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

The aim of the current study was to determine whether immunization with synthetic peptides corresponding to the joining region segment of p210 bcr-abl chimeric protein can elicit CD8+ cytotoxic T lymphocytes (CTLs) capable of specifically lysing leukemia cells. BALB/c mice were immunized with peptides identical to the joining region segment of p210 bcr-abl protein. Class I major histocompatibility complex (MHC)-restricted bcr-abl peptide-specific CD8+ CTLs were elicited. The CTL clones were H-2 Kd restricted and specifically recognized a nonamer peptide of the combined sequence of bcr-abl amino acids but neither bcr nor abl amino acid sequence alone. Despite specificity and substantial lytic potential against syngeneic cell line incubated with exogenously supplied peptides, the bcr-abl peptide-specific CTLs failed to lyse syngeneic murine leukemia cells expressing human p210 bcr-abl protein containing the same bcr-abl joining region peptide sequence. Similarly, the bcr-abl peptide-specific CTLs did not lyse human bcr-abl-positive chronic myelogenous leukemia cells expressing murine class I MHC antigen (i.e., K562 cells infected with vaccinia virus expressing H-2 Kd). The appropriateness of the joining region segment of bcr-abl protein to serve as a T cell target depends upon whether that segment is presented by class I MHC in a concentration high enough to stimulate CTLs. The current experiments using murine peptide-specific CTLs could not establish that the joining region of bcr-abl protein is processed and presented by class I MHC antigen-processing pathway, but the possibility was not ruled out. Alternative models and/or strategies are necessary.
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PMID:CTLs specific for bcr-abl joining region segment peptides fail to lyse leukemia cells expressing p210 bcr-abl protein. 967 47

We describe the use of a high-throughput, fluorescent, polymorphism-detection system, based on single-strand conformation polymorphism to screen for polymorphism in the RING3 gene. This is the first extensive mutation screen of this major histocompatibility complex-linked gene, and the entire coding region and intron-exon junctions were examined by multiplexing over 3000 polymerase chain reaction products. These techniques should be applicable for analysis of variation in other human genes. Investigation of DNA from acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML) patients, as well as healthy individuals revealed low levels of polymorphism across the RING3 gene. Comparison of the distribution of genotypes at each polymorphic site between patients and healthy individuals revealed a single site which significantly deviates from Hardy-Weinberg proportions.
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PMID:Detection of polymorphism in the RING3 gene by high-throughput fluorescent SSCP analysis. 1007 88

Chronic myeloid leukemia (CML) is characterized by the chromosomal translocation t(9;22) resulting in the chimeric bcr-abl oncogene that encodes the P210 fusion protein, which contains a unique amino acid sequence. If peptides derived from the leukemia-specific part of P210 are expressed in HLA molecules on the cell membrane of leukemic cells, an immunological response may occur. Recent studies using synthetic peptides identical to the bcr-abl fusion region showed that some peptides are capable of binding to HLA-A3, -A11, and -B8 molecules. Cytotoxic T-cell responses have been induced against bcr-abl-derived synthetic peptides bound to HLA-A3 and -B8. We hypothesized that if antigen processing of the P210 fusion protein leads to presentation of peptides from the fusion region by major histocompatibility complex (MHC) molecules in vivo, this may be reflected in a diminished incidence of CML in individuals expressing HLA-A3, -A11, or -B8. Consequently, lower frequencies of these antigens would be expected in patients with CML compared with unaffected individuals. A case-control study and a meta-analysis were performed to test this hypothesis. The multicenter case-control study compared patients with CML from the data base of the European Group for Blood and Marrow Transplantation (EBMT) with unaffected individuals from the registry of Bone Marrow Donors Worldwide. Patients and controls were matched per country. The meta-analysis consisted of five studies reported in the literature. The multicenter case-control study consisting of 1,899 patients and 512, 363 bone marrow donors as controls yielded odds ratios (ORs) of 0.90 (95% confidence interval [CI], 0.80 to 1.00) for HLA-A3, 1.16 (95% CI, 1.02 to 1.33) for HLA-A11, and an OR of 0.73 (95% CI, 0.65 to 0. 82) for HLA-B8. Coexpression of HLA-A3 and HLA-B8 gave an OR of 0.51 (95% CI, 0.40 to 0.67). This can be translated in a protective effect of 27% for HLA-B8, 10% for HLA-A3, and 49% protection for the combination of HLA-A3 and HLA-B8. The meta-analysis comprising 463 CML patients and 4,912 controls showed a 29% risk reduction for individuals expressing HLA-B8 (OR of 0.71; 95% CI, 0.52 to 0.97), but an OR of 1.19 (95% CI, 0.90 to 1.56) for HLA-A3 and an OR of 1. 09 (95% CI, 0.80 to 1.50) for HLA-A11. In conclusion, these results indicate that HLA-B8 expression, in particular when HLA-A3 is coexpressed, is associated with a diminished incidence of CML. A biological mechanism may be that presentation of bcr-abl breakpoint peptides in these HLA molecules can induce a protective immune response.
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PMID:HLA-B8 and HLA-A3 coexpressed with HLA-B8 are associated with a reduced risk of the development of chronic myeloid leukemia. The Chronic Leukemia Working Party of the EBMT. 1033 94

Adoptive immunotherapy in form of donor leukocyte infusions is effective in a significant number of patients with chronic myeloid leukemia (CML) that have relapsed after allogeneic bone marrow transplantation (BMT). However, the therapy is associated with clinically significant side effects such as graft-versus-host disease (GVHD) and bone marrow (BM) hypoplasia that may be avoided through the administration of T cells with specific antileukemic activity. Dendritic cells (DC) functioning as potent antigen presenting cells (APC) may play an important role in the generation of T cells with specificity against CML. We examined a subpopulation of CD1a+/CD14- DC generated in vitro from BM of normal subjects and patients with CML using granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4). These DC derived from both the BM of normal subjects and of patients with CML, differentiated and matured in culture in a similar way. However, DC derived from patients with CML, displayed decreased activity when tested with allogeneic T cells in a mixed lymphocyte reaction (MLR). Addition of interferon-alpha (IFN-alpha) to DC cultures significantly upregulated the expression of major histocompatibility complex (MHC) molecules (class I and class II) and costimulatory molecules (B7.1 and B7.2) on DC from normal donors and CML patients. However, DC grown from CML patients required a higher concentration of IFN-alpha. IFN-alpha also significantly improved the capacity of CML DC to stimulate T-lymphocyte responses. Fluorescence in situ hybridization (FISH) showed that only some CD1a+/CD14- DC derived from BM of patients with CML expressed the bcr/abl fusion gene. Incubation with INF-alpha decreased the proportion of bcr/abl positive DC.
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PMID:Clonal heterogeneity of dendritic cells derived from patients with chronic myeloid leukemia and enhancement of their T-cells stimulatory activity by IFN-alpha. 1039 Jan 93

The advanced understanding of the molecular biology and immunology of chronic myeloid leukemia (CML) has led to novel therapeutic strategies unique to this disease. CML responds to immune-mediated therapies, including stem cell transplantation, donor lymphocyte infusion (DLI), and interferon alfa. T cells and other immune effectors are implicated in the mechanisms of action of these immune therapies. Recently, clinical observations supported by laboratory data have demonstrated the presence of CML-specific T cells in patients. Several proteins may potentially act as leukemia-specific antigens for major histocompatibility complex (MHC)-restricted cytotoxicity in CML, and active specific therapies (vaccines) are in development. Antigens under investigation include bcr-abl, PR1, Wilms tumor protein (WT1), minor histocompatibility antigens (mH), CML-66, CML-28, and survivin. Other strategies target vascular endothelial growth factor (VEGF) and heat shock protein 90 (Hsp90) inhibitors or make use of CML-derived dendritic cells (DC).
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PMID:Novel targeted and immunotherapeutic strategies in chronic myeloid leukemia. 1256 15

The graft-versus-leukemia (GVL) effect, mediated by donor T cells, has revolutionized the treatment of leukemia. However, effective GVL remains difficult to separate from graft-versus-host disease (GVHD), and many neoplasms are GVL resistant. Murine studies aimed at solving these problems have been limited by the use of leukemia cell lines with limited homology to human leukemias and by the absence of loss-of-function leukemia variants. To address these concerns, we developed a GVL model against murine chronic-phase chronic myelogenous leukemia (mCP-CML) induced with retrovirus expressing the bcr-abl fusion cDNA, the defining genetic abnormality of chronic-phase CML (CP-CML). By generating mCP-CML in gene-deficient mice, we have studied GVL T-cell effector mechanisms. mCP-CML expression of Fas or tumor necrosis factor (TNF) receptors is not required for CD8-mediated GVL. Strikingly, maximal CD4-mediated GVL requires cognate interactions between CD4 cells and mCP-CML cells as major histocompatibility complex-negative (MHC II(-/-)) mCP-CML is relatively GVL resistant. Nevertheless, a minority of CD4 recipients cleared MHC II(-/-) mCP-CML; thus, CD4 cells can also kill indirectly. CD4 GVL did not require target Fas expression. These results suggest that CPCML's GVL sensitivity may in part be explained by the minimal requirements for T-cell killing, and GVL-resistance may be related to MHC II expression.
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PMID:Graft-versus-leukemia in a retrovirally induced murine CML model: mechanisms of T-cell killing. 1498 74

Donor leukocyte infusion (DLI) can induce graft-versus-leukemia (GvL) reactions in patients with chronic myeloid leukemia (CML) relapsing after allogeneic bone marrow transplantation (BMT), but the mechanisms of the antileukemic effect of DLI are unknown, and the procedure is complicated by graft-versus-host disease (GvHD) and graft failure. Here, we adapted a murine retroviral BMT model of Philadelphia(+) leukemia by combining allogeneic bone marrow (BM) from C57Bl/6 (H-2(b)) mice with BCR-ABL-transduced Balb/c (H-2(d)) BM, inducing mixed chimerism and myeloproliferative disease in recipients resembling relapse of CML following allogeneic BMT. Infusions of allogeneic splenocytes eliminated BCR-ABL-induced CML-like disease in the majority of mixed chimeras, with significant GvL effects mediated by both CD4(+) and CD4(-) cells. BCR-ABL-induced acute B-lymphoblastic leukemia was also eradicated by DLI in major histocompatibility complex (MHC)-mismatched chimeras. Most DLI-treated mice converted to full allogeneic chimerism but succumbed frequently to GvHD or graft failure. When MHC-matched B10.D2 (H-2(d)) mice were the allogeneic donors, CML-like disease was more resistant to DLI. These results suggest that depletion of CD8(+) cells from DLI could impair GvL against CML, while increased MHC disparity between donor and recipient may improve the responsiveness of Philadelphia(+) B-lymphoblastic leukemia to DLI.
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PMID:Adoptive immunotherapy of BCR-ABL-induced chronic myeloid leukemia-like myeloproliferative disease in a murine model. 1530 67

In chronic myeloid leukemia, bcr-abl+ monocytes provide a unique opportunity to generate dendritic cells (DC) expressing a broad spectrum of leukemic antigens, and bcr-abl+ DC vaccines may allow immunological eradication of leukemic cells persisting under treatment with the tyrosine kinase inhibitor imatinib. However, the efficiency of bcr-abl+ DC vaccines will critically depend on the absence of deleterious effects of bcr-abl and of imatinib on DC functions. We show that bcr-abl+ monocytes, devoid of contamination of CD14low granulocytic precursors, differentiate into DC with typical immunophenotypical and functional features, and bcr-abl transcription decreases simultaneously. During differentiation, imatinib induces a slight increase of DC apoptosis and prevents CD1a up-regulation in a dose-dependent manner in bcr-abl+ and normal monocyte-derived DC, but at most, 25% of DC fail to acquire CD1a. When DC maturation is induced in the presence of imatinib, bcr-abl+ and normal monocyte-derived DC up-regulate major histocompatibility complex and costimulatory molecules, CC chemokine receptor 7 and CD83. However, secretion of interleukin-12p70 is decreased in a dose-dependent manner. Imatinib exposure of bcr-abl+ and normal monocyte-derived DC during differentiation and maturation is not detrimental to T cell immunostimulatory functions of DC. In sharp contrast, imatinib, when added to DC-T cell cultures, profoundly suppresses DC-mediated T cell proliferation, despite reciprocal DC-T cell activation attested by up-regulation of CD25 on T cells and of CD86 on DC. Our findings demonstrate that T cells, not normal or bcr-abl+ monocyte-derived DC, are major targets for imatinib immunomodulatory effects. It can be envisioned already that imatinib-free windows will be required to enable vaccination-induced, leukemia-specific T cell expansion.
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PMID:Imatinib mesylate minimally affects bcr-abl+ and normal monocyte-derived dendritic cells but strongly inhibits T cell expansion despite reciprocal dendritic cell-T cell activation. 1646 46

Identification of cytotoxic T lymphocyte (CTL) epitopes from additional tumor antigens is essential for the development of specific immunotherapy of malignant tumors. CML28, a recently discovered cancer-testis (CT) antigen from chronic myelogenous leukemia, is considered to be a promising target of tumor-specific immunotherapy. Because HLA-A*0201 is one of the most common histocompatibility molecule in Chinese, we aim at identifying CML28 peptides presented by HLA-A*0201. A panel of CML28-derived antigenic peptides was predicted using a computer-based program. Four peptides with highest predicted score were synthesized and tested for their binding affinities to HLA-A*0201 molecule. Then these peptides were assessed for their immunogenicity to elicit specific immune responses mediated by CTLs both in vitro, from PBMCs sourced from four healthy HLA-A*0201(+) donors, and in vivo, in HLA-A*0201 transgenic mice. One of the tested peptides, CML28((173-181)), induced peptide-specific CTLs in vitro as well as in vivo, which could specifically secrete IFN-gamma and lyse major histocompatibility complex (MHC)-matched tumor cell lines endogenously expressing CML28 antigen and CML28((173-181) )pulsed Jurkat-A2/Kb cells, respectively. These results demonstrate that CML28((173-181) )is a naturally processed and presented CTL epitope with HLA-A*0201 motif and has a promising immunogenicity both in vitro and in vivo. As CML28 is expressed in a large variety of histological tumors besides chronic myelogenous leukemia, we propose that the newly identified epitope, CML28((173-181)), would be of potential use in peptide-based, cancer-specific immunotherapy against a broad spectrum of tumors.
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PMID:Identification of a new HLA-A*0201-restricted cytotoxic T lymphocyte epitope from CML28. 1653 71

The purpose of this study was to investigate the mechanism of effects of interferon-alpha (IFN-alpha) on chronic myeloid leukemia (CML). Bone marrow mononuclear cells (BMMNC) were obtained from heparinized blood of CML patients by Ficoll-Paque density gradient centrifugation. The expressions of CD1a, CD83, CD86, HLA-ABC, HLA-DR and CD54 on DC induced by IFN-alpha + GM-CSF, IFN-alpha + GM-CSF+IL-4 and IL-4 + GM-CSF for 7 days in vitro were assayed by flow cytometry. The morphologic features were observed by transmission and optical microscopy. The mixed lymphocyte reactions (MLR) with DC were evaluated by MTT assay. The results showed that the DC cultured in different cytokine combinations expressed significantly higher levels of CD1a, HLA-ABC, HLA-DR, CD86, CD54, and CD83 than those in the precultured. The DC growing with IFN-alpha + GM-CSF expressed significantly higher levels of HLA-ABC, HLA-DR than those in GM-CSF + IL-4. The CD86 expression and MLR levels in IFN-alpha + GM-CSF + IL-4 increased significantly. The expression rate of DC antigens and MLR in the IFN resistant group significantly lower than those in the newly diagnosed and the effectively treated groups after at least 6 months of IFN-alpha treatment (P < 0.05). The DC from the IFN resistant group did not express significantly CD86 and MLR in IFN-alpha + GM-CSF + IL-4 groups compared to those in the newly diagnosed and IFN effective treated groups. It is concluded that the BMMNC from CML cultured in combination with IFN-alpha and other cytokines can be induced into DC with typical morphologic and immunophenotypic characteristics. Addition of IFN-alpha + GM-CSF + IL-4 to DC cultures can significantly up-regulate the expression of major histocompatibility complex molecules, co-stimulatory molecules and various adhesion molecules. The deficiency of DC differentiation and function may play a role in the development of clinical resistance to IFN-alpha.
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PMID:[In vitro cytokines-induced differentiation in mononuclear cell derived dendritic cells from chronic myeloid leukemia]. 1658 10


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