Functional discrimination between interleukin 6 and interleukin 1

Abstract

In this study we have investigated the specificity of bioassays in which interleukin (IL)1 and/or IL6 are active. The thymocyte assay cannot be used to discriminate between IL1 and IL6; both monokines are active in this assay. Moreover the detection limit for both IL1 and IL6 is around 100 pg/ml. IL6 activity can be measured with a murine hybridoma cell line (B9). The detection limit for human as well as murine IL6 is about 0.5 pg/ml. The assay is specific for IL 6 and is not influenced by a variety of other cytokines except for murine IL4 which shows some activity in this assay. IL1 can be measured specifically with D10 cells. The detection limit for IL1α and IL1β is around 1 pg/ml whereas IL6 is not active in this assay at all. Upon stimulation by IL1 and/or IL2 D10 cells produce IL6. However, this IL6 does not seem to be involved in the proliferation of these cells.