The differing patterns of antigen release and local retention following anterior chamber and intravenous inoculation of soluble antigen. Evidence that the eye acts as an antigen depot

Abstract

The route by which antigen is administered plays an important role in dictating quantitative and qualitative characteristics of systemic immune responses. Antigens such as BSA injected into the anterior chamber (AC) of the eye evoke a deviant systemic immune response (anterior chamber-associated immune deviation--ACAID) characterized by a selective deficiency of delayed hypersensitivity (DH). It has been claimed that the deviant immunity which follows an AC injection is related to the uniqueness of the route of antigen administration. However, others have argued that since the aqueous humor which fills the AC of the eye drains directly into the venous circulation, and since the anterior chamber lacks demonstrable lymphatic drainage pathways, an AC injection is a de facto intravenous (i.v.) injection. To determine which of these proposals is correct, we have studied the kinetics of antigen retention and release following inoculations of 125iodine-labeled BSA into the AC, into the subconjunctival space (SC), and into the blood stream. The results indicate that both AC and the SC inoculation sites function as antigen depots: significant amounts of BSA are retained within the eye in both situations for at least 4 weeks. Moreover, BSA was released from the eyes into the blood stream for greater than 21 days post-inoculation. Sites of i.v. inoculation exhibit no such properties. Interestingly, removal of the eye of AC inoculated groups, but not the site of i.v. inoculation in i.v. recipients, up to 5 days post-inoculation prevented the induction of immune deviation.(ABSTRACT TRUNCATED AT 250 WORDS)