Hypersensitivity to
ribitol teichoic acid (RTA), the major
antigenic determinant of Staphylococcus aureus, may be important in a rabbit model of corneal phlyctenules and catarrhal infiltrates. Over a 5-month period, an
enzyme-linked
immunosorbent assay was used to measure
immunoglobulin (Ig) G and
IgA antibody levels to RTA in sera, tears, and corneas from rabbits immunized using the following routes: Group 1,
intradermal injections of S. aureus cell wall (CW) mixed with complete
Freund's adjuvant (CFA); Group 2, subconjunctival
injections of CW-CFA; Group 3, prolonged topical application of viable S. aureus to the eye; Group 4,
intradermal injections of CW-CFA plus prolonged topical application of viable S. aureus; and Group 5, subconjunctival
injections of CW-CFA plus prolonged topical application of viable S. aureus. Over the 5-month period, the
IgG and
IgA antibody levels were correlated to RTA with the development of corneal phlyctenules and catarrhal infiltrates. The
IgG titers to RTA were higher than
IgA titers in serum, tears, and cornea. The highest antibody titers were
IgG titers in cornea. Only rabbits immunized by intradermal or subconjunctival
injections of CW-CFA followed by prolonged topical application of viable S. aureus (Groups 4 and 5) developed moderate to severe conjunctival
hyperemia and
edema with corneal phlyctenules and catarrhal infiltrates. When corneal lesions developed between 2-3 months, both groups had the highest corneal
IgG and
IgA antibody titers to RTA with
IgG titers being more than 60 times higher than
IgA titers. In the remaining 2 months of the study, the conjunctival response in both groups decreased from moderate-to-severe to mild, and no new corneal lesions developed, despite continued topical application of viable S. aureus and elevated antibody titers in cornea, serum, and tears. In this study,
IgG and
IgA antibody levels to RTA were measured in serum, tears, and cornea in a rabbit model of corneal phlyctenules and catarrhal infiltrates, and the antibody response was correlated with the development of these
hypersensitivity lesions.