 also contained antigenic determinants of murine ... | 1984 | 6203214 |
| functional activity in vivo of effector t cell populations. ii. anti-tumor activity exhibited by syngeneic anti-momulv-specific cytolytic t cell clones. | the functional activity in vivo of murine tumor-specific cytolytic t lymphocyte populations and clones was studied. tumor cell destruction induced after the i.v. injection of cytolytic effector cells was quantitated by monitoring the elimination of 131iudr-labeled tumor cells in the peritoneal cavity by using whole-body counting techniques. mixed leukocyte-tumor cell cultures were established by using spleen cells from c57bl/6 regressor mice that had rejected an intramuscular tumor induced by th ... | 1984 | 6205090 |
| transformation by murine sarcoma virus alters the sensitivity of clonal cells derived from nih/3t3 mouse fibroblasts to interferon. | in contrast to normal clonal cells (a5) derived from nih/3t3 mouse fibroblasts, another clone (a10) derived from the same source was found to be resistant to the anti-lytic-virus activity of ifn and to be deficient in the induction of (2'-5') oligoadenylate synthetase (2-5a synthetase) by ifn. following infection of either a5 or a10 cells with moloney murine sarcoma virus (msv), a few transformed colonies were isolated, expanded, and tested for their sensitivity to ifn. it is clearly demonstrate ... | 1984 | 6206644 |
| murine retrovirus pr65gag forms a 130k dimer in the absence of disulfide reducing agents. | gazdar-murine sarcoma virus (gz-msv) particles, obtained from tissue culture fluids of chronically infected htg-2 hamster cells are immature in morphology and contain uncleaved pr65gag as the predominant protein (greater than 95% coomassie blue stain) (a. pinter and e. deharven, 1979, virology 99, 103-110; y. yoshinaka and r. b. luftig, 1982, virology 118, 380-388). when gz-msv particles are disrupted in 1% sodium dodecyl sulfate (sds) and then analyzed by sds-polyacrylamide gel electrophoresis ... | 1984 | 6087546 |
| expression of normal and transforming h-ras genes in escherichia coli and purification of their encoded p21 proteins. | the h-ras gene of the balb murine sarcoma virus (balb-msv) was placed under the transcriptional control of the tightly regulated pl promoter of bacteriophage lambda in the expression vectors pev-vrf-1 and prc23. upon derepression of the pl promoter, large amounts (10-20% of total cellular protein) of the h-ras gene product p21 are synthesized in escherichia coli. we constructed three h-ras gene expression vectors, designated pjcl-h5, pjcl-e30, and pjcl-33. pjcl-h5 directs the synthesis of p21, a ... | 1984 | 6089191 |
| sequences in the long terminal repeats of the moloney murine sarcoma virus-124 genome which control transforming gene function. | the role of long terminal repeat (ltr) sequences in the efficient expression of moloney murine sarcoma virus (msv-124) transforming gene function was investigated. recombinant plasmids containing a single ltr positioned 3' of v-mos were subjected to sequential deletions, and the relative transforming efficiency of these recombinants was analyzed in the nih/3t3 transfection assay. recombinants lacking caat, tata, and poly(a) signals within the ltr were able to transform with an efficiency compara ... | 1984 | 6089418 |
| use of the mouse mammary tumor virus long terminal repeat to promote steroid-inducible expression of v-mos. | we used the mouse mammary tumor virus long terminal repeat to promote dexamethasone-regulated expression of the moloney murine sarcoma virus (m-msv) transforming gene, v-mos. a recombinant dna vector containing the mouse mammary tumor virus long terminal repeat fused to the m-msv 124 v-mos gene was cotransfected with a plasmid containing the herpes simplex virus thymidine kinase gene (tk) into 3t3tk- cells. individual clones of cells which grew in hypoxanthine-aminopterin-thymidine medium were t ... | 1984 | 6092668 |
| latent beta-transforming growth factor in nontransformed and kirsten sarcoma virus-transformed normal rat kidney cells, clone 49f. | normal rat kidney cells of the clone 49f and their ki-msv-transformed counterparts spontaneously release the same transforming growth factor (tgf) activity in an inactive form. by acidification followed by neutralization prior to assay, this tgf activity is unmasked and promotes anchorage-independent growth of the nrk-49f indicator cells in the presence of epidermal growth factor. the tgf activity released by both cell types has an apparent molecular weight of 9,000 under acidic conditions, does ... | 1984 | 6093998 |
| introduction of a selectable gene into different animal tissue by a retrovirus recombinant vector. | the potential use of retrovirus vectors to transduce foreign genetic information into cells of different tissues of an animal was explored by introducing a recombinant genome carrying the eco gpt gene into postimplantation mouse embryos. to obviate the need for preparing concentrated virus stocks, psi 2-2-5 cells producing the replication-defective murine sarcoma virus (msv)-gpt virus were microinjected directly into embryos. the psi 2-2-5 cells were mixed with cells producing replication-compet ... | 1984 | 6095271 |
| homologous cell-derived oncogenes in avian carcinoma virus mh2 and murine sarcoma virus 3611. | retroviral oncogenes (v-onc) are derived from cellular genes (c-onc) which are highly conserved among different species. retrovirus-transduced oncogenes are most commonly associated with the induction of haematopoietic tumours and sarcomas. the avian retrovirus mill hill no. 2 (mh2) was isolated from a spontaneous ovarian tumour of a chicken and is distinguished by the predominant induction of liver and kidney carcinomas in fowl. mh2 also induces transformation of fibroblasts, macrophages and ep ... | 1984 | 6319999 |
| a common onc gene sequence transduced by avian carcinoma virus mh2 and by murine sarcoma virus 3611. | a common cellular sequence was independently transduced by avian carcinoma virus mh2 (v-mht) and murine sarcoma virus (msv) 3611 (v-raf). comparison of the nucleotide sequences of v-mht and v-raf revealed a region of homology that extends over 969 nucleotides. the homology between the corresponding amino acids was about 95 percent with only 19 of 323 amino acids being different. with this example, 5 of the 19 known different viral onc genes have been observed in viruses of different taxonomic gr ... | 1984 | 6320371 |
| regulation of b cell lymphomagenesis by a malignant qal+ inducer t cell clone. | a series of thy-1.2+ ly-1+ qa-1+ malignant t cell clones have been isolated from murine sarcoma virus-murine leukemia-moloney (msv-mulv-m)-induced b cell lymphomas or from msv-mulv-m-infected b6 mice. these t cell clones enhance both antigen-independent and -dependent lymphocyte differentiation and function. they also induce the differentiation of granulocytes and erythrocytes in the stem cell compartment, a function that parallels the immunopathology of the disease in vivo. the malignant t cell ... | 1984 | 6321629 |
| nucleotide sequence of avian retroviral oncogene v-mil: homologue of murine retroviral oncogene v-raf. | eukaryotic cells contain genes termed proto-oncogenes (c-onc) which have the potential to transform cells in culture and induce tumours in vivo. most of these genes have been identified by their occasional incorporation into retroviral genomes which can act as natural transducing vectors for these and perhaps other cellular genes. cell-derived oncogenes of retroviruses (v-onc) are associated mostly with the induction of mesenchymal tumours whereas carcinoma induction is rare. one of these rare c ... | 1984 | 6325930 |
| tolerance to viral antigens in mov-13 mice carrying endogenized moloney-murine leukemia virus. | in virus-positive (v+) c57bl/6 mov-13 mice, moloney-murine leukemia virus (m-mulv) is integrated into the germ line and expressed early in lymphoid and nonlymphoid organs. the pattern of immune reactivity to viral antigens in these mice was studied and compared to that of their virus-negative (v-) counterparts. using a radioimmuno-binding or -precipitation assay, v- mice showed good antibody production after challenge with moloney-murine sarcoma virus (m-msv), but no antibodies were detected in ... | 1984 | 6607132 |
| transformation of nih 3t3 cells by microinjection of ha-ras p21 protein. | alteration in gene structure has been shown to occur in some human tumours. these altered genes, termed oncogenes, were originally identified by their ability to induce foci of transformed cells on transfected mouse 3t3 cultures. the oncogene identified in the ej/t24 human bladder carcinoma is similar to the transforming gene of balb and harvey murine sarcoma virus (msv) and differs from its counterpart in normal cells by a single amino acid. all three of these ha-ras genes direct the production ... | 1984 | 6611509 |
| a new oncogene, c-raf, is located on mouse chromosome 6. | the recently described acute transforming virus 3611-msv contains cellular sequences designated v-raf. mouse cellular dna contains a single-copy sequence homologous to this oncogene (c-raf), and southern blot analysis of hamster-mouse somatic cell hybrid dnas showed that the mouse c-raf sequence is present on chromosome 6. | 1984 | 6690719 |
| the effect of vitamin b-6 deficiency on host susceptibility to moloney sarcoma virus-induced tumor growth in mice. | the effect of vitamin b-6 deficiency on in vivo host susceptibility to primary moloney sarcoma virus (msv)-induced tumor growth and to secondary challenge with msb sarcoma cells was examined in mice. female c57bl/6 mice, 6 weeks of age, were fed 20% casein diets with pyridoxine (pn) added at 1, 0.5, 0.1 or 0 mg/kg diet for 21 weeks. after 4 weeks of dietary treatment the mice were challenged with msv. vitamin b-6 deficiency resulted in an enhancement of tumor susceptibility as well as an increas ... | 1984 | 6726463 |
| comparison of myeloproliferative sarcoma virus with moloney murine sarcoma virus variants by nucleotide sequencing and heteroduplex analysis. | the myeloproliferative sarcoma virus (mpsv) was derived by passage of moloney sarcoma virus (mo-musv) in adult mice. mo-musv variants transform fibroblasts. however, mpsv also affects erythroid, myeloid, and hematopoietic stem cells. the mpsv proviral genome, two temperature-sensitive mutants derived from it, mo-musv variant m1, and moloney murine leukemia virus (mo-mulv) were compared by heteroduplex mapping. mpsv wild type was found to have 1 kilobase pair deleted from the pol gene and to cont ... | 1984 | 6328002 |
| nucleotide sequence of avian carcinoma virus mh2: two potential onc genes, one related to avian virus mc29 and the other related to murine sarcoma virus 3611. | the 5.2-kilobase (kb) rna genome of avian carcinoma virus mh2 has the genetic structure 5'-delta gag (0.2 kb)- mht (1.2 kb)-myc (1.4 kb)-c (0.4 kb)-poly(a) (0.2 kb)-3'. delta gag is a partial retroviral core protein gene, mht and myc are cell-derived mh2-specific sequences, and c is the 3'-terminal retroviral vector sequence. here we have determined the nucleotide sequence of 3.5 kb from the 3' end of delta gag to the 3' end of molecularly cloned proviral mh2 dna, in order to elucidate the genet ... | 1984 | 6328485 |
| contacts between hormone receptor and dna double helix within a glucocorticoid regulatory element of mouse mammary tumor virus. | glucocorticoid hormones enhance the transcription of mouse mammary tumor virus dna by mechanisms involving a direct interaction of the hormone receptor with four binding sites in a glucocorticoid regulatory element located between -72 and -192 base pairs upstream of the main transcription initiation site within the proviral long terminal repeat regions. methylation at the n-7 position of any of three g residues within one of the binding sites prevents binding of the receptor. in addition, in the ... | 1984 | 6328488 |
| effects of retinoids on the proliferation of murine sarcoma virus-transformed cells in serum-free culture: potentiation of autocrine stimulation. | in a recent report, we described a growth stimulatory effect of vitamin a derivatives (retinoids) on murine sarcoma virus (msv)-transformed cell lines when tested in a serum-free culture condition. these cell lines were presumed to proliferate via autostimulatory (autocrine) mechanism when serum was omitted from culture medium. in the present communication, we examined the effect of 6 synthetic derivatives on the serum-free proliferation of 2 msv-transformed cell lines. we confirmed essentially ... | 1984 | 6331634 |
| physical structure and genetic organisation of the genome of maize streak virus (kenyan isolate). | the structure of the maize streak virus genome (kenyan isolate, msv-k), as determined from the sequence of clones obtained from dna isolated from virus particles, is composed of one major dna component of about 2.6 kb. msv virion dna is partially double-stranded, composed of a full-length virion (v) strand and a short (70-80b) primer (p) strand. the primer strand has a fixed 5'-end capped with alkaline labile material, presumably 1-2 ribonucleotides. the msv genome has two major coding regions o ... | 1984 | 6493977 |
| the nucleotide sequence of maize streak virus dna. | the nucleotide sequence of the dna of maize streak virus (msv) has been determined. the data were accommodated into one dna circle of 2687 nucleotides, in contrast to previously characterised geminiviruses which have been shown to possess two circles of dna. comparison of the nucleotide sequences of the dna of msv with those of cassava latent virus (clv) and tomato golden mosaic virus (tgmv) showed no detectable homology. analysis of open reading frames revealed seven potential coding regions fo ... | 1984 | 6526009 |
| a putative primer for second-strand dna synthesis of maize streak virus is virion-associated. | we have isolated, from maize streak virus (msv) preparations, a population of 'nested' dna molecules. these molecules have ribonucleotides covalently linked to the dna species' discrete 5' deoxyribonucleotide terminus. the major species has a dna sequence of 80 nucleotides which is complementary to a region 5' of two hairpin structures on the msv genome, almost exclusively in an intergenic region. these molecules have been used to prime the synthesis in vitro of a complementary strand to virion ... | 1984 | 6526010 |
| murine sarcoma virus-induced brain tumors. concurrent measurements of blood flow and transcapillary transport. | intracerebral inoculation of murine sarcoma virus (msv) into rats induces highly vascular brain tumors. blood flow, f, and a unidirectional blood-to-tissue transfer constant, k, were measured concurrently in 16 separate brain tumors in 13 rats. regional measurements of f and k were obtained using double-label quantitative autoradiography with 131i-iodoantipyrine, 14c-alpha aminoisobutyric acid, and computerized microdensitometry with image analysis. regional tissue extraction fractions (e) were ... | 1984 | 6530618 |
| serine- and threonine-specific protein kinase activities of purified gag-mil and gag-raf proteins. | retroviruses carry cell-derived oncogenes (v-onc) that have the potential to transform cells in culture and induce tumours in vivo. one of the few carcinoma-inducing viruses is the acutely transforming retrovirus mh2, which carries the putative oncogene v-mil and the known oncogene v-myc. recently, a high degree of homology was discovered between v-mil and v-raf, the transforming gene of the murine retrovirus 3611 murine sarcoma virus (msv), whereas homology to v-src is low. both viruses express ... | 1984 | 6438534 |
| computer analysis identifies sequence homologies between potential gene products of maize streak virus and those of cassava latent virus and tomato golden mosaic virus. | the amino acid sequences of the putative polypeptides of maize streak virus (msv) have been systematically compared with those of cassava latent virus (clv) and tomato golden mosaic virus (tgmv) using the programme diagon (8).conserved sequences have been detected between peptides encoded by the complementary (-) sense of msv and those of clv and tgmv, viz; the 40 200 mr polypeptide of clv-1 (3) and the 40 285 mr polypeptide of tgmv-a (4) show extensive homologies with the 17 768 mr and 31 388 m ... | 1985 | 24306572 |
| the nucleotide sequence of cloned wheat dwarf virus dna. | restriction analysis and cloning of virus-specific double-stranded dna isolated from plants infected with wheat dwarf virus (wdv) indicated that the virus genome, like that of maize streak virus (msv), consists of a single dna circle. the complete nucleotide sequence of cloned wdv dna (2749 nucleotides) has been determined. comparison of the potential coding regions in wdv dna with those in the dna of two strains of msv suggests that these viruses encode at least two functional proteins, the coa ... | 1985 | 15938050 |
| mmc-e cells--origin and changes in karyotype accompanying malignant transformation. | karyotype analysis of an established nontumorigenic cell line (mmc-e) indicated that the cells are of rat origin instead of mouse, as interpreted earlier. this cell line, now termed re (rat epithelial) had a karyotype of 39,x,-5,-15,-?16,+t(3q11q) in the stem line. there was also one subline that had a karyotype of 40,x,-5,-15,-?16,+t(3q11q), +?t(5;?). chromosome changes and frequency of sister chromatid exchanges (sces) were studied from seven malignantly transformed re cell lines. these includ ... | 1985 | 3971317 |
| sequence homology among the coat proteins of gemini viruses. | the coat proteins of the gemini viruses - african cassava latent virus, tomato golden mosaic virus and maize streak virus - are shown to have reasonable to good amino acid sequence homology. it is suggested that the maize streak virus genome is ancestral and the bipartite genomes of the other viruses evolved from it. | 1985 | 4026858 |
| sarcoma viruses carrying ras oncogenes induce differentiation-associated properties in a neuronal cell line. | the growth-promoting and/or differentiation-blocking activities of kirsten (ki-msv) or harvey murine sarcoma virus (ha-msv) on various types of cells in vitro are well documented. here we report an unexpected effect of these viruses on a rat phaeochromocytoma cell line, pc12. pc12 cells, which multiply indefinitely in growth medium, are known to respond to nerve growth factor (ngf) by cessation of cell division and expression of several properties resembling those of differentiated sympathetic n ... | 1985 | 4058592 |
| polykaryocytosis induced by amphotropic murine c-type virus (ap129) in sac-cells nonproductively transformed by moloney murine sarcoma virus (mo-msv). | nonproducer cells of stu mouse origin (sac) transformed with moloney murine sarcoma virus (mo-msv) and superinfected with the amphotropic murine c-type virus strain ap 129 unexpectedly formed polykaryocytes. the multinuclear giant cells appeared about 30 days after ap 129 infection as confirmed in three independently performed experiments. the majority of the sac-cells became involved in syncytium formation. the polykaryocytes disappeared during continued culture transfers. various cell lines ob ... | 1985 | 2859766 |
| [development and regression of tumors induced by m-msv virus in mice after administration of rutin and quercetin]. | 1985 | 3831630 | |
| t-cell regulation of erythropoiesis during acute lymphoblastic leukemia. | how and where erythropoiesis is maintained during advanced leukemic disease is an important and, as yet, unresolved question in hematology. to address the potential role of t-lymphocytes as cells that regulate cfu-e differentiation during leukemogenesis, an experimental model of disease has been developed in inbred balb/c mice. specifically, three-week-old balb/c by mice were injected with murine sarcoma virus-murine leukemia virus-moloney (msv-mulv-m), which resulted 6-8 months later in the dev ... | 1985 | 3871705 |
| transformation of mononuclear phagocytes in vivo and malignant histiocytosis caused by a novel murine spleen focus-forming virus. | the study of retrovirus-induced leukaemias in mice is a powerful tool for the elucidation of the normal regulation of the haematopoietic system. the acute murine spleen focus-forming viruses (sffv) can be classified according to the haematopoietic lineage on which they exert their effects in the adult mouse. here we report a new sffv isolate, the af-1 virus, with the novel ability to transform cells of the mononuclear phagocyte lineage. the virus was isolated from sarcomas that were induced on p ... | 1985 | 3873013 |
| characterization of gp85gag as an antigen recognized by moloney leukemia virus-specific cytolytic t cell clones that function in vivo. | the gag membrane protein gp85gag, encoded by moloney murine leukemia virus (m-mlv), was identified as a target molecule recognized by moloney murine sarcoma virus--m-mlv (m-msv--m-mlv)-specific cytolytic t lymphocyte (ctl) clones. target cells infected with ab-x-mlv, an m-mlv-derived mutant virus not encoding gp85gag, were not lysed by the ctl clones. the same ctl clones were shown previously to induce the destruction of m-mlv-induced tumor cells in the peritoneal cavity. we have now characteriz ... | 1985 | 3891902 |
| the ras oncogene product p21 is not a regulatory component of adenylate cyclase. | harvey (ha-msv) and kirsten (ki-msv) murine sarcoma viruses induce tumours in animals and transform various cells in culture because of the expression of the ras oncogene product, p21 (ref. 1). proto-oncogenes homologous with these genes are highly conserved evolutionarily and activated ras oncogenes have been detected in many human cancers. whether c-ras oncogenes are directly responsible for human carcinogenesis is uncertain; however, it is clear that p21 mediates virus-induced transformation, ... | 1985 | 3929144 |
| retrovirus-induced changes in major histocompatibility complex antigen expression influence susceptibility to lysis by cytotoxic t lymphocytes. | retrovirus infection of murine fibroblasts was found to alter the expression of major histocompatibility complex (mhc) antigens. fibroblasts infected with moloney murine leukemia virus (m-mulv) exhibited up to a 10-fold increase in cell surface expression of all three class i mhc antigens. increases in mhc expression resulted in the increased susceptibility of m-mulv-infected cells to lysis by allospecific cytotoxic t lymphocytes (ctl). m-mulv appears to exert its effect at the genomic level, be ... | 1985 | 2411792 |
| bidirectional transcription of maize streak virus dna and identification of the coat protein gene. | three rna transcripts encoded by maize streak virus dna were detected in polyadenylated rna from virus-infected maize leaves. two of the transcripts, a major 0.9 kb and a minor 1.05 kb rna, were mapped on the virion (+) sense dna and the other minor transcript of 1.2 kb was mapped on the complementary (-) sense dna, demonstrating that transcription of msv dna was bidirectional. the two virion sense transcripts were 3' coterminal at nucleotide 1114 but had 5' termini at nucleotides 2682 and 163 r ... | 1985 | 2414736 |
| the effect of interferon treatment of targets on susceptibility to cytotoxic t-lymphocyte killing: augmentation of allogeneic killing and virus-specific killing relative to viral antigen expression. | the effect on ctl lysis of treatment of ctl targets with ifns has been investigated. treatment of targets for alloreactive ctl with either ifn-alpha beta or ifn-gamma markedly augmented cytotoxicity. cold competition experiments implied that ctl recognized the same target structure on both untreated and ifn-treated cells. this augmented lysis is presumably caused by ifn increasing expression of target mhc antigens. in the case of sfv-specific lysis of sfv-infected fibroblasts, ifn-alpha beta or ... | 1985 | 2416676 |
| cyclic amp-independent processes mediate kirsten sarcoma virus-induced changes in collagen production and other properties of cultured cells. | previous studies suggested that the decreased collagen production observed in kirsten sarcoma virus (ki-msv)-transformed balb 3t3 cells could be reversed by treating cells with bt2camp. we examined the relationship between intracellular camp, collagen production, and other properties in nrk and balb 3t3 cells transformed by ki-msv. two 3t3 transformants (ki-3t3-234 and ki-3t3cl1) had lower camp levels than nontransformed cells. the level in a temperature-sensitive transformant, tski-3t3-714, was ... | 1985 | 2578130 |
| reversibility of lymphokine-induced nk-like activity in virus-specific cytotoxic t-lymphocyte clones. | a limiting dilution microculture system, supplemented with a source of interleukin-2 (il-2), was employed to evaluate the frequency of moloney-murine leukaemia/sarcoma virus (m-mulv/m-msv)-specific cytotoxic t-lymphocyte precursors (ctl-p) which also exhibited nk-like activity. spleen cells, obtained from m-mulv/m-msv regressor mice, were restimulated in bulk secondary mixed leucocyte-tumour cell cultures (mltc), and subsequently plated in a culture medium supplemented with two different superna ... | 1985 | 2578429 |
| characterization of chemically and virally transformed variants of madin-darby canine kidney (mdck) epithelial cells. | oncogenic derivatives of madin-darby canine kidney (mdck) cells were isolated in the nude mouse, and nononcogenic anchorage-independent transformants were isolated in vitro following chemical mutagenesis in vitro. these transformed cell lines as well as a moloney sarcoma virus (msv) transformed line were characterized with respect to their serum and anchorage requirements, growth rates, final saturation densities, and sensitivities to contact inhibition. none of these in vitro growth characteris ... | 1985 | 2981894 |
| thyroid hormone modulation of transformation induced by kirsten murine sarcoma virus. | we have investigated the effect of triiodothyronine (t3) on the transformation of normal rat kidney (nrk) cells by the kirsten strain of murine sarcoma virus (ki-msv). when nrk cells were grown and infected with ki-msv in medium lacking t3, the yield of transformed foci was about one-half that observed in the cultures supplemented with t3. individual foci appeared somewhat later in cells grown out in medium devoid of t3. the yield of ki-msv released from transformed nrk cells was lower when thes ... | 1985 | 2983886 |
| two oncogenes in avian carcinoma virus mh2: myc and mht. | the 5.2-kilobase (kb) rna genome of avian carcinoma virus mh2 has the genetic structure 5' - delta gag (0.2 kb)-mht (1.2 kb)-myc (1.4 kb)-c(0.4 kb)-poly (a) (0.2 kb)-3'. delta gag is a partial retroviral core protein, mht and myc are cell-derived mh2-specific sequences, and c is the 3'-terminal retroviral vector sequence. the following results were obtained from the complete nucleotide sequences of the mht and myc genes in mh2. (i) delta gag-mht forms a hybrid gene with a contiguous reading fram ... | 1985 | 2986522 |
| neoplastic transformation of mast cells by abelson-mulv: abrogation of il-3 dependence by a nonautocrine mechanism. | normal mast cells can be propagated in culture when medium is supplemented with interleukin-3 (il-3). we demonstrate that abelson-mulv (ab-mulv) infection of mast cells eliminates dependence on il-3 for growth. by contrast, harvey, balb, and moloney msv, which also productively infect mast cells, are unable to relieve il-3 dependence. ab-mulv-induced il-3-independent lines express the v-abl-specific transforming protein and have phenotypic characteristics of mast cells. these cells also possess ... | 1985 | 2988783 |
| mutational analyses of the moloney murine sarcoma virus enhancer. | retroviral enhancers seem to play an integral role in determining tissue tropism. in an attempt to define the sequences essential for moloney murine sarcoma virus (mo-msv) enhancer activity, we have undertaken deletion and insertion mutational analyses of the 72-bp repeats. we demonstrate that, in contrast to simian virus 40 (sv40), the proximal 19 bp of the 72-bp unit of mo-msv are not essential for enhancer function in mouse fibroblasts. our analysis further localizes the 5' boundary of the mo ... | 1985 | 2988891 |
| deletion of the gag region from fbr murine osteosarcoma virus does not affect its enhanced transforming activity. | both fbj murine osteosarcoma virus (fbj-msv) and fbr-msv induce transformation in tissue culture and osteogenic sarcomas in mice. in tissue culture, however, fbr-msv induces larger foci with a shorter latency than those induced by fbj-msv. transformation is dependent on expression of the fos oncogene in fbj-msv and of a gag-fos fusion protein in fbr-msv. we have determined that the gag sequences can be deleted from fbr-msv without affecting the high transforming activity of this virus in compari ... | 1985 | 2991577 |
| monoclonal antibody detects a common surface antigen on two independently established murine moloney sarcoma virus non-producer transformants. | monoclonal antibodies were raised against a cell surface glycoprotein (46k antigen) expressed by a moloney sarcoma virus (mo-msv)-transformed stu mouse cell line (sac). although non-productively transformed sac cells expressed the 46k antigen at their surface, transplantation of sac non-producer cells into immunocompetent mice failed to induce anti-46k antibody production. only transplantation of helper virus-superinfected sac cells led to the development of anti-46k antibodies in addition to an ... | 1985 | 2993478 |
| h-2ld antigen encoded by a recombinant retrovirus genome is expressed on the surface of infected cells. | a recombinant murine retrovirus was constructed which contains, within its genome, a truncated version of the gene encoding the murine h-2ld major histocompatibility antigen. the h-2ld gene, which was inserted 3' of the env splice acceptor site in the recombinant retrovirus msv-neo, lacked the 5' promoter and tata sequences and the 3' transcription termination and polyadenylate addition sites of the normal h-2ld gene. transfection of the msv-neo/h-2ld plasmid (pltv-11) into y-2 cells resulted in ... | 1985 | 2993861 |
| detection of the myristylated gag-raf transforming protein with raf-specific antipeptide sera. | the post-translational modifications of the gag-raf fusion proteins of the 3611 murine sarcoma virus (msv) have been examined by inhibiting glycosylation with tunicamycin and by in vivo labeling with [3h]myristic acid. the results show that p75gag-raf is myristylated but not glycosylated and that p90gag-raf is glycosylated but not myristylated (and is now termed gp90gag-raf). gp90gag-raf expression appeared to become lost during passage of the transformed cells, and consequently does not appear ... | 1985 | 2994296 |