Prefusion RSV F proteins and their use
Disclosed are immunogens including a recombinant RSV F protein stabilized in a prefusion conformation. Also disclosed are nucleic acids encoding the immunogens and methods of producing the immunogens. Methods for generating an immune response in a subject are also disclosed. In some embodiments, the method is a method for treating or preventing a RSV infection in a subject by administering a therapeutically effective amount of the immunogen to the subject.
1. An isolated immunogen, comprising:
a recombinant RSV F protein comprising S 190F and V207L amino acid substitutions compared to a native RSV F protein that stabilize the recombinant RSV F protein in a prefusion conformation;
wherein the prefusion conformation comprises an antigenic site Ø comprising RSV F residues 62-69 and 196-209 that specifically binds to a D25 antibody or an AM22 antibody after incubation at 20° C. in phosphate buffered saline at physiological pH for at least 24 hours in the absence of the D25 antibody or the AM22 antibody.
2. The immunogen of claim 1 , wherein the RSV F protein further comprises one or more additional amino acid substitutions.
3. The immunogen of claim 1 , wherein the RSV F protein is a human subtype A or subtype B, or bovine RSV F protein comprising the amino acid substitutions.
4. The immunogen of claim 1 , wherein the recombinant RSV F protein comprises a F 2 polypeptide and a F 1 polypeptide comprising or consisting of RSV F positions 26-109 and 137-513, respectively.
5. The immunogen of claim 1 , wherein the recombinant RSV F protein comprises a F2 polypeptide and a F 1 polypeptide, wherein a C-terminal residue of the F 2 polypeptide is linked to an N-terminal residue of the F 1 polypeptide by a heterologous peptide linker.
6. The immunogen of claim 1 , wherein the recombinant RSV F protein comprises an F 1 polypeptide comprising the amino acid sequence set forth as residues 137-513 of SEQ ID NO: 191.
7. The immunogen of claim 1 , wherein the recombinant RSV F protein is soluble and comprises an F 1 ectodomain comprising a C-terminal residue linked to a trimerization domain.
8. The immunogen of claim 7 , wherein the trimerization domain is a Foldon domain.
9. The immunogen of claim 8 , wherein the recombinant RSV F protein linked to the trimerization domain comprises the amino acid sequences set forth as positions 26-109 and 137-544 of SEQ ID NO: 191.
10. The immunogen of claim 1 , wherein the C-terminus of recombinant RSV F protein is linked to a ferritin domain, an encapsulin domain, a Sulfur Oxygenase Reductase (SOR) domain, a lumazine synthase domain, or a pyruvate dehydrogenase domain.
11. The immunogen of claim 1 , wherein the recombinant RSV F protein comprises a F 1 ectodomain comprising a C-terminal residue linked to a transmembrane domain.
12. A virus-like particle comprising the immunogen of claim 1 .
13. A protein nanoparticle comprising the immunogen of claim 1 .
14. The protein nanoparticle of claim 13 , wherein the protein nanoparticle is a ferritin nanoparticle, an encapsulin nanoparticle, a Sulfur Oxygenase Reductase (SOR) nanoparticle, a lumazine synthase nanoparticle, or a pyruvate dehydrogenase nanoparticle.
15. A nucleic acid molecule encoding the immunogen of claim 1 .
16. A vector comprising the nucleic acid molecule of claim 15 .
17. An isolated host cell comprising the vector of claim 16 .
18. An immunogenic composition comprising an effective amount of the immunogen of claim 1 , and a pharmaceutically acceptable carrier.
19. A method for generating an immune response to RSV F protein in a subject, comprising administering an effective amount of the immunogen of claim 1 to the subject to generate the immune response.