Alternative assay procedures for cytokines and soluble receptors of the IL-6 family.
Human hepatoma cells (HepG2 cells) were transfected with expression vectors for human IL-6 (hIL-6) and rat IL-6R (rIL-6-R). The cell lines were used for testing the biological activity of different IL-6 species, soluble hIL-6R (shIL-6R) and some members of the IL-6 cytokine family by means of an ELISA procedure. The assay is based on induction of the gene expression of the acute phase protein haptoglobin in hepatoma cells and provides an alternative bioassay taking advantage of the hepatocyte stimulatory activity of IL-6 (as opposed to the B9 proliferative assay). A dose-response experiment with IL-6 showed that half-maximal stimulation was achieved with approx. 5 ng/ml of hIL-6 in HepG2 cells and with 5-10 ng/ml muIL-6 in HepG2-rIL-6R cells after 24 h. The same response was achieved with 10 ng/ml shIL-6R in HepG2-IL6 cells. In conclusion, the assay is fast and reliable and might be adopted for other cytokines and receptors with hepatocyte stimulating activity.
Oppmann
B
B
I. Department of Medicine, Johannes Gutenberg University of Mainz, Germany.
Stoyan
T
T
Fischer
M
M
Voltz
N
N
März
P
P
Rose-John
S
S
D000818:Animals; D015703:Antigens, CD / Q000032:analysis* / Q000235:genetics; D001681:Biological Assay; D018014:Gene Transfer Techniques; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis* / Q000235:genetics; D051381:Rats; D018123:Receptors, Interleukin / Q000032:analysis* / Q000235:genetics; D019947:Receptors, Interleukin-6; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D015850:Interleukin-6; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6