Immunostimulatory G, U-containing oligoribonucleotides
Compositions and methods relating to immunostimulatory RNA oligomers are provided. The immunostimulatory RNA molecules are believed to represent natural ligands of one or more Toll-like receptors, including Toll-like receptor 7 (TLR 7 ) and Toll-like receptor 8 (TLR 8 ). The compositions and methods are useful for stimulating immune activation. Methods useful for screening candidate immunostimulatory compounds are also provided.
1. An immunostimulatory composition, comprising:
single stranded RNA oligomer, wherein the RNA oligomer is synthetic and produced by nucleic acid synthesis or isolated and separated from components which it is normally associated with in nature, wherein the RNA oligomer is 5-40 nucleotides long having a base sequence comprising 5′-GUUGB-3′, wherein B represents U, G, or C, and wherein the oligomer is free of CpG dinucleotide, a pharmaceutically acceptable carrier, and, a cationic lipid.
2. The composition of claim 1 , wherein the RNA oligomer is a G,U-rich RNA.
3. The composition of claim 1 , wherein the oligomer is 5-12 nucleotides long.
4. The composition of claim 1 , wherein the oligomer comprises a non-natural backbone linkage.
5. The composition of claim 4 , wherein the non-natural backbone linkage is a phosphorothioate linkage.
6. The composition of claim 1 , wherein the oligomer comprises a modified base selected from the group consisting of 7-deazaguanosine, 8-azaguanosine, 5-methyluracil, and pseudouracil.
7. The composition of claim 1 , wherein the oligomer comprises a modified sugar.
8. The composition of claim 1 ,
wherein the cationic lipid is N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methyl-sulfate (DOTAP).
9. The composition of claim 1 , further comprising
an antigen.
10. The composition of claim 9 , wherein the antigen is a microbial antigen.
11. The composition of claim 8 , wherein the isolated RNA oligomer is a G,U-rich RNA.
12. The composition of claim 8 , wherein the oligomer is 5-12 nucleotides long.
13. The composition of claim 8 , wherein the base sequence is at least 50 percent self-complementary.
14. The composition of claim 8 , wherein the oligomer comprises a non-natural backbone linkage.
15. The composition of claim 14 , wherein the non-natural backbone linkage is a phosphorothioate linkage.
16. The composition of claim 8 , wherein the oligomer comprises a modified base selected from the group consisting of 7-deazaguanosine, 8-azaguanosine, 5-methyluracil, and pseudouracil.
17. The composition of claim 8 , wherein the oligomer comprises a modified sugar.
18. The composition of claim 9 , wherein the RNA oligomer is a G,U-rich RNA.
19. The composition of claim 9 , wherein the oligomer is 5-12 nucleotides long.
20. The composition of claim 9 , wherein the base sequence is at least 50 percent self-complementary.
21. The composition of claim 9 , wherein the oligomer comprises a non-natural backbone linkage.
22. The composition of claim 21 , wherein the non-natural backbone linkage is a phosphorothioate linkage.
23. The composition of claim 9 , wherein the oligomer comprises a modified base selected from the group consisting of 7-deazaguanosine, 8-azaguanosine, 5-methyluracil, and pseudouracil.
24. The composition of claim 9 , wherein the oligomer comprises a modified sugar.
25. The composition of claim 10 , wherein the RNA oligomer is a G,U-rich RNA.
26. The composition of claim 10 , wherein the oligomer is 5-12 nucleotides long.
27. The composition of claim 10 , wherein the base sequence is at least 50 percent self-complementary.
28. The composition of claim 10 , wherein the oligomer comprises a non-natural backbone linkage.
29. The composition of claim 28 , wherein the non-natural backbone linkage is a phosphorothioate linkage.
30. The composition of claim 10 , wherein the oligomer comprises a modified base selected from the group consisting of 7-deazaguanosine, 8-azaguanosine, 5-methyluracil, and pseudouracil.
31. The composition of claim 10 , wherein the oligomer comprises a modified sugar.