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)

Two membrane glycoproteins that bound immune complexes and inhibited Fc-receptor- (FcR-)mediated functions in vitro were purified from human FcR+ chronic-lymphocytic-leukaemia cells. A multi-step purification was developed, consisting essentially in: (i) Tween 40 extraction of crude cell membranes; (ii) solubilization of membrane fragments by Renex-30; (iii) isolation of glycoproteins by affinity chromatography on Lens culinaris haemagglutinin-Sepharose; (iv) papain treatment of the eluted glycoproteins followed by gel-filtration chromatography; (v) purification by polyacrylamide-gel electrophoresis of two molecular species from the protein-size fraction enriched for immune-complex-binding activity. The two electrophoretically isolated components displayed apparent molecular masses of 70 and 45 kDa by SDS/polyacrylamide-gel electrophoresis and restricted charge heterogeneity by two-dimensional analysis. Two-dimensional peptide mapping revealed the presence of many peptides in common between the two proteins and the absence of a number of peptides in the 45 kDa component. These two polypeptides were used as immunogens to produce polyclonal antibodies that cross-reacted with both proteins and specifically inhibited FcR-mediated reactions in vitro. Furthermore, FcR-related components from detergent-extracted lysates of the human K562 and U937 cell lines or human placental membranes were revealed by the putative anti-FcR antibodies adsorbed on Protein A-Sepharose.
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PMID:Isolation from human chronic-lymphocytic-leukaemia cells of membrane glycoproteins associated with Fc-receptor functions. Physical parameters and production of polyclonal antibodies. 366 59

We have examined the effect of tumor-promoting phorbol esters such as phorbol myristate acetate (PMA) on the murine B cell leukemia BCL-1 and its in vitro adapted derivative CW.13.20. Phorbol esters, including PMA and phorbol dibutyrate (PDBu), were potent inhibitors of BCL-1 IgM secretion induced by either LPS or lymphokines; half-maximal inhibition was obtained with 0.1 nM PMA and 0.8 nm PDBu. The inhibitory action of PDBu on BCL-1 cells was reversible for over 1 hr, but after 5 hr 70% of the inhibition was irreversible. Irreversible inhibition could be blocked by cycloheximide, suggesting a requirement for protein synthesis. The specificity of PDBu inhibition was examined by comparing the patterns of protein synthesis in PDBu-treated and control BCL-1 cells. Total incorporation of [35S]methionine into protein by BCL-1 cells cultured in the presence of PDBu was similar to that of untreated cells. Analysis of radiolabeled proteins by SDS-PAGE and autoradiography revealed no consistent changes in the pattern of protein synthesis except at those positions corresponding to the heavy and light chains of IgM. Immunoprecipitation with an affinity-purified anti-IgM indicated that PDBu inhibited the increased synthesis of heavy and light chain that follows stimulation by lymphokine but did not diminish control IgM synthesis. Induced IgM secretion from CW.13.20 cells was also inhibited by phorbol esters, indicating a direct action on B cells. Delaying the addition of phorbol ester relative to lymphokine or LPS by 24 hr significantly reduced inhibition of induced IgM secretion from both BCL-1 and CW.13.20 cells. This suggests that phorbol esters specifically interfere with the signal for induction of IgM secretion by both lymphokine and LPS.
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PMID:Phorbol esters specifically inhibit induction of immunoglobulin secretion in a murine B cell leukemia. 387 17

Experiments were performed to examine a growth-promoting activity on B cells or B leukemic cells of T cell-replacing factor (TRF) produced by a murine T cell hybridoma (B151K12) which constitutively produces TRF. The cellfree supernatant (CFS) from B151K12 cells (B151-CFS) could induce terminal differentiation of pre-activated B cells or in vivo passaged chronic B leukemia cells, BCL1, into immunoglobulin-secreting cells, while it did not exert a nominal lymphokine activity such as BCGFI (now known as BSFpl), IL 2, or gamma-interferon. However, it promoted [3H]thymidine uptake of dextran sulfate (DXS)-stimulated normal B cells and in vivo passaged BCL1 cells, suggesting that it also has BCGFII activity. We tried extensively to purify and to separate the TRF active molecule from the BCGFII active molecule by using many types of purification procedures. The purification scheme consisted of ammonium sulfate precipitation, DEAE-cellulose chromatography, Blue-Sepharose chromatography, hydroxylapatite chromatography, and gel permeation with fast protein liquid chromatography (FPLC). It was revealed that the BCGFII active molecule was hardly separable from the TRF during the entire purification procedure. The TRF as well as BCGFII active materials were glycoprotein with an apparent m.w. of 50 to 60 Kd on gel permeation chromatography and 18 Kd on SDS-PAGE under reducing conditions. The BCGFII active materials were hardly separable from the TRF active one, even after a reverse-phase FPLC, in which both BCGFII and TRF activities were recovered in the fractions eluted at 44 to 48% acetonitrile in 0.1% trifluoroacetic acid (TFA). Furthermore, the absorption of TRF and BCGFII active materials by using BCL1 cells removed not only TRF but also BCGFII activity. Moreover, B cell-specific monoclonal antibody (9T1), which can preferentially block TRF-dependent plaque-forming cell responses, also inhibited the expression of BCGFII activity to BCL1 cells. Taking all of the results together, we conclude that the TRF from B151K12 cells promotes growth of appropriately activated, such as DXS-stimulated normal cells and BCL1 tumor cells. These results suggest that B151-TRF may act on B cells as B cell growth and differentiation factors.
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PMID:BCGFII activity on activated B cells of a purified murine T cell-replacing factor (TRF) from a T cell hybridoma (B151K12). 387 7

Biochemical study of thymus leukemia antigen (TL) from thymocytes of various Tla genotypes and from leukemia cells revealed features that, given present evidence, are peculiar to TL among class I products of the H-2:Qa:Tla region of chromosome 17. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of TL from thymocytes of all TL+ mouse strains, precipitated by anti-TL antiserum or monoclonal antibodies, showed two closely migrating bands of equal intensity in the heavy (H) chain position (45-50,000 mol wt). Comparison of these two bands by two-dimensional isoelectric focusing (2D IEF)-SDS-PAGE and 2D chymotryptic peptide mapping showed no differences indicative of protein dissimilarity. Thus, the two components of the H chain doublet may differ only in a feature of glycosylation that does not affect charge. The two leukemias studied gave only a single band in the H chain position. On 2D peptide mapping and 2D IEF-SDS-PAGE, the patterns for TL of Tlaa and Tlae thymocytes, which are closely related serologically, were broadly similar, but clearly different from the pattern typical of Tlac and Tlad thymocytes. 2D peptide maps of TL from Tlaa thymocytes and Tlaa leukemia cells did not differ. Leukemia cells of Tlab origin (thymocytes TL-) gave 2D peptide and 2D IEF-SDS-PAGE patterns of a third type. With the exception of Tlaa, thymocytes of TL+ mice yielded additional TL products of higher molecular weight than the TL H chain.
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PMID:Structural characteristics of Tla products. 387 81

Sudan III treatment of Long-Evans rats results in increased hepatic monooxygenase activity using ethoxycoumarin and aniline as substrates. Monooxygenase activity towards amino-pyrine and nitrosodimethylamine is not affected. Sudan III treatment results in increased microsomal cytochrome P448 and increased amounts of a protein band which comigrates with purified cytochrome P448 during SDS polyacrylamide gel electrophoresis. The proportions of the different dihydrodiols formed during the incubation of 7,12-dimethylbenz[a]anthracene with microsomes vary between untreated and treated animals. Thus, extracts of microsomes from untreated rats were found to contain materials with chromatographic properties identical to those of the 3,4-dihydrodiol and the 5,6-dihydrodiol when examined on two different h.p.l.c. systems. Extracts of microsomes from Sudan III treated animals were found to contain materials with chromatographic properties identical to those of the 5,6-dihydrodiol and the 8,9-dihydrodiol when similarly examined. These findings suggest that the protective effect of Sudan III against DMBA induced leukaemia is mediated by an alteration in monooxygenase activity.
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PMID:Alterations in the metabolism of 7,12-dimethylbenz[a]anthracene and various xenobiotics by rat hepatic microsomes following Sudan III treatment in vivo. 391 57

5-Lipoxygenase (5-lipox) has been purified to homogeneity from the 20,000 xg supernatant of sonicated rat basophilic leukemia (RBL-1) cells using a 4-step procedure. Purification was achieved primarily through the use of anion-exchange HPLC on two different media. Using the supernatant from 1 X 10(9) cells, approximately 33 micrograms of the enzyme can be routinely isolated with an estimated net yield of 5-10%. Purified 5-lipox consists of a single Mr 73,000 band on SDS gels (reduced or unreduced). When the purified enzyme was incubated with radiolabeled arachidonic acid and products analyzed by both straight phase and reversed phase HPLC, 5-hydroperoxyeicosatetraenoic acid (5-HPETE) was the only enzymatic product detected. The purified enzyme exhibits the same characteristic lag phase and premature cessation of reaction as does the 5-lipox activity seen in crude cell homogenates.
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PMID:Purification of a mammalian 5-lipoxygenase from rat basophilic leukemia cells. 392 99

The viral antigenic determinants recognized in an autogenous immune response in mice against their endogenous C-type virus have been identified by SDS-polyacrylamide gel electrophoresis of immune precipitates between various sera and H(3)-labeled intact or disrupted AKR leukemia virus. Normal B6C3F(1) [(C57BL/6 x C3H/Anf)F(1)] serum reacts with viral envelope antigens having mol wt of approximately 68,000, 43,000, and 17,000. In addition, minor reactions with viral antigens having mol wts of approximately 19,000 and 15,000 are demonstrable. The 68,000 and 43,000 mol wt antigens can be labeled with [(3)H]glucosamine and may correspond to the major viral envelope antigens M(2) and M(1), respectively. The antigens recognized by autogenous immune sera do not differ with respect to age of the animal, nor are they significantly different in sera from various strains of mice (BALB/c, C57BL/6, and C3H/Anf). These results suggest that the age-asociated and strain variations in the autogenous immune response, as determined by radioimmune precipitation assays against intact virus, are due to quantitative and qualitative alterations of antibody levels against common antigens.
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PMID:Autogenous immunity to endogenous RNA tumor virus. Identification of antibody reactivity to select viral antigens. 436 35

LAV/HTLV-III has been closely linked to the acquired immunodeficiency syndrome (AIDS). We have studied and correlated the prevalence of AIDS-associated retrovirus and retroviral antibodies in several groups of male homosexuals from Greenwich Village. Retrovirus was detected in cultured peripheral blood lymphocytes by testing for reverse transcriptase (RT) and confirmed by establishment of virus-producer cell lines, and electron microscopy. Seventy-six percent of patients with AIDS, 93% with AIDS-related complex (ARC), 69% with generalized lymphadenopathy (LAS), and 35% of asymptomatic homosexuals were positive for virus in the RT assay. Transmission of the virus from RT-positive lymphocytes into the CEM cell line was successful in 10 of 11 randomly chosen cases. No virus isolates were obtained from lymphocytes of 8 heterosexual individuals. Serum antibodies against AIDS-associated virus were detected by indirect immunofluorescence assay and confirmed by Western blotting, using an LAV/HTLV-III-producer cell line, LAV-N1, which we established. LAV/N1 virus was purified by ultracentrifugation through sucrose gradient and the pattern of its proteins was determined by SDS-gel electrophoresis and Western blotting using sera from an AIDS patient. The major polypeptides of LAV/HTLV-III (19, 25-27, 32, 42 and 54 kilodalton) were present. These proteins did not react in Western blots with sera positive for Adult T cell leukemia virus (ATLV). thus, LAV-N1 and ATLV were not antigenically related. In our assay for LAV/HTLV-III antibodies, 18 (100%) of patients with AIDS, 13 (100%) of patients with ARC, 24 (69%) of 35 patients with LAS and 9 (39%) of 23 asymptomatic homosexuals were sero-positive. Heterosexual controls were negative. All IF-positive sera tested by Western blot contained antibodies against specific viral proteins. High titers (greater than or equal to 1:1280) of serum antibodies against LAV/HTLV-III virus were detected in 71% of AIDS patients, 62% with ARC, 38% LAS and 13% among asymptomatic homosexuals. Our data show that the presence of LAV/HTLV-III antibodies correlates with the presence of infectious virus. Antibody titers may also correlate with progression toward AIDS.
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PMID:Prevalence of AIDS-associated retrovirus and antibodies among male homosexuals at risk for AIDS in Greenwich Village. 608 26

Human T-cell leukaemia virus type III (HTLV-III) is suspected of having a key role in the pathogenesis of acquired immune deficiency syndrome (AIDS). Epidemiological data suggest that AIDS is transmitted by an infectious agent through intimate contact with body secretions, blood or blood products. To maintain haemostasis, many haemophiliac patients depend on commercially prepared clotting concentrates made from large multi-donor plasma pools and are thus at increased risk of developing the disease. We report here that, using indirect membrane immunofluorescence and radioimmunoprecipitation with SDS-polyacrylamide gel electrophoresis, we have detected antibodies to HTLV-III in 30 of 47 (64%) asymptomatic haemophiliacs and in all of three haemophiliacs who either had or soon developed AIDS. Of 34 samples drawn before 1984, 18 (53%) were antibody-positive, whereas of 16 samples drawn during 1984, 15 (94%) were positive (P less than or equal to 0.002). These data suggest that exposure to HTLV-III antigens is widespread among asymptomatic haemophiliacs.
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PMID:Aetiology of AIDS--antibodies to human T-cell leukaemia virus (type III) in haemophiliacs. 609 94

Endogenous retroviruses are not in the majority of cases the cause of any neoplasia, except for the laboratory conditions. As far as they might serve for the evolution of pathogenic retroviruses more attention should have been paid to them. In this paper we introduce some approaches to the purification of rat endogenous retroviruses to such a degree of purity that enabled satisfactory SDS-PAGE analysis of its structural proteins. Purities of samples obtained by usual purification methods, long-term isopycnic centrifugation at a high gravity force and velocity centrifugation are compared. Protein profile of rat endogenous virus in SDS-PAGE is compared with the ones of other retroviruses. For the first time the evidence was obtained for the striking similarity between electrophoretic protein profile of rat endogenous virus WERC and feline leukemia virus. The major structural proteins of rat endogenous retrovirus and feline leukemia virus cannot be distinguished even when resolution long gradient PAGE had been employed. The accordance of electrophoretic mobilities of major structural proteins in SDS-PAGE can indicate the relatedness of retroviruses.
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PMID:Purification and protein composition of endogenous rat viruses. 609 27


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