Patent ID: 7422752

Claim:
A method for delivering a peptide in vitro into the major histocompatability complex (MHC) class I antigen processing pathway of an antigen presenting cell to elicit a cytotoxic T lymphocyte (CTL) response, comprising contacting said cell with a mutant of E. coli heat labile enterotoxin B (EtxB) or cholera toxin B (CtxB) covalently linked to said peptide, wherein said mutant comprises at least one of the following point mutations within the region spanning amino acid residues E51 to I58 of the β4-α2 loop of EtxB or CtxB: CtxB (E51A) (SEQ ID NO: 17), CtxB (Q56A) (SEQ ID NO: 18), CtxB (H57A) (SEQ ID NO: 13), and EtxB (H57S) (SEQ ID NO: 19) thereby delivering said peptide into said cell.