Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunomagnetic beads are well suited for positive selection of CD34+ cells. However, both unspecific binding of beads to cells as well as the effectiveness of detachment of beads from cells may represent significant problems. We used an anti-Fab antiserum (DETACHaBEAD, Dynal) for rapid and effective detachment of immunomagnetic beads from the positively selected cells. By this detachment technique, the cells remained phenotypically unaltered. To reduce unspecific binding, we have coated various anti-CD34 monoclonal antibodies directly to paramagnetic beads M450 (Dynal). Use of beads coated with BI-3C5 was found to be optimal with regard to yield and purity of the isolated cells. The yield was on average 1.5% (range 0.5-2.5%) of bone marrow mononuclear cells and the purity was usually greater than 95% CD34+ cells of the isolated cells. Subpopulations of the cells expressed myeloid markers (CD13, CD33, and to a lesser extent CD15 and CD14) or early B-lineage markers (CD19 and CD10). Most of the cells expressed CD38, and a majority of the cells also expressed CD41. In general, most of the CD34+ cells with low forward scatter expressed B-lineage markers, as was also the case for the few contaminating CD34- cells which were found to be predominantly CD37+ mature B cells. Reactivity with antibodies against T-lineage markers (CD2, CD3, CD4, CD7, and CD8) was generally detected only on 1-2% of the cells or less. Isolated cells responded to interleukin 3, granulocyte-macrophage colony-stimulating factor, mast cell growth factor, and/or granulocyte colony-stimulating factor alone or in combinations in short-term liquid cultures. The cells were also markedly enriched for granulocyte-macrophage colony-forming units as well as for early progenitor cells capable of forming blast colonies on preformed stromal feeder layers. Moreover, the CD34- population was depleted of 70-80% of CFU-GM and cells capable of blast colony formation. Thus, we conclude that the isolated cells are phenotypically unaltered after isolation, and show a normal response in various in vitro assays.
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PMID:Isolation and characterization of human hematopoietic progenitor cells: an effective method for positive selection of CD34+ cells. 137 14

Two novel cytokines, stem cell factor (SCF) and PIXY321 (a fusion protein, granulocyte macrophage colony-stimulating factor+IL-3), have recently been demonstrated to enhance in vitro adult myelopoiesis. In this study, we compared the success of separating very early hematopoietic progenitor cells (CD34+) from both cord blood (CB) and adult bone marrow (ABM) and their differential response to SCF, PIXY321, and other later-acting colony-stimulating factors (CSF). Briefly, CD34+ cells were isolated from CB and ABM with an anti-CD34 MAb, HPCA-1, and incubated with various combinations of SCF, PIXY321, and other CSF. The percentage of CD34+ cells was decreased in CB compared to ABM before separation (0.54 versus 1.71%) (p = 0.05). Isolated CD34+ cells from CB and ABM were similar in lineage with respect to CD38, HLA-DR, CD33, and CD5, but decreased in CB with respect to B-lineage expression (CD19, CD10, and CD22) (p = 0.05). SCF increased colony forming unit-granulocyte-macrophage (CFU-GM) formation from CB CD34+ cells compared to unconditioned media and had a significant additive increase with IL-3 (p = 0.006) and granulocyte colony-stimulating factor (p = 0.03). SCF also had an additive increase in CB CFU-GM formation with PIXY321 (p = 0.007). PIXY321 had a similar increase in CFU-GM formation from both CB and ABM CD34+ cells compared to the combination granulocyte macrophage colony-stimulating factor + IL-3. When SCF was added to IL-3, PIXY321, or PIXY321 + IL-6, there was an increase in CFU-GM from CB versus ABM CD34+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The in vitro effects of stem cell factor and PIXY321 on myeloid progenitor formation (CFU-GM) from immunomagnetic separated CD34+ cord blood. 138 18

The CD33 antigen, identified by murine monoclonal antibody anti-MY9, is expressed by clonogenic leukemic cells from almost all patients with acute myeloid leukemia; it is also expressed by normal myeloid progenitor cells. Twelve consecutive patients with de novo acute myeloid leukemia received myeloablative therapy followed by infusion of autologous marrow previously treated in vitro with anti-MY9 and complement. Anti-MY9 and complement treatment eliminated virtually all committed myeloid progenitors (colony-forming unit granulocyte-macrophage) from the autografts. Nevertheless, in the absence of early relapse of leukemia, all patients showed durable trilineage engraftment. The median interval post bone marrow transplantation (BMT) required to achieve an absolute neutrophil count greater than 500/microL was 43 days (range, 16 to 75), to achieve a platelet count greater than 20,000/microL without transfusion was 92 days (range, 35 to 679), and to achieve red blood cell transfusion independence was 105 days (range, 37 to 670). At the time of BM harvest, 10 patients were in second remission, one patient was in first remission, and one patient was in third remission. Eight patients relapsed 3 to 18 months after BMT. Four patients transplanted in second remission remain disease-free 34+, 37+, 52+, and 57+ months after BMT. There was no treatment-related mortality. Early engraftment was significantly delayed in patients receiving CD33-purged autografts compared with concurrently treated patients receiving CD9/CD10-purged autografts for acute lymphoblastic leukemia or patients receiving CD6-purged allografts from HLA-compatible sibling donors. In contrast, both groups of autograft patients required a significantly longer time to achieve neutrophil counts greater than 500/microL and greater than 1,000/microL than did patients receiving normal allogeneic marrow. CD33(+)-committed myeloid progenitor cells thus appear to play an important role in the early phase of hematopoietic reconstitution after BMT. However, our results also show that human marrow depleted of CD33+ cells can sustain durable engraftment after myeloablative therapy, and provide further evidence that the CD33 antigen is absent from the human pluripotent hematopoietic stem cell.
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PMID:Human bone marrow depleted of CD33-positive cells mediates delayed but durable reconstitution of hematopoiesis: clinical trial of MY9 monoclonal antibody-purged autografts for the treatment of acute myeloid leukemia. 157 39

Initiation of DNA synthesis by recombinant colony-stimulating factors (CSFs) was assessed in normal human marrow blast cells isolated by expression of CD34 antigen (tritiated thymidine incorporation). Continuous exposure to CSF was required. A mild increase in DNA synthesis was initiated by granulocyte CSF (G-CSF; greater than or equal to 1 ng/ml), to approximately 1.5 times control levels. A greater increase was initiated by granulocyte-macrophage CSF (GM-CSF), with a threshold of approximately 0.1 ng/ml and a plateau increment 2.5 times control levels. CD34+ cells were stimulated by interleukin 3 (IL-3) over a wide concentration range: two times control at 0.1/ml, three times control at 1 ng/ml, and four times control at 10 ng/ml. Overlap between responding populations was analyzed. G-CSF plus GM-CSF induced DNA synthesis greater than GM-CSF alone and supported the growth of much larger granulocyte-monocyte colonies. At saturating IL-3 concentrations, neither G-CSF nor GM-CSF induced additional DNA synthesis; at lower concentrations of IL-3, however, GM-CSF recruited additional cells into DNA synthesis. Using CD10 and CD19 antibodies to separate B-lineage cells, the CD34+ cells responding to CSF were observed to be in the non-B-lineage subset. Therefore 1) the response of CD34+ cell subsets CSFs is IL-3 greater than GM-CSF greater than G-CSF, and the IL-3-responsive population is heterogeneous for dose requirement; 2) a CD34+ subpopulation responding to concurrent G-CSF and GM-CSF includes increased proliferative potential cells; 3) IL-3-responsive cells include GM-CSF- and G-CSF-responsive cells, but cells responding to lower IL-3 concentration do not respond to GM-CSF; and 4) B-cell precursors do not respond to GM-CSF or IL-3 in this assay.
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PMID:Initiation in DNA synthesis by colony-stimulating factors in subsets of human CD34+ marrow cells. 171

Patients in first remission of acute lymphoblastic leukaemia (ALL) considered to be at high risk of relapse were offered autologous bone marrow transplantation (ABMT) using purged marrow as a therapeutic alternative to cranial irradiation and maintenance chemotherapy. Twenty-seven bone marrows taken in remission, were purged using monoclonal antibodies (anti CD7 for T lineage and anti CD10 and/or anti CD19 for B lineage leukaemias) plus rabbit complement. Retrospective analysis of 19 purged marrows by immunophenotyping or immunoglobulin gene rearrangement studies demonstrated no evidence of disease. Engraftment was seen in 26 of the patients. No correlation was found between the numbers of infused nucleated cells or colony forming units-granulocyte-macrophage (CFU-GM) and subsequent engraftment kinetics. The actuarial disease-free survival (DFS) is 32% at 7 years (median follow-up 3.4 years). There were two transplant related deaths (actuarial risk 8%); the main cause of treatment failure has been disease recurrence with an overall actuarial risk of 67%; 76% for T-ALL (five of nine), 62% for common ALL (five of 10), two of five pre B and none of three patients with B-ALL. In these 27 high risk patients in vitro purging of remission marrow as part of ABMT appears not to improve patient outcome, although confirmation of this would require a randomized trial.
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PMID:Failure of purged autologous bone marrow transplantation in high risk acute lymphoblastic leukaemia in first complete remission. 171 92

We show here that analysis of VpreB gene transcription can be a specific way to identify acute leukemias of cells at very early stages of B-cell development. Northern blot analysis of RNAs from 63 leukemia samples showed that VpreB RNA was present in malignancies of precursor B cells, the expression being a feature of both common acute lymphoblastic leukemia (ALL) (CD10+) and null ALL (CD10-). It was absent from malignancies of mature B cells (surface Ig positive), from acute leukemias of the T-cell lineage and granulocyte-macrophage lineages, and from normal tonsil B and T lymphocytes. Chronic myeloid leukemia blast crises of the B-precursor-cell type expressed the VpreB gene while myeloid blast crises did not. VpreB RNA was also expressed in the neoplastic cells of one of three patients with acute undifferentiated leukemias. These data show that VpreB RNA expression is a marker of the malignant forms of precursor B cells, and that it appears at least as early as cytoplasmic CD22 and CD19 in tumors of the B-cell lineage.
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PMID:VpreB gene expression in hematopoietic malignancies: a lineage- and stage-restricted marker for B-cell precursor leukemias. 188 24

Immunomagnetic bone marrow purging is becoming a widely used technique in many bone marrow transplant centres. Most centres use Dynabead magnetic particles to facilitate the procedure. The suitability of a novel magnetic particle (BioMag) for immunomagnetic purging was addressed in this study. Common acute lymphoblastic leukemia (ALL) cells were targeted using CD9 and CD10 mouse monoclonal antibodies prior to attachment of magnetic particles coated with anti-mouse immunoglobulin and depleted with samarium cobalt magnets. Immunofluorescent and clonogenic assays capable of measuring more than four log depletions of the Nalm 6 cell line showed that a single cycle of purging reduced target cells by 3.1 +/- 0.9 BioMag particles and 1.8 +/- 1.0 logs with Dynabeads. A second cycle of purging was advantageous, increasing target cell depletions to more than 4.5 logs with either particle type. Bone marrow granulocyte-macrophage colony-forming units were not significantly reduced. The results indicate that BioMag particles can be used for the efficient depletion of common ALL cells from bone marrow for transplantation.
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PMID:Immunomagnetic bone marrow purging of common acute lymphoblastic leukemia cells: suitability of BioMag particles. 205 57

A human plasma cell leukaemia cell line (HSM-2) and a subclone (HSM-2.3) have been established from the bone marrow of a patient with bi-phenotypic leukaemia. Proliferation assays using a variety of cytokines demonstrated that HSM-2 proliferated in response to recombinant interleukin-6 (rIL-6), but did not respond to rIL-1, rIL-2, rIL-3, rIL-4, rIL-5, recombinant granulocyte-colony stimulating factor (rG-CSF), or recombinant granulocyte-macrophage-colony stimulating factor (rGM-CSF), and that HSM-2.3 responded to rIL-3 and rIL-6. HSM-2 expressed the CD38 (OKT10), PCA-1, cytoplasmic-IgM, and surface kappa light chain. HSM-2.3 expressed the CD14 (My4), CD33 (My9), CD38 (OKT10), CD19 (B4), CD24 (OKB2), CD10 (J5), PCA-1. HSM-2 and HSM-2.3 are useful tools for analysing the possible role of IL-3 and IL-6 in the oncogenesis of plasma cell leukaemia.
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PMID:Establishment and characterization of a plasma cell leukaemia cell line dependent for growth on IL-6 and a bi-phenotypic subclone dependent upon both IL-3 and IL-6. 206 60

The effectiveness of a simple immunorosette technique for the depletion of common acute lymphatic leukemic (cALL) blasts from autologous bone marrow transplants was studied. Erythrocytes were sensitized with tetramolecular complexes consisting of rat anti-mouse IgG1 monoclonal antibodies (McAbs) that crosslink two different mouse McAbs. One of the McAbs was directed against glycophorin A, and the other was directed against marker glycoproteins of B cells and their precursors (CD9, CD10, CD19, or CD22). Immunorosettes were formed by addition of the sensitized erythrocytes to the cALL+ cells. After density-gradient separation of immunorosettes from mixtures of cALL+/terminal deoxynucleotidyl transferase-positive (TdT+) leukemic blasts and mononuclear bone marrow cells, nearly a 2-log depletion of leukemic cells was measured by flow cytometry. Clonogenic assays with two cALL+B-cell lines (Ros-17 and Nalm-16) were performed to compare the efficacy of complement-mediated cell lysis, immunorosette depletion, and a combination of both procedures. Complement-mediated cytotoxicity with the three McAbs in combination with baby rabbit complement yielded a 1- to 2-log cell kill. Immunorosette depletion resulted in a 3-log reduction of clonogenic units. Sequential application of the two methods (immunorosette depletion with CD19 McAb followed by a complement lysis with CD9 and CD10 McAbs) led to superior results in causing a 4- to 5-log purging effect. These purging procedures did not cause a loss of normal myeloid (granulocyte-macrophage colony-forming units, CFU-GM) or erythroid (erythroid burst-forming units, BFU-e) progenitors from the bone marrow. This study indicates that the combination of the two methods results in a highly efficient purging procedure for the removal of cALL+ cells from autologous bone marrow cells.
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PMID:Effective purging of bone marrow by a combination of immunorosette depletion and complement lysis. 229 69

We describe an immunomagnetic assay applicable to bone marrow purging of leukemic patients before an autologous bone marrow transplantation. An iron colloidal suspension with a CD10 monoclonal antibody (MoAb) against the common acute lymphoblastic leukemia antigen (CALLA) covalently bound to the surface of the particles has been used. NALM-6 cells, a pre-B leukemic cell line expressing the CALLA, were labeled with supravital DNA dye (Hoechst 33342), mixed with peripheral blood, and incubated with the MoAb coated to iron particles. Using this reagent, at a cell concentration of 2000/microliters, a purging effect greater than 3.5 logs is observed with 0.1 mg of coated particles. Three successive rounds of treatment with the same coated particles at the same dose showed approximately the same depletion after each treatment. The recovery of clonogenic myeloid progenitors (granulocyte-macrophage colony-forming units; CFU-GM) is around 75%. No depletion was observed when the iron particles were not attached to the CD10 MoAb, or when they were attached to a MoAb not recognizing CD10+ cells. A comparison with another commercially available magnetic support was also performed in order to evaluate the performance of our assay, which appears simple, efficient, cheap, and capable of handling large volumes of cells in sterile conditions and minimal time.
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PMID:Malignant leukemic cell separation by iron colloid immunomagnetic adsorption. 267 May 97


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