Signaling through mutants of the IgA receptor CD89 and consequences for Fc receptor gamma-chain interaction.

CD89: the human myeloid IgA Fc receptor.

CD89 (Fc alphaRI) is the human myeloid IgA Fc receptor expressed on cells, such as neutrophils, eosinophils and monocytes/macrophages. Cross-linking of CD89 on these cells, by IgA-opsonised particles (e.g. bacteria, viruses) or anti-CD89 monoclonal antibodies, can trigger various immunological effector functions which are generally protective but may also cause harm to the body. CD89 is a trans...

Crosslinking of the human Fc receptor for IgA (CD89) triggers FcR gamma-chain dependent shedding of soluble CD89

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

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 (...

Absence of CD89, polymeric immunoglobulin receptor, and asialoglycoprotein receptor on human mesangial cells.

IgA nephropathy (IgAN) is characterized by raised serum IgA and predominant mesangial IgA deposits of polymeric nature. The expression of IgA receptor molecules in white blood cells and glomerular mesangial cells has recently attracted much attention in relation to the uptake of IgA by these cells. This study investigates the expression of IgA Fc receptor (Fc alphaR1 or CD89), asialoglycoprotei...

A subset of human dendritic cells expresses IgA Fc receptor (CD89), which mediates internalization and activation upon cross-linking by IgA complexes.

Immature dendritic cells (DC) sample Ags within nonlymphoid tissues and acquire exogenous proteins/pathogens via scavenger receptors or Ig FcR such as Fc gamma R and Fc epsilon R. IgA is present in a significant proportion among serum Ig and is the main isotype in mucosae, where DC are numerous. We found that a functional Fc alpha R (CD89) was expressed in situ and in vitro on interstitial-type...