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)

CD86 (B70/B7.2) is an antigen of the immunoglobulin superfamily expressed on monocytes, dendritic cells and activated B, T, and natural killer cells. CD86 was recently identified as a second ligand for the T cell antigens CD28 and CTLA-4, and plays an important role in the co-stimulation of T cells in a primary immune response. We report here the assignment of the CD86 gene to human chromosome 3 using Southern blot analysis on a panel of hamster x human somatic cell hybrid genomic DNA. Fluorescence hybridization in situ on metaphase chromosomes coupled with GTG banding (G-bands by trypsin using Giemsa staining) confirmed this assignment and localized the CD86 gene to 3q13-q23 region. The CD86 gene is, therefore, located in the proximity of the CD80 (B7/B7.1) gene, the first identified ligand for CD28 and CTLA-4, previously mapped to chromosome 3q13.3-q21. Deletions, inversions and insertions of chromosome 3q21-q26, as well as translocations of 3q21 with other chromosomes have been described in many cases of acute myeloid leukemia (AML), acute non-lymphocytic leukemia (ANLL), chronic myeloid leukemia (CML) and myelodisplastic syndromes (MDS), suggesting that this region contains several genes involved in the leukemic process.
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PMID:CD28/CTLA-4 ligands: the gene encoding CD86 (B70/B7.2) maps to the same region as CD80 (B7/B7.1) gene in human chromosome 3q13-q23. 753 61

Dendritic cells (DC) are professional antigen-presenting cells specialized in the initiation of primary immune responses. We were interested to know whether mature DC can be grown in vitro from peripheral blood mononuclear cells (PBMC) of patients with chronic myelogenous leukemia (CML), and whether they carry the Philadelphia (Ph) translocation. Using a method recently described, DC were generated from PBMC precursors of 12 patients with CML using GM-CSF, IL-4, and monocyte-conditioned medium. DC exhibited the typical morphology with thin cytoplasmatic processes and expressed high levels of MHC class II, CD86, and CD83 typical for mature DC. After sorting with the monoclonal antibody CD83, a cell population of more than 95% CD83 positive cells was obtained. The presence of the Ph translocation was analyzed in these cells, in PBMC, lymphoblastoid cell lines (LCL), and in phytohemagglutinin (PHA)-induced T blasts from the same patients by fluorescence in situ hybridization (FISH). In contrast to all other cells analyzed, the vast majority of DC (95.9 +/- 0.7%) displayed the Ph translocation, irrespective of disease stage or therapy. PBMC were predominantly positive for the Ph chromosome (67.6 +/- 7.3%), whereas only 11.4 +/- 1% of the B cells and 4.4 +/- 1.1% of the PHA blasts carried the Ph translocation. Using such leukemic DC as antigen-presenting cells, a primary CML-directed cytotoxic immune response in vitro was obtained, as shown by the specific recognition of Ph chromosome positive cells. We conclude that DC can be generated from blood progenitors of CML patients in vitro and exhibit, to a large extent, the Ph translocation. Such DC, which in a preliminary experiment have been able to induce a primary CML-directed cytotoxic immune response in vitro, might be ideal candidates for adoptive immunotherapy either by direct transfer of DC for in vivo generation of a T-cell response or by in vitro generation of CML-specific cytotoxic autologous or HLA-matched normal T-cell clones for use in vivo.
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PMID:Dendritic cells generated from blood precursors of chronic myelogenous leukemia patients carry the Philadelphia translocation and can induce a CML-specific primary cytotoxic T-cell response. 936 28

Various clinical and laboratory observations suggest that the leukaemia cells in chronic myeloid leukaemia (CML) are potentially immunogenic. Whilst the ability of the leukaemia cells to elicit an anti-leukaemic immune response in the allogeneic setting is established, it remains unclear why such anti-leukaemic response does not occur in vivo in the autologous setting. We previously demonstrated the presence of leukaemia-reactive T cells in a patient with CML. However, we found that the T cells were normally anergic unless pre-incubated in vitro in high-dose recombinant interleukin-2. We speculated that the T cell anergy was the result of a lack of the appropriate immune costimulatory molecules on the leukaemia cell surface. In this study, we confirm the absence of immune costimulatory molecules, CD80 (B7-1) and CD86 (B7-2), on leukaemia cells and demonstrated that these costimulatory molecules on the leukaemia cells can be upregulated by a combination of GM-CSF and IL-4. There was an associated restoration of leukaemia cell immunogenicity to autologous T cells in mixed lymphocyte leukaemia reactions, suggesting a possible enhancement of anti-leukaemic reaction. More importantly, T cells primed with 'activated' leukaemia cells were able to recognise fresh cytokine-naive leukaemia cells. Furthermore, leukaemia cells expressing the dendritic cell marker, CD1a, were also generated. Our findings therefore suggest the opportunity in future to use these combination cytokines in vivo or these leukaemia cells which have been activated in vitro for leukaemia immunotherapy.
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PMID:Cytokine enhancement of immunogenicity in chronic myeloid leukaemia. 944 20

We previously showed that in chronic myeloid leukaemia (CML), it is possible to induce costimulatory molecules, CD80/CD86, on leukaemia cells by culturing adherent peripheral blood mononuclear cells from these patients with IL-4 and GM-CSF. In addition to the expression of CD80/CD86 molecules, some of the leukaemia cells also expressed the dendritic cell marker, CD1a. When these leukaemia cells were used in mixed lymphocyte leukaemia reactions, they mediated autologous T cell proliferation not seen when fresh leukaemia cells were used as the stimulator cells. In this study, we showed that reinfusion of these immunogenic leukaemia cells to the autologous hosts resulted in priming in vivo of T cells so that they could respond to subsequent rechallenge in vitro with fresh autologous leukaemia cells. Although cytotoxic T cells against leukaemia cells were not demonstrated, these T cells could proliferate and produce interferon-y when cocultured in vitro with the leukaemia cells. Our findings therefore provide further evidence for the immunogenicity of these cultured leukaemia cells in CML.
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PMID:In vitro cytokine-primed leukaemia cells induce in vivo T cell responsiveness in chronic myeloid leukaemia. 989 22

In order to elucidate the possibility of costimulatory molecules-mediated immuno or immuno-gene therapy for human hematological malignancies, we analyzed 30 hematopoietic cell lines and cells obtained from 48 patients with hematological malignancies for the expression of costimulatory molecules such as CD80 and CD86. The 30 hematopoietic cell lines were composed of 4 cell lines derived from the patients with T-cell acute lymphoblastic leukemia (T-ALL), 3 from Philadelphia chromosome positive ALL (Ph1+ALL), 8 from acute myeloblastic leukemia (AML), 3 from acute promyelocytic leukemia (APL), 8 from chronic myeloid leukemia at blast crisis (CML-BC), 3 from Burkitt's lymphoma and one from follicular cell lymphoma. The expression of CD80 or CD86 was frequent on cell lines derived from the patients with CML-BC or Burkitt's lymphoma, while it was rare on cell lines from T-ALL. Subsequently we analyzed the cells obtained from 48 patients with hematological malignancies, which consisted of 6 samples from patients with ALL, 30 from AML, 2 from CML-BC, 3 from B-cell lymphoma and one from each acute mixed leukemia (AMixL), adult T cell leukemia (ATL), T-cell large granular lymphocytic leukemia (T-LGL leukemia), chronic lymphocytic leukemia (CLL), myelodysplastic syndrome (MDS)-RAEB in T, multiple myeloma (MM) or T-cell lymphoma. Among all the 48 cases, all cases except one case with CLL and two with B cell lymphoma were demonstrated to be negative for CD80 on the neoplastic cells. CD86 and HLA-DR were shown to be expressed in 50% and 88% of total 48 cases respectively. In 30 AML samples, CD86 was positive in 15 cases (50%), which was sharply in contrast with the finding that CD80 was not detected in any AML samples. HLA-DR was expressed in 25 AML samples (83%). We also treated seven human hematopoietic cell lines with IFN-gamma, IL-12 or IL-15 and observed whether these cytokines could induce or enhance the expression of CD40, CD54, CD58 and HLA-DR as well as CD80 and CD86. The present study demonstrated that the expression of CD86 could be upregulated not only by IFN-gamma, but also by IL-12 or IL-15 in some cell lines. These findings suggested the possibility that the absence of CD80 on neoplastic cells may be associated with the lack of efficient anti-tumor immunity in most patients with hematological malignancies and that the immuno or immuno-gene therapy manipulating the expression of costimulatory molecules such as CD80 may be a useful treatment modality for hematological malignancies.
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PMID:Expression patterns of costimulatory molecules on cells derived from human hematological malignancies. 989 58

Effective host T lymphocyte sensitization to malignant cells depends on successful antigen presentation. In this study, we examined the capacity of malignant myeloid progenitor cells of patients in the chronic phase of chronic myelogenous leukemia (CML) to acquire characteristics of activated dendritic cells (DCs) after intracellular calcium mobilization, thereby bypassing a need for third-party antigen-presenting cells. Treatment of purified CD33(+) CML cells from 15 patients with calcium ionophore (CI) consistently resulted in de novo expression of the costimulatory molecules CD80 (B7.1) and CD86 (B7.2), CD40 and the DC-specific activation marker CD83, as well as marked up-regulation of MHC class I and II molecules and the adhesion molecule CD54. Most of these changes occurred within 24 hr of treatment. Morphologically, CI-treated CML cells developed long dendritic projections similar to those seen in mature DCs. Functionally, CI-treated CML cells provided stimulation of allogeneic T lymphocytes 10- to 20-fold that of untreated CML cells or untreated monocytes. Fluorescent in situ hybridization of CI-activated CML cells confirmed their leukemic origin by displaying the typical bcr/abl fusion signal. No difference in bcr/abl translocation percentages between untreated and CI-treated CML nuclei was observed. These observations indicate that calcium mobilization may constitute a valuable approach for rapidly and reliably generating CML-derived DCs for immunotherapy of CML.
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PMID:Calcium signaling induces acquisition of dendritic cell characteristics in chronic myelogenous leukemia myeloid progenitor cells. 1046 8

CD34(+) hematopoietic stem cells from normal individuals and from patients with chronic myelogenous leukemia can be induced to differentiate into dendritic cells (DC). The aim of the current study was to determine whether acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) cells could be induced to differentiate into DC. CD34(+) AML-M2 cells with chromosome 7 monosomy were cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor alpha (TNFalpha), and interleukin-4 (IL-4). After 3 weeks of culture, 35% of the AML-M2 cells showed DC morphology and phenotype. The DC phenotype was defined as upmodulation of the costimulatory molecules CD80 and CD86 and the expression of CD1a or CD83. The leukemic nature of the DC was validated by detection of chromosome 7 monosomy in sorted DC populations by fluorescence in situ hybridization (FISH). CD34(+) leukemic cells from 2 B-ALL patients with the Philadelphia chromosome were similarly cultured, but in the presence of CD40-ligand and IL-4. After 4 days of culture, more than 58% of the ALL cells showed DC morphology and phenotype. The leukemic nature of the DC was validated by detection of the bcr-abl fusion gene in sorted DC populations by FISH. In functional studies, the leukemic DC were highly superior to the parental leukemic blasts for inducing allogeneic T-cell responses. Thus, CD34(+) AML and ALL cells can be induced to differentiate into leukemic DC with morphologic, phenotypic, and functional similarities to normal DC.
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PMID:CD34(+) acute myeloid and lymphoid leukemic blasts can be induced to differentiate into dendritic cells. 1047 34

We report a method to generate dendritic cells (DC) from frozen leukapheresis products of patients with chronic myeloid leukemia (CML), using sterile culture bags and serum-free culture medium, ie conditions feasible for re-infusion into the patient as part of immunotherapeutic protocols. Leukapheresis products were stored from harvests performed either at diagnosis (13 patients) or after chemotherapy with subsequent granulocyte colony stimulating factor (G-CSF) administration (9 patients), for Peripheral Blood Stem Cell (PBSC) collections. In the presence of optimal concentrations of GM-CSF (50 ng/ml) and IL-4 (40 ng/ml) CML progenitors differentiated on day 7 and 14 of culture to DC, expressing CD1a,HLA-DR and CD86 surface antigens. Mature DCs exhibited on average 12-fold higher allo-stimulatory capacity for CD4+ and CD8+ cells compared to non-cultured PBMC in mixed lymphocyte reaction (MLR). Only DCs obtained from CML patients at diagnosis exhibited bcr/abl fusion gene when tested by fluorescent in situ hybridization (FISH). CD34-selection on leukapheresis products from diagnosis (7 patients) resulted in later maturation of DCs (after 14-15 d), compared to the nonselected PBMC. CD34-selection significantly increased the DC growth, and improved the allo-stimulatory capacity in MLR (on average on day 14, 3.5- and 2.3-fold, respectively). Large differences were observed between individual patients and different leukapheresis products from the same patient. Our report demonstrates the possibility to generate ex vivo autologous functionally active DC in CML in a way that allows their clinical application as immunotherapeutic agents.
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PMID:Generation of dendritic cells from peripheral blood of patients at different stages of chronic myeloid leukemia. 1111 5

Although interferon alpha (IFN-alpha) is able to induce haematological remission in 60-80% of patients with chronic myeloid leukaemia (CML) in early chronic phase, major cytogenetic remissions are only achievable in 30-40%. Recent clinical data suggest that the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to IFN-alpha therapy can significantly improve the cytogenetic response in some patients, although the mechanism remains unknown. We hypothesized that the combination of GM-CSF and IFN-alpha induces the differentiation of dendritic cells, which subsequently stimulates a specific anti-leukaemic response. Monocytes from CML patients were cultured in GM-CSF and interleukin (IL)-4 (GM/IL-4)or in GM-CSF and IFN-alpha (GM/IFN-alpha). After 7 d, the number of cells exhibiting typical antigen-presenting cell (APC) morphology was equal in both groups, and fluorescence in situ hybridization (FISH) analysis confirmed that the APCs generated with GM/IFN-alpha were of leukaemic origin. Phenotypically, both sets of APCs expressed typical surface markers; however, CD86, CD83, CD11c, HLA-ABC and HLA-DR expression was significantly higher in the GM/IFN-alpha APCs, whereas CD1a expression was significantly lower. In mixed lymphocyte reactions (MLR), GM/IFN-alpha APCs stimulated the proliferation of allogeneic T cells significantly better than GM/IL-4 APCs. However, both groups of APCs stimulated autologous T-cell proliferation equally. Finally, we assessed the ability of GM/IFN-alpha APCs to induce a leukaemia-specific cytotoxic T-cell response. Some samples generated cytotoxic T lymphocytes (CTLs) that specifically lysed bcr-abl-positive target cells. These data show that the combination of GM-CSF and IFN-alpha, when used in vitro, induces the differentiation of malignant APCs with potent T-cell stimulatory capacity. Although there is no in vivo evidence to support these findings, it is possible that, when administered to CML patients, GM-CSF in combination with IFN-alpha results in the generation of highly stimulatory leukaemic APCs.
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PMID:Interferon alpha in combination with GM-CSF induces the differentiation of leukaemic antigen-presenting cells that have the capacity to stimulate a specific anti-leukaemic cytotoxic T-cell response from patients with chronic myeloid leukaemia. 1112 8

The ability of interferon-alpha (IFN-alpha) to induce dendritic cell (DC) differentiation in chronic myeloid leukemia (CML) was evaluated. Peripheral blood mononuclear cells from CML patients cultured with IFN-alpha and granulocyte-macrophage colony-stimulating factor (GM-CSF) developed a dendritic morphology. Fluorescence in situ hybridization demonstrated that the DCs harbored the bcr/abl translocation. The DCs prepared with IFN-alpha/GM-CSF expressed significantly higher levels of class I and II HLA than those grown in interleukin-4 (IL-4) and GM-CSF. The DCs prepared from newly diagnosed CML patients using IFN-alpha/GM-CSF expressed immunoregulatory proteins at levels comparable to normal DCs. In contrast, DCs cultured from CML patients who did not achieve a cytogenetic response to IFN-alpha expressed significantly lower levels of class I HLA, CD40, CD54, CD80 and CD86 than normal DCs. The expression of CD86 by CML DCs was enhanced when they were cultured with IFN-alpha/IL-4/GM-CSF, or when IFN-alpha/GM-CSF-treated cells were induced to mature by CD40 ligand. The DCs from IFN-alpha failures were less stimulatory than normal DCs in the allogeneic mixed leukocyte reaction. CML patients who had a cytogenetic response to IFN-alpha initially had low numbers of bone marrow DCs that increased significantly with treatment, while nonresponders had more prevalent DCs at baseline that showed no consistent change with treatment. Therefore, IFN-alpha can induce DC differentiation from CML progenitor cells both in vitro and in vivo. The therapeutic activity of IFN-alpha in CML may be due to its ability to stimulate the generation of DCs that can present CML-specific antigens. Resistance to IFN-alpha may result when DC differentiation becomes impaired.
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PMID:Interferon-alpha induces dendritic cell differentiation of CML mononuclear cells in vitro and in vivo. 1275 Jul 16


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