N protein mutants of porcine reproductive and respiratory syndrome virus
View Patent ↗The present invention provides a genetically modified PRRS virus, methods to make it and related polypeptides, polynucleotides and various components. Vaccines comprising the genetically modified virus and polynucleotides are also provided.
1. An isolated genetically modified PRRS virus, comprising an N protein which has been modified in the NLS-2 region thereof compared to wild-type sequence, wherein the modification to the NLS-2 region of the N protein is in the pat8 or pat7 motif thereof, wherein the genetically modified PRRS virus is attenuated as a result of said modification to the N protein, and wherein said NLS-2 region modification is selected from the group consisting of: (a) residues 43 and 44 of the N protein are glycines; and (b) residues 43 and 44 of the N protein are glycine, and residue 45 is an asparagine.
2. An infectious RNA molecule encoding the genetically modified PRRS virus of claim 1 .
3. An isolated polynucleotide molecule comprising a DNA sequence encoding the infectious RNA molecule of claim 2 .
4. A vaccine for protecting a porcine animal from infection by a PRRS virus comprising the genetically modified PRRS virus of claim 1 , in an amount effective to produce immunoprotection against infection by a PRRS virus; and a carrier acceptable for veterinary use.
5. A vaccine for protecting a porcine animal from infection by a PRRS virus comprising the infectious RNA molecule of claim 2 , in an amount effective to produce immunoprotection against infection by a PRRS virus; and a carrier acceptable for veterinary use.
6. A vaccine for protecting a porcine animal from infection by a PRRS virus comprising the polynucleotide molecule of claim 3 , in an amount effective to produce immunoprotection against infection by a PRRS virus; and a carrier acceptable for veterinary use.