0000000000053333
AUTHOR
Jutta Goldschmitt
Extramedullary Expansion of Hematopoietic Progenitor Cells in Interleukin (IL)-6–sIL-6R Double Transgenic Mice
Soluble cytokine receptors modulate the activity of their cognate ligands. Interleukin (IL)-6 in association with the soluble IL-6 receptor (sIL-6R) can activate cells expressing the gp130 signal transducer lacking the specific IL-6R. To investigate the function of the IL-6–sIL-6R complex in vivo and to discriminate the function of the IL-6–sIL-6R complex from the function of IL-6 alone, we have established a transgenic mouse model. Double-transgenic mice coexpressing IL-6 and sIL-6R were generated and compared with IL-6 and sIL-6R single-transgenic mice. The main phenotype found in IL-6–sIL-6R mice was a dramatic increase of extramedullary hematopoietic progenitor cells in liver and spleen…
A bioactive designer cytokine for human hematopoietic progenitor cell expansion
Efficient expansion of hematopoietic progenitor cells requires, at least, the simultaneous stimulation of the receptors c-kit and gp130. While c-kit is activated by SCF; gp130, in cells which do not express sufficient amounts of IL-6R, can be activated by the complex of soluble IL-6R (sIL-6R) and IL-6. The therapeutic use of IL-6/sIL-6R, however, has been hampered by the high concentrations of the sIL-6R protein required. We have designed a fusion protein of sIL-6R and IL-6, linked by a flexible peptide chain, that was expressed to high levels. On gp130 expressing cells the fusion protein turned out to be fully active at 100 to 1,000-fold lower concentration than the combination of unlinked…
Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells
Abstract nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and…
BMP-2 and bFGF release and in vitro effect on human osteoblasts after adsorption to bone grafts and biomaterials.
Objectives Combination of scaffolds and growth factors is a promising option for several clinical problems in bone biomaterials. Simplified growth factor loading by adsorption from aqueous solution is one important option for this technology. We evaluated the adsorption followed by PBS rinsing, release and biological effect of transient loading with basic fibroblast growth factor (bFGF) and bone morphogenic protein 2 (BMP-2) on fresh frozen bone, processed bone matrix, collagen, and a ceramic material with immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and qRT-PCR. Materials and methods The study consisted of three in vitro experiments (immunofluorescence, ELISA, and qRT-PCR…
Effect of interleukin-3 pretreatment on granulocyte/macrophage colony-stimulating factor induced mobilization of circulating haemopoietic progenitor cells.
Recombinant human colony stimulating factors (CSFs) as single agents are increasingly used for mobilizing peripheral blood progenitor cells (PBPCs) for stem cell transplantation. We have shown in rhesus monkeys that interleukin-3 (IL-3) pretreatment markedly potentiated the increase in PBPC numbers of subsequent administration of granulocyte/macrophage-CSF (GM-CSF). Here we studied the effect of IL-3 pretreatment on GM-CSF-induced mobilization of PB progenitors in patients who were potential candidates for autologous stem cell transplantation (n = 16). Patients were treated with GM-CSF at a dose of 5 micrograms/kg/d for 5 d and after a treatment free interval received another cycle of GM-CS…