T-CELL EPITOPE DETERMINATION

Synthetic approaches to T-cell epitope determination have recently bee n developed that complement the search for natural T-cell epitopes and the investigation of the preferences of the different MHC alleles for particular motifs in cognate peptide sequences. The combination of th ese different strategies opens new possibilities for basic, as well as for applied, immunology. The outlines of the strategies for determina tion of natural T-cell epitopes are well established. These strategies have contributed substantially to our understanding of the nature of T-cell epitopes and of many diseases. Positional scanning approaches w ith random synthetic peptide libraries allow comprehensive surveys of the sequence requirements for peptide selection by MHC molecules and f or induction of T-cell responses. Synthetic T-cell epitopes can be det ermined independently of the knowledge of the natural T-cell antigen. This opens new perspectives for the development of synthetic vaccines, TCR antagonists and MHC blockers.