Binding sites for immunoglobulin G in rabbit ciliary processes

This article demonstrates the presence of selective binding activity for the Fc fragment of IgG on the ciliary processes of rabbit eye. Other parts of the eye, including the cornea, iris, choroid, and retina, were negative for such activity. Binding activity was demonstrated in vitro by the specific adherence of IgG-coated sheep red blood cells (IgGEA) to the ciliary processes in frozen sections of whole rabbit eye. IgGEA binding was specifically blocked by IgG but not by albumin or the F(ab')2 fragment of IgG. The data suggest that the ciliary processes, like the choroid plexus and the renal interstitium, have intrinsic binding activity for Fc IgG, which might be involved in the local entrapment of immune components present either in the circulation or in the aqueous humor.