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)

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

An experimental procedure for detecting and characterizing tumor-associated, virion, and histocompatibility antigens has been developed. The method takes advantage of the high resolution that proteins, solubilized by Triton X-100 and reduced, display after sodium dodecyl sulfate gel electrophoresis. The antigens can be detected as distinct molecular weight species by a highly sensitive inhibition of cytotoxic reaction. When coupled to the lactoperoxidase-catalyzed iodination of intact cells, the procedure permits the determination of externally exposed antigens. In the present study, the method has been applied to the Moloney leukemia virus-induced YAC lymphoma cells of strain A mice, which express a Moloney leukemia virus-determined cell surface antigen (MCSA) in addition to the type C viral proteins gp71, p30, p15, p15(E), p12, and p10. MCSA was identified as an exposed surface protein distinct in size and antigenic determinants from the major envelope and core protein of Moloney leukemia virus and the histocompatibility antigens. Multiple molecular weight species possessing antigenic determinants for MCSA, gp71, and H-2(a) have been detected. These results provide direct confirmation that MCSA is unrelated to the known virion structural proteins or to the H-2(a) antigen. This method should permit the direct identification and molecular weight characterization of any antigen whose determinants are not solely dependent on a complex quaternary structure and for which serological reagents are available.
 ...
PMID:Moloney leukemia virus-induced cell surface antigen: detection and characterization in sodium dodecyl sulfate gels. 7 31

Previous studies from this laboratory have mapped resistance and/or susceptibility to radiation-induced leukemia virus (RadLV)-induced neoplasia to the H-2D region. H-2 linked effects on virus replication can be detected subsequent to the initial virus infection, and clear-cut differences in numbers of virus infected thymus cells can be detected as early as 5 wk after RadLV inoculation. Rapid increases in cellular synthesis and cell surface expression of H-2 antigens are detectable immediately after virus inoculation. These changes have been studied by immunofluorescence, absorption, cell surface iodination followed by sodium dodecyl-sulfate-polyacrylamide gel electrophoresis, and two dimensional gel electrophoretic analysis of internally labeled lymphocyte proteins. Expression of H-2K molecules is significantly increased in cells of susceptible and resistant animals. However, significant increases in expression of H-2D antigens occurs only on thymus cells from resistant strains (H-2Dd). Transformed cells of resistant and susceptible H-2 haplotypes adapted to tissue culture lack detectable H-2 antigens as determined by serological absorption studies. It is argued that altered expression of H-2 antigens plays a very significant role in the mechanism of host defense to virus infection.
 ...
PMID:Increased synthesis and expression of H-2 antigens on thymocytes as a result of radiation leukemia virus infection: a possible mechanism for H-2 linked control of virus-induced neoplasia. 7 39

beta2-Microglobulin has been isolated in useful quantities from the urine of strain-2 guinea-pigs after either treatment with sodium chromate or induction of the L2C leukaemia. Antibodies raised against the beta2-microglobulin were used to set up a radioimmunoassay which measured its export into culture fluid by normal and leukaemic lymphocytes. Material containing beta2-microglobulin was also obtained by digestion of the lymphocytic surfaces with papain; fractionation demonstrated both free and combined forms, with no qualitative difference between those from normal and those from leukaemic cells.
 ...
PMID:beta2-Microglobulin from normal and leukaemic guinea-pig lymphocytes. 8 17

Appropriately absorbed antisera to the lymphoblastoid cell lines HSB and SB detect a human T-lymphocyte-associated antigen (TLAA) and the human Ia-like antigens, respectively. Cells from some patients with acute myelomonocytic leukemia (AMML) and chronic myelogenous leukemia in blast crisis expressed both TLAA and Ia antigens when tested in a complement-dependent microcytotoxicity assay (greater than 90% lysis with both antisera). When patients were in remission, expression of TLAA and Ia antigens returned to normal values. Quantitative absorption of anti-TLAA serum with increasing numbers of AMML cells showed that these cells could remove reactivity of the serum for both HSB and human thymocytes. Similarly, absorption of anti-Ia serum with AMML cells removed all serological reactivity when this serum was tested on chronic lymphocytic leukemia cells or normal B-cells. These serological findings were confirmed by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies using radiolabeled antigens. Cells from an AMML patient were labeled with 125I using lactoperoxidase; both the TLAA and Ia antigens were precipitated from the resulting solubilized membrane preparation. Leukemic cells from one AMML patient and one patient with chronic myelogenous leukemia in blast crisis were studied for Ia and TLAA antigens with a double fluorescence technique. Over 80% of the cells showed dual fluorescence.
 ...
PMID:Detection of both T-cell and Ia-like antigens on cells from patients with acute myelomonocytic leukemia and chronic myelogenous leukemia in blast crisis. 9 28

The reverse transcriptase (RNA-dependent DNA nucleotidyltransferase) of the type C RNA virus produced by the human lymphoma cell line SU-DHL-1 was purified by ion-exchange chromatography of SU-DHL-1 culture fluids and repetitive affinity chromatography on poly(rC).agarose, as were the polymerases of several other type C viruses. The DHL-1 enzyme used template-primers at levels expected of a viral reverse transcriptase, and sodium dodecyl sulfate gel electrophoretic analysis of radioiodinated DHL-1 enzyme revealed a peak at a position corresponding to those of several other type C viral reverse transcriptases (namely, at 72,000-78,000 daltons). The purified enzyme was partially neutralized by antibodies specific for the reverse transcriptase of simian sarcoma virus. Two-dimensional analysis on thin-layer cellulose plates of tryptic hydrolysates of the radioiodinated enzymes of several viruses revealed that six peptides are common to the polymerases of simian sarcoma virus, gibbon ape leukemia virus, baboon endogenous virus, and the DHL-1 virus, and that two to four peptides are unique to each of these enzymes. The DHL-1 viral reverse transcriptase appears to be most closely related structurally to the enzymes of simian sarcoma virus, gibbon ape leukemia virus, and baboon endogenous virus. However, the DHL-1 viral enzyme differed from any one or combination of the other subhuman primate viral enzymes by virtue of its unique peptides. The implications of these findings with respect to the probable origin of the DHL-1 virus are discussed.
 ...
PMID:Characterization of the reverse transcriptase of a type C RNA virus produced by a human lymphoma cell line. 9 23

A single-cell clone of C3Hf mammary tumor cells (clone 14) was developed into a continuous cell line expressing high levels of endogenous mouse mammary tumor virus (MMTV) with less than 0.1% murine leukemia virus expression. Comparison of the C3Hf MMTV protein profile on sodium dodecyl sulfatepolyacrylamide gel electrophoresis with that of C3H MMTV revealed that the protein content of the two viruses was quite similar. However, oligonucleotide fingerprints obtained of MMTV 70S RNA revealed that approximately 20% of the large oligonucleotides examined were unique to each virus. The oligonucleotide fingerprint indicated that although the viruses were similar, they differed in their genetic content. The differences in the two viruses extended to immunological differences in the major envelope glycoprotein, gp52. C3Hf MMTV competed only partially in a homologous radioimmunoassay for gp52 of C3H MMTV, whereas C3H MMTV gave complete competition, indicating that gp52 of C3H MMTV contained type-specific determinants not present on gp52 of C3Hf MMTV. Comparison of C3Hf MMTV with highly oncogenic C3H, GR, and RIII MMTVs in a homologous C3H MMTV gp52 assay gave two patterns of reactivity: complete competition by GR and C3H MMTV and incomplete competition by C3Hf and RIII MMTV. Absorption of anti-C3H MMTV serum by either C3Hf MMTV or RIII MMTV removed all antibodies against both viruses but not against GR and C3H MMTVs. These results indicate that C3H and GR MMTVs are more closely related to each other than to RIII and C3Hf MMTVs.
 ...
PMID:Establishment of a C3Hf mammary tumor cell line expressing endogenous mouse mammary tumor virus: antigenic and genetic relationships of this virus with highly oncogenic mouse mammary tumor viruses. 9 76

The possibility that some or all of the viral proteins, gp70, p30, and the histocompatibility antigen, H-2, function as the tumor-specific transplantation antigen (TSTA) of the R-MuLV-induced leukemia, RBL-5, and also in the secondary in vitro induction of cytotoxic T lymphocytes (CTL), was investigated. The antigen was obtained by isolating the plasma membranes of RBL-5 cells and solubilizing with sodium deoxycholate (DOC) followed by gel filtration chromatography. A fraction containing excellent tumor-rejection activity but low amounts of gp70, p30 and H-2 was chromatographed on goat anti-gp 70 goat anti-p 30 and sheep anti-H-2b immunoaffinity columns. The data obtained indicate that gp 70, p 30 or H-2 do not function as TSTA of RBL-5 leukemia, individually or as a complex. Similarly, the antigen responsible for the specific secondary induction of CTL in vitro is distinct from these three proteins.
 ...
PMID:Rauscher leukemia virus-induced tumor antigens: complete separation from gp70, p30 and H-2. 9 83

5-Selenium-substituted derivatives (diselenides) or uracil, 2'-deoxyuridine, and 2'-deoxyuridylic acid were synthesized via the addition of methyl hypobromite to the 5,6 double bond, followed by reaction of the adducts with sodium diselenide. The physical and chemical properties of these compounds (including their facile reduction by dithiothreitol and rapid reoxidation) were similar to those of the corresponding 5-sulfur analogues. 5-Hydroseleno-2'-deoxyuridylic acid was as potent as 5-mercapto-2'-deoxyuridylate in inhibiting thymidylate synthetase from L. casei (ki approximately 6 X 10(-8) M) but the nucleoside III was considerably less active than 5-mercapto-2'-deoxyuridine in the inhibition of growth of the leukemia L1210 cell in culture.
 ...
PMID:Synthesis of 5-selenium-substituted uracil derivatives. Inhibition of thymidylate synthetase by 5-hydroseleno-2'-deoxyuridylate. 11 Sep 31

[3H]Uridine-labeled Rauscher leukemia virus was used to infect mouse embryo fibroblasts. After the infected cells were separated into nuclear and cytoplasmic fractions nucleic acid was extracted by sodium dodecyl sulfate-phenol-chloroform treatment and analyzed by Cs2SO4 and sucrose density gradient centrifugation. Between 45 and 70 min after infection a transient and synchronized shift of the acid-insoluble radioactive peak toward the RNA-DNA hybrid region occurred in both the nuclear and cytoplasmic fractions. The density of the cytoplasmic hybrid shifted to 1.56 g/ml (RNA equals about 50%), while the sedimentation rate decreased from 36 S to 14 S; however, the density of the nuclear hybrid shifted to 1.58-1.48 g/ml (RNA equals 57-17%, respectively), while its sedimentation rate remained about 65 S. The hybrids in both the nuclear and the cytoplasmic fractions still showed hybrid density after heat denaturation. The processes of the early stages of RNA tumor virus infection are discussed with regard to the functions of viral RNA-dependent DNA polymerase (reverse transcriptase) and a possible integration of viral genetic information into the host chromosome.
 ...
PMID:Fate of viral RNA of murine leukemia virus after infection. 16 22


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