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)

A strategy to phenotype rare populations of hematopoietic cells expressing the cell-surface marker CD34 was studied. The antigenic phenotype of umbilical core blood (CB) CD34+ cells was investigated using flow cytometry and compared with the mRNA-phenotype determined by cDNA-polymerase chain reaction (cDNA-PCR) analysis. The cDNA-PCR method allowed an mRNA evaluation of small numbers of cells. Monoclonal antibodies and oligonucleotide primers that recognize myeloid, lymphoid, erythroid and platelet/megakaryocytic cell membrane antigens or corresponding mRNA transcripts were used. Evaluation by flow cytometry showed that the vast majority of CD34+ CB cells coexpressed CD38, CD18, HLA-DR, and CD33. Rare subpopulations of CD34+CD38-, CD34+CD18-, CD34+HLA-DR-, and CD34+CD33- were also identified. A large proportion of CD34+ CB cells expressed CD13, CD45R, and to a lesser extent CD71. The CD36, CD51, and CD61 antigens were identified on a small number of CD34+ cells. The three-color flow cytometry analysis showed that CD34+ cells stained with antibodies to CD61 and CD36 or CD51 can be divided into subsets that may represent progenitor cells committed to the erythroid and/or megakaryocytic lineage. A variety of other lineage-specific cell-surface antigens including pre-T-cell marker CD7 and markers of early B cells, ie, CD10 and CD19, were not coexpressed with CD34+. Using the cDNA-PCR it was seen that the mRNA phenotype of a small number of sorted CD34+ cells (purity > 98%) was negative for the markers CD2, CD14, CD16, CD20, CD21, CD22, CD41b, and glycophorin A that are expressed on differentiated cells but positive for CD34, CD7, CD19, CD36, and CD61. The results suggest that circulating CD34+CD7+ and CD34+CD19+ CB cells cannot be distinguished by flow cytometry but can be detected by cDNA-PCR. This indicates that CB either contains very low numbers of these progenitors or that the antigen density of CD7 and CD19 on CD34+ cells is below the detection limit of the flow cytometer. In contrast to flow cytometry, cDNA-PCR allows the phenotypic analysis of cells even if their number is small. Thus, the cDNA-PCR method can be useful in linking phenotype analyses, ie, markers of differentiation, to studies on gene expression within rare populations of hematopoietic stem cells.
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PMID:Phenotype analysis of hematopoietic CD34+ cell populations derived from human umbilical cord blood using flow cytometry and cDNA-polymerase chain reaction. 751 40

Circulating CD34+ progenitors were separated from normal human peripheral blood on the basis of size and density by counterflow centrifugal elutriation (CCE). The CD34+ cells, 0.15% of peripheral blood mononuclear cells, were heterogeneous with respect to their elutriation characteristics, mainly size and density. The least mature CD34+ cells, characterized by lack of CD38 antigen, were predominantly found in the small lymphoid cell fraction. In fractions containing larger and denser cells (large lymphocytes, monocytes, and granulocytes), CD38 was increasingly expressed on the CD34+ cells, as were lineage commitment markers CD10 (B lymphoid), CD33 (myeloid), CD13 (myelomonocytic) and CD71 (erythroid) antigens. The smaller and less dense CD34+ cells expressed CD34 antigen brightly while the larger and denser CD34+ cells expressed it dimly. The smaller and less dense CD34+ high cells failed to establish colony growth in short-term culture while the larger and denser CD34+low cells gave rise to high counts of colony forming units-granulocyte macrophage (CFU-GM). Physical separation on the basis of size and density by CCE differentiates between two main classes of steady-state CD34+ cells from normal human peripheral blood. The smaller and less dense CD34+high cells correspond to the earliest progenitors that express differentiation markers poorly but CD34 antigen brightly, do not give rise to short-term colony growth in vitro, and thus represent indirect evidence for pluripotent hematopoietic stem cells (PHSC). The larger and denser CD34+low cells are the more mature progenitor cells, already committed to myeloid, lymphoid or erythroid differentiation but only dimly expressing CD34 antigen, and these cells were responsible for short-term colony growth in vitro.
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PMID:Isolation and identification of two CD34+ cell subpopulations from normal human peripheral blood. 751 96

Respiratory epithelial cell surface neutral endopeptidase 24.11 (NEP-24.11) degrades proinflammatory peptides, and it has been suggested that glucocorticoids may reduce airway inflammation, in part, by upregulation of NEP-24.11. Despite the potential importance of the epithelium as a metabolic barrier, little is known regarding what other peptidases may be present on the epithelial cell surface. Using an immortalized bronchial epithelial cell line (BEAS-2B), we have shown that human epithelial cells express no detectable angiotensin-converting enzyme, carboxypeptidase N, or dipeptidyl(amino)peptidase IV, but express significant levels of aminopeptidase M (AmM), as well as NEP-24.11. The presence of these enzymes was demonstrated via their degradation of biologically active peptides and by flow cytometry. Exposure of cells to the glucocorticoid budesonide (10(-7) M) for up to 5 days did not markedly alter the expression of NEP-24.11 or AmM, as assessed by flow cytometry, nor did glucocorticoid treatment modify rates of peptide hydrolysis by NEP-24.11 or AmM. Thus, BEAS-2B cells have both AmM and NEP-24.11 on their surface, and expression of these enzymes is not altered by glucocorticoids.
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PMID:Glucocorticoids do not alter peptidase expression on a human bronchial epithelial cell line. 751 43

Using two-color flow cytometry, we analyzed the subpopulations of CD34+ stem and progenitor cells in the blood and bone marrow from 10 patients with hematological malignancies. Peripheral blood mononuclear cells (PBMNC) harvested after chemotherapy (high-dose Ara C and VP-16) and rhG-CSF, and BM mononuclear cells, which were obtained before chemotherapy (BMMNCbefore) and after the stem cell collection (BMMNCafter) were isolated by Ficoll-Hypaque centrifugation. The purified cells were stained with FITC-conjugated anti-CD34 antibody and one of the following PE-conjugated antibodies: anti-CD7, CD10, CD11b, CD11c, CD13, CD19, CD33, CD38, CD45RO, CD56, and HLA-DR. CD34+ PBMNC harvested and the CD34+ BMMNCafter expressed CD13 and CD33 more frequently than CD34+ BMMNCbefore but expressed CD10 and CD19 less frequently than CD34+ BMMNCbefore. These data suggested that harvested PBMNC contain more myeloid lineage committed progenitors than BMMNCbefore, which might contribute to the rapid recovery of neutrophils after peripheral blood stem cell transplantation. No significant phenotypic differences of CD34+ cells between harvested PBMNC and BMMNCafter were observed except for the expression of CD11c. CD34+ PBMNC harvested coexpressed CD11c more frequently than both CD34+ BMMNCbefore and CD34+ BMMNCafter, which expression might be associated with commitment to the monocyte lineage.
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PMID:Phenotypic differences of CD34-positive stem cells harvested from peripheral blood and bone marrow obtained before and after peripheral blood stem cell collection. 751 35

Analysis of SP and NKA metabolism by human vascular endothelium, relative to that in human plasma, identified integrative, multiple pathways for the processing of circulating SP (but not NKA) by angiotensin-converting enzyme (ACE; EC 3.4.15.1), dipeptidyl(amino)peptidase IV (DAP IV; EC 3.4.14.5), and aminopeptidase M (AmM; EC 3.4.11.2). In contrast, SP and NKA, which may diffuse into or be neurally released within the vessel wall, were both metabolized by smooth muscle neutral endopeptidase-24.11 (NEP-24.11; EC 3.4.24.11). Collectively, these studies indicate peptide-specific and site-specific differential processing of SP and NKA by human plasma and vasculature.
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PMID:Metabolism of substance P and neurokinin A by human vascular endothelium and smooth muscle. 752 48

Severe combined immunodeficiencies (SCID), a heterogeneous group of disorders of infancy, are fatal without treatment directed at immunologic reconstitution. Allogeneic bone marrow transplantation (BMT), which is such a treatment presents some unique features in SCID, especially when T-lymphocyte-depleted HLA haploidentical allografts are used. Donor-type T lymphopoiesis, less often B lymphopoiesis, develops, whereas myelopoiesis remains the recipient-type. Little is known about the engrafting cells in this peculiar lymphohematopoietic chimerism and the pathophysiology of the frequent failure of B-lymphocyte reconstitution. To address these issues, we purified CD34+ BM cells from a patient with selective T-lymphocyte reconstitution after HLA haploidentical BMT for B-SCID. Phenotypic analysis of CD34+ cells was performed by flow cytometry, and functional studies of donor- and recipient-type CD34+ cells were performed in vitro. Donor-type CD34+ cells, constituting approximately 2% of the CD34+ cells, were detected; both CD34+ HLA-DR- cells and CD34+ cells coexpressing B-(CD10 and CD19) and T-(CD2 and CD7) lymphocyte-associated cell surface molecules. Donor-type CD34+ cells coexpressing myeloid-associated molecules (CD13, CD14, CD15, and CD33) were undetectable. However, donor-type CD34+ myeloid progenitors could be shown in functional assays. Recipient-type CD34+ cells coexpressing B- and T-lymphocyte- as well as myeloid-associated molecules were detected, but recipient-type CD34+ cells could not be driven into T-lymphocyte differentiation in vitro. These findings provide evidence for engraftment of multipotent stem cells in our patient with B-SCID. Furthermore, the failure of B-lymphocyte reconstitution cannot be explained by lack of donor-type B-lymphocyte progenitors. Donor-type B lymphopoiesis and myelopoiesis are prevented by an unidentified mechanism.
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PMID:Evidence for engraftment of donor-type multipotent CD34+ cells in a patient with selective T-lymphocyte reconstitution after bone marrow transplantation for B-SCID. 752 43

Rat microglia in culture showed a high capacity to degrade neuropeptides compared with other glial cells. Leu-enkephalin was readily hydrolyzed to free tyrosine and Gly-Gly-Phe-Leu. Inhibition experiments and immunostaining revealed that aminopeptidase N (CD13) on the surface of microglia was responsible for enkephalin cleavage. Endopeptidase-24.11 ("enkephalinase"), angiotensin-converting enzyme, or carboxypeptidases could not be detected on microglia. Aminopeptidase N activity in microglia was considerably higher than in rat peripheral monocytes and macrophages, which both also exhibited low endopeptidase 24.11 activities. Activity of aminopeptidase N was upregulated by culture of microglia on astrocytes and down-regulated by exposure of microglia to lipopolysaccharide. The occurrence of aminopeptidase N on microglia is in line with the view that they originate from the monocytic lineage.
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PMID:Enkephalin metabolism by microglial aminopeptidase N (CD13). 753 37

Bone marrow (BM) is most frequently used to transplant hematopoietic progenitor cells, but umbilical cord blood (UCB) and mobilized peripheral blood (PB) provide alternative sources of progenitor cells for transplantation. To study whether the clonogenicity and phenotype of progenitor cells vary between the compartments, CD34+ cells from UCB, mobilized PB, and BM were analyzed for in vitro colony formation and characterized by immunophenotyping for several lineage-associated and maturation-related cell surface molecules. We found that circulating CD34+ cells, either from PB after granulocyte colony-stimulating factor (G-CSF) mobilization or from UCB, contained a large proportion of cells (86-96%) with myeloid cell-associated molecules (CD33 and CD13) and clonogenic cells (colony-forming unit-granulocyte-macrophage and burst-forming unit-erythrocyte) in excess of BM CD34+ cells. Further, UCB and PB CD34+ cells contained > or = 3% cells with a phenotype associated with immature (HLA-DR- and CD38-) progenitor cells, which was comparable to what is found among BM CD34+ cells. The proportion of CD34+ cells in UCB expressing the B cell-associated molecules (CD10 and CD19) was comparable to that found in mobilized PB (< or = 5%) but significantly lower than for BM CD34+ cells (19-24%). Further, we observed a higher proportion of CD34+ cells expressing the T cell-associated molecule CD7+ in UCB (7%) compared with both PB and BM (3-4%). In general, circulating CD34+ cells, either from UCB or G-CSF-mobilized PB, display largely the same phenotypic profile and clonogenicity, being different from resident CD34+ cells in BM.
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PMID:Comparison of the phenotype and clonogenicity of normal CD34+ cells from umbilical cord blood, granulocyte colony-stimulating factor-mobilized peripheral blood, and adult human bone marrow. 753 6

The immunophenotype of 110 adult patients with diagnosis of acute myeloblastic leukemia (AML) was analyzed using a wide panel of monoclonal antibodies (mAbs). Leukemic blasts were tested by applying direct immunofluorescence analysis and dual-fluorescence staining, and two groups of patients were identified: 56/110 (51%) expressing only myeloid antigens (My/AML) and 54/110 (49%) expressing both myeloid and lymphoid antigens (Ly/AML). CD13 and CD33 were expressed in almost all FAB subtypes, whereas CD14, frequently expressed in M4 and M5 subtypes (70%), was rarely expressed in M0 + M1 cases (9%). On the contrary, CD34, expressed in 77% of M0 + M1 cases, was practically absent in M3 and M5 subtypes (6% and 7%, respectively). CD2 and CD7 antigens were found in 34% and 42% of patients respectively, whereas B cell-associated antigens, such as CD10 and CD19, were found in 31% and 18% of patients. Cytogenetic abnormalities characteristically present in AML patients were also analyzed and, except for t(8;21) which was found in both groups of patients, the other abnormalities were frequently found in cases coexpressing lymphoid-associated antigens. Finally, the complete remission (CR) rate, survival and event-free survival were analyzed according to the presence of lymphoid markers and also of some specific antigens such as CD7 and CD34. The only prognostic difference was represented by CD34+ patients who showed a reduction in the CR rate compared with CD34- patients (65% versus 82%) (p = 0.05) which became more evident when the mean intensity of fluorescence was considered.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The presence of lymphoid-associated antigens in adult acute myeloid leukemia is devoid of prognostic relevance. 754 2

The rare t(2;14)(p13;q32) was previously described in the three pediatric patients with acute lymphatic leukemia. In these cases this abnormality was found at diagnosis, manifested the sole chromosomal abnormality, and was associated with a favorable prognosis. We here describe three cases of leukemia where such translocations were found at relapse, were associated in two of the cases with additional known characteristic chromosomal aberration, and were associated with a grave prognosis. Interestingly enough, the malignant cells of all three patients shared the same surface antigens: CD34, HLA DR, CD10, CD20, and the myeloid marker CD13. The leukemic clone exhibiting t(2;14) probably evolved from a t(1;19)6q- pre-B acute lymphatic leukemia in one of the cases, and from a chronic phase Ph1 chromosome in another. The significance of the translocation and the coexistence of CD10 and CD13 on the same cell are discussed.
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PMID:Translocation (2;14)(p13;q32) in CD10+ ;CD13+ acute lymphatic leukemia. 755 84


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