Popis: |
The hematopoietic colony stimulating factors (CSFs) affect the proliferation, differentiation, and survival of progenitor cells in the bone marrow and prime mature blood cells to carry out their differentiated functions (Metcalf, 1985; Clark and Kamen, 1987; Sieff, 1987). The in vitro proliferation of normal myeloid progenitor cells in semisolid medium requires the continuous presence of CSFs, and the types of colonies obtained, whether granulocyte, macrophage, or erythroid, depend on the types of factors added to the cultures. Unlike pluripotent cytokines such as multi-CSF (interleukin-3, or IL-3) and granulocyte-macrophage CSF (GM-CSF) which affect the growth of colonies of multiple hematopoietic lineages, macrophage CSF (M-CSF or CSF-1), granulocyte CSF (G-CSF), and erythropoietin (Epo) stimulate the lineage-specific proliferation of macrophage, granulocyte, or erythroid precursors, respectively. Recently, each of these CSFs has been purified to homogeneity, and cDNA clones encoding the factors have been exploited to produce previously unrealizable quantities of CSFs for experimental and therapeutic use. CSFs are already proving their efficacy in clinical trials and have numerous potential applications in the treatment of blood cell disorders, malignancies, and in modulating the inflammatory response (Donohue et al., 1986; Weite et al., 1987; Eschbach et al., 1987; Groopman et al., 1987). |