Staurosporine, but not Ro 31-8220, induces interleukin 2 production and synergizes with interleukin 1α in EL4 thymoma cells Activation of nuclear factor κB as a common signal for staurosporine and interleukin 1α

Protein kinase C (PKC) has been implicated in interleukin 1 (IL1) signal transduction in a number of cellular systems, either as a key event in IL1 action or as a negative regulator. Here we have examined the effects of two PKC inhibitors, staurosporine and the more selective agent Ro 31-8220, on IL1 responses in the murine thymoma line EL4.NOB-1. A 1 h pulse of staurosporine was found to strongly potentiate the induction of IL2 by IL1α in these cells. In contrast, neither a pulse nor prolonged incubation with Ro 31-8220 affected the response to IL1α. Both agents blocked the response to PMA, however. A 1 h pulse of staurosporine was also found to induce IL2 production on its own, activate the transcription factor nuclear factor κB (NFκB) and