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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over 200 established human hematopoietic cell lines of normal and malignant origin have been investigated by morphological and functional parameters. Employing morphology as the overriding parameter four types of lines were identified. (1) Lymphoblastoid cell lines, derived from normal and neoplastic hematopoietic tissue, were characterized by the wide morphologic flexibility of individual lymphoblastoid cells, constant association with Epstein-Barr virus (EBV), polyclonal derivation, differentiation for immunoglobulin production (secretion) and their diploids. (2) Lymphoma cell lines. This type of line was established at a high frequency from Burkitt's lymphoma and rarely from other types of lymphoma, but never from patients without malignancy or with non-lymphoma malignancies. Important characteristics were morphologic stereotypia within each line, monoclonal derivation, common but not obligatory association with EBV, variability in the expression of Ig synthesis (no production, or membrane bound Ig, or secretion) and aneuploidy. (3) Myeloma cell lines could only rarely be obtained from patients with myeloma. The basis for classification of these lines is their production of Ig identical to the myeloma protein in vitro. Other important distinguishing features were: plasma cell morphology, absence of EBV and aneuploidy. (4) The leukemia cell line (MOLT 4) was the only line with T-cell characteristics and was easily distinguished from the other types. Important characteristics were a typical surface ultrastructure, absence of EBV and absence of immunoglobulin production, Individual lymphoblastoid lines were in principle identical whereas each line of the other three types had its own characteristic profile. The phenotypic characteristics of the lymphoblastoid lines were very stable during prolonged serial cultivation. Only in a few cases were secondary chromosomal, functional or morphologic alterations noted. We conclude that EBV-carrying lymphoblastoid lines can be obtained from non-neoplastic precursor cells from healthy as well as from diseased individuals. Lymphoma, myeloma and leukemia lines are only obtained from the respective neoplastic tissue but generally at a low frequency. With the exception of Burkitt's lymphoma, malignant hematopoietic tissue and leukemia frequently give rise to established cell lines in vitro of the lymphoblastoid type rather than lines derived from the neoplastic cells;
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PMID:Classification and biological nature of established human hematopoietic cell lines. 16 56

Immunofluorescence absorption methods are described which permit quantitative estimation and differentiation of Epstein-Barr virus (EBV)-associated antigens (virus capsid antigen, VCA, early antigen, EA and EBV-determined nuclear antigen, EBNA) in cell extracts. EBNA was present in all cell lines (producer and non-producer) which carried the EBV-genome, while VCA and EA were present in producer lines only. All the antigens were absent from a lymphoid cell line (MOLT-4) which lacked the EBV-genome, as well as from leukemia cells from peripheral blood. The techniques demonstrated antigenic identity of the various antigens when prepared from different cell lines.
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PMID:Immunofluorescence and anti-complement immunofluorescence absorption tests for quantitation of Epstein-Barr virus-associated antigens. 16 41

Sera from healthy humans contained naturally occurring antibody against group- or subgroup-specific antigen on the envelope of the following type C viruses isolated from primates: gibbon ape leukemia virus, simian (woolly monkey) sarcoma virus, baboon endogenous type C virus, and putative human type C viruses [HL23V isolated from blood cells of a patient with acute myelogenous leukemia (HL23) and HEL-12V from human embryonic diploid cells (CIH-32)]. Two sera also reacted with C57BL/6 mouse leukemia induced by Friend virus. These results were obtained by indirect immunoelectron microscopy with various virus-producing cells and by absorption tests using as targets gibbon lymphosarcoma cells that release gibbon ape leukemia virus. In a previous report, the presence of natural antibody in sera from healthy gibbon apes was demonstrated. When the specificities of the human and gibbon natural antibodies were compared, the human natural antibody reacted with two nonproducing culture cell lines of human lymphocytic leukemia (CEM-A and MOLT) and with human embryonic diploid (CIH-1(V-) cells [which became type C virus-producing CIH-32(V+) cells after many passages], but did not react with normal gibbon spleen monolayer cells. In contrast, gibbon natural antibody showed no reaction with CEM-A, MOLT, and CIH-1(V-) cells but reacted with gibbon spleen monolayer cells. Neither human nor gibbon natural antibody that was reactive with gibbon ape leukemia virus crossreacted with feline leukemia virus and mouse wild-type AKR leukemia virus. The gibbon lymphosarcoma cells releasing gibbon ape leukemia virus were used in a screening study of sera from healthy humans. Out of 72 sera screened by indirect immunoelectron microscopy using this system, 55 were positive (76%), i.e., 26 out of 35 males (74%) and 29 out of 37 females (78%). The highest incidence of antibody production was in 1- to 10-year-olds and 31- to 40-year-olds, with the adults exhibiting higher levels. Differences in incidence of natural antibody were not found to be sex-linked. These findings suggest that type C RNA viruses related to the gibbon ape leukemia virus and simian (woolly monkey) sarcoma virus family as well as the baboon endogenous type C virus family may be widespread in humans.
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PMID:Natural antibodies in sera from healthy humans to antigens on surfaces of type C RNA viruses and cells from primates. 18 53

Plasma membranes isolated from peripheral blood lymphocytes of normal donors, lymphocytes from patients with chronic lymphatic leukaemia (CLL), a T cell and B cell line (MOLT-3 and RPMI-1788) were analysed and compared for total carbohydrate contents. T cells and peripheral blood lymphocytes contained the highest relative amounts of sialic acid and fucose, whereas chronic lymphatic leukaemic cells possessed the highest amounts of N-acetylgalactosamine and also more total cell surface carbohydrate. The Thomsen-Friedenreich antigen (TF) was detected serologically on membrane fractions by the use of anti-TF containing sera and specific lectins from Arachis hypogaea, Agaricus bisporus and Vicia graminea. The disaccharide beta-D-galactosyl(1-3)-N-acetyl-D-galactosamine is the immunogdominant carbohydrate group of the FT antigen and was detected as its reduced form, by gas chromatography, in all cells, thus correlating serological and analytical evidence. The haemagglutinating activity of the lectins and sera used was only inhibited by plasma membranes after the removal of sialic acid showong that the native form of this antigen is normally masked by sialic acid in CLL cells as well as normal lymphocytes.
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PMID:Carbohydrate composition of peripheral, cultured and leukaemic human lymphocyte plasma membranes. 20 31

The expression of complement receptors, of Fc receptors, of SRBC receptors and of S-Ig was investigated on human haematopoietic cell lines of proved malignant derivation. According to their origin and to a panel of phenotypic markers these lines have been classified into lymphoma lines, myeloma lines and leukemia lines. Results were compared with those obtained on non-malignant EBV carrying lymphoblastoid cell lines (LCL). Among the lymphoid cell lines the LCL showed a pattern of B-lymphocyte surface markers, i.e. surface immunoglobulins, C3 receptors but low density of Fc receptors. The non-Burkitt lymphoma lines bore in varying degree these B-lymphocyte markers. The lines U-698 M and DG-75 were exceptional in having only surface immunoglobulin. The Burkitt lymphoma lines had all B-lymphocyte markers. The myeloma lines differed from the lymphoid lines in lacking C3 and Fc receptors and showed only trace amounts of surface immunoglobulins. In contrast to lymphoid and myeloma lines, the leukaemia lines were completely lacking surface immunoglobulins, but showed C3 and Fc receptors in variable densities. On line, the ALL derived line MOLT-3 showed the capacity to spontaneous rosette formation with SRBC. The findings that LCL presented a homogeneous pattern of B-lymphocyte surface markers may be of value in order to discriminate between these lines and lines derived from haematopoietic malignancies other than Burkitt lymphomas.
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PMID:Surface receptors on human haematopoietic cell lines. 96 8

Lymphocyte-dependent antibodies (LDA's) directed against antigenic determinants present on lymphoblastoid cell lines as well as human leukemia blast cells were demonstrated in heterologous antisera obtained by immunizing rabbits with a membrane fraction from RPMI-4265 (a lymphoblastoid cell line derived from a patient with chronic myelogenous leukemia). LDA was present at high titers against B-lymphoblastoid, myelomonocytic, and stem cell lines. The T-lymphoblastoid cell line MOLT-4, however, did not react. LDA was demonstrated against acute myelogenous as well as lymphoblastic leukemia cells. The reactivity was not directed against phytohemagglutinin-induced blastoid antigens, fetal antigens, or fetal calf serum. Absorptions with lymphoblastoid cell lines removed all LDA reactivity. Similar results were obtained by absorbing the rabbit antiserum with acute lymphoblastic and/or acute myelogeneous leukemia cells. These findings indicate the presence of cross-reactive antigens between lymphoblastoid cell lines and leukemia cells. Furthermore, cross-reactivity between acute lymphoblastic and acute myelogenous leukemia cells was demonstrated.
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PMID:Antigens shared by leukemic blast cell and lymphoblastoid cell lines detected by lymphocyte-dependent antibody. 105 51

Rabbit antisera to myelogenous leukemia (ML) cells were raised; ML cells from line K-562 that has the Philadelphia (Ph) chromosome were used as antigen. Antibodydependent, complement-mediated cytotoxicity was demonstrated by the trypan blue test and Cr release assay for cultured ML cells, whereas no cytotoxicity was demonstrated for cells from B (SB) and T (MOLT 4) lymphoblastoid cell lines. The antisera showed no cross-reactivity for normal human peripheral leukocytes or purified granulocytes. A low level (less than 8%) of cytotoxicity was directed against cell membrane associated fetal bovine serum proteins. Absorption of the immune serum with normal human bone marrow cells of first trimester human whole embryo cells reduced the cytotoxic titer to a similar extent; this suggested the possibility of crossreactivity between ML cells and fetal antigen(s). However, the ML antigen(s) was unrelated to carcinoembryonic antigen (CEA), since absorption with CEA had no effect on the serum cytotoxic titer. The anti-ML sera were cytotoxic for cells taken from 10 patients with chronic myelogenous leukemia and from 3 with acute myelogenous leukemia. In contrast, the leukocytes of 1 of 4 patients with acute lymphocytic leukemia, and 3 of 7 with chronic lymphocytic leukemia shared similar antigenic determinants as demonstrated by cytotoxicity tests. The significance of the cross-reactivity of some lymphatic and ML cells may be the result of the use of rabbit sera that did not distinguish antigens common to both granulocytic and lymphocytic cells, or it may reflect an "immature" or "blastic" antigen present on many leukemia cells.
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PMID:Cytotoxicity of antisera to a myelogenous leukemia cell line with the Philadelphia chromosome. 106 37

To identify the cellular receptors and other cell surface molecules playing essential roles in the transmission of human T-cell leukemia virus type 1 (HTLV-1), we have been isolating monoclonal antibodies (mAbs) that are capable of inhibiting HTLV-1-induced syncytium formation. In the present study, we isolated two mAbs, H11 (IgM) and H14 (IgG1), inhibitory to syncytium formation in the coculture of TOM-1 or C91/PL (both HTLV-1-positive human T-cell lines) and MOLT-4/8 (HTLV-1-negative human T-cell line) by immunizing the membrane fraction of human osteosarcoma line HOS. By immunoprecipitation and immunoblotting, H11 and H14 were found to be specific for MHC class I heavy chain and beta 2-microglobulin (beta 2 M), respectively. Among the four commercially obtained mAbs, two mAbs for MHC class I antigen and two mAbs to beta 2 M, one mAb to MHC class I antigen and one mAb to beta 2 M were also found to be inhibitory to the syncytium formation. The functional comparison of these mAbs revealed that the syncytium-inhibitory mAbs induced strong homotypic cell adhesion particularly in the HTLV-1-positive T-cell lines. This cell adhesion was dependent on temperature, energy metabolism, and microfilament function but not on the activity of protein kinase C or divalent cations. These results suggest a novel type of LFA-1-independent cell adhesion induced by signal transduction via MHC class I antigen.
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PMID:Induction of strong homotypic adhesion in human T cell lines positive with human T-cell leukemia virus type 1 by monoclonal antibodies to MHC class I and beta 2-microglobulin. 138 Aug 95

The inhibitory effects of N10-propargyl-5,8-dideazafolic acid (CB3717), a quinazoline antifolate and a potent thymidylate synthase inhibitor, were evaluated in human leukemia cell lines resistant to methotrexate (MTX) and trimetrexate (TMQ). MTX-resistant MOLT-3 cell lines, MOLT-3/MTX200 and MOLT-3/MTX10,000, were cross-resistant to CB3717; however, the degree of resistance was only tenfold for both cell lines, and increased dihydrofolate reductase activity in MOLT-3/MTX10,000 had little influence on the degree of CB3717 resistance. The MOLT-3 cell line made resistant to TMQ, MOLT-3/TMQ200, was as sensitive to CB3717 as the parent line. The cell growth inhibitory effect of CB3717 on MOLT-3 was reversed by the addition of thymidine. Leucovorin also partially reversed CB3717-induced growth inhibition. Cellular uptake of MTX and 5-methyl-tetrahydrofolate was hindered by the presence of a high concentration of CB3717, whereas TMQ uptake was not influenced by CB3717. CB3717 appears to enter the cells not only through reduced folate transport system, but by other route(s). CB3717 does not share the transport pathway with TMQ. Our observations that MTX-resistant cells with increased dihydrofolate reductase are not more resistant than cells without increased enzyme activity, and that TMQ-resistant cells are not cross-resistant to CB3717, may have clinical relevance.
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PMID:N10-propargyl-5,8-dideazafolic acid (CB3717): inhibitory effects on human leukemia cell lines resistant to methotrexate or trimetrexate. 143 41

We have studied factors which may effect the intracellular availability of oligonucleotides to achieve antisense activity. 15-20 mer unmodified, phosphorothioate modified and liposomally encapsulated oligodeoxynucleotides have been tested in leukemia MOLT-3 cells. Phosphorothioate analogs penetrated and accumulated intact in cells in contrast to unmodified oligomers, which showed a high instability in cell culture medium. A slow decrease of intracellular concentration of undegraded phosphorothioate oligodeoxynucleotides was observed after cell treatment and could be predominantly explained by a significant efflux transport. Using laser-assisted confocal microscopy we have observed that fluorescein 5-end-labeled phosphorothioate derivatives predominantly distributed in intracytoplasmic endocytic vesicles following cell treatment. The end-capped version of phosphorothioate oligodeoxynucleotides exhibited greater cellular uptake than fully modified analogues while exhibiting similar biological stability. Liposome encapsulation made possible oligomer protection in serum-containing medium and substantially improved cellular accumulation. Furthermore, the efflux rate of oligomer initially introduced within liposomes is 2-fold lower than that observed in cells which have been incubated with free oligonucleotides. Liposomal preparations of oligodeoxynucleotides facilitate release from endocytic vesicles, and thus, cytoplasmic and nuclear localization are observed following cell treatment. Furthermore, intracellular distribution studies demonstrate that intracellular transport of unmodified oligomers is effectively achieved using the liposomal carrier.
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PMID:Intracellular availability of unmodified, phosphorothioated and liposomally encapsulated oligodeoxynucleotides for antisense activity. 145 32


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