Barcoded influenza viruses and deep mutational scanning libraries including the same
Methods to create barcoded influenza viruses without disrupting the function of the viral proteins and the proper packaging of the viral genome segments are described. The barcoded influenza viruses can be used within deep mutational scanning libraries to map influenza resistance mutations to therapeutic treatments. The libraries can also be used to predict influenza strains that may become resistant to therapeutic treatments and/or more easily evolve to infect new species. The libraries include features that allow efficient collection and assessment of informative data, obviating bottlenecks of previous approaches.
1. A method for barcoding an influenza virus genome segment that comprises:
a 3′ viral RNA genome packaging signal;
an open reading frame; and
a 5′ viral RNA genome packaging signal, comprising:
inserting a nucleic acid comprising a barcode and a copy of the 5′ viral RNA genome packaging signal between the end of the open reading frame and the non-coding portion of the 5′ viral RNA genome packaging signal,
wherein the method has minimal to no effects on viral fitness,
wherein the barcode comprises 5-100 nucleotides in length, and
wherein the open reading frame encodes hemagglutinin (HA), neuraminidase (NA), M1 matrix protein (M1), M2 ion channel protein (M2), nuclear protein (NP), nonstructural protein 1 (NS1), nonstructural protein 1 (NS2), or a subunit of an RNA-dependent RNA polymerase complex selected from PB1, PB2, and PA.
2. The method of claim 1 , further comprising inserting a nucleic acid comprising a copy of the 3′ viral RNA genome packaging signal between the non-coding portion of the 3′ viral RNA genome packaging signal and the beginning of the open reading frame.
3. The method of claim 1 , wherein the copy of the 5′ viral RNA genome packaging signal lacks a start codon.
4. The method of claim 1 , wherein the copy of the 5′ viral RNA genome packaging signal has at least 95% sequence identity with the 5′ viral RNA genome packaging signal.
5. The method of claim 2 , wherein the copy of the 3′ viral RNA genome packaging signal lacks a start codon.
6. The method of claim 2 , wherein the copy of the 3′ viral RNA genome packaging signal has at least 95% sequence identity with the 3′ viral RNA genome packaging signal.
7. The method of claim 1 , wherein the barcode is 18 nucleotides in length.