Experimental hematology
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Experimental hematology · Apr 1993
U937 cell line: impact of CSFs, IL-6 and IFN-gamma on the differentiation and the Leu-CAM proteins expression.
Differentiation of the U937 cell line can be induced by various agents. We have investigated the differentiation abilities of gamma-interferon (IFN-gamma), interleukin-6 (IL-6), macrophage and granulocyte-macrophage colony-stimulating factors (M-CSF + GM-CSF) or the combinations IL-6 + M-CSF + GM-CSF and IFN-gamma + M-CSF + GM-CSF on the U937 cells by studying the morphology, cytochemical activity and several functional properties. The expression of the Leu-CAM proteins (CD11a, CD11b, CD11c, CD18) was also evaluated during the culture period. ⋯ The adhesion molecules CD11b alpha chain and CD18 beta chain were strongly induced on the U937 cells with a maximal expression of the CD11b on the cells cultured with either M-CSF + GM-CSF or the combinations of IL-6 and IFN-gamma with M-CSF + GM-CSF. Conversely, for CD11a and CD11c alpha chains a rather low enhancement of the expression was noticed. In our culture system, cells incubated with the combination of M-CSF + GM-CSF exhibited differentiation characteristics which appeared to be largely potentialized when cytokines such as IL-6 or IFN-gamma were added.
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Experimental hematology · Mar 1993
Interleukin-3 followed by GM-CSF for delayed engraftment after autologous bone marrow transplantation.
Recombinant human interleukin-3 (IL-3) is well-tolerated according to phase I studies, and produces trilineage hematologic responses in patients with normal bone marrow. In addition, promising results have been obtained in a variety of bone marrow failure states. We studied IL-3 in 7 patients with markedly delayed engraftment after autologous bone marrow transplantation (ABMT) for hematologic malignancies (acute myeloid leukemia 4, chronic myeloid leukemia 1, myeloma 1, non-Hodgkin's lymphoma 1). ⋯ Hematopoietic colony assays of bone marrow cells obtained before and after treatment showed that granulocyte-macrophage colony-forming cell (CFU-GM) and erythroid blast-forming cell (BFU-E) levels were severely reduced and multilineage progenitors (CFU-GEMM) absent in all patients, and remained low after IL-3 treatment for 21 days. Sequential IL-3 and GM-CSF produced a significant but transient increase in the neutrophil counts of some patients. IL-3 appears to be of limited benefit in patients who are severely aplastic after ABMT and have very low levels of bone marrow progenitors.
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Experimental hematology · Feb 1993
Effects of combined administration of interleukin-6 and granulocyte colony-stimulating factor on recovery from radiation-induced hemopoietic aplasia.
Hemopoietic aplasia is the primary limitation of drug and radiation cancer therapies. We have previously demonstrated that, individually, both interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF) can accelerate recovery from radiation-induced hemopoietic aplasia. In vitro studies suggest that IL-6 affects cells early in the hemopoietic hierarchy, while G-CSF affects more committed progenitor cells. ⋯ The most notable effects in combination-treated mice were on recoveries of bone marrow and splenic CFU-S, which were significantly enhanced above those in G-CSF-treated irradiated mice as early as day 10 postirradiation. Although by day 14 postirradiation, splenic GM-CFC and CFU-S recoveries in both G-CSF- and combination-treated mice had surpassed unirradiated control values, combination-treated mice exhibited a greater overshoot. These studies demonstrate the ability of IL-6 treatment to enhance G-CSF-mediated acceleration of multilineage recovery following radiation-induced hemopoietic aplasia.
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Experimental hematology · Nov 1991
The role of monocyte-derived hemopoietic growth factors in the regulation of myeloproliferation in juvenile chronic myelogenous leukemia.
Juvenile chronic myelogenous leukemia (JCML) is a rare pediatric malignancy characterized by marked hepatosplenomegaly, leukocytosis with prominent monocytosis, elevated fetal hemoglobin, no Philadelphia chromosome, and generally a poor prognosis. In vitro, JCML peripheral blood granulocyte-macrophage progenitors (granulocyte-macrophage colony-forming units, CFU-GM) demonstrate the unique characteristic of "spontaneous" proliferation at very low cell densities in the absence of exogenous growth factors. The "spontaneous" CFU-GM proliferation can be abolished by prior adherent cell (monocyte) depletion, suggesting a paracrine mode of cellular proliferation. ⋯ Monocytes from only a minority of JCML patients produced higher than normal quantities of GM-CSF, G-CSF, IL-1 beta, IL-6, and/or TNF alpha, but no obvious pattern could be discerned. Further, only 7 of 15 JCML monocyte-conditioned media (MCM) had elevated GM-CSF, and 6 of 15 JCML patients had normal levels of all nine cytokines tested. The monocyte depletion experiments and the inhibition experiments with anti-cytokine antibodies taken together demonstrate clearly that the "spontaneous" growth of JCML CFU-GM in vitro critically depends on at least one monocyte-derived growth factor, GM-CSF.(ABSTRACT TRUNCATED AT 400 WORDS)
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Experimental hematology · Oct 1991
The development of thermotolerance in bone marrow CFU-S during chronic hyperthermia.
The purpose of this investigation was to study the response of the hematopoietic stem cell, spleen colony-forming unit (CFU-S), to hyperthermia. We have shown that CFU-S can acquire a transient resistance to further heating (thermotolerance). Hyperthermia was applied in vitro to nucleated bone marrow cells in McCoy's 5A medium plus 15% fetal bovine serum. ⋯ The thermotolerance ratio (TTR, ratio of the surviving fraction of the maximum thermotolerant cells to that of the normotolerant cells) was 2.1. Both the higher inactivation enthalpy for exposures less than 43 degrees C and the rapid increase in survival during the "step-up" heating experiments at 42 degrees C demonstrate that CFU-S can develop thermotolerance during prolonged hyperthermia. These results suggest that thermotolerance can influence the thermal response of pluripotent bone marrow stem cells heated during whole-body or local-regional clinical hyperthermia protocols.