VLPs derived from cells that do not express a viral matrix or core protein
The present invention discloses novel influenza virus-like particles (VLPs) that contain chimeric proteins or influenza membrane proteins. The chimeric proteins are derived from fragments of influenza membrane proteins fused to heterologous proteins. The invention includes antigenic formulations and vaccines comprising VLPs of the invention as well as methods of making and administering VLPs to vertebrates, including methods of inducing immunity to infections, such as influenza.
1. A method of making a virus-like particle (VLP) in a cell that comprises at least two influenza membrane proteins, comprising:
expressing at least a first influenza membrane protein and a second influenza membrane protein in a cell, wherein said first influenza membrane protein is hemagglutinin (HA) and said second influenza membrane protein is neuraminidase (NA) to obtain assembled VLPs; and
purifying the assembled VLPs, wherein the cell does not express any viral matrix or core protein.
2. The method of claim 1 , further comprising expressing at least one additional protein from an infectious agent in said cell, wherein said at least one additional protein from an infectious agent forms part of the VLP.
3. The method of claim 1 , wherein said HA is derived from a seasonal influenza virus.
4. The method of claim 3 , wherein said seasonal influenza virus is a type A influenza virus.
5. The method of claim 3 , wherein said seasonal influenza virus is a type B influenza virus.
6. The method of claim 1 , wherein said HA is derived from an avian influenza virus.
7. The method of claim 6 , wherein said influenza virus is H5N1.
8. The method of claim 6 , wherein said influenza virus is H9N2.
9. The method of claim 1 , wherein at least one influenza membrane protein is a chimeric protein comprising the cytoplasmic tail of an influenza membrane protein.
10. The method of claim 9 , wherein said cytoplasmic tail of an influenza membrane protein is from HA.
11. The method of claim 1 , wherein at least one influenza membrane protein is a chimeric protein comprising the transmembrane domain of an influenza membrane protein.
12. The method of claim 11 , wherein said transmembrane domain of an influenza membrane protein is from HA.
13. The method of claim 1 , wherein said NA protein is derived from a seasonal influenza virus.
14. The method of claim 13 , wherein said seasonal influenza virus is a type A influenza virus.
15. The method of claim 13 , wherein said seasonal influenza virus is a type B influenza virus.
16. The method of claim 1 , wherein said NA protein is derived from an avian influenza virus.
17. The method of claim 16 , wherein said influenza virus is H5N1.
18. The method of claim 16 , wherein said influenza virus is H9N2.
19. The method of claim 2 , wherein said at least one additional protein from an infectious agent is a chimeric protein.
20. The method of claim 19 , wherein said chimeric protein comprises a cytoplasmic and/or transmembrane domain of an orthomyxovirus protein.