Polymorphonuclear leukocytes (PMN) are recruited early at an inflammatory site and can modulate immune responses by secreting IL-1β. We had shown that TNF (10 ng/ml) and GM-CSF (10 ng/ml) induce IL-1β mRNA accumulation in PMN. Using nuclear run-on analysis, we had also shown that TNF and GM-CSF trigger IL-1β transcription independent of new protein synthesis. Here we show that activation of PKC and calcium mobilization are required for IL-1β transcription by TNF and GM-CSF. We have investigated the role of NF-kB, a transcription factor known to be involved in IL-1β transcription in monocytes, using electrophoretic mobility shift assays. Our results confirm that activation of NF-kB is triggered in mononuclear cells and undifferentiated HL-60 cells following cytokine stimulation. In PMN, there is a low level of constitutive NF-kB DNA binding activity, with minimal activation of NF-kB following stimulation with TNF, and no activation of NF-kB following stimulation with GM-CSF. This suggests that, in contrast to monocytes, activation of NF-kB does not play a major role in TNF or GM-CSF induction of IL-1β transcription in PMN.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology