Patent ID: 8425917

Claim:
A method of delivering a peptide to a MHC class I antigen processing pathway of an antigen presenting cell in a mammal, wherein the method comprises: providing an antigen presenting cell; contacting the cell with a mutant of E. coli heat labile enterotoxin B (EtxB; SEQ ID NO: 15) or Vibrio cholera cholera toxin B (CtxB; SEQ. ID NO. 12) covalently linked to the peptide, wherein said mutant comprises at least one of the following point mutations within a region spanning amino acid residues E51 to I58 of the β4-α2 loop of EtxB or CtxB: CtxB (E51A) (CtxB with E51A point mutation: SEQ ID NO: 17), CtxB (Q56A) (CtxB with Q56AA point mutation: SEQ ID NO: 18), CtxB (H57A) (CtxB with H57A point mutation: SEQ ID NO: 13), and EtxB (H57S) (EtxB with H57S point mutation: SEQ ID NO: 19), and has GM-1 binding activity, but reduced immunogenic and immunomodulatory activity relative to the corresponding wild type form of EtxB or CtxB.