Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Major virion low-molecular-weight polypeptides were isolated from the Moloney strain of murine leukemia virus (type C) by agarose chromatography in 6M guanidine hydrochloride and were shown to have molecular weights of 15,000 (p15), 12,000 (p12), and 10,000 (p10) by their elution volumes and by their relative mobilities in sodium dodecyl sulfate-polyacrylamide gels. Each polypeptide could be iodinated and employed in double antibody radioimmunoassay procedures. All three polypeptides demonstrated a high degree of type-specificity in serologic immunoprecipitation analysis and in corresponding competition immunoassays. The p15 was immunologically distinct from other viron polypeptides including p12 and p10; the p12 and p10 were highly related to each other but not to other virion polypeptides and were even more type-specific than the p15 in serologic tests. Competition immunoassays with p15 and p10 indicate that the Moloney strain of MuLV is only a distant relative of the Friend-Rauscher group. The combined use of the Kirsten and Moloney low-molecular-weight polypeptide immunoassays suggest that xenotropic viruses constitute yet another group(s) of murine leukemia virus with distinct type-specific antigens, further expanding an already heterogeneous group of mouse type C viruses.
 ...
PMID:Serological studies with low-molecular-weight polypeptides from the Moloney strain of murine leukemia virus. 4 41

Revistin, a substance that strongly inhibits the reverse transcriptase activity of murine leukemia virus in our screening system, was obtained from a cultured broth of a soil streptomyces which was closely related to Streptomyces filipinensis. The assay method for the activity was based on the inhibition by a test material of the incorporation of 3H-dTMP into DNA synthesized by the reverse transcriptase of an oncogenic RNA virus. Crude revistin was isolated by serial procedures of salting out with ammonium sulfate and precipitation with cetylpyridinium chloride. The crude material showed neither antibacterial nor antifungal activity. It exhibited against splenomegaly in mice caused by Rauscher leukemia virus infection.
 ...
PMID:Revistin found by screening for inhibitors of reverse transcriptase of an oncogenic virus. 5 48

Sera from normal (C57BL/6XC3H/Anf)F1(B6C3F1) mice reacted with several biologically distinct murine leukemia virus(es) (MuLV) by radioimmune precipitation assays with the use of purified tritiated leucine-labeled virus. The reactivities of this natural antibody to viral envelope antigens of two laboratory strains (Rauscher and Moloney) and two endogenous mouse C-type viruses (AKR and BALB:virus-2) were further analyzed and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Similar patterns of antibody reactivities to AKR MuLV and the two member viruses of the Friend-Moloney-Rauscher group were found. Three major antigenic determinants of the virus envelope, gp71, gp43, and p15, were recognized by and precipitated natural antibody. In all viruses examined, normal B6C3F1 sera precipitated comparable amounts of gp71 and gp43. However, compared with the other viruses, the amount of p15 (relative to the glycoproteins) precipitating from BALB:virus-2 was significantly lower. This appears to be due to a lesser amount of p15 on the xenotropic virus. While heterologous antisera to purified gp71 and p15 of MuLV reacted to a certain degree with rhabdomyosarcoma virus 114 and rat leukemia virus, natural mouse antibody did not. These results suggest that MuLV have common antigenic determinants recognized by natural antibody, and that the reactivities of natural antibody in an autogenous immune response are restrictive in contrast to immune antibody produced in a heterologous host.
 ...
PMID:Autogenous immunity to endogenous RNA tumor virus: reactivity of natural immune sera to antigenic determinants of several biologically distinct murine leukemia viruses. 5 18

A cytoplasmic particulate fraction from human leukemic cells has been shown to contain reverse transcriptase and its associated high-molecular weight RHA template. We attempted to detect the reverse-transcriptase-template complex in morphologically normal peripheral blood leukocytes from patients with acute leukemia in complete remission. Our assay system consisted of a velocity glycerol gradient and cesium sulfate equilibrium gradient analysis of the endogenous reverse transcriptase reaction product. Three of nine patients in remission had positive reactions determined by glycerol gradient analysis, and eight of 10 patients in remission had positive reactions by cesium sulfate gradient analysis. We were unable to detect the template complex in leukocytes of normal persons. Thus, normal-appearing leukocytes in the peripheral blood of some leukemia patients in remission seem to retain a number of biochemical characteristics, possibly viral related, associated with leukemic cells.
 ...
PMID:Reverse transcriptase in leukocytes of leukemic patients in remission. 5 87

The alpha beta DNA polymerase of avian myeloblastosis virus was treated with dimethyl sulfoxide to dissociate the enzyme subunits. The dimethyl sulfoxide treated enzymes were passed over phosphocellulose to purify and characterize the dissociated subunits as well as to remove the dimethyl sulfoxide. RNA-directed DNA polymerase, RNase H, and nucleic acid-binding activity were monitored, as well as the subunit structure (on sodium dodecyl sulfate-polyacrylamide gels) of the various enzyme species obtained. With 30% dimethyl sulfoxide, the majority of DNA polymerase and RNase H activities as well as the alpha subunit were displaced from the alpha beta DNA polymerase position on phosphocellulose (0.23 M potassium phosphate) to the alpha DNA polymerase position (0.1 M). The association of DNA polymerase and RNase H activities with the alpha subunit suggests that alpha is the enzymatically active subunit in alpha beta. In addition to alpha DNA polymerase, a minor polymerase species eluted from phosphocellulose at 0.4 M potassium phosphate. The dissociated beta subunit eluted from phosphocellulose at a wide range of salt concentrations (0.28 to 0.5 M potassium phosphate). The dissociated beta subunit bound 3H-labeled murine leukemia virus RNA and [3H]poly(dT)-poly(dA) approximately 20-fold more avidly than alpha DNA polymerase alone. In contrast to the results with the alpha subunit, there was no correlation between DNA polymerase and RNase H activity profiles and the elution profile of the beta subunit from phosphocellulose. These observations suggest the beta subunit is either enzymatically inactive or possesses limited DNA polymerase and RNase H activity when compared with the alpha subunit.
 ...
PMID:Dissociation of alpha beta DNA polymerase of avian myeloblastosis virus by dimethyl sulfoxide. 5 61

An alloantiserum was prepared in a strain 13 guinea pig against the GH line of the strain 2 guinea pig L2C leukemia. This serum contained antibodies to both IgM and Ia molecules. After absorption with normal spleen cells from a strain 2 guinea pig, this antiserum no longer reacted with strain 2 cells, but detected idiotypes on the IgM molecules of the L2C leukemia. These idiotypes were on the same IgM molecules detected by a xenogeneic sheep anti-L2C Fab mu antiserum. As assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the idiotype-bearing IgM molecules were synthesized by the cell, composed of normal sized mu and light chains, appeared on the cell surface as monomeric IgM, and were the only immunoglobulin molecules present on the cell. Although the alloantiserum potentially contained antibodies to unique Ia idiotypic determinants, none were found. Furthermore, the anti-IgM idiotype antisera did not react with any Ia-like molecules.
 ...
PMID:Mutant lines of guinea pig L2C leukemia. III. The reaction of an alloantiserum detecting idiotypic determinants on a clonally derived guinea pig B cell leukemia with IgM and Ia molecules. 6 99

The major internal polypeptide of the bovine leukemia virus (BLV) was purified to homogeneity with the use of gel filtration and affinity chromatography. Like previous results, the protein had a molecular weight of 25,000 daltons as determined by electrophoresis in polyacrylamide gels with sodium dodecyl sulfate. More than 90% of the 125I-labeled protein was precipitated by bovine sera that reacted in immunofluorescence tests with acetone-fixed BLV-infected cells. In contrast, minimal precipitation (less than 5%) was observed with sera from 36 cattle in leukemia-free herds; these sera, negative by immunofluorescence, included six samples that had high titers of antibodies to the foamy-like bovine syncytia virus (BSV). Antisera prepared against several other oncornaviruses or the Mason-Pfizer monkey virus (M-PMV) did not bind the BLV p25 protein. Conversely, the labeled p30 polypeptides of several oncornaviruses tested did not react with bovine sera that had high titers of antibodies to BLV p25. Competitive radioimmunoassay(s) (RIA) also failed to detect cross-reactions between BLV p25 protein and the internal polypeptides of other mammalian and avian oncornaviruses, M-PMV, or foamy-like BSV. The RIA for BLV p25 antigen was also highly sensitive and specific for the detection and quantitation of the antigen in virus preparations and cell homogenates.
 ...
PMID:Detection, quantitation, and characterization of the major internal virion antigen of the bovine leukemia virus by radioimmunoassay. 6 63

The Gross cell surface antigen (GCSA), associated with expression of endogenous Gross-type murine leukemia virus (G-MuLV) in tissues of mice, is defined by the cytotoxic reaction of a C57BL/6 antiserum, anti-AKR spontaneous leukemia K36, with cells of the Gross virus-induced C57BL/6 leukemia, Emale symbolG2. Sequential lactoperoxidase-catalyzed radioiodination of Emale symbolG2 cells, Nonidet P-40 lysis, precipitation with anti-K36 serum, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis identified molecules with properties of polyproteins encoded by the gag region of the viral genome. These cell surface species could also be labeled by in vitro culturing of Emale symbolG2 with radioactive glucosamine. The viral specificity of these molecules and their participation in the GCSA typing system were established as follows. (i) Absorption of anti-K36 serum with GCSA(+), but not GCSA(-), leukemias led to a marked decrease in precipitation of these proteins. (ii) The same Emale symbolG2 cell surface proteins were also precipitated by antisera against the MuLV virion proteins p30 and p15. (iii) Anti-K36 was shown to possess antibodies against Gross virus p30 and p15. (iv) "Clearing" the Emale symbolG2 lysate of molecules reactive with anti-p30 or anti-p15 sera removed molecules reactive with anti-K36 serum. (v) Absorption of anti-K36 serum with disrupted G-MuLV virions or with Gross p30 or p15 removed GCSA cytotoxic antibodies; partial absorption was achieved with disrupted Rauscher-MuLV (R-MuLV) or with R-MuLV p30, and no absorption was found with R-MuLV p15. These data show that Emale symbolG2 cells express, on their surfaces, MuLV core polyproteins that apparently can be glycosylated and on which the determinants of GCSA are located.
 ...
PMID:Characterization of molecular species carrying gross cell surface antigen. 6 25

A new retravirus (SMRV) isolated from a squirrel monkey, Saimiri sciureus, has an Mg2+-dependen reverse transcriptase and a buoyant density of 1.17 g/cm3 in sucrose and 1.21 g/cm3 in cesium chloride, similar to the mouse mammary tumor virus and the Mason-Pfizer monkey virus. The polypeptide patter of SMRV as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was distinct from the reported polypeptide patterns of known retraviruses. Four major polypeptides of molecular weights 40,000, 20,000, 14,000 and 8,000 were resolved in virus propagated in human, mink, and canine cells. In A204 human rhabdomyosarcoma cells, a protein of 73,000 daltons (gp73) represented the major viral glycoprotein as determined by [3H]glucosamine labeling. Additional proteins were also observed, but their presence depended on the cell type in which the virus was propagated. In both species-and interspecies-specific assays, no antigenic relatedness was observed between SMRV and Mason-Pfizer monkey virus, mouse mammary tumor virus, baboon endogenous virus (BaLV), woolly monkey virus (SSV-1), murine leukemia virus, endogenous feline type C virus (RD-114), bovine leukemia virus, and equine infectious anemia virus. These findings indicate that SMRV represents a new retravirus and the first isolate from a New World monkey.
 ...
PMID:Characterization of a retravirus isolated from squirrel monkeys. 6 28

The effect of interferon on the rate of synthesis and the cleavage processing of viral proteins in mouse cells, chronically infected with Rauscher murine leukemia virus, has been studied by immunoprecipitation of newly synthesized viral proteins from virus-infected cells pulse-labeled with [35S]methionine. Immuno-precipitated, labeled polypeptides were resolved by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and then examined by autoradiography. Cleavage processing was studied in the same manner with cells that had been pulse-labeled and then incubated with non-radioactive media for a sufficient time to allow normal cleavage processing to occur. At a concentration that strongly inhibited the release of virus particles, interferon had no effect on the synthesis of proteins carrying antigenic determinants of the major core protein p30 or of the envelope glycoprotein gp69/71. Nor did it affect the post-translational cleavage processing of the precursors to these proteins. Similarly, interferon did not affect labeling or chasing of precursor protein carrying the p15 determinants; labeling of p15 itself could not be studied because it does not contain methionine.
 ...
PMID:Synthesis and cleavage processing of oncornavirus proteins during interferon inhibition of virus particle release. 7 Apr 6


1 2 3 4 5 6 7 8 9 10 Next >>