Ex vivo expansion of human umbilical cord blood and peripheral blood CD34(+) hematopoietic stem cells.

The proliferation and expansion of human hematopoietic stem cells (HSC) in ex vivo culture was examined with the goal of generating a suitable clinical protocol for expanding HSC for patient transplantation.HSC were derived from umbilical cord blood (UCB) and adult patient peripheral blood stem cell collections. HSC were stimulated to proliferate ex vivo by a combination of two growth factors, flt-3 ligand (FL) and thrombopoietin/c-mpl ligand (TPO/ML), and assessed for expansion by flow cytometry.

Protective effects of BB-10010 treatment on chemotherapy-induced neutropenia in mice.

Chemotherapy-induced neutropenia is a major dose-limiting factor in the management of cancer patients. Most chemotherapeutic agents are active against proliferating cells, interfering with DNA replication and/or mitosis. A number of chemokines, notably macrophage inflammatory protein-1 alpha [MIP-1alpha], have been reported to induce cell-cycle arrest in immature hematopoietic progenitors, raising the possibility that chemokines, such as MIP-1alpha, could be used to reduce or even eliminate the hematologic toxicity of cycle-active chemotherapy.

Paradoxical stimulation of normal and leukemic rat hematopoiesis by monoclonal antibody to CSF-1 receptor.

We have recently developed a rat monoclonal antibody directed against the murine M-CSF receptor (c-fms). This reagent also inhibits in vitro colony formation by leukemic and normal rat splenocytes in response to M-CSF. At high antibody concentrations, the antibody augments, rather than inhibits, colony formation by rat cells in the presence of M-CSF, an effect that is not seen when murine cells are used as responders.

Enhancement of monocytopoiesis by granulocyte colony-stimulating factor: evidence for secondary cytokine effects in vivo.

Granulocyte colony-stimulating factor (G-CSF) is used with increasing frequency to reduce the neutropenic interval following dose-intensive chemotherapy. In mice, exogenous G-CSF reduces neutrophil recovery after 5-fluorouracil (5-FU) treatment from 14 to 8 days. G-CSF treatment also enhances recovery of blood monocytes; colony assays show increased numbers of macrophage and granulocyte-macrophage progenitors (CFU-M and CFU-GM) in the marrow.