In situ immune complex formation within the uvea. Potential role of cationic antibody.

A murine model has been developed to study the role of immunoglobulin charge in the regulation of the intraocular distribution of circulating IgG antibodies. Intravenously injected cationic antibodies to the tracer enzyme horseradish peroxidase bind within the ciliary body and choroid (CB/Ch). These cationic antibodies can selectively entrap and bind circulating antigens forming immune complexes (IC) within the uveal tissues. The structure of the uvea with its fenestrated CB/Ch capillaries and fixed anionic sites (within Bruch's membrane and the stroma of the CB and processes) may predispose the CB/Ch to in situ IC formation. Local IC formation mediated initially by deposition of cationic antibodies within the uvea may play an important role in the immunopathogenesis of some forms of uveitis.