NON-CODING IMMUNOMODULATORY DNA CONSTRUCT

1 . A non-coding, linear open-chained DNA construct without a phosphorothioate backbone for immunomodulation, wherein the DNA construct consists of nucleotides comprising D-DNA and at least one L-DNA nucleotide, wherein said DNA construct comprises at least one sequence motif N 1 N 2 CGN 3 N 4 and is a TLR9 agonist, wherein:

the N 1 N 2 is selected from the group consisting of GT, GG, GA, AT or AA, the N 3 N 4 is selected from the group consisting of CT or TT;

C is deoxycytidine, G is deoxyguanosine, A is deoxyadenosine, and T is deoxythymidine; and

wherein said at least one L-DNA nucleotide is located in the segment of the DNA construct consisting of five nucleotides at either the 3′-end or the 5′-end or at both the 5′- and the 3′-end of the DNA construct.

2 . The construct according to claim 1 , further comprising at least one G stretch comprising three consecutive deoxyguanosines located near the 5′ end or the 3′ end or near both ends of the DNA construct.

3 . The construct according to claim 1 , wherein:

said construct comprises at least two of the at least one sequence motifs N 1 N 2 CGN 3 N 4 ; and

said construct further comprises a G stretch comprising three consecutive deoxyguanosines located between two of said at least two sequence motifs N 1 N 2 CGN 3 N 4 .

4 . The construct according to claim 1 , wherein:

said construct comprises at least two of the at least one sequence motifs N 1 N 2 CGN 3 N 4 ; and

said construct further comprises at least five nucleotides selected from the group consisting of C, T and A wherein the at least five nucleotides are located between two of said at least two sequence motifs N 1 N 2 CGN 3 N 4 .

5 . The construct according to claim 1 , wherein the construct comprises single-stranded or double-stranded DNA.

6 . The construct according to claim 1 , wherein said at least one sequence motif N 1 N 2 CGN 3 N 4 is located within a single-stranded or a double-stranded region or within both regions of the DNA construct.

7 . A composition comprising the construct of claim 1 and further comprising at least two additional DNA constructs, wherein the at least two additional DNA constructs ligate to one another.

8 . The construct according to claim 1 , wherein one of said nucleotides comprising D-DNA or the at least one L-DNA nucleotide is modified with a functional group selected from the group consisting of carboxyl, amine, amide, aldimine, ketal, acetal, ester, ether, disulfide, thiol, and aldehyde.

9 . The construct according to claim 8 , wherein the at least one modified nucleotide is linked to a compound selected from the group consisting of peptides, proteins, carbohydrates, antibodies, lipids, micelles, vesicles, synthetic molecules, polymers, micro projectiles, metal particles, nanoparticles, and a solid phase.

10 . A non-coding, linear open-chained DNA construct without a phosphorothioate backbone for immunomodulation, wherein the DNA construct consists of nucleotides comprising D-DNA and at least one L-DNA nucleotide, wherein said DNA construct comprises at least three sequence motifs N 1 N 2 CGN 3 N 4 and is a TLR9 agonist, wherein:

N is a nucleotide selected from the group consisting of A, C, T, and G, and C is deoxycytidine, G is deoxyguanosine, A is deoxyadenosine, and T is deoxythymidine;

a first G stretch is present at the 5′ end;

the construct further comprises at least five nucleotides selected from the group consisting of C, T and A wherein the at least five nucleotides are located between a first and a second of said at least three sequence motifs;

said construct further comprises a second G stretch, which is located between a second and a third of said at least three sequence motifs; and

two of three 3′ terminal nucleotides are in L-conformation.

11 . The construct according to claim 10 , further comprising at least one additional G stretch.

12 . A pharmaceutical composition comprising a DNA construct according to claim 1 .

13 . The pharmaceutical composition according to claim 12 , further comprising a chemotherapeutic.

14 . A vaccine comprising a non-coding, linear open-chained DNA construct without a phosphorothioate backbone for immunomodulation, wherein the DNA construct consists of nucleotides comprising D-DNA and at least one L-DNA nucleotide, wherein said DNA construct comprises at least one sequence motif N 1 N 2 CGN 3 N 4 , wherein N is a nucleotide selected from the group consisting of A, C, T, and G, and C is deoxycytidine, G is deoxyguanosine, A is deoxyadenosine and T is deoxythymidine, and wherein said at least one L-DNA nucleotide is located in the segment of the DNA construct consisting of five nucleotides at either the 3′-end or the 5′-end or at both the 5′- and the 3′-end of the DNA construct.

15 . The vaccine according to claim 14 , wherein the DNA construct is an adjuvant.

16 . A method of treating cancer or an autoimmune disease, comprising administering the DNA construct according to claim 1 .

17 . A method of modulating the immune system, comprising administering the DNA construct according to claim 1 .

18 . The vaccine according to claim 14 , wherein the N 1 N 2 in the at least one sequence motif of the DNA construct is selected from the group consisting of GT, GG, GA, AT or AA, and the N 3 N 4 of the at least one sequence motif is selected from the group consisting of CT or TT.

19 . The vaccine according to claim 18 , wherein the DNA construct is an adjuvant.