Role of Tyrosine Kinases in IgE-Mediated Signal Transduction in Human Lung Mast Cells and Basophils

Tyrosine kinases are now thought to play an important role in IgE signal transduction in rodent cell lines. We have assessed the effects of four different inhibitors of tyrosine kinases on human lung mast cells and basophils to see if there is a similar requirement in human cells. Genistein proved to be a potent inhibitor of anti-IgE-induced histamine release in human basophils, though less potent in human lung mast cells. While tyrphostin produced a significant inhibition of histamine release neither lavendustin nor methyl-2,5-dihydroxy cinnamate (MDC) affected degranulation. Human lung mast cells showed a different inhibitory profile with MDC proving to be a potent inhibitor, genistein was much less effective and neither tyrphostin nor lavendustin A significantly affected histamine release. These results suggest that tyrosine kinases may have a role in IgE-dependent signal transduction in human lung mast cells and basophils but indicates that the two cell types have distinct inhibitory profiles.