IMMUNOGENIC PEPTIDES FOR USE IN THE PREVENTION AND/OR TREATMENT OF INFECTIOUS DISEASES, AUTOIMMUNE DISEASES, IMMUNE RESPONSES TO ALLOFACTORS, ALLERGIC DISEASES, TUMORS, GRAFT REJECTION AND IMMUNE RESPONSES AGAINST VIRAL VECTORS USED FOR GENE THERAPY OR GENE VACCINATION

1 - 16 . (canceled)

17 . An in vitro method for detecting or depleting CD4+ T lymphocytes, comprising contacting the CD4+ T lymphocytes with an isolated immunogenic peptide comprising:

(1) a natural killer T (NKT) cell epitope having a [F, W, H or Y]-XX-[I, L, M or V]-XX-[F, W, H or Y] (SEQ ID NO: 23) motif of an antigenic protein;

(2) a thioreductase [C, S or T]-XX-C (SEQ ID NO: 19) or C-XX-[C, S or T] (SEQ ID NO: 18) motif, which is either immediately adjacent to said NKT cell epitope, or separated from said NKT cell epitope by a linker of at most 7 amino acids, and

(3) an optional flanking amino acid sequence of up to 10 amino acids at the N and/or C terminus of the peptide, wherein said antigenic protein does not comprise in its natural sequence a [C, S or T]-XX-C (SEQ ID NO: 19) or C-XX-[C, S or T] (SEQ ID NO: 18) motif within 11 amino acids N- or C terminally adjacent to said NKT cell epitope,

wherein X stands for any amino acid, and wherein said antigenic protein is not survivin.

18 . An in vitro method for obtaining a population of antigen-specific CD4+ NKT cells, the method comprising the steps of:

contacting peripheral blood cells in vitro with an isolated immunogenic peptide; and

expanding said cells in the presence of IL-2, IL-15 or IL-7,

wherein the isolated immunogenic peptide comprises

(1) a natural killer T (NKT) cell epitope having a [F, W, H or Y]-XX-[I, L, M or V]-XX-[F, W, H or Y] (SEQ ID NO: 23) motif of an antigenic protein;

(2) a thioreductase [C, S or T]-XX-C (SEQ ID NO: 19) or C-XX-[C, S or T] (SEQ ID NO: 18) motif, which is either immediately adjacent to said NKT cell epitope, or separated from said NKT cell epitope by a linker of at most 7 amino acids, and

(3) an optional flanking amino acid sequence of up to 10 amino acids at the N and/or C terminus of the peptide, wherein said antigenic protein does not comprise in its natural sequence a [C, S or T]-XX-C (SEQ ID NO: 19) or C-XX-[C, S or T] (SEQ ID NO: 18) motif within 11 amino acids N- or C terminally adjacent to said NKT cell epitope,

wherein X stands for any amino acid, and wherein said antigenic protein is not survivin.

19 . The method according to claim 18 , wherein the antigenic protein is selected from the group consisting of: a tumour associated antigenic protein, a viral protein, an autoantigen, an allofactor, an allergen, an alloantigen shed by a graft, an antigen of an intracellular pathogen, and an antigen from a viral vector used for gene therapy or gene vaccination.

20 . The method according to claim 18 , wherein the natural killer T (NKT) cell epitope consists of 7 amino acids with a [F, W, H or Y]-XX-[I, L, M or V]-XX-[F, W, H or Y] (SEQ ID NO: 23) motif of an antigenic protein.

21 . The method according to claim 18 , wherein said NKT cell epitope has a [F or W]-XX-[I, L, M or V]-XX-[F or W] (SEQ ID NO: 13) motif.

22 . The method according to claim 18 , wherein said thioreductase motif is C-XX-C (SEQ ID NO: 14).

23 . The method according to claim 18 , wherein said antigenic protein is a multiple sclerosis autoantigen.

24 . The method according to claim 18 , wherein said antigenic protein is myelin oligodendrocyte glycoprotein (MOG).

25 . The method according to claim 18 , wherein said NKT cell epitope is FLRVPCWKI (SEQ ID NO: 38).

26 . The method according to claim 18 , wherein the thioreductase motif is C-XX-C (SEQ ID NO: 14).

27 . A population of antigen-specific CD4+ NKT cells obtained by the method according to claim 18 .

28 . A pharmaceutical composition comprising the population of antigen-specific CD4+ NKT cells obtained by the method according to claim 18 .

29 . A method of treating a subject for a disease selected from the group consisting of: an infection with an intracellular pathogen, a tumour, an autoimmune disease, an immune response to an allofactor or to allergen exposure, an allograft rejection, and an immune response against a viral vector used for gene therapy or gene vaccination, comprising administrating a therapeutic amount of the population of antigen-specific CD4+ NKT cells obtained by the method according to claim 18 .