RNA interference in respiratory epithelial cells

1. A precursor RNAi molecule capable of inhibiting the expression of a target sequence comprising

a first oligonucleotide strand that is 22-30 nucleotides in length; and

a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions,

wherein the precursor RNAi molecule is a substrate for a Dicer,

wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA,

wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and

wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274.

2. The precursor RNAi molecule of claim 1 , wherein the first and second oligonucleotide strands have a different length and wherein one of the first and second oligonucleotide strands has a 3′ overhang that enhances Dicer processing of the precursor RNAi molecule.

3. The precursor RNAi molecule of claim 1 , wherein at least one of the first and second oligonucleotide strands is modified on the 3′ end to direct Dicer processing of the RNAi molecule.

4. The precursor RNAi molecule of claim 3 , wherein the modification is a deoxyribonucleotide, dideoxyribonucleotide, acyclonucleotide, 3′-deoxyadenosine (cordycepin), 3′-azido-3′-deoxythymidine (AZT), 2′,3′-dideoxyinosine (ddI), 2′,3′-dideoxy-3′-thiacytidine (3TC), 2′,3′-didehydro-2′,3′-dideoxythymidine (d4T), a monophosphate nucleotide of 3′-azido-3′-deoxythymidine (AZT), 2′,3′-dideoxy-3-thiacytidine (3TC) or a monophosphate nucleotide of 2′,3′-didehydro-2′,3′-dideoxythymidine (d4T).

5. The precursor RNAi molecule of claim 3 , wherein the modification is 1-3 deoxynucleotides substituted for ribonucleotides at the 3′ end of the first oligonucleotide strand.

6. The precursor RNAi molecule of claim 1 , wherein the first and second oligonucleotide strands are linked by a linker, wherein the strands anneal under biological conditions.

7. The precursor RNAi molecule of claim 6 , wherein the linker is an oligonucleotide.

8. The precursor RNAi molecule of claim 7 , wherein the linker contains 4 to 10 nucleotides.

9. The precursor RNAi molecule of claim 1 , wherein a ribonucleotide of the first or second strand is modified.

10. An isolated or purified expression cassette encoding a precursor RNAi molecule, wherein the cassette comprises

a nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; and

a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions,

an oligonucleotide linker positioned between the first oligonucleotide strand and the second oligonucleotide strand; and

a promoter operably linked to the first oligonucleotide strand, and

wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA,

wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and

wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274.

11. A vector encoding a precursor RNAi molecule comprising

(a) an isolated or purified expression cassette comprising a nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi; an oligonucleotide linker positioned between the first oligonucleotide strand and the second oligonucleotide strand; and a promoter operably linked to the first oligonucleotide strand; or

(b) two expression cassettes, the first expression cassette comprising a first promoter operably linked to a first nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; and the second expression cassette comprising a second promoter operably linked to a second nucleic acid encoding a second oligonucleotide strand that is 22-30 nucleotides in length, wherein the second oligonucleotide strand comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions;

wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA,

wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and

wherein the precursor RNAi molecule comprises a first oligonucleotide strand comprising SEQ ID NO:273 and a second oligonucleotide strand of RNA comprising SEQ ID NO:274.

12. The vector of claim 11 , wherein the vector is a plasmid, adenoviral, lentiviral, adeno-associated viral (AAV), poliovirus, Herpes Simplex Virus (HSV), or murine Moloney-based viral vector.

13. A composition comprising a polymer or excipient and

(a) a precursor RNAi molecule capable of inhibiting the expression of a target sequence comprising a first oligonucleotide strand that is 22-30 nucleotides in length; and a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions, wherein the precursor RNAi molecule is a substrate for a Dicer, and wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274, or

(b) a vector encoding an RNAi molecule comprising:

(1) isolated or purified expression cassette comprising a nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi; an oligonucleotide linker positioned between the first oligonucleotide strand and the second oligonucleotide strand; and a promoter operably linked to the first oligonucleotide strand; or

(2) two expression cassettes, the first expression cassette comprising a first promoter operably linked to a first nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; and the second expression cassette comprising a second promoter operably linked to a second nucleic acid encoding a second oligonucleotide strand that is 22-30 nucleotides in length, wherein the second oligonucleotide strand comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions;

wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA wherein the RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274.

14. The composition of claim 13 , wherein the polymer or excipient is bioadhesive, mucoadhesive or viscoelastic.

15. The composition of claim 13 , wherein the polymer or excipient is a gel.

16. The composition of claim 15 , wherein the gel is a viscoelastic gel.

17. The composition of claim 16 , wherein the viscoelastic gel is methylcellulose, carboxymethylcellulose or a poloxamer polymer.

18. The composition of claim 13 , further comprising a calcium chelator.

19. A method of inducing RNA interference in a respiratory epithelial cell comprising contacting the epithelial cell with an agent, wherein the agent mediates RNA interference of an mRNA to which it corresponds, and wherein the agent is

(a) a precursor RNAi molecule capable of inhibiting the expression of a target sequence comprising a first oligonucleotide strand that is 22-30 nucleotides in length; and a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions, wherein the precursor RNAi molecule is a substrate for a Dicer, and wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA, mammal wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274;

(b) a vector encoding an RNAi molecule comprising (1) isolated or purified expression cassette comprising a nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi; an oligonucleotide linker positioned between the first oligonucleotide strand and the second oligonucleotide strand; and a promoter operably linked to the first oligonucleotide strand; or (2) two expression cassettes, the first expression cassette comprising a first promoter operably linked to a first nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; and the second expression cassette comprising a second promoter operably linked to a second nucleic acid encoding a second oligonucleotide strand that is 22-30 nucleotides in length, wherein the second oligonucleotide strand comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions; wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA, wherein the RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274, or

(c) a composition comprising a polymer or excipient and (i) a precursor RNAi molecule capable of inhibiting the expression of a target sequence comprising a first oligonucleotide strand that is 22-30 nucleotides in length; and a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions, wherein the precursor RNAi molecule is a substrate for a Dicer, and wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA, an wherein the precursor RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first strand of RNA comprises SEQ ID NO:273 and the second strand of RNA comprises SEQ ID NO:274, or (ii) a vector encoding an RNAi molecule comprising (1) isolated or purified expression cassette comprising a nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; a second oligonucleotide strand that is 22-30 nucleotides in length and comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi; an oligonucleotide linker positioned between the first oligonucleotide strand and the second oligonucleotide strand; and a promoter operably linked to the first oligonucleotide strand; or (2) two expression cassettes, the first expression cassette comprising a first promoter operably linked to a first nucleic acid encoding a first oligonucleotide strand that is 22-30 nucleotides in length; and the second expression cassette comprising a second promoter operably linked to a second nucleic acid encoding a second oligonucleotide strand that is 22-30 nucleotides in length, wherein the second oligonucleotide strand comprises a nucleotide sequence that is sufficiently complementary to a sequence of an RNA of a target gene to direct target-specific RNAi and wherein the second oligonucleotide strand anneals to the first oligonucleotide strand under biological conditions; wherein the target sequence encodes a respiratory syncytial virus (RSV)-specific mRNA, and wherein the RNAi molecule is capable of inhibiting the expression of a respiratory syncytial virus (RSV)-specific messenger RNA (mRNA) to which it corresponds, and wherein the first oligonucleotide strand comprises SEQ ID NO:273 and the second oligonucleotide strand comprises SEQ ID NO:274.