Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596978 (Leukemia)
 15,069 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.
Leukemia 1992 Aug
PMID:Isolation and characterization of human hematopoietic progenitor cells: an effective method for positive selection of CD34+ cells. 137 14

Gradual increase of CD38 on cells expressing CD34 characterizes the early cell differentiation pathway of normal human hematopoietic progenitors. In this study the coordinated expression pattern of CD34 and CD38 was assessed on leukemic blasts from bone marrow aspirates of 95 patients with newly diagnosed acute myeloid leukemia (AML). Expression was divided into six categories analogous to the differentiation pathway of normal bone marrow. The CD38 antigen was expressed on the leukemic cells of all patients and CD34+ leukemic cells were found in 79 patients (83%). In 93 patients, the leukemic cells were found along the differentiation pathway defined by CD34 and CD38. In 33 of the 93 patients, a part of the CD34+ cells did not express the CD38 antigen (categories 1 and 2). In another 33 patients, all CD34+ cells expressed CD38 (categories 3 and 4). In the remaining 27 patients, only cells were found which dimly expressed CD34 or did not express CD34 (categories 5 and 6). Of the 93 patients, 88 were treated with intensive chemotherapy according to the protocol of the German AML Cooperative Group. Of these, 21 died early and were not evaluable for treatment response. Complete remission was achieved in 14 of 22 patients (64%) in categories 1 and 2, in 19 of 26 patients (73%) in categories 3 and 4, and in 18 of 19 patients (95%) in categories 5 and 6. The event-free survival was significantly longer in patients of categories 5 and 6 compared to patients in categories 1 and 2 (p less than 0.01) and categories 3 and 4 (p less than 0.05), respectively. We conclude that in the majority of AML patients the immunophenotype of leukemic cells follows the early cell differentiation pathways defined by coordinated expression of CD34 and CD38 similar to that of normal hematopoietic progenitors. The presence of cells in the late cell differentiation stages (CD34+/-, CD38 /+) identifies patients with a higher complete remission rate and longer complete remission duration.
Leukemia 1992 Oct
PMID:Flow cytometric characterization of acute myeloid leukemia: IV. Comparison to the differentiation pathway of normal hematopoietic progenitor cells. 138 49

Non-adherent cord blood and bone marrow mononuclear cells were analyzed by multiparameter flow cytometry before and at day 2, 4, 7, and 11 of culture in recombinant interleukin 3 (IL-3) and granulocyte colony-stimulating factor (G-CSF, cord blood) or stem cell factor (SCF), IL3 and granulocyte-macrophage colony-stimulating factor (GM-CSF, BM) to assess the differentiation and maturational pathway of myeloid cells. Before cell culture cord blood contained progenitor cells (CD34+) in various differentiation stages (CD38(-)----CD38bright), mature lymphocytes, monocytes, and neutrophils, but no immature neutrophils and immature monocytes. During cell culture, all CD34+ cells acquired the CD38 antigen between day 2 and 5 of cell culture, the CD34 antigen was lost between day 5 and 11 of cell culture. Differentiation of cells into the myeloid cell lineage was characterized by the acquisition of both CD33 and CD71. The latter is indicative for the active proliferation of these cells. Maturation of the cells into the neutrophilic pathway was indicated by the acquisition of first the CD15 antigen followed by CD11b and CD16 respectively. Whereas maturation of the cells into the monocytic pathway was indicated by the acquisition of first CD11b followed by CD14 and a dim expression of both CD15 and CD16. In normal bone marrow, cells of various maturational stages are already present before cell culture. During cell culture differentiation of cells into the myeloid lineage and maturation of the cells along the monocyte and neutrophilic lineage followed identical pathways as was observed before cell culture. Differentiation and maturational pathways of cord blood and adult bone marrow were identical. The results confirm the surface-antigen-defined pathways of myeloid cell differentiation described previously for non-cultured normal bone marrow aspirates. The detailed assessment of cell maturation and differentiation of cultured cells by multidimensional flow cytometry permits the determination of the specific effects of various recombinant human growth factors on myeloid cells.
Leukemia 1992 Oct
PMID:Differentiation and maturation of growth factor expanded human hematopoietic progenitors assessed by multidimensional flow cytometry. 140 53

A new human plasma cell line, UMJF-2, has been derived from the bone marrow of a patient with multiple myeloma. Morphological studies disclosed large nucleoli, moderate numbers of mitochondria, and scant endoplasmic reticulum consistent with a plasmablastic morphology. The cells have immunologic characteristics of early plasma cells, including intense expression of cytoplasmic IgG-lambda and weaker, but discernible, expression of surface IgG-lambda. Cell surface antigens defined by the monoclonal antibodies OKT10 (CD38) and PCA-1, characteristic of mature plasma cells, and B1 (CD20), B4 (CD19), and I-2 (HLA-DR), characteristic of earlier stages of B-lymphocyte differentiation, are present on UMJF-2 cells. Cytogenetic studies reveal the presence of trisomy 12. UMJF-2 does not contain the Epstein-Barr virus by Southern blot analysis. Tissue culture media conditioned by these cells contains a soluble immunosuppressive factor, capable of inhibiting pokeweed mitogen induced IgM secretion by normal human B-lymphocytes. UMJF-2 provides a model for the study of the pathogenesis of polyclonal hypogammaglobulinemia in human multiple myeloma.
Leukemia 1991 Jul
PMID:Characterization of a new human multiple myeloma cell line, UMJF-2, which suppresses antibody production by B-lymphocytes in vitro. 164 57

Four human myeloma cell lines (MM-S1, MM-A1, MM-Y1 and MM-C1) were established from patients in the terminal stage of multiple myeloma. All the cell lines were PCA-1 positive and three were CD38 (OKT10) positive. The class of cytoplasmic immunoglobulin in each of these cell lines was identical to that of the monoclonal protein detected in each patient. Epstein-Barr virus nuclear antigen was negative in all cell lines. An examination of the tritiated thymidine uptake showed that all four cell lines proliferated in response to interleukin-6 (IL-6), while MM-S1 also responded to IL-5. Immunological staining with an anti-IL-6 receptor monoclonal antibody revealed the presence of receptors for IL-6 on the cells from each cell line. Three of them formed colonies dependent on IL-6 in methylcellulose semi-solid culture. All four cell lines grew better when human plasma was added as a supplement to the culture in comparison to fetal calf serum. Northern blot analysis showed that the three cell lines tested did not express IL-6 messenger RNA. These results indicate that these four cell lines are responsive to IL-6, but not by an autocrine mechanism, at least in the three lines examined.
Leukemia 1991 Jul
PMID:Establishment and characterization of four myeloma cell lines which are responsive to interleukin-6 for their growth. 207 43

In the past, studies on CD34+ cells have been based on the use of monoclonal antibodies conjugated with different fluorochromes that show different fluorescence intensity and yield variable results. Moreover, most of these studies have neither specifically focused on adult human BM samples nor have they used combinations to explore specifically the phenotype of myeloid committed CD34+ cells. The aim of the present study has been to characterize the normal human CD34+ precursor cells from adult BM in order to identify missing or extremely rare phenotypes that can be used for detecting minimal residual disease (MRD) in patients with AML. For this purpose we have utilized the fluorochrome conjugates that provide the most sensitive signals for identifying low antigenic expression, and the technique has been adapted to the characterization of cells present at very low frequencies. Normal human BM samples from 13 adult healthy volunteers have been analyzed using triple stainings at flow cytometry. The mean percentage of CD34+ cells detected was 0.72 +/- 0.33%; these cells displayed an heterogeneous light-scatter distribution. Most CD34+ cells coexpressed CD38 (96.7 +/- 5.7%), HLADR (81.6 +/- 14.0%), CD33 (84.7 +/- 18.3%), CD13 (84.6 +/- 16.2%) and CD71 antigens (65.5 +/- 9.1%). In addition, almost half of CD34+ cells were CD117+ (60 +/- 26.8%). Only a small proportion of CD34+ cells coexpressed CD4 (15.5 +/- 11.7%, CD36 (31.7 +/- 6.2%), CD61 (16.3 +/- 12.9%), CD41 (6.5 +/- 5.5%) or the lymphoid associated markers CD10 (18.6 +/- 11.8%) and CD19 (12.3 +/- 13.2%). Reactivity for the CD15 antigen was observed in a small population of CD34+HLADR+ cells (11.6 +/- 11.2%) although its intensity of expression was lower than that of the more mature granulocytic cells. No CD34+ cells displayed CD14, CD65, CD20, strong CD22, CD3 and CD56 antigens. Accordingly, most adult bone marrow CD34+ cells appeared to be committed to the myeloid lineage (CD13+/CD33+) and displayed an intermediate-to-large FSC/SSC while the lymphoid-committed CD34+ cells (CD19+, CD10+) were in a minority with low FSC/SSC values. By triple marker stainings several phenotypes of CD34+ precursor cells were found to be either undetectable or present at very low frequencies (< 1 x 10(-3)) in the normal human adult bone marrow. These data may be of great value for defining leukemia 'associated' phenotypes used to detect minimal residual disease in adult acute leukemia patients.
Leukemia 1995 Nov
PMID:Phenotypic analysis of CD34 subpopulations in normal human bone marrow and its application for the detection of minimal residual disease. 747 81

Retroviral gene transfer into hematopoietic cells has many experimental as well as clinical applications. Although transduction efficiency of retroviral vectors is higher than with conventional methods, selection of successfully transduced cells may become mandatory for efficient in vivo transfer. We have been evaluating a retroviral construct that meets the criteria for a clinically acceptable selection system. The Ser31 dihydrofolate reductase (DHFR) mutant confers resistance to methotrexate (MTX) due to decreased binding of the drug. while its enzymatic activity remains adequate for normal folate metabolism. Transduction of this vector into murine hematopoietic cells has been recently described and increase in MTX resistance could be observed. We investigated transduction of CD34-antigen positive subpopulations of hematopoietic progenitor cells and CD34-positive/CD38-negative subpopulations enriched for stem cells. We focused on two sources of primary hematopoietic cells, umbilical cord blood (UCB) and peripheral blood (PB) harvested from patients after mobilization with chemotherapy and/or cytokines. Both contain a large number of lineage restricted and pluripotent progenitor cells and can be expanded extensively ex vivo. Potential clinical applications of gene therapy in such cell populations include correction of inborn enzymatic diseases and support of high-dose chemotherapy by transplanting ex vivo transduced progenitor cells rendered more resistant to cytotoxic drugs. The feasibility and efficiency of retroviral transduction into UCB and PB has been reported recently.
Leukemia 1995 Oct
PMID:Increased resistance to methotrexate in human hematopoietic cells after gene transfer of the Ser31 DHFR mutant. 747 10

We previously demonstrated that TGF-beta 1 antisense oligodeoxynucleotides can release early CD34+ bone marrow progenitors from quiescence, and increase the numbers of mixed and large erythroid colonies. As Steel Factor (SF) has a similar effect on colony formation by CD34+ cells, we tested whether this factor acts by blocking the inhibitory effects of TGF-beta. That this is not generally the case was demonstrated by the finding that the combination of TGF-beta 1 antisense with SF in cultures of CD34+ bone marrow cells yielded enhanced colony formation that was more than additive when compared to cultures containing the single agents. This combination also yielded enhanced colony formation by CD34+ umbilical cord blood cells, but in this case, the effect was slightly less than additive. Thus in cord blood, some, but not all, of the progenitors that are maintained in quiescence by TGF-beta can be triggered into cycle by SF. However, the absolute number of CFU-GEMMs found in the antisense TGF-beta plus SF cultures of cord blood was 4-fold higher than that found in comparable bone marrow cultures. These data correlate well with our previous observations that umbilical cord blood contains 4-fold more CD34+ CD38- cells, the population found to respond to TGF-beta 1 antisense oligodeoxynucleotides.
Leukemia 1994 Mar
PMID:Additive effects of steel factor and antisense TGF-beta 1 oligodeoxynucleotide on CD34+ hematopoietic progenitor cells. 751 Mar 56

Acute leukemia cells express myeloid, B-lymphoid and T-lymphoid lineage specific antigens. Many acute leukemias express the hematopoietic progenitor cell antigen CD34. Three proposed models of the normal human hematopoietic stem cell include CD34+ Thy-1low Lin-, CD34+ CD38-, and CD34+ HLA-DR-. The patterns of expression of CD34, Thy-1, CD38, HLA-DR, and multiple lineage-specific antigens on 49 consecutive pediatric B-cell precursor acute lymphoblastic leukemia (ALL) cases submitted for immunophenotyping (36 at first diagnosis, 13 at relapse) were analyzed. CD34+ expression was observed in 67% of the cases. CD34+ expression correlated with Thy-1low expression and expression of myeloid antigens (p < 0.001 and < 0.025, respectively). The CD34+ Thy-1low phenotype was observed in 65% of the cases; the CD34+ CD38- or CD34+ HLA-DR- phenotypes were observed in only three cases. Examples of heterogeneous expression of CD34 and Thy-1 were found in six cases, but CD38 expression was always bright and homogeneous in all positive cases. The data from this analysis indicates that the CD34+ CD38- or CD34+ HLA-DR- phenotypes would be more useful than the CD34+ Thy-1low phenotype for distinguishing normal hematopoietic stem cells from leukemic cells in childhood B-cell precursor ALL.
Leukemia 1994 Nov
PMID:Immunophenotypic differences between putative hematopoietic stem cells and childhood B-cell precursor acute lymphoblastic leukemia cells. 752 89

A new human monoclonal plasma cell line, designated UTMC-2, was established from the pleural effusion of a patient with immunoglobulin (Ig)A kappa-related multiple myeloma. The cultured cells were Epstein-Barr virus-negative and exhibited the morphological and ultrastructural features characteristic of plasma cells. Immunohistochemical analyses revealed the presence of cytoplasmic IgA kappa as well as the plasma cell-associated surface antigens CD38 and CD56. Other B-cell markers, including CD10, CD19, CD20, and HLA-DR, were absent. The UTMC-2 cells were interleukin (IL)-6 responsive: Co-culture with IL-6 increased IgA kappa synthesis and cell proliferation in a dose-dependent manner. In contrast, an IL-6 antisense oligonucleotide had an opposite effect. Although the UTMC-2 cells expressed IL-6 mRNA (as demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR)) and contained IL-6, the concentration of this cytokine in cell culture supernatants was less than that detectable by the enzyme-linked immunosorbent assay (ELISA) employed (i.e. <3 pg/ml). Further, cell growth was not inhibited by polyclonal or monoclonal anti-IL-6 antibodies. Flow cytometric analysis revealed that IL-6 receptors present on the surface of the UTMC-2 cells were not saturated with endogenous IL-6. Taken together, these results indicate that, in this human plasma cell line, IL-6 functions uniquely in an intracellular autocrine fashion to enhance Ig synthesis and cell growth. In this respect, the UTMC-2 cells represent a novel resource for further study of the role of IL-6 in the pathogenesis of multiple myeloma.
Leukemia 1994 Dec
PMID:Characterization of a novel interleukin-6 autocrine-dependent human plasma cell line. 752 62


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