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

Spleen cells from mice immunized with human cells were transfected with DNA from the human leukemia cell line, Reh. A calcium phosphate-DNA coprecipitate was introduced into the stimulated spleen cells by treatment with a polyethylene glycol-DMSO mixture. The cells which grew out from the transfected population could be passaged continuously in culture and cloned in semisolid agarose. The cell lines contain 40 acrocentric chromosomes, and Southern blot analysis with the cloned human Alu sequence indicates that human DNA is present. The transfected cell lines exhibit markers expressed on plasmacytoma cells and produce immunoglobulin in amounts equivalent to those produced by plasmacytoma cell lines. Five of nine cell lines tested produce antibodies that react with the human cells used to immunize the mice. These cell lines have been in culture for more than a year, and one of the lines has maintained a diploid karyotype and production of the specific antibody even after being passaged through a BALB/c mouse. Preliminary experiments indicate that these cells may be a useful model system for analysis of the early proliferative phase of leukocyte transformation.
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PMID:Production of continuous mouse plasma cell lines by transfection with human leukemia DNA. 659 40

The combination of adriamycin and methotrexate was found in mice to be synergistic in cytotoxicity to L1210 leukemia cells for a range of time intervals between the two agents. Cytotoxicity for normal hematopoietic stem cells was less than additive. Spleen colony assays were used to quantitate both cell populations. Increase in life-span assays yielded similar results. Also, the extent of synergy was dependent on the dose of adriamycin only.
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PMID:Cytotoxicity of adriamycin combined with methotrexate against L1210 leukemia in mice. 692 94

The transforming capabilities of FVA, RLV and FVP have been examined using an in vitro transformation assay. Treatment of bone marrow cells with FVP in vitro led to the formation of hemoglobinized erythroid bursts even when these cells were cultured in methylcellulose for 5 days without added erythropoietin (Epo). A variety of FVA and RLV preparations also produced erythroid bursts without Epo but these bursts contained significantly less hemoglobin than those induced by FVP. When very low levels of Epo were added to cultures of FVA- and RLV-infected cells, the bursts were hemoglobinized, that is, similar to FVP-induced bursts. The burst-inducing agent in FVA preparations was shown to be a virus and not Epo. Spleen focus-forming virus (SFFV) pseudotypes, derived from FVA or FVP, also produced erythroid bursts in vitro, whereas four helper murine leukemia viruses did not. These studies indicated that the SFFV component was essential for erythroid burst transformation and specified the degree of hemoglobinization in the bursts formed.
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PMID:Polycythemia- and anemia-inducing erythroleukemia viruses exhibit differential erythroid transforming effects in vitro. 693 81

Although in vivo-primed cells are known to be rendered more effective in adoptive tumor therapy by secondary sensitization in vitro, they were tested only at the time of maximum in vitro cytolytic reactivity. Since the requirements for in vitro cytotoxicity and tumor therapy differ, the present study was designed to evaluate and compare the influence of culture duration on these two effector functions. Spleen cells from inbred C57BL/6 mice primed in vivo with the Friend virus-induced leukemia FBL-3 were secondarily sensitized in vitro by culture with tumor and tested for cytotoxicity in vitro in a 4-hour 51Cr release assay and for therapeutic efficacy in vivo against established tumor. In vivo-primed cells tested directly without prior culture were effective in therapy but were not cytotoxic in vitro. Culture of primed cells for 3 days rendered them cytotoxic as measured in vitro. This cytotoxicity increased through day 5, then it plateaued. Cultured duration modified the in vivo efficacy of primed cells differently. Cells cultured for 3 days with secondary sensitization by tumor became more effective in tumor therapy than noncultured primed cells. Increasing the duration of in vitro sensitization from 3 to 5 days did not enhance in vivo therapeutic efficacy, despite a concurrent increase in in vitro cytotoxicity. However, further lengthening of the culture duration to 7 days rendered cells more effective in vivo. These discrepancies presumably reflect different effector cell requirements and/or regulation operative for tumor lysis during a short-term in vitro assay and for tumor eradication following adoptive transfer of immune cells in vivo.
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PMID:Chemoimmunotherapy of a Friend leukemia with cells secondarily sensitized in vitro: effect of culture duration on therapeutic efficacy. 694 87

Spleen cells from Rfv-3r/s mice with Friend virus-induced erythroleukemia were analyzed for expression of virus-induced proteins with monoclonal antiviral antibodies and conventional antisera. Leukemic spleen cells, 30-60 d after virus inoculation, expressed decreased amounts of ecotropic Friend murine leukemia helper virus gag- and env-encoded cell surface and intracellular proteins compared with leukemic cells tested 8-10 d after virus inoculation. In contrast, the spleen focus-forming virus-induced protein, gp55, was present on both leukemia cell populations. This difference appeared to be mediated by the humoral antibody response in Rfv-3r/s mice, which could recognize only ecotropic gag and env proteins, and not gp55. A new gp70 molecule cross-reactive with a recombinant Friend mink cell focus-inducing virus was found in large quantities on late leukemic cells. This protein appeared to be derived from a recombinant virus produced during the course of Friend virus infection. The appearance of this new gp70 suggests that recombinant viruses other than spleen focus-forming virus may play a role in Friend virus-induced erythroleukemia.
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PMID:New cell surface gp70 related to Friend mink cell focus-inducing virus is expressed on Friend virus-induced erythroleukemic spleen cells after elimination of ecotropic Friend virus gp70 in Rfv-3r/s mice. 697 19

Spleen cells from C57BL/6 mice immunized in vivo with a syngeneic Friend virus-induced leukemia, FBL-3, were specifically activated by culture for 7 d with FBL-3, then nonspecifically induced to proliferate in vitro for 12 d by addition of supernatants from concanavalin A-stimulated lymphocytes containing interleukin 2 (IL-2). Such long-term cultured T lymphocytes have previously been shown to specifically lyse FBL-3 and to mediate specific adoptive therapy of advanced disseminated FBL-3 when used as an adjunct to cyclophosphamide (CY) in adoptive chemoimmunotherapy. Because the cultured cells are dependent upon IL-2 for proliferation and survival in vitro, their efficacy in vivo is potentially limited by the availability of endogenous IL-2. Thus, the aim of the current study was to determine whether exogenously administered purified IL-2 could augment the in vivo efficacy of long-term cultured T lymphocytes. Purified IL-2 alone or as an adjunct to CY as ineffective in tumor therapy. However, IL-2 was extremely effective in augmenting the efficacy of IL-2-dependent long-term cultured T lymphocytes in adoptive chemoimmunotherapy. The mechanism by which IL-2 functions in vivo is presumably by promoting in vivo growth and/or survival of adoptively transferred cells. This assumption was supported by the findings that IL-2 did not enhance the modest therapeutic efficacy of irradiated long-term cultured cells that were incapable of proliferating in the host and was ineffective in augmenting the in vivo efficacy of noncultured immune cells that are not immediately dependent upon exogenous IL-2 for survival.
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PMID:Augmentation of the anti-tumor therapeutic efficacy of long-term cultured T lymphocytes by in vivo administration of purified interleukin 2. 697 16

The aim of the current studies was to determine whether cells primarily sensitized in vitro are effective in adoptive therapy of established tumors. Spleen cells from normal BALB/c mice were cultured for 5 days at variable responder:stimulator ratios with an X-irradiated syngeneic Moloney virus-induced leukemia (LSTRA), denoted as BALB/c.(LSTRA)x, or with X-irradiated normal BALB/c spleen cells, denoted as BALB/c. (BALB/C)x, and tested for ability to eradicate an established lethal inoculum of LSTRA in adaptive chemoimmunotherapy. BALB/c mice inoculated with 2 X 10(3) LSTRA i.p. on Day 0 were treated on Day 5 with cyclophosphamide (180 mg/kg) plus 1 X 10(7) cultured cells. Treatment with cyclophosphamide alone cured only 3% of mice. As an adjunct to cyclophosphamide, therapy with BALB/c.(BALB/c)x cultured at responder:stimulator ratios of 8:1, 32:1, and 128:1 cured 29%, 37%, and 33% of mice, respectively; and BALB/c.(LSTRA)x cultured at the same responder:stimulator ratios cured 54, 83, and 29% of mice, respectively. Furthermore, the therapeutic efficacy of BALB/c.(LSTRA)x was abrogated by treatment with anti-Thy 1.2 + complement. Thus, culture of normal lymphoid cells with tumor at optimal responder:stimulator ratios substantially enhanced their ability to eradicate established tumor, and the enhanced therapeutic efficacy was mediated by a T-cell generated during culture. The specificity of primary in vitro sensitization in generating cells effective in the therapy of established tumors was confirmed by treating BALB/CH-2d X C57BL/6H-2b F1 (hereafter called B6F1) mice bearing either LSTRAH-2d or an antigenically distinct chemically induced leukemia, EL-4(G-)H-2b, with CB6F1 spleen cells sensitized in vitro to either of the parental tumors.
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PMID:Adoptive therapy of established syngeneic leukemia by cells primarily sensitized in vitro. 701 68

The T-cell enzyme markers, terminal deoxy-nucleotidyltransferase (TDT) and 20 alpha hydroxysteroid dehydrogenase (20 alpha SDH), were used to classify lymphomas induced by the Moloney leukemia virus (M-MuLV). Different subtypes of T cells were shown to be involved in different types of lymphoma. Thymomas were TdT-positive and grew as subcutaneous solid tumors at the site of inoculation. Spleen cells from mice with generalized lymphoma were of two types. In the majority of cases the lymphomas consisted of 20 alpha SDH-positive cells that homed to spleen and lymph nodes upon transplantation. In a few cases the cells of enlarged spleens were TdT-positive and, like the TdT-positive thymomas, could be transplanted as subcutaneous tumors. Thus, TdT-positive and 20 alpha SDH-positive T-cell lymphomas can be distinguished by their homing properties. Preleukemic thymus cells from M-MuLV inoculated mice can, after transfer to 400 -R irradiated syngeneic hosts, induce new lymphomas by virus release or grow in an autonomous fashion in the recipients. Whether of donor or recipient type, these lymphomas are TdT-positive. In contrast, preleukemic bone marrow cells give lymphomas of donor type which are as heterogeneous for T-cell enzymes as are lymphomas induced by neonatal inoculation of M-MuLV.
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PMID:Different T-cell subtypes are associated with pathologically distinct forms of Moloney leukemia virus (M-MuLV)-induced lymphoma. 703 58

Tumor-specific transplantation antigens unique to each of MM2, MM46 and Ehrlich mouse ascites tumor cells (cell line-specific antigens) were released from the cells into the medium during incubation in 0.12M saline at 37 degrees for 30 min. The released antigens were purified by identical procedures which consisted of ultracentrifugation, affinity chromatography using Sepharose 4B conjugated with Ricinus communis lectin, and DEAE-cellulose column chromatography. The recovery was about 700 micrograms (protein) from 100 g (wet weight) cells. The recovered materials induced specific immunity in C3H/He mice against transplantation of the corresponding tumor cells only when they were administered after treatment with the corresponding tumor-regressor C3H/He mouse serum. Single injection into the peritoneal cavity of 10 mcrograms of each of the pretreated materials inhibited transplantation of 5 x 10(3) corresponding tumor cells. Spleen cells from mice immunized by repeated injections of the pretreated antigen neutralized transplantability of the tumor cells. Specific humoral antibody was also detected. The specific antigens obtained from these cells were similar to each other with respect to sedimentation coefficient (16S), electrophoretic characteristics and xenogeneic antigenicity, and were free of beta-2 microglobulin, murine leukemia virus major structural proteins such as gp70 or p30 and murine mammary tumor virus proteins such as gp55 and p28.
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PMID:Purification of cell line-specific transplantation antigens from mouse ascites tumor cells. 711 55

Spleen from nine patients with hairy-cell leukemia (HCL) were studied for ultrastructural alterations. In all cases, hairy cells with typical ultrastructural characteristics were observed within splenic cords and sinuses. Hairy cells had numerous cytoplasmic processes that interdigitated with cytoplasmic processes of other hairy cells. Hairy cells also adhered to sinus endothelial cells and ring fibers and protruded into spaces between endothelial cells. Some normal sinuses were filled with aggregated hairy cells. Other sinuses appeared dilated. Many sinuses were lined by hairy cells that covered thinned endothelial cells and ring fibers. In these abnormal sinuses, endothelial cells were decreased and many appeared injured. The splenic cords were expanded by an infiltration of hairy cells and by large blood-filled spaces. These findings suggest that hairy cells adhere to many cell surfaces, produce endothelial cell injury and death, and impede the venous flow of blood in the spleen. All of the factors appear to influence the formation of the abnormal splenic sinuses and the blood-filled spaces that characterize HCL.
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PMID:Splenic alterations in hairy-cell leukemia: II. an electron microscopic study. 719 70


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