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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bovine leukemia virus (BLV), an oncovirus related to human T-cell leukemia virus type I, causes a B-cell lymphoproliferative syndrome in cattle, leading to an inversion of the T-cell/B-cell ratio and, more rarely, to a B-cell lymphosarcoma. Sheep are highly sensitive to BLV experimental infection and develop B-cell pathologies similar to those in cattle in 90% of the cases. BLV tropism for B cells has been well documented, but the infection of other cell populations may also be involved in the BLV-induced lymphoproliferative syndrome. We thus looked for BLV provirus in other leukocyte populations in sheep and cattle by using PCR. We found that while B cells harbor the highest proviral load, CD8+ T cells, monocytes, and granulocytes, but not CD4+ T cells, also bear BLV provirus. As previously described, we found that persistent lymphocytosis in cows is characterized by an expansion of the CD5+ B-cell subpopulation but we did not confirm this observation in sheep in which the expanded B-cell population expressed the CD11b marker. Nevertheless, BLV could be detected both in bovine CD5+ and CD5- B cells and in sheep CD11b+ and CD11b- B cells, indicating that the restricted BLV tropism for a specific B-cell subpopulation cannot explain its expansion encountered in BLV infection. Altogether, this work shows that BLV tropism in leukocytes is wider than previously thought. These results lead the way to further studies of cellular interactions among B cells and other leukocytes that may intervene in the development of the lymphoproliferative syndrome induced by BLV infection.
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PMID:In vivo leukocyte tropism of bovine leukemia virus in sheep and cattle. 820 33

Surface phenotypes and adhesion activity to human umbilical vein endothelial cells (HUVECs) were studied using leukemic cells from 12 Japanese patients with B-cell chronic lymphoid leukemias including 7 with chronic lymphocytic leukemia (CLL), 1 with prolymphocytic leukemia (PLL), 2 with hairy cell leukemia (HCL) and 2 with HCL variant (HCL-V). CD13 and CD23 were found to be characteristically positive in CLL, whereas they were not expressed in non-CLL cases except for positivity of CD23 in two such cases. Except for CD11b, all other leukocyte integrins examined (CD11a, CD11c and CD18) and their ligand (CD54) were highly expressed in non-CLL cases. Adhesion activity of leukemic cells to HUVECs after co-culture with HUVECs was well correlated with the expression of CD11b, CD18 and CD54, but showed no predilection for any leukemia subtype. Positivity for CD5, CD21, CD23 and CD13 changed after the co-culture with HUVEC. These results suggest that adhesion activity after co-culture. does not correlate with the leukemia subtype and that endothelial cells activate or differentiate leukemic cells.
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PMID:Surface phenotype and adhesion activity of B-cell chronic lymphoid leukemias. 822 Jan 19

The cell line AG-F was isolated from the marrow of a neuroblastoma patient undergoing myeloablative treatment and autologous bone marrow rescue. A year later, the patient developed a Hodgkin's type lymphoma. AG-F cell line demonstrated an unusual phenotype, lacking surface CD2 and CD3, but expressing high levels of CD4, CD5, CD7, CD29, and CD45RO. Markers associated with Hodgkin's lymphoma cells, CD15 and CD30, were also positive. AG-F cells grow in suspension in clusters of 50-200 cells, with a doubling time of 9 h. They can also grow in serum-free medium and form tumors in nude mice. AG-F cells have amplified N-myc and c-myc and high levels of the corresponding mRNA transcripts. Cytogenetic analysis revealed a DNA index by flow cytometry of near tetraploid cells and a karyotype of 85-87 chromosomes, with consistent abnormalities in chromosomes 1, 5, and 9. Gene rearrangement studies revealed rearrangement of the beta gene of the T-cell receptor. AG-F cells secrete high levels of IL-6, IL-8, IL-10, and GM-CSF. Cell adherence and formation of long processes could be induced by fibronectin and were enhanced by exposure to PMA. Cells exposed to phorbol myristate acetate (PMA) had increased expression of CD11a, CD11b, CD18, CD45RO, and HLA-DR, whereas expression of CD15 and CD30 was markedly decreased. Similarly, the level of c-myc and N-myc oncoproteins and the levels of the cytoskeletal proteins, actin, tubulin, and vimentin markedly decreased early after PMA-induced differentiation.
Leukemia 1993 Dec
PMID:Isolation and characterization of an early T-helper/inducer cell line with a unique pattern of surface phenotype, constitutive cytokine secretion and myc oncogene expression. 825 4

Leukemia cells from ten patients with B-cell chronic lymphocytic leukemia (B-CLL) and one with B-CLL of mixed cell type (B-CLL/PL) were analyzed to delineate the cellular characteristics, especially the myelomonocytic nature. Most of the surface phenotypes were consistent with the previous reports. However, the frequency of positivity for CD22 and CD25 was much higher in the examined cases of B-CLL than in Western reports. B-CLL cells frequently possessed antigens which are mainly expressed in myelomonocytic cells: 8/10 for CD11b and 4/10 for CD11c, although the presence of CD14 was not apparent (0/10). In addition, colony stimulating factor-1 receptors (CSF-1R) were expressed in 6 of the 10 B-CLL cases. The reactivity with antigens such as CD14, CD11c, and CSF-R was markedly enhanced by in vitro incubation. Alterations in antigen expression and in in vitro survival by growth factors for myelomonocytic lineage were observed in certain cases. These data imply that not only are B-CLL cells phenotypically closely related to myelomonocytic lineage but that they may also be influenced by growth factors for that lineage.
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PMID:Myelo-monocytoid immunophenotypes of B-cell chronic lymphocytic leukemia cells. 828 29

Morphologically well classifiable leukemias can reveal a mixed phenotype. A case of acute myeloid leukemia (CD13, CD33, CD14, CD11b) which at presentation showed a co-expression of B-lymphoid markers (CD19, CD10, CD20), at the time of the first relapse revealed a morphologic, phenotypic and genotypic switch of the blasts to a purely lymphoid form. Analysis of the immunoglobulin (Ig) H chain locus and of the T-cell receptor (TCR) genes showed at diagnosis a germline configuration of the IgH, TCR beta and tau genes, and a deletion of the TCR delta gene at the second chromosome. At relapse, monoclonal rearrangements of the IgH, TCR tau, and TCR delta were detected. At a subsequent relapse, the blasts re-expressed myeloid morphologic features and myeloid-associated antigens, while they retained the same rearranged configuration of the IgH and TCR beta and delta genes. The TCR delta gene configuration, which links each phase of the disease, may represent an early pathogenetic event and makes the emergence of a second malignancy unlikely. Each phenotypic change occurred after anti-myeloid and anti-lymphoid oriented chemotherapy. The close correlation between the progressive acquisition of different phenotypes and the switch at the genomic level represent the peculiar features of this unusual case.
Leukemia 1993 Jul
PMID:Mixed acute leukemia with genotypic lineage switch: a case report. 832 Oct 22

The FAB classification of myelodysplastic syndromes (MDS) has been useful in predicting prognosis; however, additional methods are required to detect patients at high risk for early conversion to acute nonlymphoblastic leukemia (ANLL). Using a panel of monoclonal antibodies to myelomonocytic surface antigens (MMSA) and flow cytometry, we studied bone marrow cells from 26 patients with MDS of all five FAB subtypes. The MMSA studied included Ia (HLA-DR), CD11b (Mo1), CD14 (Mo2, My4), CD13 (My7), and CD33 (My9). Marrows were considered "positive" for a given MMSA if the percentage of reactive cells exceeded the upper limit of the normal range. Twenty-four of twenty-six patients (92.3%) were CD13 (My7)+, suggesting that CD13 may serve as a diagnostic marker for MDS. Ten of twelve patients who developed ANLL during a median follow-up of 44 weeks were Ia(HLA-DR)+. The Kaplan-Meier estimated median time to leukemia (TTL) was 16 weeks for Ia+ patients and 88 weeks for Ia- patients (P = 0.004). All six patients who developed ANLL before 16 weeks from diagnosis were Ia+, while none of the Ia- patients converted to ANLL before 24 weeks. Nine of thirteen patients with low CD11b (Mo1) expression (< 53% reactive cells) developed ANLL, compared with only two of 11 patients with high CD11b expression (> 53% reactive cells). Kaplan-Meier estimated TTL was 29 weeks for patients with low CD11b, compared to 160 weeks for patients with high CD11b (P < 0.05). Patients who met both criteria, Ia+ and low CD11b, represented the poorest prognostic subgroup, with median TTL of 13 weeks compared with 88 weeks for the others (P = 0.017). Ia and CD11b patterns were not specific for MDS subtype, and their expression did not correlate with blast count. These data suggest that MDS patients whose bone marrow cells demonstrate high Ia (HLA-DR) and low CD11b (Mo1) expression represent a poor prognostic subgroup with short TTL. These patients may be candidates for early aggressive or investigational treatment.
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PMID:High Ia (HLA-DR) and low CD11b (Mo1) expression may predict early conversion to leukemia in myelodysplastic syndromes. 835 30

We have investigated the effects of 1,25-dihydroxyvitamin D3 (D3) and/or transforming growth factor (TGF)-beta on one monocytic (U-937) and two human promyelocytic (HL-60 and AML-193) leukemic cell lines. D3 addition induces a partial monocytic maturation of the cell lines, whereas TGF-beta treatment is largely ineffective. Combined treatment with TGF-beta and D3 causes terminal monocytic maturation, as evaluated both by assessment of a large spectrum of membrane Ag and by functional assays. Furthermore, sequential addition of the two inducers showed that pretreatment with TGF-beta 1 followed by incubation with D3, but not vice versa, induces monocytic maturation as effectively as simultaneous treatment with both agents. In liquid culture the proliferative activity of these cell lines is slightly decreased by D3 and virtually unaffected by TGF-beta, whereas combined treatment with D3 and TGF-beta induces a markedly potentiated inhibitory effect. Furthermore, TGF-beta/D3 treatment (but not D3 alone) elicits the expression of membrane CD14, FcRI, FcRII, CD11a, CD11b, CD11c, ICAM-1, and PECAM-1 Ag at a level comparable to that observed on normal human monocytes. It is noteworthy that several of these Ag play an important role in monocyte physiology (e.g., CD14 Ag mediates the binding of bacterial LPS to monocytes). Treatment with both TGF-beta and D3 (but not D3 alone) induces superoxide anions and H2O2 production similar to that of circulating monocytes. In semisolid culture, D3 and TGF-beta alone cause, respectively, a marked and slight loss of cloning efficiency of the cell lines, whereas their combined addition synergistically results in a complete loss of the cloning capacity. These findings suggest a physiologic role for TGF-beta in monocyte maturation. Furthermore, they may pave the way to the design of clinical protocols combining D3 and TGF-beta in the differentiation therapy of acute promyelocytic/myelomonocytic leukemia.
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PMID:Transforming growth factor-beta potentiates vitamin D3-induced terminal monocytic differentiation of human leukemic cell lines. 838 19

The protease gamma-glutamyl transpeptidase (gamma-GT) activity was detected at the surface of human blood granulocytes and monocytes and myeloblastic HL-60 and monoblastic U937 leukemia cell lines using an enzymatic assay (cleavage of gamma-glu-p-nitroanilide and inhibition by the specific irreversible inhibitor of gamma-GT, i.e., acivicin). Flow cytometric analysis of gamma-GT expression and detection of a 2.4-kb gamma-GT mRNA species by Northern blot analysis confirmed the presence of gamma-GT in cells of the monocytic-granulocytic lineage. Differentiation of HL-60, U937 cells, and blood monocytes along the macrophage pathway or granulocytic maturation of HL-60 cells was accompanied by an increase in gamma-GT mRNA levels without modulation of cell surface gamma-GT activity and protein. When added to leukemic cell cultures, acivicin produced a dose- and time-dependent inhibitory growth effect associated with the induction of morphological features characteristic of macrophage maturation and enhanced surface expression of phenotypic markers CD11b and CD71 characteristic of monocyte development. When cultured in the presence of acivicin, freshly isolated monocytes also underwent characteristic changes in morphology and antigenic phenotype (increase in CD71 and HLA-DR class II) consistent with their differentiation into macrophages. In parallel, a marked production of latent transforming growth factor (TGF)-beta was observed in supernatants of cells cultured with acivicin, although TGF-beta 1 mRNA species were expressed in these cells at a level almost similar to that in unstimulated cell cultures. Moreover, acivicin-treated cells still differentiated into macrophages in the presence of a neutralizing antibody to TGF-beta 1/beta 2.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibition of gamma-glutamyl transpeptidase activity at the surface of human myeloid cells is correlated with macrophage maturation and transforming growth factor beta production. 851 93

The phenotypic and biologic properties of malignant cells in a case of aggressive mastocytosis with multi-organ involvement, circulating mast cell precursors and absence of skin infiltrates were analyzed. Circulating mast cell precursors were detected by immunostaining using antibodies against mast cell tryptase as well as by electron microscopy. These progenitors were tryptase+/chymase- (MCT) and accounted for 10 to 20% of nucleated mononuclear blood cells (MNC). A subset of them contained metachromatic granules. As assessed by combined toluidine blue/immunofluorescence staining, the granulated mast cell precursors were found to express CD9 (P24), CD33 (gp67) and CD44 (Pgp-1), but not basophil-related markers (CD11b (C3biR), CDw17 (lactosylceramide), CD123 (il-3R alpha))or monocyte-related antigens (CD14, CD15). Expression of the mast cell growth factor (MGF) receptor, c-kit(CD117), was also demonstrable, whereas the skin mast cell marker C5aR (CD88) could not be detected on mast cell precursors. The ligand of c-kit, recombinant human (rh) stem cell factor (SCF = MGF), induced histamine release from circulating mast cell progenitors, whereas rhC5a, a potent skin mast cell-/basophil-agonist, was ineffective over the dose-range (10(-9) to 10(-7(M)) tested. Analysis of mast cell antigens in malignant mastocytosis or mast cell leukemias may be helpful to establish a diagnosis and to determine the phenotype of the clone.
Leukemia 1996 Jan
PMID:A case of malignant mastocytosis with circulating mast cell precursors: biologic and phenotypic characterization of the malignant clone. 855 22

Examinations of 174 children and 188 adult patients with acute nonlymphoblastic leukemia (ANLL) demonstrated a similar structure of distribution of ANLL FAB-variants in children and adults, although the incidence of M0 and M4 blasts was somewhat higher in infants aged under 2. In patients under 15 and over 60 peroxidase activity in myeloblasts was reliably lower than in the rest patients. HLA-Dr, Thy-1, CD11a, T-CD19, Gly-A, and Eb antigens were equally incident in the cells of children and adults. The expression of CD11b, CD38, and CD10 antigens on the blasts was higher in children than in adults. An abnormal blast karyotype was detected in 81.8% children and 73.7% adults. Translocation (8;21) was observed in patients with the M2 variant, as a rule (82%), and reliably more frequently in children; t(9;22) and t(11q23) occurred in children somewhat more frequently than in adults. A group of children with primary ANLL (n = 3) was distinguished for the first time, in whose cell karyotype a deletion of chromosome 5 was found. The findings indicate that the biological characteristics of blast cells differ in children and adults. Evidently, the level of hemopoiesis involvement in ANLL is earlier in infants under 2 and subjects over 60 than in the rest patients.
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PMID:[Acute nonlymphoblastic leukemias in children and adults]. 858 69


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