IgA Fc receptor (CD89) activation enables coupling to syk and Btk tyrosine kinase pathways: differential signaling after IFN-gamma or phorbol ester stimulation.

Abstract

IgA Fc receptors (Fc alphaR) can mediate a variety of inflammatory responses. It has been demonstrated that the FcRgamma subunit is critical in mediating signaling through Fc alphaR. We show that aggregation of Fc alphaR on U937 cells and blood neutrophils results in tyrosine phosphorylation of several intracellular proteins, including the FcR gamma subunit, p72syk, and Bruton tyrosine kinase (Btk). Syk was found to be associated with Fc alphaR and its phosphorylation was increased in phorbol myristate acetate (PMA)- and interferon-gamma (IFN-gamma)-treated U937 cells. In contrast, phosphorylation of Btk was only detected after cell treatment with PMA but not IFN-gamma. These data indicate that signaling through Fc alphaR gamma2 involves at least two subfamilies of tyrosine kinases, syk and Btk. Our results also suggest that activation of tyrosine kinase pathways through Fc alphaR depends on the activation state of the cell. This may be an important regulatory mechanism in IgA-mediated responses at inflammatory sites.

Extracted Key Phrases

5 Figures and Tables

Statistics

050100'00'02'04'06'08'10'12'14'16
Citations per Year

272 Citations

Semantic Scholar estimates that this publication has 272 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Launay1998IgAFR, title={IgA Fc receptor (CD89) activation enables coupling to syk and Btk tyrosine kinase pathways: differential signaling after IFN-gamma or phorbol ester stimulation.}, author={Pierre Launay and Agn{\`e}s Lehuen and Tatsumi Kawakami and Ulrich Blank and Renato C Monteiro}, journal={Journal of leukocyte biology}, year={1998}, volume={63 5}, pages={636-42} }