Regulation of interleukin-6 receptor expression by interleukin-6 in human monocytes - a re-examination

Abstract
We have studied the expression and regulation of the interleukin-6 receptor (gp80) and its signal transducer gp13O in primary human blood monocytes. Here, we show that freshly isolated human monocytes express mRNAs for gp80 and gp130. In contrast to a previous report [(1989) FEBS Lett. 249, 27–30] we find that neither lipopolysaccharide nor interleukin-6 (IL-6) lead to a down-regulation of IL-6 receptor mRNA in monocytes. Also in the human monocytic cell line Mono Mac 6 no effect of IL-6 on receptor mRNA levels was observed. For signal transducer gp13O mRNA in monocytes a small and transient up-regulation by IL-6 was found.