Methods and compositions for activation of innate immune responses through RIG-I like receptor signaling
Compositions and methods are provided that enable activation of innate immune responses through RIG-I like receptor signaling. The compositions and methods incorporate synthetic nucleic acid pathogen associated molecular patterns (PAMPs) that comprise elements initially characterized in, and derived from, the hepatitis C virus genome.
1. An isolated nucleic acid molecule with a non-naturally occurring sequence, the isolated nucleic acid comprising:
a 5′-arm region comprising a terminal triphosphate;
a poly-uracil core comprising at least 8 contiguous uracil residues; and
a 3′-arm region comprising at least 8 nucleic acid residues, wherein the 5′-most nucleic acid residue of the 3′-arm region is not a uracil and wherein the 3′-arm region is at least 80% uracil residues,
wherein the 5′-arm region and the poly-uracil core do not naturally occur contiguously together in a Hepatitis C virus.
2. The isolated nucleic acid molecule of claim 1 , wherein the poly-uracil core consists of between 8 and 30 uracil residues.
3. The isolated nucleic acid molecule of claim 1 , wherein the 5′-most nucleic acid residue of the 3′-arm region is a cytosine residue or a guanine residue.
4. The isolated nucleic acid molecule of claim 1 , wherein the 3′-arm region is at least 90% uracil residues.
5. The isolated nucleic acid molecule of claim 1 , wherein the 3′-arm region comprises at least 7 contiguous uracil residues.
6. The isolated nucleic acid molecule of claim 1 , wherein the 5′-arm region further comprises one or more nucleic acid residues disposed between the terminal triphosphate and the poly-uracil core.
7. The isolated nucleic acid molecule of claim 1 , wherein the nucleic acid molecule is capable of inducing retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) activation.
8. The isolated nucleic acid molecule of claim 7 , wherein the RLR is RIG-I.
9. A pharmaceutical composition comprising the isolated nucleic acid molecule of claim 1 and an acceptable carrier.
10. The pharmaceutical composition of claim 9 , further comprising a viral antigen, a bacterial antigen, a protozoal antigen, a fungal antigen, and/or a helminth antigen, or an attenuated, inactivated, or killed virus, bacterium, protozoan, fungus, and/or helminth.
11. The pharmaceutical composition of claim 9 , further comprising an anti-viral therapeutic, an anti-bacterial therapeutic, an anti-protozoal therapeutic, an anti-fungal therapeutic, an anti-helminth therapeutic, and/or an adjuvant.
12. The isolated nucleic acid molecule of claim 1 , wherein the 5′-arm region consists of the terminal triphosphate, and wherein the terminal triphosphate is linked directly to the 5′-end of the poly-uracil core.