Ii-key/Her-2/neu hybrid cancer vaccine
Provided are methods and compositions for treating cancer in humans, the cancer being characterized by expression of Her-2/neu. The methods involve vaccinating a patient with an Ii-Key/MHC class II hybrid construct and thereby stimulating an immune response to the native Her-2/neu protein. The construct may be in the form of an Ii-Key hybrid peptide or a nucleic acid encoding an Ii-Key hybrid peptide. Methods are described wherein the cancer being treated is breast cancer. Also claimed is a pharmaceutical composition comprising an Ii-Key/MHC class II hybrid construct with and without an adjuvant. The adjuvant can include GM-CSF. The Ii-Key hybrid construct includes the LRMK (SEQ ID NO: 2) residues of Ii-Key protein and an MHC Class II epitope of a protein or portion thereof which is used in the vaccine or a DNA encoding the same hybrid peptide.
1. A pharmaceutical composition for use in the treatment of cancer, the pharmaceutical composition comprising an Ii-Key peptide/MHC class II hybrid construct in a pharmaceutically acceptable carrier, the Ii-Key peptide/MHC class II hybrid construct consisting of:
a) the amino acid sequence LRMK (SEQ ID NO.: 2) of the Ii-Key peptide; and
b) an MHC Class II epitope-containing segment of Her-2/neu linked at its N-terminus to the residues of element a) wherein the MHC Class II epitope containing segment is GVGSPYVSRLLGICL (SEQ ID NO.: 3).
2. The pharmaceutical composition of claim 1 further comprising an adjuvant.
3. The pharmaceutical composition of claim 2 wherein the adjuvant is GM-CSF.
4. A composition consisting essentially of a peptide consisting of the amino acid sequence LRMKGVGSPYVSRLLGICL (SEQ ID NO: 4).