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)

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

Three monoclonal antibodies (mAbs), termed SN2, SN2a and SN2b, were used in the present work to study a human T-cell leukemia-associated cell surface glycoprotein, GP37. Strong specificity of mAbs SN2, SN2a and SN2b for T leukemia cells was demonstrated by radioimmunoassay and fluorescence-activated cell sorter (FACS) analysis. GP37 was not detected on normal human peripheral blood lymphocytes, purified normal T-cells, normal thymocytes nor normal bone marrow cells. Furthermore, GP37 was barely detectable on phytohemagglutinin (PHA)- and Concanavalin A (Con A)-activated T-cells. The results indicate clinical utility of these mAbs. Competitive binding experiments show that the epitopes recognized by SN2 and SN2a are sufficiently close to each other to allow complete reciprocal inhibition of binding whereas the epitopes recognized by SN2 and SN2b are less close to allow only partial reciprocal binding inhibition. The biochemical nature of antigenic determinants defined by these mAbs was studied by treating T leukemia cells with trypsin, chymotrypsin, thermolysin, neuraminidase and mixed glycosidases. The results suggest that the antigenic determinants defined by these mAbs all consist of the protein moiety of the glycoprotein GP37. No significant antigenic modulation was observed when T leukemia cells were reacted with SN2. In a sequential immunoprecipitation experiment, a 125I-labeled leukemia antigen preparation was first treated with a rabbit anti-T leukemia antiserum. The latter had been prepared by immunizing a rabbit with a partially purified human T leukemia antigen preparation and showed a good specificity for T leukemia cells. Subsequent treatment of the labeled antigen preparation with SN2 showed that SN2 antigen had been precleared. Thus, both mouse mAb SN2 and the rabbit anti-T leukemia antiserum react with the same GP37 molecule.
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PMID:Human T-cell leukemia-associated cell surface glycoprotein GP37: studies with three monoclonal antibodies and a rabbit antiserum. 348 64

A new mouse monoclonal antibody (HIEI, IgG1 type) that reacts with a cell surface glycoprotein of human lymphocytes was isolated. Membrane immunofluorescence assay showed that HIEI, like the anti-Tac monoclonal antibody, reacted preferentially with activated normal human T-cells and adult T-cell leukemia (ATL) virus (ATLV)-carrying human T- and B-cell lines. However, an interesting difference between HIEI and anti-Tac antibody was that HIEI did not react with ATLV-transformed simian cell lines or those cultured with interleukin-2 (IL-2), whereas the anti-Tac antibody did. The immunoprecipitation assay showed that both HIEI and anti-Tac antibody precipitated a glycoprotein with a molecular weight of 60,000 daltons (gp60) from activated normal T-cells and ATLV-positive T- and B-cells, and also gp53 from MT-2 and MT-2-related T-cell lines transformed with ATLV in vitro by the MT-2 cocultivation method. HIEI inhibited the IL-2-dependent proliferation of normal T-cells, but its inhibitory effect was much weaker than that of the anti-Tac antibody. The anti-Tac antibody interfered with the binding of HIEI to target cells, but HIEI did not block binding of the anti-Tac antibody to the cells. These observations indicate that HIEI antibody recognizes a new antigenic determinant of the human Tac antigen.
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PMID:A new monoclonal antibody recognizing an antigen of human lymphocytes similar or identical to Tac antigen. 608 38

We generated a monoclonal antibody, termed SN2, which defines a human T cell leukemia-associated cell surface glycoprotein, GP37, with an approximate m.w. of 37,000. This antibody was generated by using a human leukemia antigen preparation. The reactivity and specificity of SN2 were characterized by a sensitive radioimmunoassay against a variety of cultured and uncultured human cells. In selected cases, the cell specimens were tested further by indirect immunofluorescence staining. Among the various cultured malignant and nonmalignant human cell lines tested, SN2 reacted only with leukemic T cell lines, with one exception. It reacted with 10 of 11 leukemic T cell lines tested; the 10 reactive cell lines are PEER, JM, MOLT-4, CCRF-CEM, CCRF-H-SB2, RPMI 8402, DND-41, HPB-ALL, SKW-3, and HPB-MLT; the unreactive line was HUT 78. The reactive cell lines were derived from patients either with T cell-type acute lymphoblastic leukemia (the first eight cell lines), with T cell chronic lymphocytic leukemia (SKW-3), or with Japanese adult T cell leukemia-lymphoma (HPB-MLT). The unreactive cell line, HUT 78, was from a patient with Sezary syndrome. Results consistent with the above were obtained from studies in which uncultured malignant cell specimens from different cancer patients were tested against SN2; SN2 reacted only with T leukemia cells. Among various uncultured normal cell specimens tested, SN2 did not react with thymocytes, bone marrow cells, peripheral blood lymphocytes containing B and T cells, purified T cells, monocytes, granulocytes, or erythrocytes. It did, however, react with platelets.
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PMID:Monoclonal antibody SN2 defining a human T cell leukemia-associated cell surface glycoprotein. 660 54

We have isolated a mutant Rauscher murine leukemia virus (R-MuLV) with a mutation in its envelope (env) glycoprotein gene. This mutant encodes a membrane glycoprotein with an apparent Mr = 80,000 (gPr80env) that contains both gp70 and p15E antigenic determinants found in the larger wild type R-MuLV env precursor molecule gPr90env. Glycosylation inhibition and peptide mapping analyses indicate that the smaller size of the mutant glycoprotein is caused by a shortening of its polypeptide chain rather than by reduced glycosylation. Unlike gPr90env of wild type R-MuLV which contains Asn-linked high mannose oligosaccharides and is processed by partial proteolysis and by further glycosylation in the Golgi apparatus to produce gp70 plus p15E, the mutant glycoprotein can reach the cell surface without proteolysis. The uncleaved plasma membrane component, which undergoes further glycosylation during its transit through the Golgi apparatus, has an apparent Mr = 85,000. Furthermore, this cell surface glycoprotein is incorporated into released virions which are infectious. However, the mutant envelope glycoproteins on the cell surface do not block the receptors needed for superinfection by wild type MuLV. These results indicate that transport of uncleaved env gene-encoded glycoproteins to the cell surface is not a unique attribute to leukemia-producing recombinant of dual tropic MuLVs (Famulari, N. G., and English, J. K. (1981) J. Virol. 40, 971-976) but can also occur with a mutant of ecotropic MuLV.
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PMID:Role of partial proteolysis in processing murine leukemia virus membrane envelope glycoproteins to the cell surface. A viral mutant with uncleaved glycoprotein. 714 94

Murine monoclonal antibody (mAb) 7C11 binds to the same cell surface epitope as anti-APO-1 and anti-Fas and reacts specifically with cells transfected with a cDNA encoding the human Fas antigen. Furthermore, incubation with 7C11 causes death of hematopoietic cell lines that express APO-1/Fas but not APO-1/Fas-negative cell lines. 7C11 therefore recognizes the human APO-1/Fas (CD95) antigen, a 40 to 50 kDa cell surface glycoprotein that can trigger apoptosis or programmed cell death. Expression of APO-1/Fas antigen by normal and neoplastic hematopoietic cells was determined by flow cytometry using 7C11. APO-1/Fas is expressed by approximately 30 to 40% of resting peripheral blood T cells, B cells, and monocytes and by approximately 5% of resting NK cells and thymocytes. It was not detected on granulocytes, erythrocytes, or platelets. Approximately 80 to 90% of activated T cells, B cells, and thymocytes express APO-1/Fas, as do the majority of activated NK cells. Perturbation of APO-1/Fas by 7C11 does not affect the viability of resting lymphocytes or monocytes. In contrast, activated T cells and NK cells undergo apoptosis within 3 hours of exposure to 7C11. Other mAb that stimulate T cells or NK cells do not cause rapid induction of programmed cell death. APO-1/Fas antigen is expressed by many cell lines of lymphoid and myeloid lineage. However, this antigen was detected on neoplastic cells from only one of 69 patients with acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, or multiple myeloma. Only 3 out of 25 tumor samples from patients with non-Hodgkin's lymphoma were found to express APO-1/Fas. All three of these lymphomas harbored the bcl-2-Ig fusion gene associated with the chromosomal translocation t (14;18). Conversely, only 27% of lymphomas that possessed the bcl-2-Ig gene were found to express the APO-1/Fas antigen. Like normal activated lymphocytes, leukemia and lymphoma cells that expressed APO-1/Fas antigen were found to undergo apoptosis in vitro after incubation with 7C11. The APO-1/Fas antigen appears to regulate the growth of normal hematopoietic cells, and the marked upregulation of this antigen on activated normal lymphocytes contrasts sharply with the absence of APO-1/Fas on neoplastic cells of hematopoietic lineage. Defects in the apoptotic signal delivered through this antigen might contribute to the pathogenesis of hematopoietic neoplasms. Thus, the gene encoding APO-1/Fas can be considered a novel type of tumor suppressor gene, just as bcl-2 can be considered a cellular proto-oncogene.
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PMID:Functional consequences of APO-1/Fas (CD95) antigen expression by normal and neoplastic hematopoietic cells. 753 60

CD2 is a T cell surface glycoprotein that participates in T cell adhesion and activation. These processes are dynamically interrelated, in that T cell activation regulates the strength of CD2-mediated T cell adhesion. The lateral redistribution of CD2 and its ligand CD58 (LFA-3) in T cell and target membranes, respectively, has also been shown to affect cellular adhesion strength. We have used the fluorescence photobleaching recovery technique to measure the lateral mobility of CD2 in plasma membranes of resting and activated Jurkat T leukemia cells. CD2-mediated T cell activation caused lateral immobilization of 90% of cell surface CD2 molecules. Depleting cells of cytoplasmic Ca2+, loading cells with dibutyric cAMP, and disrupting cellular microfilaments each partially reversed the effect of CD2-mediated activation on the lateral mobility of CD2. These intracellular mediators apparently influence the same signal transduction pathways, because the effects of the mediators on CD2 lateral mobility were not additive. In separate experiments, activation-associated cytoplasmic Ca2+ mobilization was found to require microfilament integrity and to be negatively regulated by cAMP. By directly or indirectly controlling CD2 lateral diffusion and cell surface distribution, cytoplasmic Ca2+ mobilization may have an important regulatory role in CD2 mediated T cell adhesion.
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PMID:Intracellular mediators regulate CD2 lateral diffusion and cytoplasmic Ca2+ mobilization upon CD2-mediated T cell activation. 769 99

Embryonic hematopoiesis is initiated in part in the blood islands of the yolk sac. Previous confocal microscopic analysis has shown that the CD34 antigen, a mucin-like cell surface glycoprotein that is expressed by hematopoietic progenitors and all endothelial cells of the adult and embryo, is also found on a subset of luminal hematopoietic-like cells in the yolk sac blood islands as well as on the vascular endothelium lining these early hematopoietic locations. We show here that, as in all other hematopoietic sites thus far examined, immunoaffinity-purified CD34+ nonadherent cells from murine yolk sacs contain the vast majority of erythroid and myeloid progenitor cell colony forming activity. To examine the developmental interactions between these CD34+ hematopoietic progenitor cells of the yolk sac and the CD34+ yolk sac endothelium, we have immunaffinity-purified adherent endothelial cells from day 10.5 yolk sacs using CD34 antiserum and produced cell lines by transformation with a retrovirus expressing the polyoma middle T antigen. Analysis of these cell lines for CD34, von Willebrand's factor, FLK 1 and FLT 1 expression, and capillary growth in Matrigel indicates that they appear to be endothelial cells, consistent with their original phenotype in vivo. Coculture of yolk sac CD34+ hematopoietic cells on these endothelial cell lines results in up to a 60-fold increase in total hematopoietic cell number after approximately 8 days. Analysis of these expanded hematopoietic cells showed that the majority were of the monocyte/macrophage lineage. In addition, examination of the cultures showed the rapid formation of numerous cobblestone areas, a previously described morphologic entity thought to be representative of early pluripotential stem cells. Scrutiny of the ability of these endothelial cell lines to expand committed progenitor cells showed up to a sixfold increase in erythroid and myeloid colony-forming cells after 3 to 6 days in culture, consistent with the notion that these embryonic endothelial cells mediate the expansion of these precursor cells. Polymerase chain reaction analyses showed that most of the cell lines produce FLK-2/FLT-3 ligand, stem cell factor, macrophage colony-stimulating factor, leukemia-inhibitory factor, and interleukin-6 (IL-6), whereas there is a generally low or not measurable production of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, IL-1, IL-3, transforming growth factor beta-1, erythropoietin, or thrombopoietin. The output of mature hematopoietic cells from these cocultures can be modified to include an erythroid population by the addition of exogenous erythropoietin. These data suggest that endothelial cell lines derived form the yolk sac provide an appropriate hematopoietic environment for the expansion and differentiation of yolk sac progenitor cells into at least the myeloid and erythroid lineages.
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PMID:CD34+ endothelial cell lines derived from murine yolk sac induce the proliferation and differentiation of yolk sac CD34+ hematopoietic progenitors. 854 34

Ligation of the CD2 cell surface glycoprotein expressed on T lymphocytes and NK cells induces protein tyrosine phosphorylation and activation of the Src kinases, LCK and FYN. We show here that in Jurkat T leukemia cells and in peripheral blood T cells, CD2 stimulation also leads to tyrosine phosphorylation and activation of the Tec family kinase, EMT/ITK/TSK. Activation of EMT by CD2 was induced by mitogenic pairs of CD2 mAb, certain single CD2 mAb followed by secondary antibody cross-linking, and CD58-bearing sheep red blood cells. With the use of different Jurkat cell mutants it was demonstrated that CD2-mediated activation of EMT required expression of LCK, but not require surface expression of the CD3 zeta chain. Receptor-mediated activation of LCK does not in itself lead to activation of this Tec kinase since induction of LCK by ligation of CD4 or CD5 did not result in activation of EMT. The activation of EMT during CD2 signaling suggests an important role for this kinase in CD2 co-stimulation of T cell responses.
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PMID:CD2 signaling in T cells involves tyrosine phosphorylation and activation of the Tec family kinase, EMT/ITK/TSK. 894 65

The monoclonal antibody 013, which detects the cell surface glycoprotein p30/32mic2 (CD99) is a characteristic, if nonspecific, marker for peripheral neuroepithelioma and Ewing's sarcoma. 013 was first produced against a human thymus leukemia antigen and has also been found in immature terminal deoxynucleotidyl transferase (TdT)-positive T cells and in a small group of hematopoietic precursor cells in the bone marrow. 013 is reactive in lymphoblastic lymphomas and acute leukemias, as well as in a variety of other hematologic malignancies. Because the distribution of 013 positivity in hematopoietic proliferations is similar to that of TdT, we hypothesized that 013 might correlate with TdT positivity. We studied 67 lymphoblastic lymphomas and acute lymphoblastic leukemias, 6 chronic myelogenous leukemias in blast crisis, a variety of acute myeloid leukemias, 5 granulocytic sarcomas, and a spectrum of 94 diffuse lymphomas other than lymphoblastic type. With the use of heat-induced epitope retrieval and automated immunostaining, we compared the results obtained with 013 and TdT, a well-established marker of lymphoblastic lymphomas and acute lymphoblastic leukemias that can also be successfully demonstrated in tissue sections by use of a similar technique. In our study, all of the 013-positive cases were also TdT positive. 013 reacted with 44 (71%) of 62 of the TdT-positive lymphoblastic lymphomas and acute lymphoblastic leukemias cases studied. We also found 013 to be positive in one case of TdT-positive acute myeloid leukemia, in two cases of chronic myelogenous leukemia in blast crisis, and in three TdT-positive granulocytic sarcomas. 013 was negative in all of the other high-grade malignant lymphomas and in TdT-negative leukemias. With use of our technique, 013 positivity appears to be restricted to hematologic proliferations that demonstrate TdT positivity. 013 may be a helpful additional marker in the diagnosis of TdT-positive leukemias and lymphomas in conventionally processed tissue sections.
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PMID:013 (CD99) positivity in hematologic proliferations correlates with TdT positivity. 911 Feb 87


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