Ontogeny and localization of the IgG Fc receptor of rabbit ciliary processes.

We have previously demonstrated the presence of IgG Fc binding sites in adult rabbit ciliary processes. The present study of 22 perinatal rabbit eyes defines the age-related expression of the IgG receptor activity and the selective localization of this activity on the posterior portions of the ciliary processes where it appears to be associated with the superficial non-pigmented epithelium. Our findings indicate that the rabbit ciliary processes IgG binding activity is only slightly expressed at birth but develops rapidly after birth, reaching adult levels within 2 weeks. Moreover, our results support the concept of important regional specialization within the ciliary body and suggest that the posterior ciliary processes, like other tissues similarly endowed with IgG binding sites, may have specialized immune functions.