Effects of endotoxin on proliferation of human hematopoietic cell precursors

• Published in: Cytotechnology (Dordrecht) 1997-07, Vol.24 (2), p.153-159
• Main Authors: RINEHART, J. J, KEVILLE, L
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Bone marrow; CD14 antigen; Cell culture; Cell differentiation; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Cell proliferation; Colony-stimulating factor; Corticosteroids; Fetal calf serum; Fundamental and applied biological sciences. Psychology; Granulocyte colony-stimulating factor; Granulocyte-macrophage colony-stimulating factor; Granulocytes; Growth factors; Hematopoietic stem cells; Hemopoiesis; Interleukin 1; Interleukin 6; Leukocytes (granulocytic); Leukocytes (mononuclear); Lipopolysaccharides; Macrophages; Molecular and cellular biology
• ISSN: 0920-9069; 1573-0778
• DOI: 10.1023/A:1007904122406

In examining the effects of corticosteroids on hematopoiesis in vitro, we observed that results were highly dependent on the lot of commercial fetal calf serum (FCS) utilized. We hypothesized that this variability correlated with the picogram (pg) level of endotoxin contaminating the FCS. Randomly obtained commercial lots of FCS contained 0.39 to 187 pg/ml of lipopolysaccharide (LPS). Standard FCS concentrations in hematopoietic precursor proliferation assays (granulocyte-marcrophage colony forming units [CFU-GM]) resulted in final LPS levels as high as 40 pg/ml. LPS (2-5 pg/ml) added to essentially endotoxin-free cultures, induced human mononuclear cell release of interleukin (IL)-1, IL-6 and granulocyte colony stimulating factor (G-CSF). Lots of FCS induced the release of IL-1, IL-6, and G-CSF from human mononuclear cells and the release of these factors correlated with the level of contaminating LPS. Human bone marrow CFU-GM proliferation, in response to granulocyte-macrophage colony stimulating factor (GM-CSF), positively correlated with the level of LPS contaminating the FCS and the FCS-induced release of IL-6 from mononuclear cells. CFU-GM proliferation of human bone marrow cluster of differentiation (CD) 34+CD14-cells were not affected by the presence of endotoxin. These data suggest that LPS at 2-5 pg/ml may induce bone marrow accessory cell release of hematopoietic growth factors, thus altering proliferative response of hematopoietic precursors and confounding the study of exogenously added cytokines to culture systems.