Immunostimulatory nucleic acid molecules

1. A method of decreasing IgE in a subject who has been exposed to an allergen comprising administering to the subject an immunostimulatory oligonucleotide/delivery complex, said delivery complex comprising an oligonucleotide linked to a biodegradable delivery complex, wherein the oligonucleotide comprises the sequence 5′-C, G-3′, wherein the immunostimulatory oligonucleotide is 8 to 40 nucleotides in length and comprises: 5′ X 1 X 2 CGX 3 X 4 3′, wherein C and G are unmethylated and X 1 , X 2 , X 3 , and X 4 are nucleotides, in an amount sufficient to decrease IgE in the subject, wherein the decrease in IgE is relative to that observed in the subject who has been exposed to an allergen but is not treated with an immunostimulatory oligonucleotide/delivery complex.

2. The method of claim 1 , wherein said complex is antigen-free.

3. The method of claim 1 , wherein said complex further comprises an antigen.

4. The method of claim 1 , wherein said delivery complex is a liquid phase microcarrier.

5. The method of claim 1 , wherein said immunostimulatory oligonucleotide is covalently linked to said delivery complex.

6. The method of claim 1 , wherein said immunostimulatory oligonucleotide is non-covalently linked to said delivery complex.

7. The method of claim 1 , wherein said immunostimulatory oligonucleotide comprises a phosphate backbone modification.

8. The method of claim 7 , wherein said phosphate backbone modification is a phosphorothioate.

9. The method of claim 1 , wherein the immunostimulatory oligonucleotide does not include a GCG trinucleotide at a 5′ and/or 3′ terminal.

10. The method of claim 1 wherein the immunostimulatory oligonucleotide does not contain a 5′X 1 X 2 CGX 3 X 4 3′ palindrome.

11. The method of claim 1 , wherein said oligonucleotide comprises the sequence 5′-T, C, G-3′.

12. The method of claim 1 , wherein the individual has a viral infection.