Lactoferrin (If) is a negative regulator of myelopoiesis which operates by suppressing the release from mononuclear phagocytes of GM colony-stimulating factor (GMCSF) or monokines which can then induce the release of GM-CSA from accessory cells. In this study. endotoxindepleted. purified iron-saturated human If was assessed for its effect on the production of interleukin-1 by cultured monocytes...

We have cloned, expressed, and partially purified a naturally occurring, truncated, soluble form of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha subunit to investigate its biochemical and biologic properties. The soluble receptor species lacks the transmembrane and cytoplasmic domains that are presumably removed from the intact receptor cDNA by a mechanism ...

Human recombinant GM-CSF (rGM-CSF) was tested on highly purified and fractionated CFU-GM subsets. The fractionation was performed with the DS1-1 monoclonal antibody (MoAb), which distinguishes early and late CFU-GM. On whole bone marrow cells, rGM-CSF had a colony-stimulating activity comparable to that of known sources of CSFs, ie, the supernatant (SN) of TPA 30-1 or 5637 cell lines, used as c...

Human recombinant granulocyte-macrophage colony-stimulating factor (hrGM-CSF) stimulated granulocyte-macrophage (GM) colony formation from human marrow mononuclear cells (MMCs) in a dose-dependent manner in methylcellulose culture. When phagocytes were depleted from MMCs, GM colony formation from the phagocyte-depleted (PD) MMCs by hrGM-CSF markedly decreased. Experiments in which PD-MMCs were ...

Activated neutrophils play a major role in the pathogenesis of acute respiratory distress syndrome (ARDS), and persistence of pulmonary neutrophilia is related to poor survival. Interleukin (IL)-8 is implicated in recruiting neutrophils to the lungs but it has been postulated that granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), which ...

Peripheral blood progenitor cells (PBPC) are increasingly being used in the clinic as a replacement for bone marrow (BM) in the transplantation setting. We investigated the capacity of several different growth factors, including human flt3 ligand (FL), alone and in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF ) or granulocyte colony-stimulating factor (G-CSF ), to m...

We studied the effects ofIL4 on the spontaneous proliferation of chronic myelomonocytic leukemia (CMMoL) cells in vitro. ILA (100 U/ml) suppressed the spontaneous DNA synthesis by 50% in 5 of 8 cases examined. 1L4 (100 U/ml) also inhibited the spontaneous colony formation by CMMoL cells in a methylceliulose culture by 50-97% in all of the 10 cases in which spontaneous colonies were formed. This...

An electrophoretically pure preparation of natural human interleukin-1 (IL-1) was shown to stimulate in vitro colony formation in human bone marrow cultures. Day 4 myeloid cluster-forming cells (CFC), as well as early (day 7) and late (day 10) granulocyte-macrophage colony-forming units (CFU-GM) were stimulated in a dose-dependent fashion. At optimal concentrations of IL-1, the number of day 4 ...

Colony-forming cells in ten cases of acute myeloid leukemia (AML) were studied with six cytotoxic monoclonal antibodies that react with antigens expressed at discrete stages of differentiation of normal and leukemic hematopoietic cells. The reactivity of the whole leukemic population was measured by indirect immunofluorescence, and the reactivity of the colony-forming cells was established by c...

Leptin, the product of obese gene, was originally identified as a factor regulating body-weight homeostasis and energy balance. The present study has shown that leptin acts on murine hematopoiesis in vitro. In the culture of bone marrow cells (BMC) of normal mice, leptin induced only granulocyte-macrophage (GM) colony formation in a dose-dependent manner, and no other types of colonies were det...