Signal for packaging of influenza virus vectors
The invention provides a packaging (incorporation) signal for influenza virus vectors, and methods of using the signal to transmit and maintain influenza viral and foreign nucleic acid in virus and cells.
1. An influenza viral vector, comprising influenza virus incorporation sequences, which vector comprises:
sequences corresponding to the 3N noncoding region of influenza virus PB2 vRNA and optionally about 150 to about 250 nucleotides corresponding to N-terminal PB2 coding sequences that are adjacent to the 3N noncoding region in the wild-type viral PB2 gene segment, a heterologous nucleic acid segment comprising sequences corresponding to an open reading frame, and the 5N noncoding region of PB2 vRNA and optionally about 150 to about 250 nucleotides corresponding to C-terminal PB2 coding sequences that are adjacent to the 5N noncoding region in the wild-type viral PB2 gene segment, wherein the about 150 to about 250 nucleotides include incorporation sequences, wherein the vector includes the about 150 to about 250 nucleotides corresponding to N-terminal PB2 coding sequences, the about 150 to about 250 nucleotides corresponding to C-terminal PB2 coding sequences, or the about 150 to about 250 nucleotides corresponding to N-terminal PB2 coding sequences and the about 150 to about 250 nucleotides corresponding to C-terminal PB2 coding sequences;
wherein vRNA corresponding to sequences in the vector, when present in a cell expressing influenza virus proteins and comprising vRNAs other than the vRNA corresponding to the vector, is packaged into virions more efficiently than a corresponding vector that lacks the about 150 to about 250 nucleotides corresponding to N-terminal PB2 coding sequences and the about 150 to about 250 nucleotides corresponding to C-terminal PB2 coding sequences.
2. The vector of claim 1 wherein the heterologous nucleic acid segment comprises sequences corresponding to an internal ribosome entry sequence.
3. The vector of claim 1 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a marker gene.
4. The vector of claim 1 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for an immunogenic protein or a peptide of a pathogen, or a therapeutic protein.
5. The vector of claim 1 wherein incorporation sequences are from a type A influenza virus.
6. The vector of claim 1 wherein the incorporation sequences are from a type B influenza virus.
7. The vector of claim 1 wherein the heterologous nucleic acid segment is fused to another nucleic acid segment so as to encode a fusion protein.
8. A recombinant influenza virus comprising a vRNA corresponding to the vector of claim 1 .
9. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a marker gene.
10. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for an immunogenic protein or peptide of a pathogen.
11. The recombinant virus of claim 10 wherein the open reading frame encodes an influenza virus HA protein.
12. The recombinant virus of claim 10 wherein the open reading frame encodes an influenza virus NA protein.
13. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a transmembrane protein.
14. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a protein with membrane fusing activity.
15. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a viral capsid protein.
16. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for vesicular stomatitis virus G protein.
17. The recombinant virus of claim 8 wherein the heterologous nucleic acid segment comprises sequences corresponding to an open reading frame for a therapeutic protein.
18. The recombinant virus of claim 11 wherein the HA protein is a type B HA protein.
19. A method to express a heterologous nucleic acid segment in a cell, comprising: contacting a cell with the recombinant virus of claim 8 and detecting or determining whether a product encoded by the heterologous nucleic acid segment is expressed in the cell.
20. The vector of claim 1 wherein vRNA corresponding to the vector, when present in the cell, is packaged into virions at an efficiency at least 10% that of a corresponding wild-type vRNA.
21. The vector of claim 1 wherein vRNA corresponding to the vector, when present in the cell, is packaged into virions at an efficiency at least 30% that of a corresponding wild-type vRNA.
22. The vector of claim 1 wherein vRNA corresponding to the vector, when present in the cell, is packaged into virions at an efficiency at least 60% that of a corresponding wild-type vRNA.
23. The vector of claim 1 which includes the incorporation sequences in the about 150 to about 250 nucleotides at each end of the PB2 coding region.
24. The vector of claim 1 which includes the incorporation sequences in the about 150 to about 250 nucleotides at one end of the PB2 coding region.
25. The vector of claim 1 which includes the incorporation sequences in the about 250 nucleotides at one or each end of the PB2 coding region.
26. The vector of claim 1 which includes the incorporation sequences in the about 250 nucleotides at each end of the PB2 coding region.
27. The vector of claim 1 which includes the incorporation sequences in the about 250 nucleotides at one end of the PB2 coding region.