T-cell response in penicillin allergy.

Drugs, such as antibiotics, become immunogenic only upon binding to proteins. Among beta-lactams, penicillins constitute a typical example of allergy inducing drugs in humans. Previous work on their immunological properties focused mainly on the examination of IgE-mediated hypersensitivity reactions. However, drug-specific T-cell reactions are also involved in causing a serious allergic inflammatory response. The experimental data on the reactivity of T cells with penicillin G point to penicilloyl-modified, MHC-associated peptides as T-cell epitopes. The recognition specificity of the respective T-cell receptors appears to be directed at both, the backbone and the specific side-chain of penicillin. In contrast, the sequence of the carrier peptides contribute as holder for the haptenic determinant.