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)

The surface immunoglobulin of the transplantable L2C leukaemia of strain 2 guinea-pigs has been investigated. The immunoglobulin is seen to be synthesized when the cells are maintained in culture, indicating its intrinsic origin. Immunolabelling of the cell surface and immunochemical study of the Fab released by limited surface proteolysis indicate the presence of immunoglobulin of class IgM. IgG and free light chains were not detected, and there is unlikely to be an appreciable amount of immunoglobulin of any other class. The amount of immunoglobulin present, in terms of 4-chain monomers, is approximately 100,000 molecules per cell. Its half-life, calculated from the rate of reappearance in vitro of surface Fab after proteolytic clearing, is approximately 5 hours. Immunoglobulin secreted into the environment appears to arise predominantly or entirely from the cell surface: there is no evidence of an appreciable export of immunoglobulin which does not have a surface phase. Papain at 0.06 mg/ml rapidly removes the surface Fab. Residual Fcmu can then be detected by immunofluorescence, suggesting that papain cleaves surface IgM at a hinge region with the molecule in situ on the membrane. The released Fab is only moderately susceptible to degradation by papain at the enzyme: substrate ratio prevailing. It has been possible to isolate it from the papain digest by immuno-adsorption, with a notional yield of 75 mug per 10-10 cells, and then to prepare antisera against it.
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PMID:Surface immunoglobulin of guinea-pig leukaemic lymphocytes. 4 98

The majority of human lymphocytic and myelocytic leukemia cells express a polymorphic antigen that is found on peripheral blood B-lymphocytes and cultured lymphoblastoid B-cell lines. These B-lymphocyte antigens were detected by 34 human alloantisera that were repeatedly absorbed with pooled platelets to remove all activity against HLA antigens and T-lymphocytes. Absorption studies indicated that a common antigen was present on both B-lymphocytes and positive leukemia cells. Leukemia cells could be subdivided into two groups based on the presence of the B-lymphocyte antigen. Fourteen of 18 acute myelocytic leukemia cells, 10 of 13 acute lymphoblastic leukemia cells, 4 of 6 chronic myelocytic leukemia cells, and 2 of 2 chronic lymphocytic leukemia cells were positive. This group of leukemia cells also reacted with rabbit anti-B-cell sera raised to papain digests of spleen cell membranes. F(ab')2 fragments of the rabbit antsera were shown to specifically block the reactions of the human antisera against B-cells and leukemia cells. These results suggested that the rabbit and human anti-B-cell sera were reacting with identical molecules. This conclusion was supported by immunoprecipitation data.
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PMID:Human B-lymphocyte antigens expressed by lymphocytic and myelocytic leukemia cells. II. Detection by human anti-B-cell alloantisera. 6 14

A human serum (obtained from a multiparous and multiple-transfused patient with chronic myelogenous leukemia) and a rabbit antiserum (obtained by immunization with papain extracts from a B-lymphoblastoid cell line) showed reactivity against antigenic specificities (different from HLA) expressed on peripheral blood B-lymphocytes, unmarked lymphocytes, and monocytes. These antigenic determinants were expressed on myeloblasts and lymphoblasts from patients with acute leukemia (during the active phase of their disease) and on B-lymphoblastoid cell lines and lymphocytes from patients with chronic lymphocytic leukemia. Purified peripheral blood T-lymphocytes, mitogen (phytohemagglutinin)-activated T-lymphocytes, and lymphoblasts (with T-cell characteristics) obtained from patients with acute lymphoblastic leukemia or established lymphoblastoid cell lines lacked these antigenic specificities. Absorption experiments indicate that the antigen(s) detected on normal mononuclear cell populations, leukemia cells, and B-lymphoblastoid cell lines were either identical or highly cross-reactive.
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PMID:Recognition by human and rabbit sera of common antigens to leukemia blast cells, peripheral blood B-lymphocytes, and monocytes. 7 Nov 97

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.
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PMID:beta2-Microglobulin from normal and leukaemic guinea-pig lymphocytes. 8 17

Plasma membranes were isolated from the leukemia cell line ASL1w and extracted with detergent (DOC). DOC solubilized more TL activity than could be detected on isolated membranes. However, extraction of membranes with LDS or EDTA solubilized only 17% and 4%, respectively, of the activity. This indicated that TL was not loosely associated with the membrane but rather was integrated into the lipid bilayer. At low concentrations of DOC (0.05%), TL was found to be largely aggregated and was also prone to autolysis. Neither aggregation nor autolysis was observed at a higher DOC concentration (0.5%). The apparent molecular weight of TL in 0.5% DOC was determined by Sephadex G-200 chromatography to be about 65,000-70,000. Digestion of a 0.5% DOC extract of TL with either papain or trypsin produced a fragment of TL of about 35,000 molecular weight. These fragments were similar in size to a fragment produced by autolysis. These data suggested that a region of the TL molecule was very prone to proteolytic attack. The 35,000 molecular weight proteolytic fragments bound specifically to lentil lectin affinity columns, which indicated that they retained at least part of the carbohydrate present on the native molecule.
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PMID:Some structural properties of thymus leukemia antigen (TL) solubilized with detergent. 9 17

A method for preparation of soluble feline oncornavirus-induced cell surface antigens was described. This technique relied upon the natural release of antigen(s) from FL-74 feline lymphoblastoid cells during their maintenance at 37 degrees in serum-deficient medium. When concentrated and clarified spent medium from 4-day cultures was tested for its antigen content by inhibition of humoral cytotoxicity, it was found that this natural production of soluble antigen provided more feline oncornavirus-associated cell membrane antigen per cell than did a solubilization procedure in which papain was used. The shed antigen preparation was immunogenic in cats, eliciting humoral antibody that was reactive with the surface of FL-74 Cells and feline sarcoma virus-transformed nonproducer mink cells but was not reactive with feline leukemia virus in a virus neutralization assay.
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PMID:Detection and evaluation of feline oncornavirus-induced cell surface antigen(s) shed from cells in vitro. 19 29

Relative amount of surface antigen was compared on L 1210 leukaemia cells treated with soluble or insoluble derivatives of trypsin and papain. Trypsin or trypsin insoluble derivative do not change the amount of antigen significantly as compared with control. However, papain insoluble derivative decrease the relative amount of antigen within 45 min to the value of 0.43 or 0.55 respectively as compared with the control specimen.
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PMID:Changes in the relative amount of surface antigens on the living cells after treatment with insoluble protease derivatives. 70 May 4

A previously uncharacterized human B-lymphocyte antigen has been detected by rabbit antisera raised to papain digests of spleen cell membranes. The unabsorbed sera reacted in both cytotoxicity and immunofluorescent tests with normal B lymphocytes and cultured B-cell lines but not with normal T lymphocytes or cultured T-cell lines. The cytotoxicity titers against B cells were as high as 1:32,000, whereas the same sera undiluted were negative against T cells. By immunofluorescent staining 6-14% of unfractionated normal lymphocytes and 48-85% of B-rich lymphocyte preparations were positive. Normal peripheral blood granulocytes, platelets, erythrocytes, and phytohemagglutinin blasts were negative. The antisera reacted with the same high titers against leukemia cells from approximately 70% of the patients with acute lymphocytic leukemia, acute myelocytic leukemia, chronic myelocytic leukemia, and seven of eight cases of chronic lymphocytic leukemia. From absorption studies it appeared that the same antigen was being expressed by leukemia cells and normal B lymphocytes. Using immunofluorescent staining the anti-B-cell antisera were able to detect positive leukemia cells in the bone marrow of patients with advanced leukemia and to monitor the elimination of these cells after chemotherapy. Soluble B-cell antigen was found in the serum of some leukemia and lymphoma patients do but not in normal serum.
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PMID:Human B-lymphocyte antigens expressed by lymphocytic and myelocytic leukemia cells. I. Detection by rabbit antisera. 77 23

The murine thymus leukemia antigen (TL) has been solubilized from the tumor ASL1 and from an established cell line ASL1W, by papain digestion. When a 15-min digest was chromatographed on Sephadex G-200, two peaks of TL activity were eluted with apparent molecular weights of approximately 58,000 and 31,000. Chromatography of a 30-min digest under the same conditions resulted in elution of a single peak of activity with an apparent molecular weight of 58,000. Additional purification was carried out on the 58,000 molecular weight material by absorption to, and elution from DEAE-cellulose. The combination of gel filtration and ion exchange chromatography resulted in approximately a 150-fold purification.
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PMID:Purification of murine thymus leukemia antigen (TL). A quantitative assessment of limited proteolysis. 118 18

Cell-mediated immunity (CMI) and tumor rejection were studied in the Friend virus leukemia system of C57Bl/6 mice. Mice were immunized with Friend leukemia virus (FLV) or X-irradiated FBL-3 leukemic cells and studied temporally for the development of CMI reactivity by assays of 51Cr release lymphocyte cytotoxicity, lymphocyte transformation, migration inhibition, Winn tumor cell neutralization and transplantation rejection. High levels of specific lymphocyte cytotoxicity were observed by day 7 f0llowing FLV infection; this reactivity reached a peak between 17 and 21 days, and returned to background levels by day 36. Further, positive Winn assays were obtained with spleen cells from mice immunized with FLV at times when the mice resisted live FBL-3 tumor challenge. Positive lymphocyte transformation was obtained with spleen cells from mice immunized with FLV or FBL-3, but not with cells from normal mice or mice immune to a syngeneic methycholanthrene-induced tumor, when cultured with papain-soluble FBL-3 or RBL-5 tumor-cell extracts or mitomycin-C (MMC)-treated FBL-3 or RBL-5 cells. Positive reactivity in the lymphocyte transformation assay occurred after reactivity had peaked in the lymphocyte cytotoxicity test. Similar positive macrophage migration inhibition patterns were also obtained with peritoneal exudate cells (PEC) from FLV-immunized mice using papain-solubilized tumor-associated antigen (TAA) from FBL-3 cells. These data suggest that sequential development and modulation of CMI reactivity occurs as observed in different assays following immunization in this system.
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PMID:Cellular immune reactivity in vitro and tumor rejection provided by tumor-associated antigens of friend-virus-induced leukemia. 118 39


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