Prefusion coronavirus spike proteins and their use
Coronavirus S ectodomain trimers stabilized in a prefusion conformation, nucleic acid molecules and vectors encoding these proteins, and methods of their use and production are disclosed. In several embodiments, the coronavirus S ectodomain trimers and/or nucleic acid molecules can be used to generate an immune response to coronavirus in a subject. In additional embodiments, the therapeutically effective amount of the coronavirus S ectodomain trimers and/or nucleic acid molecules can be administered to a subject in a method of treating or preventing coronavirus infection.
1. An immunogen, comprising:
a recombinant coronavirus S ectodomain trimer comprising protomers comprising one or two proline substitutions at a junction between a heptad repeat 1 (HR1) and a central helix that stabilize the S ectodomain trimer in a prefusion conformation.
2. The immunogen of claim 1 , wherein the recombinant coronavirus S ectodomain trimer comprises two consecutive proline substitutions at the junction between the HR1 and the central helix.
3. The immunogen of claim 1 , wherein the coronavirus is one of MERS-CoV, SARS-CoV, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
4. The immunogen of claim 1 , wherein the coronavirus is a betacoronavirus.
5. The immunogen of claim 1 , wherein the protomers of the recombinant coronavirus S ectodomain trimer further comprise one or more additional amino acid substitutions that stabilize the recombinant coronavirus S ectodomain trimer in the prefusion conformation.
6. The immunogen of claim 1 , wherein the protomers of the S ectodomain trimer further comprise one or more mutations to a S 1/S2 protease cleavage site and/or a S2′ protease cleavage site to inhibit protease cleavage.
7. The immunogen of claim 1 , wherein the recombinant coronavirus S ectodomain trimer is soluble.
8. The immunogen of claim 1 , wherein a C-terminal residue of the protomers in the ectodomain is linked to a transmembrane domain by a peptide linker, or is directly linked to the transmembrane domain.
9. The immunogen of claim 1 , wherein a C-terminal residue of the S2 ectodomain is linked to a protein nanoparticle subunit by a peptide linker, or is directly linked to the protein nanoparticle subunit.
10. The immunogen of claim 9 , wherein the protein nanoparticle subunit is a ferritin nanoparticle subunit.
11. A protein nanoparticle, comprising the immunogen of claim 9 .
12. A virus-like particle comprising the immunogen of claim 1 .
13. An isolated nucleic acid molecule encoding a protomer of the recombinant coronavirus S ectodomain trimer of claim 1 .
14. The nucleic acid molecule of claim 13 , operably linked to a promoter.
15. The nucleic acid molecule of claim 13 , wherein the nucleic acid molecule is an RNA molecule.
16. A vector comprising the nucleic acid molecule of claim 13 .
17. The vector of claim 16 , wherein the vector is a viral vector.
18. An immunogenic composition comprising the immunogen of claim 1 , and a pharmaceutically acceptable carrier.
19. A method of producing a recombinant coronavirus S ectodomain trimer stabilized in a prefusion conformation, comprising:
expressing the nucleic acid molecule or vector of claim 13 in an isolated host cell to produce the recombinant coronavirus S ectodomain trimer; and
purifying the recombinant coronavirus S ectodomain trimer.
20. The recombinant coronavirus S ectodomain trimer produced by the method of claim 19 .
21. A method for generating an immune response to a coronavirus S ectodomain in a subject, comprising administering to the subject an effective amount of the immunogen of claim 1 to generate the immune response.
22. The method of claim 21 , wherein the immune response treats or inhibits infection with the coronavirus.
23. The method of claim 21 , wherein generating the immune response inhibits replication of the coronavirus in the subject.