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M Aglietta

Publications and source records attributed to M Aglietta.

At least 19 recordsLinked to original sources
PubMed1991

In vivo effect of human granulocyte-macrophage colony-stimulating factor on megakaryocytopoiesis.

The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on megakaryocytopoiesis and platelet production was investigated in patients with normal hematopoiesis. Three findings indicated that GM-CSF plays a role in megakaryocytopoiesis. During treatment with GM-CSF (recombinant mammalian, glycosylated; Sandoz/Schering-Plough, 5.5 micrograms protein/kg/d, subcutaneously for 3 days) the percentage of megakaryocyte progenitors (megakaryocyte colony forming unit [CFU-Mk]) in S phase (evaluated by the suicide technique with high 3H-Tdr doses) increased from 31% +/- 16% to 88% +/- 11%; and the maturation profile of megakaryocytes was modified, with a relative increase in more immature stage I-III forms. Moreover, by autoradiography (after incubation of marrow cells with 125I-labeled GM-CSF) specific GM-CSF receptors were detectable on megakaryocytes. Nevertheless, the proliferative stimulus induced on the progenitors was not accompanied by enhanced platelet production (by contrast with the marked granulomonocytosis). It may be suggested that other cytokines are involved in the regulation of the intermediate and terminal stages of megakaryocytopoiesis in vivo and that their intervention is an essential prerequisite to turn the GM-CSF-induced proliferative stimulus into enhanced platelet production.

Cell Differentiation↗
PubMed1991

Essential thrombocythemia: impaired regulation of megakaryocyte progenitors.

In this paper, the in vitro growth of bone marrow early (megakaryocyte burst-forming units, BFU-meg) and late (megakaryocyte colony-forming units, CFU-meg) progenitors was evaluated in 18 essential thrombocythemia (ET) patients and 22 normal control subjects. BFU-meg clonality was demonstrated both in normal and ET bone marrows, cultivating these primitive progenitors at limiting dilutions in plasma clot assay: 1 to 7 BFU-meg/2.5 x 10(4) mononuclear non-adherent cells were observed, with a strong correlation in ET [r = 0.955 stimulated by recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) plus recombinant human interleukin (rhIL) 3], as well as in normal controls (r = 0.969). In order to clearly elucidate the in vitro response of ET megakaryocyte (meg) progenitors to recombinant growth factors, the interference of accessory cells (i.e., monocytes, T lymphocytes, and natural killer cells) and human serum were avoided by performing experiments on CD34+ cells in a serum-free fibrin clot assay. The number of both early and late meg progenitors in ET was significantly increased in response to rhIL-3, rhIL-3 plus rhIL-6, and rhIL-3 plus rhGM-CSF, but not in response to rhGM-CSF alone. Furthermore, both meg progenitors were investigated for their response to rh transfer growth factor (TGF)-beta 1, tested at concentrations from 0.01 to 10 ng/ml. rhTGF-beta 1 was able to inhibit CFU-meg and BFU-meg in a dose-response manner normal, whereas ET CFU-meg appeared less sensitive to the lower doses investigated (p less than 0.05) and ET BFU-meg were slightly reduced in number only at the higher concentrations of rhTGF-beta 1 (p less than 0.01). Our data suggest that the increased thrombopoiesis in ET may depend on an increased sensitivity of meg progenitors to some of the physiological growth factors and to a disrupted sensitivity to at least one negative regulator of megakaryocytopoiesis. Since these abnormalities involve both meg progenitors, this can be considered a demonstration that the neoplastic event hits the most primitive hemopoietic progenitors.

Cell Division↗
PubMed1991

Trisomy 8 and an unbalanced t(5;17)(q11;p11) characterize two karyotypically independent clones in a case of idiopathic myelofibrosis evolving to acute nonlymphoid leukemia.

In a patient with idiopathic myelofibrosis (MFI) that had progressed to acute nonlymphoid leukemia (ANLL) after a long-lasting cytotoxic treatment, we observed two karyotypically independent cell populations, one showing trisomy of chromosome 8 as the only anomaly and one with an unbalanced translocation t(5;17)(q11) resulting in partial monosomy of 5q and 17p. The overall karyotypic configuration suggested that chromosome changes occurred as secondary events during the multistep process of leukemogenesis. The probable sequence of cytogenetic events in this patient and a review of the literature indicated that the t(5;17) may represent a therapy-induced abnormality nonrandomly related to the terminal phase of myeloid disorders.

Aged↗
PubMed1991

Effect of recombinant human IL-3 on the mitotic index and karyotype of hemopoietic cells.

The proliferative induction by hemopoietic growth factors may provide a useful tool to improve the mitotic yield of hemopoietic cells, allowing a more accurate cytogenetic analysis in hematologic malignancies. For such a purpose, we studied the effects of the recombinant human IL-3 (rhIL-3) on the mitotic index and the karyotype of bone marrow cells from 14 patients with myelodysplastic (MDS) and myeloproliferative syndromes (MPS). The mitotic response to IL-3 of normal bone marrow samples was also evaluated. Total bone marrow cells were cultured for 24 to 72 hours either in presence or absence of rhIL-3. In most cases, IL-3--stimulated samples showed a considerably higher (4-70 times) mitotic index than unstimulated controls. Although a great patient-to-patient variability was observed, a common pattern of mitogenic response to IL-3 emerged among MPS, MDS, and normal cases. At 48 hours of incubation, the mean mitotic index from MPS and MDS cases stimulated with IL-3 was significantly higher (p less than 0.01) than unstimulated controls, whereas the mean mitotic increase from normal samples did not reach statistical significance (p greater than 0.1). Even though not statistically evaluable, a similar trend of response was observed at 24 and 72 hours of culture. Chromosome studies of MPS and MDS cases showed the same karyotype either in stimulated and unstimulated samples.

Bone Marrow↗
PubMed1991

Thrombocytopenia in acute leukaemia patients treated with IL2: cytolytic effect of LAK cells on megakaryocytic progenitors.

In vivo administration of recombinant interleukin 2 (IL2) has been associated, in acute leukaemia as well as in other tumours, with a variable degree of thrombocytopenia. In two patients with acute myeloid leukaemia who showed a progressive and severe fall in platelet count during daily continuous i.v. infusion of IL2, we assessed whether peripheral blood IL2-generated lymphokine activated killer (LAK) lymphocytes could affect growth of the autologous bone marrow megakaryocytic progenitor cell compartment (CFU-MK) in vitro. Following overnight pre-incubation in liquid culture of the marrow cells with autologous LAK effectors, there was an almost complete abrogation of the CFU-MK colony growth (97% and 89% inhibition). Pre-incubation in the presence of a monoclonal antibody to tumour necrosis factor alpha (TNF) completely reversed the inhibitory effect. The role played by TNF was confirmed by the finding that recombinant TNF caused a dose-dependent inhibition of the growth of CFU-MK. IL2 alone was ineffective. These results suggest that the often severe thrombocytopenia observed in patients with acute leukaemia treated with IL2 is at least partly due to autologous LAK cells activated in vivo following the administration of IL2.

Adult↗
PubMed1991

MACOP-B for advanced stage large cell lymphoma (DLCL). More is better? Italian Multiregional Cooperative Study Group (IMCSGL).

A study of the predictive value for CR, DFS and OS of the presenting features was carried out on 180 patients with advanced stage DLCL treated with MACOP-B between June 1986 and March 1989. A multivariate regression analysis identified LDH level, bone marrow involvement and tumor burden as independent risk factors with a 4 year survival rate of 79%, 58% and 28% respectively. Therefore MACOP-B proved to be an adequate treatment for the first two groups of patients but not for the third which requires a more aggressive treatment. A sequential single drug high dose chemotherapy with collection of peripheral blood stem cell program followed by bone marrow harvesting, super-intensive radio-chemotherapy and bone marrow transplant has been activated. Seven patients have been so far enrolled: preliminary results demonstrated the feasibility of the program. A larger number of cases and a longer follow-up is required for assessing the efficacy of this approach.

Adolescent↗
PubMed1991

Responsiveness of highly enriched CFU-GM subpopulations from bone marrow, peripheral blood, and cord blood to hemopoietic growth inhibitors.

Human early and late granulocyte-monocyte progenitors (granulocyte-macrophage colony-forming units, CFU-GM), depleted of accessory cells, were physically separated using an antimyeloid monoclonal antibody (DS1.1). They were separately cultured at optimal growth conditions and tested for responsiveness to prostaglandin E2 (PGE2), recombinant tumor necrosis factor alpha (TNF alpha), and transforming growth factor beta-1 (TGF beta 1). Late (DS1.1+) CFU-GM displayed the highest sensitivity to PGE2 and TNF alpha, the first significant inhibition being evident at 10(-9)M PGE2 and 1 U/ml TNF alpha. Conversely, their growth was stimulated (211%-217%) by 0.25-2.5 ng/ml TGF beta 1. Early (DS1.1-) marrow CFU-GM evidenced a lower sensitivity to PGE2 and TNF alpha. Their growth, however, was inhibited by 0.25-2.5 ng/ml TGF beta 1. Early CFU-GM constitute the totality of peripheral blood myeloid progenitors. Cord blood CFU-GM were also demonstrated here to be entirely DS1.1-. Both adult and cord blood CFU-GM displayed the highest resistance to PGE2 and TNF alpha. By contrast, they showed the maximum sensitivity to growth inhibition by TGF beta 1, active at 0.025-0.25 ng/ml. For the first time, therefore, highly purified subsets of human CFU-GM were separated that displayed a different responsiveness to well-defined growth-regulatory molecules. Our results indicate that TGF beta 1 has a dual activity; it is inhibitory on early and stimulatory on late CFU-GM, whereas PGE2 and TNF alpha preferentially inhibit late CFU-GM growth.

Adult↗
PubMed1991

In vivo effect of granulocyte-macrophage colony-stimulating factor on the kinetics of human acute myeloid leukemia cells.

Granulocyte-macrophage colony-stimulating factor, (GM-CSF) was given at 8 micrograms/kg daily by continuous i.v. infusion for 72 h to six patients with acute myeloid leukemia (AML) in expansion and one with chronic myeloid leukemia in blastic crisis to determine whether it was possible to augment the proliferative activity of the neoplastic population. The percentage of marrow blasts in S phase (labeling index, LI) was increased in five patients (1.3-, 1.5-, 1.9-, 2.3- and 3.2-fold change). The increase in LI was similar 24 and 48 h after beginning GM-CSF. The RNA Index also increased in patients who showed an increased LI, suggesting that GM-CSF had recruited quiescent neoplastic cells into the cell cycle. Forty eight hours after beginning GM-CSF, chemotherapy was started. The fate of S phase cells, labeled in vivo with bromodeoxyuridine (BrdU) immediately before cytostatic treatment, was monitored. BrdU positive cells were identified by fluorescent antibody for up to 28 days. A preferential killing of BrdU (S phase) cells was observed in 5/7 patients who obtained a complete remission, whereas this was not apparent in the two patients who achieved only a partial remission. Chemotherapy induced a rapid and profound aplasia; its duration, however, was not significantly different from that observed in historical controls. GM-CSF may have a potential role in the treatment of AML, as this study shows that it recruits leukemic cells into the cell cycle without adversely prolonging aplasia after cycle-specific therapy.

Adolescent↗
PubMed1990

Opposite effect of tumor necrosis factor alpha on granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor-dependent growth of normal and leukemic hemopoietic progenitors.

The effect of recombinant human tumor necrosis factor alpha (TNF-alpha) on normal and chronic myeloid leukemia granulocyte-macrophage progenitors (CFU-GM) growing in semisolid agar cultures in the presence of recombinant granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor was studied. Granulocyte-macrophage colony-stimulating factor-dependent growth of normal and chronic myeloid leukemia bone marrow CFU-GM was greatly enhanced by TNF-alpha at doses of 0.1 to 100 units/ml. Growth enhancement included neutrophil, eosinophil, and monocyte-macrophage colonies and clusters at 7 and 14 days of culture. Since similar results were achieved with highly enriched progenitor cell populations, devoid of accessory cells, an indirect effect on CFU-GM growth through the release by accessory cells of other cytokines upon TNF-alpha stimulation was thus ruled out. By contrast, the same doses of TNF-alpha inhibited the growth of normal CFU-GM in granulocyte colony-stimulating factor-dependent cultures. Taken together, our findings indicate that the final effect of TNF-alpha on normal bone marrow granulocyte-macrophage progenitor growth is dependent on the specific growth factor interacting with it, and that both normal and chronic myeloid leukemia CFU-GM are equally responsive to the combined effects of TNF-alpha and a given colony-stimulating factor.

Bone Marrow↗
PubMed1990

Human GM-CSF in vivo: identification of the target cells and of their kinetics of response.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was given for three days (8 micrograms/kg/day) to 14 subjects who had solid tumors and normal hemopoiesis. The treatment induced a rapid 3- to 5-fold increase in the number of circulating neutrophils, eosinophils and monocytes. Lymphocytes, platelets and reticulocytes were unmodified during treatment. Activation of circulating neutrophils during GM-CSF treatment was demonstrated by a significant, increased release of neutrophil-derived platelet-activating factor after stimulation with N-formyl-methionyl-leucyl-phenylalanine, tumor necrosis factor-alpha or phagocytosis. The granulomonocytosis was dependent on increased bone marrow production of mature cells. Using the thymidine suicide technique, we observed that GM-CSF more than doubled the percentage of granulocyte-macrophage and megakaryocyte colony-forming units (CFU-gm and CFU-meg) and erythroid burst-forming units (BFU-e) in the S phase of the cell cycle. However, at the level of morphologically recognizable cells with autoradiography, we observed that GM-CSF increased the labeling index of the granulo-monopoietic cells, whereas that of the erythroblasts was unchanged. These data suggest that in accordance with in vitro observations, GM-CSF exerts its activity through all granulo-monopoietic lineages, whereas other cytokines (erythropoietin, thrombopoiesis-stimulating factors) may be needed to fully exploit the proliferative stimulus of GM-CSF on BFU-e and CFU-meg. After treatment discontinuation, the proliferative activity drops to values lower than before treatment, suggesting a period of relative refractoriness of marrow progenitors to the cytocidal effect of cell cycle-specific antineoplastic agents. This hypothesis is under evaluation in a controlled clinical trial where GM-CSF is given prior to chemotherapy.

Bone Marrow Transplantation↗
PubMed1990

In vivo priming of human normal neutrophils by granulocyte-macrophage colony stimulating factor: effect on the production of platelet activating factor.

The effect of granulocyte-macrophage colony stimulating factor (GM-CSF) (recombinant, mammalian, glycosylated, Sandoz, Schering Plough; 4 micrograms/kg every 12 h for 3 d, s.c.) on platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn glycero-3 phosphorylcholine) production from neutrophils was studied in five cancer patients with normal haemopoiesis. Peripheral blood counts, PAF production and lyso-PAF: acetyl transferase (EC 2.3.1.67) (AT) activity in neutrophils were evaluated before treatment, during treatment and 3 d after treatment had been discontinued. GM-CSF induced a three-fold increase in the number of circulating neutrophils. Neutrophils obtained during treatment produced about twice as much PAF than before treatment in response to a variety of stimuli (N-formyl-methionyl-leucyl-phenylalanine, tumour necrosis factor-alpha, phagocytosis of baker's yeast spores opsonized with C3b). This increased PAF synthesis and release is concomitant with a 2-3-fold increase in AT activity. Moreover, lower concentrations of stimuli are sufficient to induce PAF synthesis from neutrophils obtained during GM-CSF treatment. Three days after treatment had been discontinued, stimulus induced PAF production had returned to baseline levels. Since GM-CSF induces a marked shift to the left in the Arneth score, the increased PAF release might have been due to the presence of younger granulocytes. This was, however, ruled out by experiments showing that normal neutrophils primed in vitro with GM-CSF produce more PAF when challenged with the same stimuli. The potential relevance of this effect of GM-CSF treatment lies on the crucial role of PAF in inflammatory reactions and its intervention in some immune reactions, including delayed hypersensitivity, and in endotoxic shock. Lastly, increased PAF production from neutrophils may explain some toxicities observed during treatment with high doses of GM-CSF.

Acetyltransferases↗
PubMed1989

Granulocyte- and granulocyte-macrophage-colony stimulating factors induce human endothelial cells to migrate and proliferate.

Granulocyte-colony stimulating factor (G-CSF) and granulocyte-macrophage-colony stimulating factor (GM-CSF) belong to a family of glycoprotidic growth factors required for the survival, growth and differentiation of haematopoietic precursors and which affect the function of circulating mature cells. They are produced by resting or stimulated stromal cells of the haematopoietic microenvironment (fibroblasts and endothelium) and by immunocompetent cells (T cells and monocytes/macrophages). The action of these CSF molecules was thought to be restricted to cells of haematopoietic origin. Here, we report that G-CSF and GM-CSF influence the migration and proliferation of human endothelial cells suggesting that these molecules may act as regulatory signals outside the haematopoietic system.

Cell Division↗
PubMed1989

Kinetics of human hemopoietic cells after in vivo administration of granulocyte-macrophage colony-stimulating factor.

The kinetic changes induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) on hemopoietic cells were assessed in physiological conditions by administering GM-CSF (8 micrograms/kg per d) for 3 d to nine patients with solid tumors and normal bone marrow (BM), before chemotherapy. GM-CSF increased the number of circulating granulocytes and monocytes; platelets, erythrocytes, lymphocyte number, and subsets were unmodified. GM-CSF increased the percentage of BM S phase BFU-E (from 32 +/- 7 to 79 +/- 16%), day 14 colony-forming unit granulocyte-macrophage (CFU-GM) (from 43 +/- 20 to 82 +/- 11%) and day 7 CFU-GM (from 41 +/- 14 to 56 +/- 20%). The percentage of BM myeloblasts, promyelocytes, and myelocytes in S phase increased from 26 +/- 14 to 41 +/- 6%, and that of erythroblasts increased from 25 +/- 12 to 30 +/- 12%. This suggests that GM-CSF activates both erythroid and granulomonopoietic progenitors but that, among the morphologically recognizable BM precursors, only the granulomonopoietic lineage is a direct target of the molecule. GM-CSF increased the birth rate of cycling cells from 1.3 to 3.4 cells %/h and decreased the duration of the S phase from 14.3 to 9.1 h and the cell cycle time from 86 to 26 h. After treatment discontinuation, the number of circulating granulocytes and monocytes rapidly fell. The proportion of S phase BM cells dropped to values lower than pretreatment levels, suggesting a period of relative refractoriness to cell cycle-active antineoplastic agents.

Bone Marrow↗