IL-2 and IL-4 mediate through two distinct kinase pathways for the activation of alphaCD3-induced activated killer cells.
The present study has examined the role of IL-2 and IL-4 in the regulation of different kinase pathways for the generation of alphaCD3-induced activated killer cells, CD3-AK. It has previously been shown that the IL-2 promoted CD3-AK cell response is mediated through a PKC (protein kinase C)-dependent pathway, which is susceptible to PKC inhibitors and resistant to inhibitors of PTK (protein tyrosine kinase), and that IL-4 synergized with IL-2 to induce CD3-AK cells. However, the IL-4-promoted CD3-AK cell response was PKC-independent as assessed by its resistance to PKC inhibitors. These findings suggest a dichotomy in the pathways leading to CD3-AK cell generation. To further determine whether IL-4 mediated a different kinase pathway to activate the T cells, we studied its effect on protein tyrosine phosphorylation. IL-4 up-regulated protein tyrosine phosphorylation in CD3-AK cells in a dose-dependent fashion, and resulted in increased levels of a number of phosphorylated proteins. Of particular note was the increase of tyrosine phosphorylated p56(lck) and p59(fyn) in CD3-AK cells. The changes in global protein tyrosine phosphorylation were correlated with the up-regulation by IL-4 of CD3-AK cell cytolytic activity, and the production of granzyme A. alphaIL-4 specifically blocked all the effects which were induced by IL-4. The PTK inhibitor genistein inhibited the IL-4-augmented cytolytic activity of CD3-AK cells as well as the IL-4-induced augmentation of protein tyrosine phosphorylation to the basal level of CD3-AK cells cultured in IL-2 alone. Consistent with a dichotomy in pathways for IL-2- and IL-4-mediated CD3-AK generation, genistein had no effect on the generation of CD3-AK cells cultured in IL-2 alone. Thus while PKC is primarily involved in the generation of IL-2-promoted CD3-AK cells, PTK appears to be required for the regulation of IL-4-promoted CD3-AK response.
Wang
J
J
Laboratory of Immune Cell Biology, Division of Basic Science, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Hargrove
M E
ME
Ting
C C
CC
D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D019833:Genistein; D016130:Immunophenotyping; D007375:Interleukin-1 / Q000276:immunology*; D015847:Interleukin-4 / Q000276:immunology*; D007529:Isoflavones / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
D017252:CD3 Complex; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D007529:Isoflavones; D047428:Protein Kinase Inhibitors; D015847:Interleukin-4; D014443:Tyrosine; D019833:Genistein; D011494:Protein Kinases; D011493:Protein Kinase C