An antibody capable of binding, with a human major histocompatibility complex (MHC)-restricted specificity, a MHC being complexed with an HLA-restricted peptide antigen is provided. The antibody having a binding specificity dictated by at least 4 amino acid residues in said HLA-restricted peptide such that at least 70 % reduction in binding of said antibody to said complex is observed when each of said at least 4 amino acid residues is substituted as determined by FACS of cells loaded with said HLA- estricted peptide comprising said substitution, said at least 4 amino acid residues not being anchor residues.
