Effect of interleukin-10 on NF-kB and AP-1 activities in interleukin-2 dependent CD8 T lymphoblasts.

Interleukin-10 is a multifunctional cytokine, which regulates the function of various cell types of the immune system. In CD8 T cells it is known to accelerate the interleukin-2 dependent proliferation and to induce the differentiation of these cells to active cytolytic cells. Now we have studied interleukin-10 induced intracellular signaling mechanisms in human interleukin-2 dependent CD8 T lymphoblasts. The data obtained demonstrate that interleukin-10 alone can activate the AP-1 transcription factor and potentiate the interleukin-2 induced NF-kappa B activity. Moreover, interleukin-10 induced a rapid tyrosine phosphorylation of several proteins. The pattern of proteins phosphorylated was very similar to that induced by interleukin-2. Together, these findings suggest that tyrosine kinase dependent activation of NF-kappa B and AP-1 transcription factors are involved in the signaling mechanism of interleukin-10. This activation pathway resembles that of interleukin-2 in the same cell type.