NF-κB was identified as one of the transcription factors leading to antigen-independent stimulation through activation of integrin receptors. This effect was dependent upon stimulation of a α4β1 and α5β1 integrins, the major fibronectin-binding integrins of Jurkat T cells, since either RGD or CS-1 peptides at 10-4 M could prevent NF-κB activation. At variance with fibroblasts and smooth muscle cells, in which only p50 and p65 components of the NF-κB complex are induced, adhesion of T cells to fibronectin resulted in a strong upregulation of p50 and c-Rel and in a partial increase in p65 activity. The upregulation of NF-κB activity was abrogated by calphostin C, an inhibitor of protein kinase C. Cell adhesion determined a strong reduction in the cytoplasmic levels of the NF-κB inhibitor IκBα, reduction that was prevented after treatment with calphostin C, suggesting that PKC-dependent IκBα phosphorylation might be involved in the upregulation of NF-κB.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Feb 24 1998|
ASJC Scopus subject areas
- Molecular Biology