Immune responses in rabbits with phlyctenules and catarrhal infiltrates

Corneal phlyctenules and catarrhal infiltrates developed in rabbits immunized with Staphylococcus aureus cell walls (CWs) mixed with complete Freund's adjuvant (CFA) after topical challenge with viable S aureus. The immune responses of these rabbits to CWs and ribitol teichoic acid (RTA) before and after immunization with CW/CFA were studied and the results of skin tests with lymphocyte blastogenesis and hemagglutination tests correlated. After immunization of rabbits with CW/CFA, their lymphocytes showed a greater proliferative response to CWs in the lymphocyte blastogenesis test that correlated with delayed hypersensitivity reactions found in skin tests. Both tests suggested that the lymphocytes of immunized rabbits showed cellular immunity to CWs. Skin tests to RTA suggested an Arthus but not a delayed hypersensitivity reaction to this antigen. The results of skin tests and hemagglutination tests suggested that immunized rabbits expressed humoral and immunity to RTA, the major antigenic determinant of S aureus.