Abstract: The present invention relates to methods for changing the load state of MHC molecules with ligands, the change in the load state being catalysed by a compound of formulae I, IA, II, III or IV1 to IV3. The invention relates further to the use of compounds of formulae I, IA, II, III or IV1 to IV3 or to the use of MHC molecules loaded with ligands, which molecules can be prepared by a method according to the invention, for the treatment of disorders or conditions that are associated with various pathologically excessive or absent immune responses and also for triggering tumour-specific, pathogen-specific or autoreactive immune responses. The invention additionally relates to the use of such compounds for the treatment and diagnosis of cancer, infectious diseases, autoimmune diseases and for attenuating aggressive immune reactions, as well as to the preparation of a vaccine or of a pharmaceutical composition for the treatment of the mentioned disorders or conditions.

Abstract: Disclosed are oligomers comprising at least two MHC binding peptides joined by a flexible molecular linker. The MHC binding peptides can be MHC class I binding peptides or MHC class II binding peptides. Also disclosed is an oriented cloning method for producing such oligomers. The disclosed oligomers can be used, for example, in connection with methods for specifically activating or inhibiting the activation of CD4+ or CD8+ T cells. Such methods provide therapeutic approaches for the treatment of tumors, autoimmune disorders, allograft rejection and allergic reactions.

Abstract: The present invention concerns a method for the determination of allele-specific peptide motifs on molecules of the major histocompatibility complex (MHC) of classes I and II as well as the peptide motifs which are obtainable by the method according to the invention. In addition the use of the peptide motifs according to the invention for the production of a diagnostic or therapeutic agent is disclosed.