title: Activity of stem cell factor and IL-7 in combination on normal bone marrow B lineage cells.
abstract: The production of B cells is regulated by soluble and cell contact signals presumably provided by bone marrow stromal cells. Among these is IL-7, a well characterized proliferative stimulus for a subset of pre-B cells. Stem cell factor (SCF), a stromal cell-derived cytokine with broad hemopoietic effects, has been reported to synergize with IL-7 to drive the proliferation and differentiation of B220- bone marrow cells into B220+ B cell precursors in long term culture. A subsequent report has cast doubt on this result by showing that SCF and IL-7 were incapable of producing mu+ pre-B cells after short term culture. Here, using the cell sorter to assure discrete separation of B220+ and B220- cells followed by soft agar culture to prevent interaction with accessory cells, we demonstrate that the combination of SCF and IL-7 does not stimulate the expansion or differentiation of B220- lymphoid precursors but can act synergistically in the clonal proliferation of B220+ cells.
authors.affiliation: Department of Microbiology and Immunology, Loyola University Medical Center, Maywood, IL 60153.
authors.forename: P E
authors.initials: PE
authors.lastname: Funk
authors.forename: A
authors.initials: A
authors.lastname: Varas
authors.forename: P L
authors.initials: PL
authors.lastname: Witte
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000502:physiology; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D005260:Female; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000502:physiology; D015851:Interleukin-7 / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019089:Stem Cell Factor
chemical_list: D016298:Hematopoietic Cell Growth Factors; D015851:Interleukin-7; D019089:Stem Cell Factor