Anti-murine (m) interleukin-5 (IL-5) antibody was found to inhibit eosinophil (Eo) colony formation stimulated by recombinant human (rh) IL-5, but did not inhibit the production of Eo stimulated by rh lL-3 or granulocyte-macrophage colony-stimulating factor (GM-CSF). Conditioned medium (CM) prepared from eosinophilic patients’ T cells with interleukin-2 (IL-2) stimulation (T-lL-2-CM), was found...

The present studies investigated the effects of the recently cloned flt3 ligand (FL) on the in vitro growth and differentiation of primitive and committed subsets of human CD34+ bone marrow (BM) progenitor cells. FL alone was a weak growth stimulator of CD34+ BM cells, but synergistically and directly enhanced colony formation in combination with interleukin (IL) 3, granulocyte colony-stimulati...

The effect of biosynthetic recombinant insulin-like growth factor I/somatomedin C (IGF-I/Sm-C) and human growth hormone (hGH) on the in vitro growth and maturation of human marrow myeloid progenitors was investigated. Myeloid colony formation was maximally enhanced by 60 ng/ml IGF-I/Sm-C and by 250 ng/ml hGH, resulting in an increase in colony numbers of 41 +/- 7 and 38 +/- 4%, respectively (P ...

Granulocyte colony-stimulating factor (G-CSF) is the cytokine critical for directing neutrophilic granulocyte differentiation. Acute myelogenous leukemia (AML) cells, which frequently arise from this lineage, respond aberrantly to G-CSF by proliferating without differentiating. The basis for this abnormal response is unknown. In the present study, we investigated whether G-CSF signaling in imma...

Five monoclonal antibodies that identify the My-1 human granulocyte surface antigen were not reactive with other peripheral blood cells. These antibodies effected complement-dependent cytolysis of a large fraction of normal human marrow leukocytes. This My-1-positive marrow cell population consisted of morphologically identifiable granulocytic precursor cells. Colony-forming cells of the granul...

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...