Profound immunological tolerance in the antibody response against bovine alpha s1-casein induced by intradermal administration of a dominant T cell determinant.

Immunological tolerance induced by intradermal administration of a peptide from a major milk protein antigen, alpha s1-casein, was investigated. When the peptide corresponding to amino acid residues 91-110 of alpha s1-casein, which included the dominant T cell determinant, was administered intradermally to mice which were subsequently immunized with alpha s1-casein, immunological tolerance in T cell response against alpha s1-casein was induced. Furthermore, intradermal administration of P91-110 induced profound immunological tolerance in the antibody response against native whole protein alpha s1-casein. The anti-alpha s1-casein antibody responses of IgG2a and IgG2b (the subclasses induced by Th1) and of IgG1 (the subclass induced by Th2) were all greatly suppressed by injecting P91-110 or alpha s1-casein. Our study is the first to demonstrate that intradermal administration of a dominant T cell determinant induces profound immunological tolerance in the antibody response against the native protein antigen.