Immune inducer containing polynucleotide-peptide conjugate and pharmaceutical composition containing same

1 . An immunity-inducing agent composition comprising a polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof,

wherein the polynucleotide-peptide conjugate consists of: a single-chain polynucleotide or polynucleotide derivative comprising a CpG motif; a peptide; and a spacer which is covalently bonded at one end thereof to the polynucleotide or polynucleotide derivative and covalently bonded at the other end thereof to the peptide,

wherein the peptide is a peptide modified by substituting one or more contiguous amino acids at the N-terminus of an MHC-binding peptide with an amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer, wherein the one or more contiguous amino acids contain no anchor residues for MHC binding,

wherein the polynucleotide derivative is a polynucleotide comprising a modification for increasing nuclease resistance, and

wherein the amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer is cysteine or an analogue thereof, wherein the analogue is an amino acid having a side chain containing thiol.

2 . The immunity-inducing agent composition according to claim 1 , wherein one or both of the covalent bond between the spacer and the polynucleotide or polynucleotide derivative, and the covalent bond between the spacer and the peptide are a covalent bond or bonds cleavable in biological environment.

3 . The immunity-inducing agent composition according to claim 1 , wherein the covalent bond between the spacer and the peptide is a disulfide bond.

4 . The immunity-inducing agent composition according to claim 1 , wherein the MHC-binding peptide is an MHC-1-binding peptide.

5 . The immunity-inducing agent composition according to claim 4 , wherein the MHC-1-binding peptide is an HLA-A-binding peptide or an HLA-B-binding peptide.

6 . The immunity-inducing agent composition according to claim 4 , wherein the MHC-1-binding peptide has an amino acid length of not less than 8 and not more than 11.

7 . The immunity-inducing agent composition according to claim 1 , wherein the MHC-binding peptide is an MHC-2-binding peptide.

8 . The immunity-inducing agent composition according to claim 1 , wherein the polynucleotide or polynucleotide derivative is a polydeoxyribonucleotide (DNA) or DNA derivative comprising two or more CpG motifs.

9 . The immunity-inducing agent composition according to claim 1 , wherein the polynucleotide or polynucleotide derivative has a nucleotide length of not less than 15 and not more than 40.

10 . The immunity-inducing agent composition according to claim 9 , wherein the polynucleotide or polynucleotide derivative has a nucleotide length of not less than 20 and not more than 30.

11 . The immunity-inducing agent composition according to claim 1 , wherein the polynucleotide or polynucleotide derivative is a polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds.

12 . The immunity-inducing agent composition according to claim 11 , wherein, in the polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds, not less than 50% of the phosphodiester bonds are substituted with phosphorothioate bonds.

13 . The immunity-inducing agent composition according to claim 12 , wherein, in the polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds, not less than 90% of the phosphodiester bonds are substituted with phosphorothioate bonds.

14 . The immunity-inducing agent composition according to claim 1 , wherein the spacer comprises repeating units represented by the following formula:

wherein

X represents an oxygen atom or a sulfur atom, wherein each X may be the same or different,

R represents any of (CH 2 ) p O, (CH 2 ) q NH, and (CH 2 CH 2 O) m (wherein m, p and q each independently represent a natural number of not more than 10), and

n represents a natural number of not more than 10.

15 . The immunity-inducing agent composition according to claim 1 , wherein the spacer has a structure represented by any of the following formulas:

16 . The immunity-inducing agent composition according to claim 1 , wherein the spacer has a structure represented by any of the following formulas:

17 . The immunity-inducing agent composition comprising a polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof, according to claim 1 ,

wherein one or both of the covalent bond between the spacer and the polynucleotide or polynucleotide derivative, and the covalent bond between the spacer and the peptide are a covalent bond or bonds cleavable in biological environment,

wherein the polynucleotide or polynucleotide derivative is a polydeoxyribonucleotide (DNA) or DNA derivative comprising two or more CpG motifs,

wherein the polynucleotide or polynucleotide derivative is a polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds.

18 . The immunity-inducing agent composition comprising a polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof, according to claim 1 ,

wherein the amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer is cysteine or an analogue thereof, wherein the analogue is an amino acid having a side chain containing thiol,

wherein the covalent bond between the spacer and the peptide is a disulfide bond,

wherein the MHC-binding peptide is an MHC-1-binding peptide,

wherein the MHC-1-binding peptide is an HLA-A-binding peptide or an HLA-B-binding peptide,

wherein the MHC-1-binding peptide has an amino acid length of not less than 8 and not more than 11,

wherein the polynucleotide or polynucleotide derivative is a polydeoxyribonucleotide (DNA) or DNA derivative comprising two or more CpG motifs,

wherein the polynucleotide or polynucleotide derivative has a nucleotide length of not less than 20 and not more than 30,

wherein, in the polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds, not less than 90% of the phosphodiester bonds are substituted with phosphorothioate bonds,

wherein the spacer has a structure represented by any of the following formulas:

19 . The immunity-inducing agent composition according to claim 1 , further comprising a substance having immunostimulatory activity as an adjuvant.

20 . A pharmaceutical composition comprising the immunity-inducing agent composition according to claim 1 .

21 . A method for treating or preventing infections, tumors, or allergic diseases, the method comprising administering the immunity-inducing agent composition according to claim 1 to a patient.

22 . A method for treating or preventing tumors, the method comprising administering the immunity-inducing agent composition according to claim 1 to a patient.

23 . A polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof,

wherein the polynucleotide-peptide conjugate consists of: a single-chain polynucleotide or polynucleotide derivative comprising a CpG motif; a peptide; and a spacer which is covalently bonded at one end thereof to the polynucleotide or polynucleotide derivative and covalently bonded at the other end thereof to the peptide,

wherein the peptide is a peptide modified by substituting one or more contiguous amino acids at the N-terminus of an MHC-binding peptide with an amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer, wherein the one or more contiguous amino acids contain no anchor residues for MHC binding, and

wherein the polynucleotide derivative is a polynucleotide comprising a modification for increasing nuclease resistance, and

wherein the amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer is cysteine or an analogue thereof, wherein the analogue is an amino acid having a side chain containing thiol.

24 . The polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof according to claim 23 ,

wherein one or both of the covalent bond between the spacer and the polynucleotide or polynucleotide derivative, and the covalent bond between the spacer and the peptide are a covalent bond or bonds cleavable in biological environment,

wherein the polynucleotide or polynucleotide derivative is a polydeoxyribonucleotide (DNA) or DNA derivative comprising two or more CpG motifs,

wherein the polynucleotide or polynucleotide derivative is a polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds.

25 . The polynucleotide-peptide conjugate or a pharmaceutically acceptable salt thereof according to claim 23 ,

wherein the amino acid having a reactive functional group which allows for the formation of a covalent bond with the spacer is cysteine or an analogue thereof, wherein the analogue is an amino acid having a side chain containing thiol,

wherein the covalent bond between the spacer and the peptide is a disulfide bond,

wherein the MHC-binding peptide is an MHC-1-binding peptide,

wherein the MHC-1-binding peptide is an HLA-A-binding peptide or an HLA-B-binding peptide,

wherein the MHC-1-binding peptide has an amino acid length of not less than 8 and not more than 11,

wherein the polynucleotide or polynucleotide derivative is a polydeoxyribonucleotide (DNA) or DNA derivative comprising two or more CpG motifs,

wherein the polynucleotide or polynucleotide derivative has a nucleotide length of not less than 20 and not more than 30,

wherein, in the polynucleotide derivative in which phosphodiester bonds are at least partially substituted with phosphorothioate bonds, not less than 90% of the phosphodiester bonds are substituted with phosphorothioate bonds,

wherein the spacer has a structure represented by any of the following formulas:

26 . A method for inducing protective immune response, the method comprising administering the immunity-inducing agent composition according to claim 1 to a patient.