Differential expression of cytokine mRNAs in human cell lines.

We investigated the expression of several cytokine genes known to be differentially expressed in human mononuclear cells depending on the way of stimulation. In order to investigate cytokine gene expression in cell lines we stimulated peripheral blood mononuclear cells, the human cell lines UBC 5637, Wil-2, K562, U937 and Jurkat with PHA or a phorbol ester. The patterns of cytokine expression were assessed at 8 and 20 hours after stimulation by Northern blot analysis. Our data show that after stimulation each cell line expressed its own pattern of cytokine mRNA levels. Additionally, superinduction with cycloheximide revealed no change of a stimulation dependent pattern. Furthermore, we found that each cytokine has its own kinetic suggesting that signal transduction may be followed by cell type specific intracellular mechanisms.