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)

Expression of decay-accelerating factor (DAF or CD55) and of CD59 during hematopoietic cell development in normal bone marrow and on peripheral blood leukocytes were characterized by three-color immunofluorescence experiments. With this technique cell subsets were identified by forward light scatter, orthogonal light scatter, and two cell-surface antigens. For each cell lineage, specific combinations of two monoclonal antibodies labeled with different fluorochromes were used. DAF or CD59 were then quantitated on the defined cell subsets from the fluorescence signal of the respective antibody conjugated with a third fluorochrome. Early uncommitted hematopoietic progenitor cells (CD34+, CD38-) all expressed both proteins homogeneously. Initial commitment to the erythroid (CD71+, CD45dim), myeloid (CD33+), or B lymphocyte (CD10+) lineages was not associated with changes in DAF or CD59 levels. With erythroid development, i.e., after loss of CD45 and decrease of CD71, expression of both proteins decreased. With myeloid maturation, expression of CD59 remained constant and expression of DAF varied. During neutrophil maturation, DAF decreased initially and then reemerged on maturing neutrophils concurrently with the appearance of CD16 (Fc gamma RIII), whereas during monocyte maturation, DAF increased concurrently with up-regulation of CD14. With B cell development, expression of DAF increased concurrently with down-regulation of CD10 and up-regulation of CD20, whereas expression of CD59 diminished slightly late in B cell maturation. Analysis of peripheral blood elements showed that monocytes, neutrophils, and B lymphocytes expressed both proteins homogeneously, but that in contrast to other cell subsets, which all expressed CD59, only a subset of (CD3+) T lymphocytes and (CD16+) Natural killer cells expressed DAF. The absence of DAF was not related to CD4 or CD8 expression or to the presence of activation markers (CD25+, CD38+), memory cell markers (CD58+, CD45RO+), or virgin T cell markers (CD45RA+), but was correlated with expression of CD11b (CR3) and CD11c (gp150/95). Although CD21+ (CR2) and CD35+ (CR1) cells all expressed DAF, CD11a (LFA-1) levels correlated inversely with those of DAF. Although the presence of CD55 and CD59 on early progenitor cells and throughout hematopoietic cell development is consistent with the requirements for both proteins in protection of host cells from complement-mediated injury, the physiological relevance of the unique patterns of variation for each cell lineage is unclear. Nevertheless, the availability of a detailed DAF and CD59 expression map in normal marrow will facilitate analyses of alterations during hematopoietic development that may occur in hematological disorders including paroxysmal nocturnal hemoglobinuria (PNH).
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PMID:Expression of the DAF (CD55) and CD59 antigens during normal hematopoietic cell differentiation. 128 89

To further characterize the function of the common acute lymphoblastic leukemia antigen (CALLA; CD10, neutral endopeptidase 24.11, NEP) in early lymphoid development, we have identified murine lymphoid progenitors expressing CD10/NEP and analyzed the effects of inhibiting the enzyme in in vitro assays of murine lymphoid differentiation. CD10/NEP transcripts and enzymatic activity were primarily restricted to the subpopulation of murine lymphoid progenitors, termed pro-B cells, which were isolated from bone marrow (BM) and modified Whitlock-Witte cultures and defined by coexpression of B220 and low levels of Thy-1. CD10/NEP transcripts and cell surface enzymatic activity were also detected in BM stromal cells known to support the development of B-lymphoid progenitors. In contrast, Abelson and H-ras transformed pre-B-cell lines were CD10/NEP- as were Thy-1-B220+ pre-B cells from BM and modified Whitlock-Witte cultures and Thy-1lowLin- (B220-Mac-1-GR-1-Ly-2/3-) uncommitted hematopoietic progenitors from BM. The expression of CD10/NEP on murine pro-B cells and BM stromal cells suggests a role for the enzyme in early B-cell ontogeny. In modified Whitlock-Witte cultures in which Thy-1lowLin- progenitors plated on BM stromal cells differentiate into Thy-1lowB220+ pro-B and Thy-1-B220+ pre-B cells, the addition of specific CD10/NEP inhibitors increased the number of lymphoid colonies at days 5 through 7 by 34% (P < .001). The results suggest that CD10/NEP participates in the regulation of the earliest stages of stromal cell-dependent B lymphopoiesis.
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PMID:CD10/NEP is expressed on Thy-1low B220+ murine B-cell progenitors and functions to regulate stromal cell-dependent lymphopoiesis. 138 16

The CD10/neutral endopeptidase (NEP) gene was identified in murine genomic DNA using a human CD10 cDNA probe. It is transcribed most abundantly in kidneys resulting in RNA transcripts of 3.4, 6.0, and 6.2 kb. The activity of the murine CD10/NEP shows identical kinetic parameters, Km and Ki, to those observed for this enzyme in other species. Two mAbs raised against rabbit NEP detect a 100 kDa protein by Western blot analysis; the antigen immunoprecipitated from extracts of lung shows specific NEP activity. CD10/NEP, as analyzed by Western blot and enzymatic activity, is expressed at high levels in kidney and lung, and at lower levels in liver, brain, thymus, spleen, and bone marrow. Analysis of bone marrow subpopulations indicate that the majority of CD10/NEP is associated with cells adherent to plastic and with subpopulations that do not express the surface markers AA4.1, B220, Mac-1, and Gr-1. These results suggest that CD10 is primarily associated with the stromal elements in murine bone marrow. A bone marrow stromal line, BMS 2.2, also expresses high levels of CD10/NEP. This peptidase activity on the surface of stromal cells may influence lymphopoiesis or other hematopoietic processes through the hydrolysis of regulatory peptides in the microenvironment.
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PMID:Characterization of murine CD10, an endopeptidase expressed on bone marrow adherent cells. 139 Apr 35

Leukocyte membrane markers have been examined within cryostat sections and cell suspensions of human fetuses aged between 4 and 18 weeks of gestation using a panel of monoclonal antibodies. The HLA-DR molecule was present on a population of erythroid cells and macrophages in liver sinuses at 34 days and periarteriolar splenic macrophages at 60 days of gestation. CD5, CD15 and CD45 antigens were detected at 6 weeks of gestation, whereas CD4, CD8, CD10, CD11c, CD14 and IgM were not expressed at this stage. These findings and ultrastructural examination of embryonic liver confirm early differentiation of macrophages in the pre-lymphatic developmental period.
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PMID:Expression of HLA-DR molecules and some other differentiation antigens within early human fetus. 147 23

The origin of the malignant stem cell in multiple myeloma, despite years of investigation by many laboratories, remains elusive. We have described a population of monoclonal circulating B-lineage lymphocytes that has been detected in all myeloma patients analyzed, both at diagnosis and after chemotherapy, and that has many properties consistent with its definition as either a stem cell compartment or an intermediate between the stem cell and the bone marrow localized plasma cells. On average, 40% to 50% of peripheral blood mononuclear cells are abnormal B cells that express CD10 and PCA-1 in conjunction with B-lineage markers CD19, CD20, and CD24 and variable expression of CD5. The B cells are monoclonal by Southern blot analysis and represent a highly pleiomorphic population. The migratory patterns of these cells are unknown, and their presence in blood may reflect cells in transit from a parent organ such as spleen to bone marrow for terminal differentiation, or they may originate in the bone marrow prior to circulation and seeding of other skeletal or extraskeletal sites. The working hypothesis underlying this work postulates that these abnormal B cells originate outside the marrow, giving rise to plasma cells only after migration to the bone marrow, which provides a microenvironment conducive to terminal plasma cell differentiation. Bone marrow plasma cells do not include an actively proliferating component and are terminally differentiated end stage cells. In contrast, the circulating abnormal B cells include proliferating cells and appear to be heterogeneous in differentiation stage. Analysis of CD45 isoform expression indicates a population continuously differentiating from a late B-cell stage through the early plasma cell stages to an end stage plasma cell. Quantitative and qualitative expression of CD45 has been shown to characterize B-cell development, with a high density of the CD45RA isoform on mature resting B cells, a transition to CD45R0 on activated B cells, and a gradual loss of total CD45, predominantly of the CD45R0 isoform, during plasma cell development until, on end stage plasma cells, all CD45 expression is lost. In myeloma patients, all of these B-cell stages are represented, with the least differentiated B cells occurring in blood, intermediate stages in both blood and marrow, the most differentiated B and/or plasma cells in the bone marrow.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Monoclonal circulating B cells in multiple myeloma. A continuously differentiating, possibly invasive, population as defined by expression of CD45 isoforms and adhesion molecules. 153 57

To provide baseline information on the immunoarchitecture of normal bone marrow, we studied cryostat-cut, frozen, and paraffin-embedded, fixed tissue sections prepared from 21 core biopsies of normal bone marrow obtained during bone marrow harvests for transplantation. A large panel of antibodies was applied that included, for frozen tissue, Leu-6 (CD1), T11 (CD2), Leu-3a (CD4), Leu-1 (CD5), Leu-2a (CD8), J5 (CD10), My7 (CD13), Leu-11 (CD16), B4 (CD19), B1 (CD20), B2 (CD21), Tac (CD25), My9 (CD33), T200 (CD45), NKH-1 (CD56), kappa and lambda chains, beta F1, Ki-67, HLA-DR, TQ1, and keratin, and for fixed tissue, leukocyte common antigen (CD45), L26 (CD20), LN1 (CDw75), LN2 (CD74), LN3, LN4, LN5, MB1 (CD45R), MB2, MT1 (CD43), MT2 (CD45R), UCHL1 (CD45R0), BM1, Ki-1 (CD30), Leu-M1 (CD15), lysozyme, KP1 (CD68), actin, S100, neuron-specific enolase, vimentin, and keratin. On fresh-frozen sections CD19 and CD2 were the most reliable and sensitive markers for B and T cells, staining 5% and 9% of marrow cells, respectively. Immunoglobulins generally showed heavy background staining, which frequently precluded an accurate assessment. The CD4 to CD8 ratio in the bone marrow was reversed from that of peripheral blood. On fixed tissues, leukocyte common antigen was found in 14% of the marrow cells, corresponding roughly to the lymphocyte population. L26, a pan-B-cell marker, stained 3% of the marrow cells. Among the other B-cell markers, LN1 and MB2 stained a large number of cells (40% to 70%), indicating reactivity with cells of the myeloid or erythroid series in addition to lymphocytes. Among the T-cell markers, UCHL1 and MT1 stained 66% and 50% of the cells, respectively, which could be explained by their cross-reactivity with myeloid cells. Nonspecific myelomonocytic markers (Leu-M1, KP1, and lysozyme) also showed reactivity in a high percentage of cells. No particular architectural distribution patterns of B or T lymphocytes were noted in either frozen or fixed bone marrow specimens. The results of this study provide normal baseline data for the immunohistologic application of hematopoietic and lymphoid markers on frozen or fixed bone marrow biopsy specimens.
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PMID:Immunoarchitecture of normal human bone marrow: a study of frozen and fixed tissue sections. 159 93

Rapid increases in the membrane expression of C3 receptors on granulocytes and monocytes in response to the anaphylatoxin C5a have previously been described. In this study we demonstrate increases in the membrane expression of neutral endopeptidase (NEP, CD10, CALLA), aminopeptidase N (APN, CD13), tyrosine phosphatase (CD45/CD45Ro) and the Fc R Fc gamma-RIII (CD16) on granulocytes within minutes of treatment with human C5a. Monocytes responded to C5a with increases in CD13 and CD45/CD45Ro. These membrane modulations could be prevented by preincubating the C5a preparations with anti-C5a mAb C17/5 but not by pretreating the cells with cycloheximide. Increases of CD10, CD13, and CD11b but not CD11a (LFA-1) were also observed in leukocytes from patients undergoing hemodialysis with cuprophan membranes. The increase of CD16 on granulocytes was dependent on the presence of plasma during in vitro activation with C5a indicating that plasma contains inhibitors which prevent the previously described loss of Fc gamma-RIII upon stimulation of the cells.
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PMID:Rapid increases in the membrane expression of neutral endopeptidase (CD10), aminopeptidase N (CD13), tyrosine phosphatase (CD45), and Fc gamma-RIII (CD16) upon stimulation of human peripheral leukocytes with human C5a. 168 87

Recombinant interferon alpha enhanced the MHC class I antigen density on human leukaemia/lymphoma cell lines REH, U-937 and HL-60, as measured by immunocytofluorometry using specific monoclonal antibodies. A similar effect was induced (as demonstrated in REH cells), also by human leukocyte interferon-alpha. The latter, however, caused no major alterations in the expression of leukocyte common antigen (ICA; CD45) and transferrin receptor (CD71) in the cell lines examined. In REH cells, there was no interferon-induced alteration of CD10 antigen (CALLA), which in this cell line is markedly down-regulated by 12-0-tetradecanoyl-phorbol-13-acetate (TPA). A decrease of CD4 antigen density on the cell membrane was induced by interferon-alpha in monoblastoid U-937 cells. No induction of MHC class I and II antigens by interferon-alpha was found in K-562 cell subline.
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PMID:Interferon alpha-induced modulation of leukocyte cell surface antigens: immunocytofluorometric study with human leukaemia/lymphoma cell lines. 168 18

Maturation of adult human bone marrow (BM) B cells is accompanied by the sequential acquisition and loss of characteristic cell surface antigens (Loken et al., Blood 70:1316). Little is known about these changes in fetal BM B cells. In order to compare fetal with adult B cell development, we performed three-color, flow cytometric analyses of cell surface antigens, as well as nuclear TdT staining, on lymphoid cells from fetal BM. Mononuclear cells isolated from fetal BM (18-22 weeks) were stained with combinations of antibodies against CD3, CD10, CD19, CD20, CD21, CD22, CD34, CD45, PCA-1, IgM, and HLA-DR. Analysis of six separate fetal BM specimens indicated that combinations of cell surface antigens were expressed on analogous populations in fetal and adult BM. Consistent with adult BM, greater than 95% of TdT+ cells within the CD10+ population were CD34+, whereas less than 5% were CD34-. This CD10+/CD34+/TdT+ population constituted 30-40% of the total B cell compartment, compared with 10% in adults. Quantitative changes in CD45 expression on fetal BM B cells defined three clear populations, as has been observed in adults. In striking contrast to adult BM, greater than 95% of CD19+ and greater than 95% of surface IgM+ cells were CD10+, indicating that CD10 is a pan-B cell antigen in fetal BM. Virtually no mature B cells expressing CD21, CD22, or PCA-1 were detected in fetal BM. Our results indicate a preponderance of immature phenotypes exist in the fetal BM B cell compartment. These immature cells can be grouped into three distinct populations, and probably correspond to expanded populations found less frequently in adult BM. This striking increase in the earliest identifiable stages of B cell ontogeny is consistent with an active expansion of cells destined to constitute the humoral immune system during fetal development.
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PMID:Multiparameter flow cytometric analysis of human fetal bone marrow B cells. 169 9

Waldenstrom's macroglobulinemia (WM) has been hypothesized to be a pleomorphic B-cell malignancy with persistent maturation towards plasma cells in all lymphoid tissue. This proposal is based on detection of a heterogeneous density of monoclonal Ig on peripheral blood B-cells in patients with WM. We now present data derived from 2- and 3-color immunofluorescence and flow cytometric analysis that strongly supports this hypothesis. Abnormally high numbers of B lineage cells, defined by expression of CD19, CD20, and CD24, were found among peripheral blood mononuclear cells (PBMC). These B-cells are monoclonal as defined by light chain expression and by the existence of rearranged Ig genes (Southern blot analysis), although they exhibit heterogeneity in the density of surface light chain. Unlike normal PBMC B-cells, the monoclonal B-cells bear CD5 and CD10 (CALLA), express adhesion and adhesion-related molecules (CD11b, CD9), and appear to be actively differentiating during the course of the disease, based on the pattern of CD45 isoform expression. At any given point in time, the population of monoclonal B-cells is heterogeneous in differentiation stage based on transitions in the expression of CD45 isoforms from expression of CD45RA, the high molecular mass isoforms of CD45, to the low molecular mass isoform CD45R0 which appears only on very late stage B-cells and early plasma cells. For one patient, analysis of CD45 isoform expression over 2 years showed that the monoclonal B-cell population as a whole progressed towards terminal differentiation as defined by loss of CD45RA and acquisition of CD45R0. This indicates a continuously differentiating lineage of an unusual B-cell phenotype, and/or malignant transformation of a distinct lineage of B-cells in WM.
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PMID:Transitions in CD45 isoform expression indicate continuous differentiation of a monoclonal CD5+ CD11b+ B lineage in Waldenstrom's macroglobulinemia. 170 44


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