Recombinant influenza viruses for vaccines and gene therapy
The invention provides compositions and methods useful to prepare segmented, negative strand RNA viruses, e.g., orthomyxoviruses such as influenza A viruses, entirely from cloned cDNAs and in the absence of helper virus.
1. A method of preparing infectious influenza virus in the absence of a helper virus comprising:
i) introducing into a host cell a vector comprising a promoter operably linked to an influenza virus PA cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus PB1 cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus PB2 cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus HA cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus NP cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus NA cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to an influenza virus M cDNA linked to a transcription termination sequence, and a vector comprising a promoter operably linked to an influenza virus NS cDNA linked to a transcription termination sequence, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus PA, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus PB1, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus PB2, and a vector comprising a promoter operably linked to a DNA segment encoding influenza virus NP; and
ii) isolating infectious influenza virus from said host cells.
2. The method of claim 1 further comprising a vector comprising a promoter operably linked to a DNA segment encoding influenza virus HA, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus NA, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus M1, a vector comprising a promoter operably linked to a DNA segment encoding influenza virus M2, and a vector comprising a promoter operably linked to a DNA segment encoding influenza virus NS2.
3. The method according to claim 1 wherein each DNA segment encoding an influenza viral protein is on a separate vector.
4. The method according to claim 1 wherein the promoter of the vectors of (i) comprise a RNA polymerase I promoter, RNA polymerase H promoter, RNA polymerase III promoter, T7 promoter, or T3 promoter.
5. The method according to claim 4 wherein the RNA polymerase I promoter is a human RNA polymerase I promoter.