title: Haemopoietic growth factor production by normal and aplastic anaemia stroma in long-term bone marrow culture.
abstract: Defective marrow stroma, or microenvironment, have been proposed as one of several mechanisms to account for bone marrow failure in aplastic anaemia (AA). This could involve defects in positive- or negative-acting haemopoietic regulator expression by AA stroma, or alteration of normal stroma-stem cell interactions. We have used a sensitive bioassay to investigate production of granulocyte-colony stimulating factor (G-CSF), granulocyte-macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-3, IL-6 and stem cell growth factor (SCF), by normal and AA stroma in long-term bone marrow culture (LTBMC). LTBMC were grown to confluence, irradiated and harvested to yield a single cell suspension. These cells were cocultured with normal target bone marrow mononuclear cells (BMMC), or CD34+ cells, in clonogenic assays, in the absence of exogenous cytokines. Cytokines responsible for the colony-stimulating activity (CSA) and burst-promoting activity (BPA) produced by stromal cells were identified by neutralizing antibodies to specific cytokines. All normal stroma populations produced G-CSF and GM-CSF, 93% produced IL-3, 80% produced IL-6, and 70% produced SCF. Similarly, all AA stroma produced G-CSF and GM-CSF, and 71% produced SCF. In contrast, only 71% of AA stroma produced IL-3 and 36% produced IL-6. Target cell stimulation was not dependent on direct stroma-target cell contact, suggesting production of soluble cytokines. However, although both IL-6 and G-CSF were detected in LTBMC supernatants by enzyme-linked immunoassay (ELISA), IL-3 and GM-CSF were undetectable, perhaps indicating low-level local production of these factors.
authors.affiliation: Department of Cellular and Molecular Sciences, St George's Hospital Medical School, London.
authors.forename: F M
authors.initials: FM
authors.lastname: Gibson
authors.forename: J
authors.initials: J
authors.lastname: Scopes
authors.forename: S
authors.initials: S
authors.lastname: Daly
authors.forename: S
authors.initials: S
authors.lastname: Ball
authors.forename: E C
authors.initials: EC
authors.lastname: Gordon-Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000741:Anemia, Aplastic / Q000378:metabolism / Q000473:pathology*; D000906:Antibodies / Q000378:metabolism; D001853:Bone Marrow / Q000473:pathology*; D002478:Cells, Cultured; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D016298:Hematopoietic Cell Growth Factors / Q000096:biosynthesis*; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D017154:Stromal Cells / Q000378:metabolism
chemical_list: D000906:Antibodies; D016298:Hematopoietic Cell Growth Factors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor