Immunogenic peptides comprising an MHC class II T cell epitope and a redox motif
The invention relates to isolated immunogenic peptides comprising a MHC class II T cell epitope, and immediately adjacent or separated from said epitope a H-X(0,2)-C-X(2)-[CST] or [CST]-X(2)-C-X(0,2)-H redox motif.
1. An isolated immunogenic peptide of between 13 and 50 amino acids comprising
(a) a human MHC class II T cell epitope of an antigen, said epitope having a length of between 8 and 16 amino acids that binds into the cleft of the human MHC class II molecule, and
(b) a redox motif consisting of H-X(0,2)-C-X(2)-[CST] [SEQ ID NO: 78, 90 or 91] or [CST]-X(2)-C-X(0,2)-H [SEQ ID NO: 79, 92 or 93], wherein H is His, C is Cys, S is Ser, T is Thr and X is any amino acid,
wherein said human MHC class II T cell epitope is immediately adjacent to said redox motif or separated from said redox motif by a linker of at most 7 amino acids,
with the proviso that said antigen does not contain in its sequence said redox motif within a distance of 10 amino acids of said epitope.
2. The peptide according to claim 1 , with the proviso that said antigen does not contain in its sequence said redox motif.
3. The peptide according to claim 1 , wherein said redox motif is located N terminally from the human MHC class II T cell epitope.
4. The peptide according to claim 1 , wherein said peptide has a length of between 13 and 30 amino acids.
5. The peptide according to claim 1 , wherein the linker comprises at most 4 amino acids.
6. The peptide according to claim 1 , wherein the MHC class II T cell epitope is separated from said redox motif by 2 amino acids.
7. The peptide according to claim 1 , wherein X within the C-X(2)-[CST] (SEQ ID NO: 76) or [CST]-X(2)-C(SEQ ID NO: 77) sequence is Gly or Pro.
8. The peptide according to claim 1 , wherein X within the C-X(2)-[CST] (SEQ ID NO: 76) or [CST]-X(2)-C(SEQ ID NO: 77) sequence is not Cys.
9. The peptide according to claim 1 , wherein the at most 2 amino acids separating said histidine and said C-X(2)-[CST] (SEQ ID NO:76) or [CST]-X(2)-C (SEQ ID NO: 77) sequence do not comprise Cys, Ser or Thr.
10. The peptide according to claim 1 , wherein the redox motif consisting of H-C-X(2)-[CST] [SEQ ID NO: 78] or [CST]-X(2)-C-H [SEQ ID NO: 79].