Mice do not respond with delayed hypersensitivity to penicillin-derived determinants.

Penicillin structures of varying lipophilicity were used to induce delayed hypersensitivity (DH) in different strains of mice. Epicutaneous application on inflamed skin or intracutaneous or subcutaneous injection with Freund's complete adjuvant did not induce DH, despite the fact that picrylchloride readily produced such responses. Sheep, rabbit and mouse red cells as well as mouse lymph node and epidermal cells conjugated with various amounts of penicillin injected subcutaneously in the base of the tail did not induce a DH reaction to penicillin either, whereas such responses to other cellular components and also to the TNP determinant after using picryl sulphonic acid conjugated spleen cells were recorded. Since the mice in other studies have been shown to respond with antibodies to soluble penicilloyl protein conjugates, but never to penicillin itself, we concluded that this species of animal is incapable of responding to penicillin with DH.