Stimulation-dependent lymphokine mRNA levels in human mononuclear cells.

Steady-state mRNA levels for lymphokines were studied in human peripheral blood mononuclear cells stimulated by various agents. The pattern of mRNA levels differed according to the way in which cells were stimulated or activated. Stimulation by anti-CD3 antibodies led to increased mRNA levels for interferon-gamma but only extremely low levels of interleukin 2 mRNA were detected. In order to observe levels of interleukin 2 mRNA, it was necessary to use phorbol myristate acetate (PMA) in addition to either lectins or anti-CD3 antibodies. PMA by itself was already able to induce high levels of mRNA for granulocyte macrophage colony-stimulating factor. Most interestingly, different patterns of lymphokine production were obtained with stimuli yielding the same number of activated cells and the same ratio of activated CD4 and CD8 cells. Thus, different T cell stimuli induced distinct patterns of lymphokine mRNA levels.