title: Differentiation commitment and regulator-specific granulocyte-macrophage maturation in a novel pro-B murine leukemic cell line.
abstract: The cloned pro-B-lymphocyte murine leukemic cell line GB2, was established from a leukemic Max41 x Emu-myc double transgenic mouse. Its Igh alleles are rearranged and its surface markers are primarily B-lymphoid, but a small proportion of the cells also express surface Gr-1 and some cells develop the morphology of maturing granulocytes. The cell line grows continuously in suspension culture without the addition of growth factors, but expresses mRNA for M-CSF, TPO and Flt-3-ligand. When stimulated in agar cultures by GM-CSF, G-CSF, M-CSF, IL-3, SCF, IL-6, leukemia inhibitory factor (LIF), IL-5 or IFNgamma, GB2 cells generated blast colonies or colonies of maturing granulocytes and macrophages. There was a striking similarity in colony types, relative colony numbers and maturation of colony cells to those formed by normal bone marrow cells in response to the same stimuli. GB2 blast colony-forming cells exhibited self-renewal as well as an ability to form granulocyte-macrophage colony-forming progeny, with evidence that a hierarchical sequence of clonogenic cells is generated in the cell line even after subcloning. Factor-specific maturation was clearly initiated by the action of the added growth factors. In contrast, FACS-sorting experiments showed that commitment to various types of colony-forming cell occurs in maintenance suspension cultures in the apparent absence of potentially relevant growth factors.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Post Office, Royal Melbourne Hospital, Victoria, Australia.
authors.forename: Y
authors.initials: Y
authors.lastname: Laâbi
authors.forename: D
authors.initials: D
authors.lastname: Metcalf
authors.forename: S
authors.initials: S
authors.lastname: Mifsud
authors.forename: L
authors.initials: L
authors.lastname: Di Rago
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology*; D015448:Leukemia, B-Cell / Q000473:pathology*; D008264:Macrophages / Q000166:cytology*; D051379:Mice; D010641:Phenotype; D014407:Tumor Cells, Cultured
chemical_list: D016178:Granulocyte-Macrophage Colony-Stimulating Factor