| revertants of mouse cells transformed by murine sarcoma virus: flat variants without a rescuable sarcoma virus from a clone of balb/3t3 transformed by kirsten msv. | | 1974 | 4140213 |
| sarcoma-virus-related rna sequences in normal rat cells. | a rat type c virus spontaneously activated from the nrk (normal rat kidney) cell line was found to have two major size classes of viral rna subunits sedimenting at 35 and 30 s. virus-producing cells contained both rna species, while normal "virus-free" rat cells contained primarily virus-specific 30s rna species. a dna transcript, specific for kirsten sarcoma virus, prepared from virus activated in nonproducer balb/c cells originally transformed by kirsten sarcoma virus and rendered specific for ... | 1974 | 4140505 |
| [proceedings: small molecular weight rna from a murine oncornavius: 85 rna from murine sarcoma virus (msv-m-mlv)]. | | 1974 | 4141442 |
| transformation of a cloned renal epithelial cell line by moloney murine sarcoma virus (m-msv). | | 1970 | 4142389 |
| intracranial tumours in rats injected intracerebrally with murine sarcoma virus (msv), moloney's strain. preliminary report. | | 1966 | 4293629 |
| [ultrastructural studies of a murine sarcoma virus (msv)]. | | 1967 | 4295344 |
| the differential action of neonatal thymectomy in mice infected with murine sarcoma virus-harvey (msv-h). | | 1968 | 4302084 |
| susceptibility of praomys (mastomys) natalensis to the murine sarcoma virus-harvey (msv-h). | | 1968 | 4302086 |
| replication of murine sarcoma virus-harvey (msv-h) in tissue cultures of virus-induced sarcomas. | | 1968 | 4304098 |
| enhancing effect of the murine sarcoma virus (msv) on the replication of the mouse hepatitis virus (mhv) in vitro. | | 1969 | 4306053 |
| [antigenic properties of a "graffi" pseudotype of the murine rhabdomyosarcoma virus (msv)]. | | 1969 | 4306855 |
| [the role of immunity in the rejection of tumours induced by the msv virus. the effect of antithymocyte serums]. | | 1968 | 4307754 |
| biological activity and separation of a leukaemogenic virus from murine sarcoma virus-harvey (msv-h). | | 1969 | 4310639 |
| murine sarcoma and leukemia viruses: assay using clonal lines of contact-inhibited mouse cells. | a continuous cell line of highly contact-inhibited cells (nih/3t3) has been developed from nih swiss mouse embryo cultures. its growth properties are similar to those of 3t3 and balb/3t3. although 3t3 is relatively insensitive to focus formation by murine sarcoma viruses, cloned lines of both nih/3t3 and balb/3t3 have been isolated that are highly sensitive to sarcoma virus focus formation and leukemia virus growth. the sensitivity and specificity are comparable to those found with primary embry ... | 1969 | 4311790 |
| trans-species rescue of defective genomes of murine sarcoma virus from hamster tumor cells with helper feline leukemia virus. | this report describes a trans-species rescue of defective msv genome with helper leukemia virus derived from cats. this rescue was achieved by in vitro co-cultivation of hamster tumor cells with feline embryo cells in the presence of helper feline leukemia virus (felv), or by inoculation of tumor cells into felv-infected newborn cats. the rescued focus-forming viruses produced foci in feline embryo cultures but not in cultures of mouse, rat, and hamster species. one isolate was tested and found ... | 1970 | 4313195 |
| host-range restrictions of murine leukemia viruses in mouse embryo cell cultures. | murine leukemia virus strains fall into three categories with respect to their ability to propagate in cells of national institutes of health (nih) swiss and balb/c mouse embryos. cultures of nih cells are 100- to 1,000-fold more sensitive to "n-tropic" strains than balb/c cell cultures, but are 30- to 100-fold less sensitive to "b-tropic" strains. some virus strains (dually tropic or "nb-tropic") propagate equally well in both cells. m-msv pseudotypes show the host-range characteristics of the ... | 1970 | 4317349 |
| complementary nuclear rna's of murine sarcoma-leukemia virus complex in transformed cells. | the high molecular weight rna (s(20,w) = 69s) of murine sarcomaleukemia virus (msv-mlv) complex dissociated into 37s subunits when heated to 95 degrees c for 2 minutes. specific annealing tests revealed that the viral rna had complementarity with two heterogeneous rna species from the nuclei of cells (78 a1) transformed by and chronically infected with this virus complex. the two nuclear rna species that hybridized with the viral rna had sedimentation constants ranging from 31-36s and 18-22s, re ... | 1969 | 4318348 |
| [transplantable osteosarcoma caused by the "moloney strain of murine sarcoma virus (m-msv)" in osborne-mendel rats]. | | 1970 | 4319060 |
| immunity to murine sarcoma virus (msv)-induced tumors demonstrated by "in vivo" elimination of 51-chromium labeled tumor cells. | | 1970 | 4322224 |
| nucleic acid and proteins isolated from a strain of murine sarcoma virus (msv-o). | | 1971 | 4327113 |
| isolation of a rat-tropic helper virus from m-msv-o stocks. | | 1971 | 4328487 |
| rescue of murine sarcoma virus from a sarcoma-positive leukemia-negative cell line: requirement for replicating leukemia virus. | the nature of murine sarcoma virus (msv) "defectiveness" was investigated by employing an msv-transformed mouse 3t3 cell line which releases noninfectious virus-like particles. rescue kinetics of msv, observed after murine leukemia virus (mulv) superinfection of these "sarcoma-positive leukemia-negative (s + l -)" mouse 3t3 cells, consisted of a 9- to 12-hr eclipse period followed by simultaneous release of both msv and mulv with no evidence for release of infectious msv prior to the production ... | 1971 | 4332138 |
| clonal isolation of murine sarcoma virus (msv): characterization of virus produced from transformed cells. | | 1971 | 4332977 |
| the murine sarcoma virus (msv). | | 1971 | 4333859 |
| deficiency of viral ribonucleic acid-dependent deoxyribonucleic acid polymerase in noninfectious virus-like particles released from murine sarcoma virus-transformed hamster cells. | virions from hamster cells transformed by a new strain of murine sarcoma virus (msv) appear to represent a form of msv deficient in one or more of the viral components necessary for infectivity. both the noninfectious virions and the sarcoma virus-transformed cells, which have no detectable replicating leukemia helper virus of either murine or hamster origin, are deficient in viral-type ribonucleic acid (rna)-dependent deoxyribonucleic acid (dna) polymerase activity (i.e., reverse transcriptase ... | 1972 | 4335663 |
| replication of radiation-induced murine leukemia virus in normal and transformed mouse cells. | autonomous radiation-induced leukemia virus (radlv) replication could be detected in mouse 3t3 cells by the development of interference with murine sarcoma virus (msv), the appearance of covert helper activity for defective msv, and by the induction of cytopathic effect type foci in msv-transformed, leukemia virus-negative (s+l-) cells. a chronic infection of either 3t3 or s+l- cells with radlv could be established. both radlv infectivity and helper activity were demonstrated in the same peak at ... | 1972 | 4335664 |
| immunological studies on viral polypeptide synthesis in cells replicating murine sarcoma-leukemia virus. | antibodies to disrupted murine sarcoma-leukemia virus (msv[mlv]) were used to study the synthesis of viral polypeptides in the transformed, virus-producing rat cell line 78a1. when cultures were labeled for 10 min with radioactive amino acids, about 9% of the total labeled proteins were precipitated with antiserum against purified msv(mlv), and 3 to 4% were precipitated with the same antiserum after it had been absorbed with an extract from uninfected rat cells. the difference is due to the pres ... | 1972 | 4342052 |
| transformation of rat liver cells with chicken sarcoma virus b77 and murine sarcoma virus. | rat liver cells in vitro were transformed with chicken sarcoma virus b77, giving rl(b77) cells, and with murine sarcoma virus (harvey), giving rl(msv) cells. rat liver cells transformed spontaneously in vitro were designated rl cells. in addition, the rl(msv) cell line was adapted for growth in culture fluid containing 25 mug of 5-bromodeoxyuridine per ml. all cell lines were tumorigenic in 1-wk-old rats. the number of cells needed for induction of tumor growth was 1,000-fold higher in the case ... | 1973 | 4347422 |
| infectivity and rna patterns as functions of high- and low-dilution passage of murine sarcoma-leukemia virus: evidence for autointerference within an oncornavirus population. | heterogeneity of buoyant density and rna content of virions of moloney murine leukemia-sarcoma complex [msv (mlv)] was the result of passage at low dilution. heterogeneous stocks revealed two major rna components in the population, with the smaller component, apparent mol wt 4 x 10(6) to 5 x 10(6), becoming predominant upon serial passage at low dilution. concomitantly, infectivity titers of both mlv and msv decreased upon serial passage at low dilution. msv (mlv) passaged at high dilution retai ... | 1973 | 4350709 |
| mutants of nonproducer cell lines transformed by murine sarcoma viruses. i. induction, isolation, particle production, and tumorigenicity. | a variety of cell mutants were obtained by a single 5'-bromodeoxyuridine (brdu) treatment of an nonproducer (np) cell line transformed by the kirsten strain of murine sarcoma virus (ki-msv). isolation procedures of these cell see pdf for structure mutants are described. the cell mutants obtained were classified by tumorigenic potential and shedding of type c virus particles. the cell mutants were classified into four groups: (a) tumorigenic, without particles; (b) tumorigenic, with type c partic ... | 1973 | 4352583 |
| dna polymerase of murine sarcoma-leukemia virus: lack of detectable rnase h and low activity with viral rna and natural dna templates. | kirsten murine sarcoma-leukemia virus (ki-msv[mlv]) was found to contain less rnase h per unit of viral dna polymerase than avian rous sarcoma virus (rsv). upon purification by chromatography on sephadex g-200 and subsequent glycerol gradient sedimentation the avian dna polymerase was obtained in association with a constant amount of rnase h. by contrast, equally purified dna polymerase of ki-msv(mlv) and moloney [mo-msv(mlv)] lacked detectable rnase h if assayed with two homopolymer and phage f ... | 1973 | 4357518 |
| ribonucleic acid components of murine sarcoma and leukemia viruses. | defective kirsten murine sarcoma virus was present as leukemia virus pseudotype [ki-msv(mlv)] in a 10- to 100-fold excess over its helper, kirsten murine leukemia virus (ki-mlv), when the two viruses were propagated in an nrk rat cell line. the s(omega,20) of the fastsedimenting rna complex of ki-mlv and of ki-msv-(mlv) was 62 s and 55 s, respectively. gel electrophoresis in buffered aqueous or formamide solution of the dissociated 62s rna complex of ki-mlv showed a single major peak of molecula ... | 1973 | 4357879 |
| murine virus-induced proteins synthesized by hamster tumor cells transformed by, but not producing, murine sarcoma virus. | the 8303 hamster tumor cells transformed by moloney strain of murine sarcoma virus (m-msv), but which do not produce virus, do contain murine virus-induced proteins. the virus-induced proteins within the cell were identified either as free proteins or in association with membranous material, including the plasma membrane. in addition, some were excreted by the 8303 hamster tumor cells into the growth medium. most virus-induced proteins were larger than 68,000 daltons, and they did not dissociate ... | 1974 | 4359302 |
| control of gene expression in rat cells transformed by a cold-sensitive murine sarcoma virus (msv) mutant. | | 1973 | 4359760 |
| properties of noninfectious and transforming viruses released by murine sarcoma virus-induced hamster tumor cells. | the cell culture lines htg2 and htg3 were established from a transplantable hamster tumor induced by a murine sarcoma virus (strain gz-msv) after 17 and 60 in vivo passages, respectively. the viruses released by these two cell lines markedly differ in morphology, antigenic composition, infectivity, transforming ability, and enzymatic activity. htg2 virions contained the sarcoma genome but were noninfectious for mouse and hamster cells (s+h-virus). htg3 virions transformed hamster but not mouse c ... | 1973 | 4359960 |
| recovery of the genome of murine sarcoma virus (msv) after infection of cells with nuclear dna from msv transformed non-virus producing cells. | | 1973 | 4360277 |
| comparative in vitro studies on effector cell diversity in the cellular immune response to murine sarcoma virus (msv)-induced tumors in mice. | | 1974 | 4360862 |
| non-infectious intracisternal a-type particles in a sarcoma-positive, leukemia-negative mouse cell line transformed by murine sarcoma virus (msv). | | 1973 | 4362933 |
| the histogenesis of tumours induced in golden hamsters by murine sarcoma virus-harvey (msv-h). | | 1973 | 4364799 |
| isolation and characterization of revertant cell lines. vi. susceptibility of revertants to retransformation by simian virus 40 and murine sarcoma virus. | the susceptibility of two classes of revertants of simian virus 40 (sv40)-transformed 3t3 cells to retransformation by sv40 or murine sarcoma virus (msv) was studied. both serum-sensitive and density-sensitive revertants are not retransformable by sv40. msv can transform both types of revertants. the msv-transformed revertants grow to high cell densities and form colonies when suspended in semi-solid methylcellulose medium, but are unable to grow in 1% calf serum. the msv-transformed revertants ... | 1974 | 4372404 |
| immunological responsiveness in rats infected with the soehner-dmochowski murine sarcoma virus (msv-sd). | | 1974 | 4372740 |
| tumour-associated transplantation antigens of neoplasms induced by a naturally occurring murine sarcoma virus (fbj-msv). | | 1973 | 4516007 |
| leukemic mitochondria. i. acute myeloblastic leukemia. | quantitative and qualitative electron microscopic studies were performed on the mitochondria of leukemic myeloblasts in 3 patients with myeloblastic leukemia and in 3 patients with myelomonoblastic leukemia. in addition, to confirm the presence of virus-like particles within mitochondria and better understand the interaction between the virus and mitochondrion, a rat embryo tissue culture infected with msv-mlv (moloney sarcoma virus-moloney leukemia virus) was selected for detailed electron micr ... | 1974 | 4520328 |
| immunity to murine sarcoma virus induced tumours. 3. analysis of the cell populations involved in protection from lethal tumour progression of sublethally irradiated, msv inoculated, mice. | | 1974 | 4547542 |
| antigenic properties of murine sarcoma virus-transformed balb-3t3 nonproducer cells. | the isolation of clonal lines of murine sarcoma virus-transformed, non-producer balb/3t3 cells has provided a model system for determining whether rna tumor virus-transformed cells possess virus-specific transplantation antigens. msv nonproducer cells (k-234) were clonally derived from an inbred mouse cell line, balb/3t3. a parallel virus-producing cell line was obtained by infection of the msv nonproducer cells with rauscher leukemia virus. k-234 was much more tumorigenic than k-234(r). preimmu ... | 1972 | 4550769 |
| proceedings: "wild" type antigens of sarcomata induced by a natural amine sarcoma virus (msv-fbj). | | 1974 | 4595171 |
| evidence of suppressor cell activity in spleens of mice bearing primary tumors induced by moloney sarcoma virus. | spleens from moloney sarcoma virus (msv) tumor-bearing c57bl/6n mice contained four times the normal number of mononuclear cells and displayed a markedly elevated "spontaneous" (mitogen-independent) dna synthesis on a per cell basis. the number of macrophages were increased three-fold while there was a slight reduction in the percentage of t lymphocytes. the phytohemagglutinin (pha) response on a per cell basis of spleens from tumor-bearing mice was decreased about 90% when compared with normal ... | 1974 | 4598016 |
| tumor induction by murine sarcoma virus in akr and c58 mice. reduction of tumor regression associated with appearance of gross leukemia virus pseudotypes. | adult akr and c58 mice injected intramuscularly with murine sarcoma virus, moloney isolate (m-msv), developed high incidence of nonregressing local tumors. histologically, these tumors revealed the typical pleomorphism of m-msv sarcomas; in some cases, however, neoplastic tissue showed a nodular or diffuse growth of monomorphic myoblastlike cells, reminiscent of clonal aggregates. no depression of immune reactivity was found in m-msv-injected mice as evaluated by direct hemolytic plaque-forming ... | 1974 | 4608945 |
| studies on tumorigenicity of rat bone tumor virus. (sd-msv-m) in mice, rats and hamsters. | | 1972 | 4657994 |
| the lymphocyte response to primary moloney sarcoma virus tumors in balb-c mice. definition of the active subpopulations at different times after infection. | adult balb/c mice were injected with moloney sarcoma virus (msv) after which the animals' lymphocytes were examined for activity against moloney leukemia virus (mlv) antigen-bearing target cells at 5-day intervals for 30 days. lymphocytes from these animals and appropriately matched controls were fractionated into b cell-deficient (primarily t cells) and t cell-deficient (primarily b cells) subpopulations. macrophages were removed using iron powder and magnetism. the unfractionated lymphocytes, ... | 1973 | 4709269 |
| prevention of murine sarcoma virus oncogenesis in offspring of immunized female mice. | | 1973 | 4795530 |
| antigens of tumours induced by naturally occurring murine sarcoma virus (msv-fbj). i. detection of group and type specific antigens by complement fixation. | | 1974 | 4820943 |
| intracellular viral rna species in mouse cells nonproductively transformed by the murine sarcoma virus. | the size and quantity of virus-specific rna in five non-virus-producing mouse cells transformed by the moloney isolate of murine sarcoma virus (msv) was determined. hybridization of rna from transformed cells with the [(3)h]dna product of the rna-directed dna polymerase of the murine sarcoma-leukemia virus was used to detect and quantitate virus-specific rna. the amount of virus-specific rna in non-virus-producing cells was less than one-sixth of that found in virus-producing cells. a striking c ... | 1974 | 4852536 |
| induction of virus ribonucleic acids in non-permissive msv-if+ cells infected with ndv. | | 1974 | 4855927 |
| lack of distinctive surface antigen on cells transformed by murine sarcoma virus. | some murine sarcoma virus (msv)-transformed mouse 3t3 cells contain the msv genome in the absence of infectious helper murine leukemia virus (mulv) and msv production. these cells, designated s+l- (sarcoma positive, leukemia negative), were analyzed for the presence of a possible msv-determined membrane antigen by the mixed hemadsorption test and in vitro lymphocyte cytotoxicity assay. two different serological approaches were used: (a) isoantibody-free sera were obtained by immunizing with msv ... | 1972 | 5043415 |
| a spleen weight assay for murine sarcoma virus harvey (msv-h). | | 1969 | 5346883 |
| effectiveness of therapy with a multistranded synthetic polynucleotide complex against a murine sarcoma virus. | a known interferon stimulator, polyriboinosinic acid:polyribocytidylic acid (ri:rc), was shown to have a protective effect against a highly tumorigenic variant of the murine sarcoma virus (moloney) designated as (msv-pv). mice treated intraperitoneally with different regimens of ri:rc survived significantly longer than untreated controls. the treatment was effective whether the infection with msv-pv was intraperitoneal or intracerebral. the antiviral effectiveness of ri:rc was demonstrated by ma ... | 1969 | 5373679 |
| pathological effects in hamsters of murine sarcoma virus (msv harvey). | | 1970 | 5420785 |
| the role of dna synthesis in virus replication and the morphological transformation of normal mouse embryo cells by msv (moloney). | | 1970 | 5466002 |
| studies on hypodiploid and hyperdiploid virus-induced mouse leukemias and the vertical transmission of msv-moloney. | | 1970 | 5538519 |
| transformation by murine sarcoma virus: fixation (deoxyribonucleic acid synthesis) and development. | transformation of rat embryo cells by murine sarcoma virus (msv) was contingent upon synthesis of deoxyribonucleic acid (dna) during the first 12 hr of infection. inhibition of dna synthesis by thymidine (20 mm) or cytosine arabinoside (0.1 mm) resulted in the protection of cells from transformation by msv. transient suppression of dna synthesis prior to infection or after a 12-hr delay had little effect on subsequent transformation, emphasizing the critical time period in in which dna synthesis ... | 1968 | 5701824 |
| biological and serological properties of viral particles from a nonproducer rat neoplasm induced by murine sarcoma virus (moloney). | the viral particles present in a nonproducer rat neoplasm induced by murine sarcoma virus (msv) moloney isolate, as detected by electron microscopy, were found to be biologically active on normal kidney cells of random-bred osborne-mendel rats. the virus is designated here as msv (0). msv (0) differs from other pseudotypes of msv in its host range, antigenicity, and interference pattern. | 1968 | 5725318 |
| rescue in vivo in adult mice of murine sarcoma virus (msv) from a nonproducer rat neoplasm. | | 1969 | 5791815 |
| plasmacytomas occurring in the bones of rats injected intracerebrally with murine sarcoma virus (msv), moloney' strain. preliminary report. | | 1966 | 5985024 |
| 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 |
| 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 |
| type i and type ii interferons: differential antiviral actions in transformed cells. | in transformed mouse embryo cells, type ii interferon had much less antiviral activity than type i interferon. in non-transformed cells, the two interferons had similar high activity, reversal of the phenotype of moloney sarcoma virus (msv) transformed cells by sodium butyrate restored their sensitivity to the antiviral action of type ii interferon. additional evidence for a role of the cytoskeletal network in the action of type ii interferon is that its antiviral effect is reduced by cytochalas ... | 1980 | 6155431 |
| restriction of the rat-specific rns sequences of ki-msv to the nucleus of dibutyryl cyclic amp-treated k-a31 cells. | the treatment of oncogenically transformed cells in culture, with dibutyryl cyclic amp (camp) has, in many cases, resulted in a general phenotypic change towards the normal state. a virus-specific gene product(s) is responsible for the transformation of cells by sarcoma viruses and it has been suggested that the src gene product may act through the alteration of camp levels. with these premises we have studied the effects of dibutyryl camp on cell growth and virus genome expression in a kirsten ... | 1980 | 6161990 |
| interferon effect on collagen and fibronectin distribution in the extracellular matrix of murine sarcoma virus-transformed cells. | the transformation of murine balb/c embryonic fibroblasts by murine sarcoma virus, moloney strain, followed by prolonged treatment with murine interferon, resulted in the appearance of a new cell population (msv-if+). these msv-if+ cells are characterized by the recovery of a normal phenotype, contact inhibition, and lack of colony formation in agar. this phenotypic change of the msv-if+ cells is associated to the neosynthesis of a dense fibrous matrix beyond the cell periphery. ultrastructural ... | 1981 | 6167350 |
| further studies on anti-tumor activity of adenovirus fibre protein on murine sarcoma tumours. | the present study demonstrates that subcutaneous injection of purified adenovirus 12 fibre protein (fp) to 4-week-old balb/c mice, 4, 2 and 1 day(s) before intramuscular injection of murine sarcoma virus (msv-m) or 2 and 1 day before and 1 day after msv-m injection causes significant inhibition of tumour growth (p less than 0.001). the evidence suggests that treatment with fp leading to tumour inhibition is due to neither an interferon mechanism nor to inhibition of virus multiplication of fp in ... | 1981 | 6169787 |
| complete nucleotide sequence and organization of the moloney murine sarcoma virus genome. | the complete nucleotide sequence of a mammalian transforming retrovirus. moloney murine sarcoma virus, has been determined. msv, recombinant virus derived of helper viral and cellular sequences, possesses termini resembling prokaryotic transposable elements. the viral genome has the coding capacity for the moloney murine leukemia virus gag gene product and contains large deletions in pol and env genes. a large open reading frame encompassing its cell-derived sequences codes for its putative tran ... | 1981 | 6170110 |
| rapid syncytium formation induced by moloney murine sarcoma virus in 3t3/nih cells and its delay by mouse interferon. | moloney murine sarcoma virus (msv) clone 124 was found to induce rapid syncytium formation upon infection of 3t3/nih at a high multiplicity of infection. this effect became apparent, by light microscopy, within 1 to 2 hours, whereas by scanning electron microscopy, clusters of 4 to 25 cells were seen in their initial steps of syncytium formation within 20 to 30 minutes after virus addition. it appeared that the cell fusion was initiated by connection between the cells through virus bound to thei ... | 1981 | 6174107 |
| use of hybridoma-resident variant cell lines to study h-2db/fmr-specific cytotoxic t cells. | an h-2db heterozygous tumor cell line and a variant subclone bearing a mutant gene product were used to analyze the h-2db specificity of cytotoxic t lymphocytes (ctl) generated during a moloney murine sarcoma virus (msv) infection. when the mutant cells were used as targets for msv-specific ctl, the amount of cell lysis, compared with that seen with the nonmutant parental cells, was drastically decreased. however, cells of the mutant clones remained susceptible to allogeneic ctl specific for the ... | 1981 | 6174439 |
| effect of mouse interferon on cell transformation and virus production in rat cells exogenously infected with moloney murine sarcoma and leukemia viruses. | foci of transformed cells, produced by msv(124), appeared to result only from the primary infection, since this virus stock yielded a virus-nonproducing infection. on the other hand, the majority of foci scored in msv/mlv-infected cultures, were generated by multiple secondary infections with the progenies of the primary infection. mouse interferon (if) was highly inhibitory for cell transformation by both virus stocks. however, this inhibition was apparent in msv(124) infected cultures only if ... | 1982 | 6177647 |
| reorganization of the cytoskeleton by interferon in msv-transformed cells. | beta and gamma interferons were found to enhance the organization of microfilaments, intermediate filaments, and fibronectin in the murine sarcoma virus (msv)-transformed cell line. furthermore, both interferons increased the number of intermediate-type junctions. sodium butyrate was also found to act in a similar way and, when associated with interferon, an additive effect was observed. in the cell line, cultured for many passages in the presence of beta interferon (msv-if+), the cytoskeletal n ... | 1981 | 6180063 |
| viral-versus non-viral-induced yolk sac tumors in the rat. | yolk sac tumors were induced in fetectomized rats by displacement of the visceral yolk sac outside the uterus with or without injection of murine sarcoma virus (msv) into the placenta. some of the animals were immunized with msv prior to surgery. the biological, morphological and immunological characteristics of the tumors which develop in animals either injected or not with virus are compared. the results indicate that msv inoculation into the placenta increases the tumor incidence, shortens th ... | 1982 | 6181488 |
| [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 |
| 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 |
| t cell-mediated immunity to oncornavirus-induced tumors. i. ly phenotype of precursor and effector cytolytic t lymphocytes. | regression of tumor induced by murine sarcoma virus (msv) is accompanied by the formation of specific cytolytic t lymphocytes (ctl). selection of t-cells sets by ly phenotype determination allows separation of t sets involved in the cytolytic reaction. after msv inoculation we demonstrate that a) ly123+ cells contain precursors of ctl, b) direct cytolysis is mainly mediated by ly23 cells, 3) cytolytic memory is divisible into "early" memory, carried by ly23 cells, and "late" memory, which revert ... | 1980 | 6243332 |
| properties of a normal mouse cell dna sequence (sarc) homologous to the src sequence of moloney sarcoma virus. | a 15.0-kilobase (kb) eco ri dna fragment from normal mouse balb/c genomic dna that contains sequences (sarc) homologous to the acquired cell sequences (src) of moloney sarcoma virus (msv) has been cloned in phage lambda. the sarc region (1.2 to 1.3 kb) of the 15.0-kb cell fragment is indistinguishable from the src region of two isolates of msv as judged by heteroduplex and restriction endonuclease analyses. the cellular sequences flanking sarc show no homology to other msv sequences. whereas clo ... | 1980 | 6243788 |
| envelope properties of murine sarcoma virus-zero (msv-z). | | 1980 | 6243828 |
| localization of the src gene product of the harvey strain of msv to plasma membrane of transformed cells by electron microscopic immunocytochemistry. | using electron microscopic immunocytochemistry, we have investigated the intracellular location of the src protein (p21) in cells transformed by the harvey strain of murine sarcoma virus (ha-msv). antibodies to p21 were derived from tumor-bearing rats inoculated with ha-nrk cells. the distribution of p21 in intracellular sites in mdck dog cells transformed by ha-msv was examined and quantified using a recently developed immunocytochemical technique. more than 95% of p21 was localized to the inne ... | 1980 | 6247068 |
| double transformation of indian muntjac cells by avian and murine sarcoma viruses. | avian sarcoma virus-transformed indian muntjac cells, sr-mm-1, formed foci by murine sarcoma-xenotropic murine leukemia virus complex [msv(x-mulv)] superinfection. the response of sr-mm-1 and parental normal indian muntjac mm-2k cells to msv(x-mulv) infection was compared. focus formation by msv(x-mulv) followed two-hit kinetics in mm-2k, but one-hit kinetics in sr-mm-1 cells. msv(x-mulv)-infected sr-mm-1 cells formed larger colonies than uninfected sr-mm-1 cells in soft agar, while no colony wa ... | 1980 | 6247523 |
| 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 |
| 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 |
| 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 |