Lipopolysaccharide in concentrations above 40 ng/ml stimulates proliferation of the IL-6-dependent B9 cell line.
The B9 assay is known to be a specific and sensitive assay for the estimation of interleukin-6 activity. This assay was found to be compromised by lipopolysaccharide in concentrations > or = 40 ng lipopolysaccharide per ml. The lipopolysaccharide stimulates proliferation of the B9 cell line in a dose-dependent manner both when measuring the proliferation by thymidine incorporation and when using the MTT assay. However the LPS dose-response curve is different compared to the dose-response curve for IL-6. A sample containing 100 ng LPS/ml but no IL-6 would be estimated erroneously to contain 12 pg IL-6. The interference of lipopolysaccharide is totally abolished by the addition of polymyxin B to the samples but the addition has no effect on the IL-6 induced proliferation.
Pedersen
M R
MR
Royal Danish School of Pharmacy, Department of Biological Sciences, Copenhagen, Denmark.
Jensen
S
S
Christensen
J D
JD
Hansen
E W
EW
D000818:Animals; D001681:Biological Assay; D002455:Cell Division / Q000187:drug effects* / Q000276:immunology*; D002460:Cell Line; D015850:Interleukin-6 / Q000032:analysis* / Q000502:physiology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D051379:Mice; D011112:Polymyxin B / Q000494:pharmacology; D011994:Recombinant Proteins / Q000032:analysis
D015850:Interleukin-6; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D011112:Polymyxin B