Cloning and Characterization of the IgA Fc Receptor from Swine

The myeloid-specific IgA Fc receptor (FcαR) is a cell surface molecule on immunocytes that provides a fundamental connection between humoral and cellular immunity. In this study, the full-length cDNA sequence of swine FcαRI (swFcαRI) was isolated and characterized and found to contain a 792-base-pair open reading frame, encoding a 264-amino-acid transmembrane glycoprotein with a predicted molecular mass of 29.4 kDa. The swFcαRI shares high amino acid sequence homology (>50%) with its counterparts from cattle, seal, and horse. Rosetting analysis confirmed that COS-7 cells transfected with an swFcαRI expression plasmid was able to combine with chicken erythrocytes sensitized with porcine IgA, but not IgG.