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

Human T lymphocytes express either alpha/beta- or gamma/delta-TCR in association with the CD3 complex. We have isolated a mAb, delta TCS1, that immunoprecipitated the gamma/delta-TCR heterodimer from cell lysates of Peer and Molt-13 leukemia cell lines. After dissociation of the gamma- and delta-chains of TCR by treatment with SDS, delta TCS1 specifically immunoprecipitated the delta-chain. This antibody bound to the surface of other gamma/delta-positive T cell lines and clones and was able to stimulate the proliferation of a minor cell population (0.9 to 4.0%) of resting human PBL. Upon binding to gamma/delta-TCR-bearing Molt-13 cells and PBL, delta TCS1 elicited a fura-2 Caa+ signal indicating that the gamma/delta-receptor is functionally similar to the alpha/beta-heterodimer. These data indicate that the delta TCS1 antibody recognizes an epitope on TCR delta-chain and its mitogenic activity should be useful in characterizing the functional properties of human gamma/delta-positive T lymphocytes.
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PMID:Signal transduction of gamma/delta T cell antigen receptor with a novel mitogenic anti-delta antibody. 326 50

N-Myristoyl (N-Myr-) glycinal (aminoacetoaldehyde, GO) diethylacetal (A), which is abbreviated as N-Myr-GOA, and other N-Myr-compounds (N-Myr-Gly-GOA, N-Myr-Gly-Gly-GOA, and N-Myr-Gly-Gly-Gly-GOA) were newly synthesized and then employed for NH2-terminal antimyristoylation of structure proteins in the human T-cell leukemia virus (HTLV-I) and the human immunodeficiency virus (HIV). The protein myristoylation of structure proteins p19gag, of HTLV-I, and p17gag, of HIV, was determined separately, using radiolabeled myristic acid, in vitro. The radiolabeled proteins, after immunoprecipitation with an antiserum to adult T-cell leukemia (ATL) or the anti-p17gag monoclonal antibody of HIV, were identified as p19gag of HTLV-I and p17gag of HIV by fluorography after SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The protein myristoylation was resistant to NH2OH-treatment. Of the N-Myr-compounds tested, N-Myr-GOA remarkably prevented the myristoylation of p19gag and p17gag, but N-Myr-Gly-Gly-GOA and N-Myr-Gly-Gly-Gly-GOA did not.
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PMID:Antimyristoylation of gag proteins in human T-cell leukemia and human immunodeficiency viruses with N-myristoyl glycinal diethylacetal. 326 65

We studied the multimeric composition of plasma von Willebrand factor (vWf) in 26 patients with chronic myelocytic leukaemia (CML); 13 in chronic phase, 8 in blast crisis, 5 in both chronic phase and blast crisis. The relative amount of large (multimer band greater than or equal to 11) multimers calculated by densitometer scan following SDS-agarose gel electrophoresis was 14.6 +/- 2.9% (mean +/- SD) in normal controls, 8.7 +/- 4.7% in chronic phase and 15.0 +/- 5.2% in blast crisis. CML patients in chronic phase (but not in blast crisis) had a significantly lower percentage of large multimers than normal controls (p less than 0.001). The relative amount of large multimers was positively correlated with a ratio of ristocetin cofactor/vWf antigen (p less than 0.005), and was negatively correlated with platelet count (p less than 0.001), WBC count (p less than 0.05) and granulocyte count (p less than 0.05). We conclude that some patients with CML, especially in chronic phase, lack large multimers. The negative correlation of the relative amount of large multimers with platelet and granulocyte count suggests that large multimers may be consumed in high platelet count states or degraded by protease(s) from increased blood cells.
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PMID:Multimeric composition of plasma von Willebrand factor in chronic myelocytic leukaemia. 326 24

A high-resolution technique has been used to study differentiation-related and leukemia-associated glycoproteins. Cells are labeled with the membrane-impermeable probe sulfo-N-hydroxysuccinimidyl-biotin. Nonionic detergent extracts are subjected to affinity chromatography on a number of immobilized lectins and after polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE) and western transfer, the biotin-labeled glycoproteins are visualized by using avidin-horseradish peroxidase and 4-chloronaphthol. With the aid of the lectins concanavalin A, Dolichos biflouros agglutinin, Lens culinaris hemagglutinin, peanut agglutinin, pokeweed mitogen, Ricinus communus agglutinin I, soybean agglutinin, Ulex europeus agglutinin I (UEA), and wheat germ agglutinin, each purifies different glycoprotein subsets from the same cell type. Mature cells of distinct hematopoietic lineages differ considerably in their cell surface glycoprotein patterns. This technique was used to analyze the glycoproteins of human leukemia cells before and after the induction of differentiation. K562 cells differentiated along different lineages after treatment with phorbol 12-myristate 13-acetate, sodium butyrate, dimethyl sulfoxide, or hemin. Limited specific alterations were observed with a number of lectins when K562 erythroleukemia cells were induced to differentiate. Among these, a number of bands were identified that were either lost or appeared after induction of differentiation with all four agents. In contrast, the glycoproteins bound by UEA were drastically diminished after induction of differentiation, and the remaining UEA-bound glycoproteins bore little resemblance to those of the cells before treatment. This high-resolution technique may be useful as a general method for the examination of cell surface glycoprotein differences. Once specific glycoprotein alterations are detected, lectin affinity chromatography and SDS-PAGE allow purification of antigens for the production of monoclonal antibodies.
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PMID:Analysis of cell surface glycoprotein changes related to hematopoietic differentiation. 339 8

We have studied protein acylation using [3H]myristate in the two leukemia cell lines HL-60 and HL-60 Blast II. The latter is a variant which does not differentiate after treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA). The acylation profiles of the two cell lines as examined by SDS-PAGE differed. TPA induced the myristylation of an approximately 82 kDa protein in the sensitive cells, but not in the resistant cells. Myristic acid was shown to be covalently linked to these proteins. Analysis of the cell lipids labelled with [3H]myristate showed that in contrast to observations with the proteins, the changes induced by TPA were observed in both TPA-sensitive and TPA-resistant cells. We conclude that the induction of myristylation may be an important step in the mechanism of differentiation.
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PMID:12-O-tetradecanoyl phorbol 13-acetate stimulates the myristylation of an approximately 82 kDa protein in HL-60 cells. 347 31

A new matrix for affinity chromatography using pteroylglutamic acid coupled to an epoxy-activated matrix via hexanediamine resulted in negligible ligand leakage and permitted the purification of soluble and membrane-associated folate-binding proteins from human leukemia cells contained in a human spleen. Two species of membrane-associated folate-binding proteins were purified from the solubilized membrane fraction of the tissue using 2 M guanidine-HCl to elute the proteins from the affinity matrix. The higher molecular weight binding protein had an Mr of approximately 310,000 and the smaller species had an Mr of approximately 28,000 by gel filtration. By SDS-polyacrylamide gel electrophoresis the smaller species of membrane-associated protein had a molecular weight of 35,500, but the molecular weight of the larger membrane-associated species could not be determined by this method because of the high concentration of residual Triton X-100 in the sample which interfered with the silver staining of the gel. Two folate-binding proteins, which by SDS-polyacrylamide gel electrophoresis had molecular weights of 34,500 and 32,000, were purified from the 44,000 X g supernatant fraction of the tissue homogenate by acid elution from the affinity matrix. Despite the different cell components from which the soluble and membrane-associated folate-binding proteins were purified, the amino acid compositions were similar, especially with respect to the apolar amino acids. All these forms of folate-binding proteins had higher affinity for oxidized than for reduced folates, and very low affinity for 5-formyltetrahydrofolate and methotrexate. Although these proteins cross-react with one antiserum raised previously to a folate-binding protein from other human leukemia cells, they do not cross-react with the folate-binding proteins purified from two other sources of human leukemia cells, from human placenta, or from the human KB cell line.
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PMID:Purification, properties, and immunological characterization of folate-binding proteins from human leukemia cells. 347 29

Gross murine leukemia virus (GV) is not leukemogenic in adult mice whereas a variant of GV, WB91, is highly leukemogenic regardless of the age of the inoculated animal. FACS and SDS-PAGE analysis have demonstrated that these viruses differ at least with respect to the env-encoded gp70 molecule. FACS analysis of virus infected or virus transformed cells with a type specific monoclonal antibody (mAb #55) indicated a difference in determinants associated with gp70 expressed by the two viruses. Rat antisera raised against GV- or WB91-induced tumor cells demonstrated that there were no crossreactive determinants between the gp70 molecules expressed on these tumor cells as recognized by the rat antisera. This difference in the gp70 molecules encoded by WB91 and GV may account for the ability of the WB91 virus to induce leukemia in adult mice, possibly by affecting the immunogenicity of the virus.
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PMID:Antigenic changes in gp70 associated with the adult variant of Gross murine leukemia virus, WB91. 350 91

Monoclonal and polyclonal antibodies to the variable portions of antigen receptors (anti-idiotypes and anti-idiotopes) are often employed to study the molecular nature and the biological role of these antigen receptors. Such antibodies are operationally defined as those antibodies which bind to a particular immunoglobulin but not to other immunoglobulins of the same class in a radioimmunoassay or ELISA. The monoclonal antibodies 32D1 and 31D1 were initially defined as anti-idiotypic as they recognized an immunoglobulin preparation from the murine B cell lymphoma BCL1, but not other immunoglobulins of the same isotype as assessed by a radioimmunoassay. A potential artifact in defining anti-idiotypic antibodies in this way is the possibility of copurification of antigen and antibody, resulting in the tentative identification of anti-antigen as anti-idiotype. Previous studies have demonstrated that BCL1-IgM is involved in binding of murine leukemia virus (MuLV), and BCL1 immunoglobulin and MuLV-gp70 apparently co-purified as an immune complex. Disruption of the immune complexes with SDS and sucrose gradient purification of the immunoglobulin was adequate to prepare BCL1 immunoglobulin free of gp70 as assessed by radioimmunoassay with the monoclonal anti-gp70 RA3-4A3. This preparation of immunoglobulin was used to show that 31D1 does not bind to BCL1 immunoglobulin, but to the contaminating gp70 in the BCL1 immunoglobulin preparation. However, MAb 32D1 was definitively proven to be anti-idiotypic as it recognized SDS sucrose density gradient purified IgM and immunoisolated heavy chain and light chain from BCL1 immunoglobulin. Several other lymphomas were recognized by mAb 32D1, including the T cell lymphoma UNC1 and the B cell lymphoma Balenlm17. To determine whether mAb 32D1 recognized immunospecific receptors on these lymphoma cell lines immunoprecipitation studies were performed. Immunoisolation and molecular analysis revealed that mAb 32D1 did not recognize the antigen receptor on these two cells, but instead recognized a cell-specific gp70. This observation demonstrates that monoclonal antibodies to known antigens (in this case an anti-idiotype) can crossreact with apparently unrelated molecules. The potential significance of this cross reaction to the antigens recognized by B cell lymphomas is discussed.
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PMID:Molecules recognized by anti-idiotypic monoclonal antibodies to the B cell lymphoma, BCL1. 350 25

A monoclonal antibody (45-2D9) produced after immunization of BALB/c mice with the c-Ha-ras NIH 3T3 tertiary transfectant (45-342) recognized a determinant expressed by the primary, three of three secondary, and one of three tertiary transfectants, but not by NIH 3T3 cells. The determinant was present on the cell surface and was distinct from murine leukemia virus gp70 by absorption studies. Biosynthetic labeling and immunoprecipitation studies with [35S]methionine and [3H]glucosamine demonstrated that 45-2D9 recognizes a 74,000 Mr glycoprotein with minor bands of 90,000 and 180,000 Mr on SDS-PAGE. Pulse chase studies demonstrated a 68,000 Mr precursor molecule that incorporated only [35S]methionine. The distribution of the epitope recognized by 45-2D9 was assessed by immunoperoxidase staining. The antigen was not detected on 10 primary and metastatic murine tumors or 11 transformed murine cell lines. However, a variety of surgically excised human tumors demonstrated intense staining, whereas staining of normal tissues was minimal or not detectable. Thus a human oncogene-transfected cell can express a new cell surface determinant apparently unrelated to the oncogene product, which is also selectively expressed by human tumors.
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PMID:Monoclonal antibody 45-2D9 recognizes a cell surface glycoprotein on a human c-Ha-ras transformed cell line (45-342) and a shared epitope on human tumors. 353 30

Purification of RNA polymerase II from chicken myeloblastosis (leukemia) cells to homogeneity and subsequent structural analysis of the purified enzyme revealed that the enzyme contained seven polypeptides with molecular masses ranging from 27 KDa to 220 KDa. Inclusion of protease inhibitors in the buffer system during purification significantly increased the molar ratio of the largest (220 KDa) polypeptide to the second largest (180 KDa) polypeptide. However, proteolytic conversion of the 220 KDa to 180 KDa polypeptide did not inhibit the DNA binding activity of the enzyme. The enzyme, after dissociation into subunits in a SDS-polyacrylamide gel containing urea was blotted onto a nitrocellulose filter. The filter was incubated with 32P-labeled calf thymus DNA and both the 220 KDa and 180 KDa polypeptides of the enzyme bind DNA, suggesting that the DNA-binding site of the enzyme resides on the 180 KDa polypeptide of the largest subunit.
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PMID:The 180 KDa polypeptide contains the DNA-binding domain of RNA polymerase II. 359 59


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