Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Donor lymphocyte responses to minor histocompatibility antigen (mHA) differences are involved in allo-responses between HLA matched pairs causing GVHD and graft-versus-leukaemia (GVL). Since some mHA are tissue-restricted, GVHD and GVL responses may be separable. We studied donor lymphocyte responses to patients with CML in a series of 10 HLA-matched sibling and 10 unrelated donor-recipient pairs comparing proliferation to recipient PHA blasts and CML cells and attempting to selectively deplete responses to PHA blasts in vitro. Responses in counts per min (c.p.m) to CML cells and PHA blasts were, respectively, 2809 +/- 2205 (SD) and 7376 +/- 1877 in related and 12,107 +/- 7191 and 26,136 +/- 22,479 in unrelated pairs. Autologous responses to PHA blasts were significantly lower (mean 779 +/- 735) (p < 0.001). Results correlated with clinical outcome: higher responses to recipient cells correlated with transplant-related death (p = 0.02 for CML and p = 0.06 for PHA blasts). Higher responses to CML correlated with GVHD grade > or = II (p = 0.025). Donor lymphocytes exposed to recipient PHA blasts for 5 days and treated with a ricin-conjugated anti-CD25 antibody retained over 75% of their response to CML but < 10% to PHA blasts. Similarly, depletion of response to CML but not to PHA blasts occurred when CML was the primary challenge. These results indicate that distinct populations of donor T cells respond to recipient leukaemic and non-leukaemic cells, and provide the basis for a clinically applicable technique to selectively deplete donor GVHD reacting cells while conserving GVL.
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PMID:Distinct T cell populations distinguish chronic myeloid leukaemia cells from lymphocytes in the same individual: a model for separating GVHD from GVL reactions. 785 26

Two patients with chronic myeloid leukaemia in cytogenetic relapse following T lymphocyte-depleted BMT were treated with transfusions of donor buffy coat leucocytes. In both patients the marrow reverted to a completely normal karyotype and was negative for the BCR-ABL fusion gene transcript by polymerase chain reaction analysis. Before buffy coat transfusion the cytotoxic T lymphocyte precursor frequency against pre-BMT patient leukaemia cells (Lk-CTLP) was lower than that against pre-BMT patient PHA-transformed lymphocytes (Ly-CTLP) in both cases. At 2 weeks (case 1) and 8 weeks (case 2) after transfusion this ratio inverted so that Lk-CTLP predominated. Natural killer (NK) function fell initially and then recovered to exceed pre-transfusion values prior to normalization of the bone marrow karyotype. These changes in cytotoxic T lymphocytes and NK cells following donor buffy coat transfusions for patients with relapsed chronic myeloid leukaemia after marrow transplantation support the concept of a graft-versus-leukaemia effect mediated by both MHC restricted and non-restricted pathways.
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PMID:T cell and NK cell mediated graft-versus-leukaemia reactivity following donor buffy coat transfusion to treat relapse after marrow transplantation for chronic myeloid leukaemia. 843 62

Monoclonal antibodies to CD3 have been shown to activate T cells in vivo and in vitro but have also been shown to render T cells anergic in vitro. In this study G4.18, a mouse IgG3 mAb, was produced that appeared to recognize CD3 by its binding to all peripheral T cells, including a population not recognized by mAb to TCR-alpha/beta that was presumed to be TCR-gamma/delta cells. It precipitated molecules in the 24-26 kd region consistent with the CD3 complex as well as molecules approximately 45 and approximately 49 kd that corresponded to TCR alpha and beta chains and a 92-kd complex. Incubating T cells for 24 hr with saturating concentrations of G4.18 caused modulation of the TCR complex. In vitro, it activated T cells but only if prebound to plastic. In solution it inhibited MLC and CML, but not PHA or Con A activation. In vivo, G4.18 was not toxic even in high doses, and this was thought to be due to the inability of this mAb to activate T cells in vitro because the rat lacks Fc receptors for mouse IgG3. Therapy with G4.18 resulted in transient modulation of TCR/CD3 on T cells and depletion of these cells from blood. G4.18 had no depleting effects by lymph node or spleen cells but caused marked, transient thymic involution. Therapy with G4.18 also induced indefinite survival (> 100 days) of PVG (RTIc) heart grafts but not skin grafts in DA (RTIa) hosts. These hosts with long-surviving cardiac transplants, when grafted from PVG skin, accepted these grafts but rejected third-party skin in first-set. Thus G4.18 was shown to induce long-term specific tolerance to an organ allograft.
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PMID:Induction of long-term specific tolerance to allografts in rats by therapy with an anti-CD3-like monoclonal antibody. 845 60

Existing evidence supports that CD4+ T lymphocytes play a role in the graft-versus-leukaemia (GVL) reaction after allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML), not only as initiators of the immune response but also as effectors of GVL. In BMT between HLA-identical pairs this CD4-mediated GVL would require CML cells to process and present antigens through MHC class II molecules. To investigate whether CML cells are capable of processing and presenting antigens, and suitable targets for CD4+ T-cell-mediated cytotoxicity, we generated HLA-DR1-restricted CD4+ cytotoxic T-cell clones that specifically recognized tuberculous purified protein derivative (PPD). We have shown that CML cells and B lymphoblastoid cell line (B-LCL) cells but not PHA-blasts from patients with CML processed exogenous antigen, PPD, and induced proliferative and cytotoxic CD4+ T-cell responses. Antigen presentation was blocked by antibodies to HLA-DR but not to MHC class I and by treatment with chloroquine and brefeldin. This indicates that CML cells use a classic MHC class II antigen processing pathway to present PPD antigens to CD4+ T cells. Cytotoxicity to CML was shown by antibody blocking studies to be mediated mainly through fas antigen. These findings indicate that donor CD4+ T cells alone are sufficient to mediate GVL effects following allogeneic BMT for CML.
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PMID:Alloreactive CD4+ T lymphocytes can exert cytotoxicity to chronic myeloid leukaemia cells processing and presenting exogenous antigen. 865 81

New understanding of the alloresponse following bone marrow transplantation supports the possibility that the graft-versus-host disease (GVHD) response can be separated from a favorable graft-versus-leukemia (GVL) effect. We used chronic myeloid leukemia (CML) cells to generate 122 recipient-reactive T cell clones from a closely HLA-matched sibling responder. Clones were tested for their proliferative response to stimulator CML cells or PHA-transformed (non-leukemic) lymphoblasts. Of 78 clones tested, 32 recognized both leukemia cells and PHA blasts, 19 only CML and four only PHA blasts. The remainder were non-specific responders. This functional specificity corresponded to distinct patterns of T cell receptor (TCR) V beta usage: clones recognizing CML cells preferentially used V beta 5, V beta 6/7 while clones recognizing both CML and PHA blasts or only PHA blasts preferentially used V beta 3 and V beta 8. It may therefore be possible to identify in vitro-generated myeloid leukemia-restricted donor T cells by their pattern of V beta usage. TCR V beta antibodies could thus be used to select and expand leukemia-restricted donor T cells for transfusion after BMT to specifically enhance the GVL response.
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PMID:Preferential usage of T cell receptor (TCR) V beta by allogeneic T cells recognizing myeloid leukemia cells: implications for separating graft-versus-leukemia effect from graft-versus-host disease. 915 63

We investigated the role of endogenous or exogenous nitric oxide (NO) on human lymphocyte function. We used sodium nitroprusside, nitroglycerine, S-nitroso-N-acetylpenicillamine, sodium nitrite and S-nitroso-L-glutathione as NO-generating compounds. All agents were used at doses that do not produce direct cytotoxicity as measured by trypan blue exclusion as well as chromium-51 release assay. The immune responses examined were peripheral blood lymphocytes (PBL) proliferation and IL-2 production after activation with OKT3 and PHA; allogeneic mediated proliferation and cell mediated cytotoxicity (CML) in MLR; IgG and IgM production after PBL activation with Con-A; proliferation and expression of IFN-gamma and IL-4 mRNA after activation of allogeneic CD4+T cell clones. Cytokine mRNA expression was measured by reverse transcriptase PCR. Our results show that proliferating lymphocytes do not produce a detectable amount of NO as measured by the Griess reaction. In separate experiments, the addition of NG-monomethyl-L-arginine (L-NMMA) did not affect lymphocyte proliferation. Sodium nitroprusside and nitroglycerine exerted a dose dependent antimitogenic effect, inhibited cytokine production and expression, CML generation and antibody production. DNA gel electrophoresis showed no evidence for enhanced programmed cell death. The antimitogenic effect could not be blocked by the NO scavengers, hemoglobin or methylene blue. In contrast, the other nitric oxide generating compounds did not inhibit lymphocyte mitogenesis. The results suggest that human lymphocytes do not produce appreciable amounts of NO to affect lymphocyte mitogenesis. Sodium nitroprusside and nitroglycerine have a potent but nonspecific immunoinhibitory effect on human lymphocyte function by a mechanism other than NO production. In addition, pharmacological levels of NO do not inhibit human lymphocyte mitogenesis.
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PMID:Analysis of the in vitro effect of exogenous nitric oxide on human lymphocytes. 920 99

The trisomy 8 found in malignancies may derive from a constitutional trisomy 8 mosaicism (CT8M), and in these cases the trisomy itself may be regarded as the first mutation in a multistep carcinogenetic process. To assess the frequency of CT8M in hematological dysplastic and neoplastic disorders with trisomy 8, an informative sample of 14 patients was collected. The data ascertained included chromosome analyses of fibroblast cultures and of PHA-stimulated blood cultures in patients with normal blood differential count, as well as possible CT8M clinical signs. One patient showed trisomy 8 in all cell types analyzed and undoubtedly has a CT8M; a second patient consistently showed trisomy 8 in PHA-stimulated blood cultures when no immature myeloid cells were present in blood and should be considered as having CT8M; a third patient, with Philadelphia-positive chronic myelocytic leukemia, was more difficult to interpret, but the possibility that she had CT8M is likely. A few clinical signs of CT8M were also present in these three patients. Our data indicate that the frequency of CT8M in hematological dysplastic and neoplastic disorders with trisomy 8 is approximately 15-20%.
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PMID:Trisomy 8 in myelodysplasia and acute leukemia is constitutional in 15-20% of cases. 1174 91

A method for preparation of purified human PWM stimulated B lymphoblasts and their usefulness as targets in CML is described. The purified B lymphoblasts were found to carry surface membrane immunoglobulin (SmIg) and HLA-DR antigens and were non E-rosette forming. In contrast, PHA-stimulated lymphoblasts were found to be E-rosetting, SmIg negative and without serologically detectable HLA-DR antigens, and thus were characterized as T lymphoblasts. Using B and T lymphoblasts in parallel as targets in CML, it was possible to demonstrate target determinants exclusively expressed by the B lymphoblasts.
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PMID:Human B-blast specific target determinants in CML: a methodological study. 1273 19

Exploiting the graft-versus-leukemia (GVL) effect in mismatched transplants requires its separation from graft-versus-host disease (GVHD). We generated leukemia-specific cytotoxic T lymphocytes (CTL) in three haplotype-mismatched, two class I-mismatched and two single HLA-A locus-matched stimulator-responder pairs. Six patients with chronic myelogenous leukemia and one patient with acute myeloid leukemia transformed from MDS were studied. CTL generated after 10 days stimulation with unselected leukemic peripheral blood mononuclear cells inhibited leukemic CFU-GM colony growth (>85% at 10:1 effector:target ratio) with no third-party colony inhibition. In five pairs, responders were cultured separately with leukemia cells, PHA-B or LCL from the stimulator. After 2-4 restimulations, the T cell repertoire was examined by flow analysis using Vbeta-specific antibodies. Test cultures (but not controls) showed preferential expansion of 1-4 Vbeta families either common to two or more stimulators or unique to a particular stimulator. Notably, we elicited leukemia-specific TCR Vbeta expansions on four out of five occasions. In two pairs, responder cells selected for the appropriate leukemia-specific Vbeta family were shown to have leukemia-specific cytotoxicity. These leukemia-restricted T-cells were CD8+ or CD4+ and CD25+ or CD57+. The results support the development of strategies to selectively deplete GVHD and conserve GVL reactivity in mismatched transplants.
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PMID:Tissue-restricted T cell alloresponses across HLA barriers: selection and identification of leukemia-restricted CTL in HLA-mismatched stimulator-responder pairs. 1290 Jul 73

The ABL tyrosine kinase inhibitor imatinib mesylate is highly effective in the treatment of CML and is increasingly used in the stem cell transplantation (SCT) setting. Since ABL-dependent intracellular signaling molecules are involved in T-cell activation, imatinib may affect T-cell responses in vivo, thus affecting T-cell function in CML patients, disrupting immune reconstitution after allogeneic SCT and/or impeding the graft-versus-leukemia effect. Here we demonstrate that imatinib inhibits PHA-induced proliferation of normal peripheral blood mononuclear cells at in vitro concentrations (1-5 micromol/l) representative of the pharmacological doses used therapeutically in vivo. The effect is not dependent on antigen-presenting cells because CD3/CD28-induced T-cell stimulation was similarly inhibited by imatinib. Dose-dependent inhibition of the proliferative response of purified CD8+ and CD4+ T lymphocytes to anti-CD3/CD28 was similarly observed and associated with reduction in IFN-gamma production. The inhibitory effect could not be ascribed to an increased rate of apoptosis but the expression of activation markers on CD3+ T cells was significantly reduced in the presence of imatinib (1-5 micromol/L). Inhibition of T-cell proliferation was reversible after removal of the drug from the cultures. Thus, imatinib inhibits T-cell proliferation in vitro, an effect that is APC-independent, reversible, and does not involve apoptosis induction.
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PMID:Imatinib inhibits the activation and proliferation of normal T lymphocytes in vitro. 1567 13


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