A composition comprising a notch ligand and an allergenb or allergen bystander antigen

A method for reducing an immune response to an allergen in a mammal comprising simultaneously, contemporaneously, separately or sequentially administering, in either order:

• i) an effective amount of a modulator of the Notch signalling pathway comprising a human Notch ligand or comprising a protein or polypeptide comprising a human Delta-Serrate-Lag (DSL) domain and a human Epidermal Growth Factor-like (EGF-like) domain;
• and
• ii) an effective amount of an allergen or bystander antigen or antigenic determinant thereof, or a polynucleotide coding for an allergen or antigenic determinant thereof.

A method for promoting immune tolerance to an allergen or antigenic determinant thereof in a mammal comprising simultaneously, contemporaneously, separately or sequentially administering, in either order:

• i) an effective amount of a modulator of the Notch signalling pathway comprising a human Notch ligand or comprising a protein or polypeptide comprising a human Delta-Serrate-Lag (DSL) domain and a human Epidermal Growth Factor-like (EGF-like) domain;
• and
• ii) an effective amount of an allergen or bystander antigen or antigenic determinant thereof, or a polynucleotide coding for an allergen or antigenic determinant thereof.

A composition comprising i) a modulator of the Notch signalling pathway comprising a human Notch ligand or comprising a protein or polypeptide comprising a human Delta-Serrate-Lag (DSL) domain and a human Epidermal Growth Factor-like (EGF-like) domain;

• and
• ii) an allergen or allergen bystander antigen or antigenic determinant thereof, or a polynucleotide coding for an allergen or antigenic determinant thereof;
• an optionally iii) a pharmaceutically-acceptable carrier, as a combined preparation for modulation of the immune system.