IgG-Fc and C3 receptors in the chicken: distribution, tissue localization and functional significance.

This paper summarizes data obtained in our laboratory on the demonstration of receptors for IgG-Fc (FcR) and complement (CR) on mononuclear cells of the fowl. A clearcut distinction of these two structures on spleen cells was achieved in rosette assays using SRBC coated with rabbit IgG as indicator cells which bind avian complement, but are not bound by the FcR. The tissue distribution and localization of FcR and CR positive cells was studied in mixed hemadsorption assays on sections of both central (bursa, thymus) and peripheral (spleen) lymphoid organs from normal chickens, as well as lymphocytic infiltrated thyroid glands from animals of the Obese strain (OS) afflicted with spontaneous autoimmune thyroiditis. The possible significance of both receptors in the pathogenesis of this autoimmune process is discussed.