| Autor: |
Hristov KK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK., Knox KA, Mitev VI |
| Jazyk: |
angličtina |
| Zdroj: |
International journal of molecular medicine [Int J Mol Med] 2005 Nov; Vol. 16 (5), pp. 937-41. |
| Abstrakt: |
The regulation of tyrosine phosphorylation is essential for BCR-triggered cellular responses during the selection process in the germinal centres. We were interested in examining the temporal regulation of tyrosine phosphorylation following CD40 cross-linking of anti-IgM-triggered Ramos-BL B cells. CD40 co-stimulation of anti-IgM-treated Ramos-BL B cells rescued them from growth inhibition and apoptosis, even when anti-CD40 Abs were added up to 12 h after the cross-linking of the BCR. The initial up-regulation of tyrosine phosphorylation triggered by BCR cross-linking is followed by tyrosine dephosphorylation after 12 h of stimulation, coinciding with pro-caspase-3 processing and PARP cleavage. We find that CD40 co-stimulation rescues BCR-triggered Ramos-BL B cells only before the irreversible inhibition of tyrosine kinase activity after 12 h of BCR cross-linking and that this is coupled with up-regulation of tyrosine phosphorylation; thus demonstrating the importance of the late regulation of tyrosine phosphorylation for CD40-mediated rescue of Ramos-BL B cells from BCR-triggered G1 growth arrest and apoptosis. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
