International Immunology Advance Access originally published online on March 28, 2006
International Immunology 2006 18(5):767-773; doi:10.1093/intimm/dxl012
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A redundant role for PKC-
in mast cell signaling and effector function
1 Department of Molecular Immunology, Institute for Biology III, University of Freiburg and Max Planck Institute for Immunobiology, Stübeweg 51, 79108 Freiburg, Germany
2 Department of Medicine, Medical School Hannover, 30625 Hannover, Germany
3 Max Planck Institute for Experimental Endocrinology, 30625 Hannover, Germany
Correspondence to: Michael Huber; E-mail: huberm{at}immunbio.mpg.de
Protein kinase (PK) C-
is strongly expressed in mast cells (MCs) and activated in response to antigen-mediated high-affinity receptor for IgE (Fc
R1) engagement. A critical role of PKC-
in antigen-triggered activation of various signaling pathways was observed in basophilic leukemia cells. To study the function of PKC-
in MCs differentiated in vitro from murine bone marrow, we used our established PKC-
null mice. Unexpectedly, we did not reveal any difference in antigen-induced activation of many central signaling molecules (PKB, mitogen-activated protein kinase, p38, Jun-N-terminal kinase, phospholipase C-
1, Bruton's tyrosine kinase, PKD, Fos and PKC-
) in time-course as well as dose-response studies between PKC-
-deficient and wild-type MCs. In correlation, antigen-triggered degranulation, release of arachidonic acid and secretion of IL-6 were unaltered by the loss of PKC-
. Furthermore, stimulation of MCs via different receptor systems [Steel factor receptor (c-kit) and toll-like receptor 4] did not lead to differences in the measured responses between both cell types. These results strongly suggest that PKC-
plays a redundant role in MCs stimulated by antigen as well as other well-known MC stimuli.
Keywords: degranulation, Fc
R1, IL-6, signal transduction, TLR4