| the isolation and characterization of a clonally related series of murine retrovirus-infected mouse cells. | starting with cloned nih 3t3 mouse cells we have isolated a series of related lines infected with the kirsten murine sarcoma/leukaemia (msv/mlv) virus complex. these lines exhibit all three possible infected cell phenotopes: (i) transformed msv/mlv producers; (ii) non-transformed mlv producers; (iii) transformed non-producers. we have also selected non-transformed revertants from one of the non-producer clones. this series of lines allows the study of the expression of the virus genome against a ... | 1980 | 6252284 |
| action of three species of propionibacteria (p. granulosum, p. acnes, p. avidum) on experimental tumor systems in mice. | the antitumor activity of three different species of propionibacteria (p. granulosum, p. avidum and p. acnes) against murine sarcoma 180 and moloney-sarcoma-virus-induced tumor (msv tumor) was investigated. all three propionibacteria injected intraperitoneally or intratumorally in multiple doses of 1 mg per mouse appeared to be effective regarding the retardation of growth and the stimulation of regression of sarcoma 180 in cfw mice. moreover, the application of propionibacteria significantly pr ... | 1980 | 6252722 |
| immunization against primary, transplanted and spontaneous murine leukaemia using a live moloney sarcoma virus vaccine. | the purpose of this study was to use an immunization protocol with moloney sarcoma virus (msv-m) as active immunogen against exogenous and endogenous leukaemia. the s.c. route was chosen since it offered advantages over the i.m. route: the primary sarcomas were smaller, the regression faster, there were fewer recurrences and there was good persistent immunity. strong protection was obtained against primary leukaemias induced by friend leukaemia virus (flv), moloney leukaemia virus (mlv), rausche ... | 1980 | 6252923 |
| the induction of immunoblastic t cell sarcomas by virus-transformed prothymocytes. | the ontogeny of thymus-dependent lymphoid tumors induced by murine sarcoma-murine leukemia virus (msv-mulv) was investigated. tumors that developed in spleens of infected mice 6 or more months after the injection of virus were diagnosed as immunoblastic t cell sarcomas. cells derived from the tumors and established as a continuous cell line expressed the thymus leukemia (tl), brain-associated theta (bat), and qa2 cell surface antigens but lacked either the ly 1 or ly 2, 3 mature t cell different ... | 1980 | 6254363 |
| multinucleation in the presence of cytochalasin b by rna tumor virus-transformed cells. | rna tumor virus-transformed cell cultures derived from rat, mouse, hamster, and mink were examined for their response to cytochalasin b (cb), and the expression of this marker was correlated with growth in soft agar and tumorigenicity in vivo. continuous cell lines transformed and chronically infected with moloney murine sarcoma-leukemia virus (m-msv-mulv) or kirsten murine sarcoma-leukemia virus were extensively multinucleated when treated with cb. similarly, nonproducer moloney murine sarcoma ... | 1980 | 6254645 |
| a non-virion surface antigen on moloney sarcoma virus-transformed non-producer and producer cells. | sera from stu mice bearing sarcomas induced by cells producing the moloney sarcoma-helper-virus (m-msv/mlv) complex were cytotoxic for these cells as well as for m-msv non-producer and m-mlv producer cells. analysis by polyacrylamide gel electrophoresis of 125i-labelled surface antigens immunoprecipitated with such sera revealed the virus envelope glycoprotein gp71 on the producer cells and an additional antigen of mol. wt 55 k on the m-msv-transformed producer and non-producer cells. this antig ... | 1980 | 6255072 |
| simian virus 40 and moloney-murine sarcoma virus infection of bona fide mouse epithelium. | moloney-murine sarcoma virus (moloney-msv) and simian virus 40 (sv40) were found to infect successfully pure cultures of epithelial cells established from mouse liver and mammary tissue. msv infection resulted in transient morphological foci with persistent production of infectious virus. sv40 infection produced detectable levels of virus-specific t antigen in the cells but morphological transformants were not observed. | 1980 | 6255079 |
| immunity to friend virus complex: analysis of protection with a sarcoma virus pseudotype. | to specify the mechanism whereby inoculation of sarcoma viruses protects against leukemia development by leukoviruses, several experiments were performed using friend virus complex (fvc) and msv-f, a sarcoma virus pseudotype prepared in vitro with fvc as source of the helper component. the sarcomatous lesions induced by msv-f were self-limited, irrespective of dose and route of inoculation and protected against the progressive, lethal erythroleukemia induced fy fvc. the sera of msv-f primed mice ... | 1980 | 6257197 |
| induction of immune reaction against rat embryonal carcinoma by activation of viral genome. | a cell line (f3/1) derived from a rat embryonal carcinoma, originally induced in fetectomized rats injected with msv, was found to be essentially non-immunogenic in a syngeneic host; the cells did not produce c-type virions. the msv genome could be rescued by superinfection of f3/1 cells with endogenous c-type mouse virus and the cells were converted in a producer line-f3/1-p. the produced virus was shown to be msv by its ability to induce focus formation in mouse fibroblasts. in contrast to its ... | 1980 | 6263807 |
| translational products of moloney murine sarcoma virus rna: identification of proteins encoded by the murine sarcoma virus src gene. | in vitro translation of virion rna of moloney murine sarcoma virus (msv) strain 124 yielded major products having molecular weights of 63,000 (63k), 43k, 40k, 31k, and 24k daltons. a molecularly cloned subgenomic fragment of moloney msv comprised of the cellular insertion (src) region was utilized in hybridization arrest translation as a means of identifying products of the msv src gene. msv src dna specifically inhibited synthesis of the 43k, 40k, 31k, and 24k proteins, implying that each of th ... | 1981 | 6264137 |
| analysis of the myeloproliferative sarcoma virus genome: limited changes in the prototype lead to altered target cell specificity. | the myeloproliferative sarcoma virus (mpsv) derived from moloney sarcoma virus (msv-mol) is a unique sarcoma virus which causes expansion of the hematopoietic stem cell compartment as well as the erythroid and myeloid cell lineages. mpsv also induces spleen focus formation in adult mice as do friend and rauscher viruses. analysis of the mpsv genome on methyl mercury gels showed that the genome size is 7.0 kilobases, which is larger than the defective genome of any known msv-mol isolate. hybridiz ... | 1981 | 6264165 |
| alterations in growth requirements of kidney epithelial cells in defined medium associated with malignant transformation. | the possibility has been investigated that 1) the supplements required for the growth of the madin darby canine kidney (mdck) cell line in serum-free medium k-1 are indeed requirements for the growth of normal kidney cells in vitro, and 2) that alterations in these growth requirements are associated with malignant transformation. consistent with the hypothesis that mdck cells resemble normal kidney cells in culture, primary cultures of baby mouse kidney epithelial cells grow in medium k-1 and re ... | 1981 | 6265706 |
| host range of murine sarcoma virus, its host modification and phenotypic mixing with endogenous virus. | the m(msv)ag-50 cells produce competent ecotropic sarcoma virus which is able to transform several rodent embryo cells and replicate in them. the expanded host range has shown that the virus acquired some host information which facilitate the transformation of heterologous cells. the transformed cells were xc positive and with transformed phenotype in vitro. the genome of mouse sarcoma virus from nonproducer rat liver cells could be rescued by xenotropic endogenous virus. the obtained virus has ... | 1981 | 6265817 |
| increased sensitivity of fibroblasts of skin from patients with adenomatosis coli and peutz-jegher's syndrome to transformation by murine sarcoma virus. | skin fibroblasts from family members of cases of adenomatosis coli (ac) and peutz-jegher's syndrome (pj) were examined for susceptibility to morphological transformation by moloney murine sarcoma virus (msv) of rate 78ai cells, which was found in the present study to contain both dualtropic and ecotropic murine leukemia virus (mlv). the fibroblasts from individuals with manifest ac (22 subjects) and manifest pj (5 subjects) were up to 5 times more susceptible to transformation by rat 78ai-msv(ml ... | 1980 | 6268477 |
| neoplastic transformation of mouse fibroblasts by murine sarcoma virus: a multi-step process. | infection of cultures of three different normal rodent cell lines with murine sarcoma virus (msv) resulted in very rapid loss of contact inhibition of growth and morphological transformation. in the case of two of these lines, anchorage dependence of growth was also rapidly lost but with the 3rd, c3h10t1/2 c1.8, an established line of mouse embryo fibroblasts, there was a delay of many cell generations before the cells became anchorage independent. this was despite 100% successful infection, as ... | 1981 | 6268740 |
| mechanisms of kirsten murine sarcoma virus transformation-induced changes in the collagen phenotype and synthetic rate of balb 3t3 cells. | specific viral transformation rather than cell selection can explain the previously observed increase in the proportion of type iii procollagen compared to type i procollagen in balb 3t3 cells transformed by kirsten murine sarcoma virus (ki-msv). two subclones of balb 3t3 a31 were productively infected with with a temperature-sensitive ki-msv in the presence of helper murine leukemia virus (mlv), resulting in virtually complete transformation of cultures and eliminating selection of transformed ... | 1981 | 6273840 |
| structural organization and biological activity of molecular clones of the integrated genome of a balb/c mouse sarcoma virus. | balb/c mouse sarcoma virus (balb-msv) is a spontaneously occurring transforming retrovirus of mouse origin. the integrated form of the viral genome was cloned from the dna of a balb-msv-transformed nonproducer nrk cell line in the charon 9 strain of bacteriophage lambda. in transfection assays, the 19-kilobase-pair (kbp) recombinant dna clone transformed nih/3t3 mouse cells with an efficiency of 3 x 10(4) focus-forming units per pmol. such transformants possessed typical balb-msv morphology and ... | 1981 | 6275097 |
| properties of a sarcoma-growth-factor-like peptide from cells transformed by a temperature-sensitive sarcoma virus. | serum-free conditioned media was collected from three sarcoma virus-transformed cell lines and an untransformed cell line. all three virally transformed lines produced and released growth factors into their serum-free media. the major activity in all cases, whether the cells were transformed by moloney sarcoma virus (msv) or kirsten sarcoma virus (kisv), or whether they were mouse or rat, was a sarcoma-growth-factor (sgf)-like activity with an apparent molecular weight of 10,000. the sgf-like po ... | 1981 | 6276416 |
| activation of sv40 genome by 72-base pair tandem repeats of moloney sarcoma virus. | the simian virus 40 (sv40) 72-base pair (bp) tandem-repeated sequences have a crucial role as an activator element in viral gene expression. we replaced the sv40 72-bp repeat with a 72-bp repeat derived from the long terminal repeat (ltr) of cloned moloney murine sarcoma virus (msv) dna. although there is no detectable sequence homology to sv40, the msv repeats can substitute functionally for the sv40 repeats and generate a viable virus in monkey kidney cells. | 1982 | 6276775 |
| pericellular matrix and cell surface glycoproteins of virus-transformed mouse epithelial cells. | mouse embryo mus musculus castaneous epithelial cells, transformed with moloney murine sarcoma virus (msv) or with ecotropic murine leukemia virus (mulv), were analyzed for production of pericellular matrix glycoproteins. the nontransformed, msv-transformed, and mulv-transformed cells produced fibronectin, laminin, type i collagen, and small amounts of type iii collagen when studied by immunofluorescence using specific antibodies. the virus-transformed epithelial cells produced enhanced amounts ... | 1982 | 6277476 |
| moloney murine leukemia virus-induced tumors: recombinant proviruses in active chromatin regions. | the dnase i sensitivity of chromosomal dna regions carrying integrated proviral genomes of moloney (m-mulv) and akr murine leukemia virus (akr-mulv), and the cellular homologue of the mos-gene (c-mos) of moloney sarcoma virus (msv) were studied in tumor tissues of leukemic mice. the genetically transmitted sequences of m-mulv, akr-mulv, and the c-mos gene are all in dnase i resistant chromatin conformations in m-mulv-induced tumors. each m-mulv-induced tumor contained at least one somatically ac ... | 1982 | 6278422 |
| receptor-associated changes of the catecholamine-sensitive adenylate cyclase in glioma cells doubly transformed with moloney sarcoma virus. | a doubly transformed rat glioma cell line, designated c6v-1, was obtained from rat glioma c6 cells by infection with a rat-adapted variant of moloney sarcoma virus (msv-m-os). the c6v-1 cells show karyotypic changes in chromosome number (43) and structure, while c6 cells possess a normal male karyotype. c6v-1 and c6 cells were employed for characterization of a receptor-adenylate cyclase system of the surface membrane. c6v-1 cells showed lower adenylate cyclase activity than that of c6 cells, th ... | 1982 | 6279681 |
| human nucleotide sequences related to the transforming gene of a murine sarcoma virus: studies with cloned viral and cellular dnas. | a recombinant plasmid, pi26, has been constructed by cloning into pbr322 a transforming gene of murine sarcoma virus (a moloney strain, clone 124, msv) synthesized by detergent-treated virions. from this plasmid a xbai-hindiii fragment has been isolated which contains only mos-specific sequences. this mos-specific probe has been used for screening a human gene library cloned in bacteriophage lambda charon 4a. of these, 19 clones have been isolated containing mos-related sequences. by physical ma ... | 1982 | 6281133 |
| a generalized method of subcloning dna fragments by restriction site reconstruction: application to sequencing the amino-terminal coding region of the transforming gene of gazdar murine sarcoma virus. | the technique of restriction site reconstruction was generalized so as to allow the subcloning of any dna fragment and its subsequent reexcision with ecori, xbai, xhoi or hindiii. after excision, the 3' terminus of each strand will be derived from the starting nucleic acid, permitting the use of such fragments as primers for nucleotide sequencing by primer extension methods. the technique was used to subclone a 56 base pair bstni-ddei fragment of moloney murine sarcoma virus (mo-msv) as a unique ... | 1982 | 6281735 |
| candidate product of the fbj murine osteosarcoma virus oncogene: characterization of a 55,000-dalton phosphoprotein. | sera from rat bearing tumors induced by inoculation of fbj murine osteogenic sarcoma virus (fbj-msv) nonproducer rat cells precipitate two proteins with molecular weights of 55,000 (p55) and 39,000 (p39) from fbj-msv-transformed cells. these proteins cannot be precipitated from uninfected cells or cells transformed by other strains of murine sarcoma virus, nor can they be precipitated by sera specific for the viral structural proteins. a methionine tryptic peptide mapping analysis showed that p5 ... | 1982 | 6283132 |
| t24 human bladder carcinoma oncogene is an activated form of the normal human homologue of balb- and harvey-msv transforming genes. | a transforming gene isolated from t24 human bladder carcinoma cells is closely related to the balb murine sarcoma virus (msv) onc gene (v-bas). this transforming gene is localized to a 4.6 kilobase pair (kbp) region and is expressed as a 1.2-kbp polyadenylated transcript, which contains v-bas related sequences. moreover, antisera known to detect the immunologically related onc gene products of balb- and harvey-msvs recognized elevated levels of a related protein in t24 cells. the normal human ho ... | 1982 | 6283384 |
| balb- and harvey-murine sarcoma virus transformation of a novel lymphoid progenitor cell. | balb- and harvey-murine sarcoma viruses (msv) comprise a family of retroviruses whose mouse- and rat-derived onc genes are closely related. these viruses induce sarcomas and erythroleukemias in susceptible animals. an in vitro colony assay that detects transformation of lymphoid cells by abelson-murine leukemia virus was used to demonstrate that balb- and harvey-msv transform a novel hematopoietic cell both in culture and in vivo. bone marrow colony formation was sarcoma virus dependent, followe ... | 1982 | 6286838 |
| 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 |
| host-specific activation of transcription by tandem repeats from simian virus 40 and moloney murine sarcoma virus. | the simian virus (sv40) 72-base pair (bp) tandem repeated sequences have recently been shown to function as activators or enhancers of early viral transcription. a recombinant viral genome was recently constructed by inserting 72-bp tandem repeats from the moloney murine sarcoma virus (msv) in place of the 72-bp repeats of sv40. although this genome replicates in monkey kidney cells, its rate of large tumor antigen expression and replication is considerably slower than that of wild-type sv40. in ... | 1982 | 6292901 |
| complementary dna copies of leukemia and sarcoma virus rna contain sequences of deoxycytidylate and deoxyguanylate. | single-stranded complementary dna (cdna) of the rna of gazdar murine sarcoma virus, gz-msv/mulv; moloney murine leukemia virus, m-mulv; mouse mammary tumor virus, mmtv; and simian sarcoma virus, ssv-1, were synthesized in endogenous reverse transcriptase reaction. gz-msv/mulv cdna was also synthesized in exogenous in vitro reverse transcriptase reactions. in the endogenous reaction, 30-35s, or 6.0- to 7.9-kilobase-length cdna transcripts were synthesized in high yield. in comparison, transcripts ... | 1981 | 6299564 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| recombinant retroviral dna yielding high expression of hepatitis b surface antigen. | a genomic fragment of hepatitis b virus encoding the surface antigen (hbsag) was inserted into the proviral genome of moloney mouse sarcoma virus (msv), obtained from the mouse cell line g8 -124. the recombinant dna was introduced into nih 3t3 mouse fibroblasts. cells, morphologically transformed by the oncogene of msv (v-mosm) were selected, established as cell lines and tested for expression of hbsag. an expression level of up to 4.5 micrograms/10(7) cells/day was detected. | 1982 | 6327280 |
| 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 |
| 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 |
| 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 |
| t cell-mediated immunity to oncornavirus-induced tumors. iii. specific and nonspecific suppression in tumor-bearing mice. | a strong cell-mediated immune response against friend, moloney, rauscher virus-induced (fmr) cell surface antigens has been demonstrated previously in mice which reject oncornavirus-induced tumors. in order to identify an eventual suppressor mechanism in animals with progressively growing tumors, experiments were initiated in c57bl/6 mice bearing either a murine sarcoma virus (msv) tumor or moloney virus-induced lymphoma (mbl2). progressive tumor growth was induced (a) in viremic animals first i ... | 1981 | 6452278 |
| t cell-mediated immunity to oncornavirus-induced tumors. iv. preliminary evidence for a specific suppression of anti-moloney cell-mediated immune response by autoimmune t cells. | previous reports have demonstrated that adult c57bl/6 mice infected with murine sarcoma virus (msv) develop a strong cell-mediated immune response against friend, moloney, rauscher virus-induced type-specific (fmr) antigens and reject their tumors. to demonstrate a possible role for auto-anti-msv t blasts, syngeneic c57bl/6 mice were immunized with highly enriched anti-fmr cytolytic t cells. one of 3 pools of these autoimmune t cells prepared from 12 surviving immunized mice (a) inhibited specif ... | 1981 | 6452279 |
| systemic and in situ natural killer and suppressor cell activities in mice bearing progressively growing murine sarcoma-virus-induced tumors. | the activity of systemic and in situ natural killer (nk) cells was measured in 3- to 5-week-old cba mice with progressively growing murine sarcoma virus (msv)-induced tumors. splenic nk activity was depressed in tumor-bearing mice. nk activity was quite low or not detectable in unfractionated cell suspensions from the tumors 10-12 days after inoculation of virus, but activity was observed upon depletion of phagocytic and/or adherent cells. to determine whether this in situ inhibition of nk activ ... | 1981 | 6457000 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| virally induced periosteal osteogenesis in mice. | inoculation of moloney murine sarcoma virus (m-msv) into shank muscles of adult nmri mice resulted in localized sarcoma and periosteal membrane proliferation with subsequent periosteal bone formation. newly formed bone arose from outer surface of shank bones. two weeks after m-msv inoculation the width of bone cortex increased nearly 4 times. the spaces between newly formed bone ossicles were filled with bone marrow. in the later stages these bone marrow cavities were merged with medullar caviti ... | 1981 | 6783270 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| antitumor effects of doxorubicin against a virally-induced rat osteosarcoma with minimal immunosuppression. | intratibial inoculation of a moloney strain of murine sarcoma virus (msv-m) in neonatal wistar-lewis rats produced osteosarcoma in 96% of animals and resulted in a median survival of 20 days. intraperitoneal (i.p.) administration of doxorubicin (adriamycin) (1-2 mg/kg/d, on day 10-12) resulted in reduced tumor growth and prolonged median survival to 95+ and 64 days, respectively. higher dose doxorubicin (3-4 mg/kg/d, on day 10-12) caused early lethal toxicity. autopsy data revealed a characteris ... | 1980 | 6937562 |
| experimental osteosarcoma in the mouse, induced by moloney's murine sarcoma virus. | the writers report an experimental trial on the mouse, consisting in the induction of osteosarcoma by inoculation of moloney's murine sarcoma virus (msv-m) into the proximal metaphysis of the tibia. this experiment was conducted on 90 balb/c female mice aged twenty-one days and of mean weight 12.8 g. one group of animals was also given immunodepressive drugs. the tumour developed in 100 per cent of cases, producing metastases in some of the animals and resulting in death in three cases. the radi ... | 1980 | 6938501 |
| non-t-cell-mediated cytotoxicity in msv tumor-bearing mice. iii. macrophage-mediated cytotoxicity against autochthonous msv tumor-isolated target cells. | cytotoxic macrophages have been isolated from moloney sarcoma virus (msv) tumors induced in uncompromised, immunosuppressed and athymic nude mice. macrophages from compromised mice were at least as active as those from uncompromised mice when tested against the autochthonous msv target cells. although both cytolytic and cytostatic activity could be demonstrated with all tumor-derived macrophages, cytostatic and cytolytic effects could be distinguished from each other only at high effector target ... | 1980 | 6966262 |
| t lymphocyte tolerance and early appearance of virus-induced cell surface antigens in moloney-murine leukemia virus neonatally injected mice. | regression of moloney-murine sarcoma virus- (m-msv) induced sarcomas in normal adult mice is accompanied by generation of virus-specific cytotoxic t lymphocytes (ctl). however, when neonatal mice that were injected with moloney-murine leukemia virus (m-mulv carrier) were subsequently challenged as adults with m-msv, the sarcomas did not regress nor did they generate ctl. this failure to produce ctl cannot be ascribed to nonspecific immunodepressive effects or to suppressor cell generation since ... | 1981 | 6969741 |
| progressing moloney sarcoma virus (m-msv) induced tumors: effect of host's immunomanipulation. | | 1980 | 6970620 |
| t cell recognition of moloney sarcoma virus proteins. ii. phenotypes of the different lymphocyte subpopulations producing and responding to blastogenic factors and their relative frequencies during tumor regression. | the characteristics of the blastogenic response of splenic lymphocytes from molv/msv immune mice was examined. splenic lymphocytes from immune mice proliferate in vitro in response to the major virion envelope glycoprotein, gp70. associated with this response is production of blastogenic factors that induce the proliferation of nylon wool-purified lymphocytes from either normal or immune mice. the phenotype of antigen-specific lymphocytes essential for the production of blastogenic factors was f ... | 1981 | 6972414 |
| quantitation and clonal isolation of cytolytic t lymphocyte precursors selectively infiltrating murine sarcoma virus-induced tumors. | a limiting dilution mixed leukocyte-tumor cell microculture system was used to quantitate cytolytic t lymphocytes and their precursors (ctl-p), which infiltrate tumors induced by injection of moloney sarcoma-leukemia virus (msv-molv) complex into c57bl/6 mice. leukocyte populations obtained from tumors collected on day 10 after virus injection were found to contain significantly higher frequencies of operationally defined (tumor-specific) ctl-p than either peripheral blood leukocytes (pbl) or sp ... | 1981 | 6973602 |
| 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 |
| 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 |
| 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 |
| characterization of the presumptive sarcoma cells in primary msv tumors. | presumptive sarcoma cells have been isolated from primary msv tumors induced in normal, immunosuppressed (alg) and athymic nude mice. these cells were atypical in appearance, induced tumors in secondary hosts and expressed the viral antigens gp70, p30 and p12. in vitro growth characteristics of the msv cells were tested in a variety of assays defining cell transformation. none of these indicated that the virus-positive cells were transformed. sex chromosome marker studies were carried out to det ... | 1980 | 6989765 |
| in vitro demonstration of in situ autologous tumour-cell cytotoxicity in msv-induced tumours in a/sn mice. | moloney sarcoma-virus (msv)-induced tumours in a/sn mice have been dispersed with collagenase and dnase 8-15 days after virus inoculation, and both "sarcoma" and inflammatory cells separated by sedimentation velocity and adherence techniques. the isolated "sarcoma" cells had the morphological characteristics of atypical cells (i.e. cytoplasmic blebbing, vacuolization and prominent nucleoli) and were easily adapted to in vitro growth. as few as 2 x 10(3) of these cells inoculated i.m. produced ne ... | 1981 | 7053211 |
| 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 |
| neoplastic transformation of rabbit cells by murine sarcoma viruses. | neoplastic transformation of rabbit cells by kirsten murine sarcoma virus (ki-msv), the ki-msv pseudotype of baboon endogenous virus (ki-msv[baev]) and the moloney-msv pseudotype of feline leukemia virus (m-msv[felv]) is reported. rabbit cells can be readily transformed by ki-msv, ki-msv(baev) and m-msv(felv). rabbit cells transformed by ki-msv and m-msv(felv) were found to be virus producers, whereas those transformed by ki-msv(baev) were nonproducers (np). the np cells were obtained by simply ... | 1982 | 7129681 |
| 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 |