Human CellExp™ CD89 Protein, Human Recombinant

FCAR, also called FcαRI or CD89, is a type I transmembrane receptor for Fc region of IgA which is the most abundant immunoglobulin present in the mucosal areas. This receptor is present on the surface of myeloid lineage cells such as neutrophils, monocytes, macrophages, and eosinophils, especially phagocytes located in mucosal areas. It interacts with IgA-opsonized targets and triggers several immunologic defense processes, including phagocytosis, antibody-dependent cell-mediated cytotoxicity and stimulation of the release of inflammatory mediators. Multiple alternatively spliced transcript variants encoding different isoforms have been described for this gene. Sustained aggregation of FCAR results in activation of target-cell functions such as antigen presentation and cytokine release. In contrast, monomeric targeting with serum IgA or with a variety of anti-FcαRI Fab fragments triggers an inhibitory response and additionally induces apoptosis. FcαRI thus play a fundamental role in preventing tumor development and growth, as well as in controlling inflammation.