WO2021249012A1 - Coronavirus vaccine compositions, methods, and uses thereof - Google Patents

Coronavirus vaccine compositions, methods, and uses thereof Download PDF

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Publication number
WO2021249012A1
WO2021249012A1 PCT/CN2021/087066 CN2021087066W WO2021249012A1 WO 2021249012 A1 WO2021249012 A1 WO 2021249012A1 CN 2021087066 W CN2021087066 W CN 2021087066W WO 2021249012 A1 WO2021249012 A1 WO 2021249012A1
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seq
coronavirus
set forth
sequence set
recombinant polypeptide
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PCT/CN2021/087066
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French (fr)
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WO2021249012A9 (en
Inventor
Peng Liang
Joshua Liang
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Sichuan Clover Biopharmaceuticals, Inc.
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Application filed by Sichuan Clover Biopharmaceuticals, Inc. filed Critical Sichuan Clover Biopharmaceuticals, Inc.
Priority to PCT/CN2021/093895 priority Critical patent/WO2021249116A1/en
Priority to PCT/CN2021/099285 priority patent/WO2021249451A1/en
Priority to CN202180002838.2A priority patent/CN114206946B/en
Priority to EP21777614.5A priority patent/EP3947475A4/en
Priority to JP2022576439A priority patent/JP2023530434A/en
Priority to CN202311163597.7A priority patent/CN117180417A/en
Priority to CN202311163567.6A priority patent/CN117180416A/en
Priority to US17/489,572 priority patent/US11389528B2/en
Publication of WO2021249012A1 publication Critical patent/WO2021249012A1/en
Publication of WO2021249012A9 publication Critical patent/WO2021249012A9/en
Priority to US17/832,664 priority patent/US20230096093A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/12—Viral antigens
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/005—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from viruses
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/78—Connective tissue peptides, e.g. collagen, elastin, laminin, fibronectin, vitronectin or cold insoluble globulin [CIG]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/545—Medicinal preparations containing antigens or antibodies characterised by the dose, timing or administration schedule
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/555—Medicinal preparations containing antigens or antibodies characterised by a specific combination antigen/adjuvant
    • A61K2039/55505—Inorganic adjuvants
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/57—Medicinal preparations containing antigens or antibodies characterised by the type of response, e.g. Th1, Th2
    • A61K2039/575—Medicinal preparations containing antigens or antibodies characterised by the type of response, e.g. Th1, Th2 humoral response
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/01—Fusion polypeptide containing a localisation/targetting motif
    • C07K2319/02—Fusion polypeptide containing a localisation/targetting motif containing a signal sequence
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/40—Fusion polypeptide containing a tag for immunodetection, or an epitope for immunisation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/70—Fusion polypeptide containing domain for protein-protein interaction
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2770/00—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA ssRNA viruses positive-sense
    • C12N2770/00011—Details
    • C12N2770/20011—Coronaviridae
    • C12N2770/20022—New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N2770/00—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA ssRNA viruses positive-sense
    • C12N2770/00011—Details
    • C12N2770/20011—Coronaviridae
    • C12N2770/20034—Use of virus or viral component as vaccine, e.g. live-attenuated or inactivated virus, VLP, viral protein

Definitions

  • the present disclosure relates in some aspects to immunogenic compositions including recombinant peptides and proteins comprising coronavirus viral antigens and immunogens, e.g., coronavirus S protein peptides, for treating or preventing a coronavirus infection.
  • coronavirus viral antigens and immunogens e.g., coronavirus S protein peptides
  • Coronaviruses are enveloped, positive-sense single-stranded RNA viruses. They have the largest genomes (26-32 kb) among known RNA viruses, and are phylogenetically divided into four genera ( ⁇ , ⁇ , ⁇ , ⁇ ) , with betacoronaviruses further subdivided into four lineages (A, B, C, D) . Coronaviruses infect a wide range of avian and mammalian species, including humans. Human coronaviruses may circulate annually in humans and generally cause mild respiratory diseases, although severity can be greater in infants, elderly, and the immunocompromised.
  • coronaviruses including the Middle East respiratory syndrome coronavirus (MERS-CoV) , the severe acute respiratory syndrome coronavirus (SARS-CoV-1) , and the most recent 2019 new coronavirus (2019-nCoV) , also known as CoVID-19 or SARS-CoV-2, are highly pathogenic and the pandemic has left millions of people infected and led to hundreds of thousands of deaths world wide.
  • MERS-CoV Middle East respiratory syndrome coronavirus
  • SARS-CoV-1 severe acute respiratory syndrome coronavirus
  • 2019-nCoV 2019 new coronavirus
  • the high pathogenicity and airbome transmissibility of these coronaviruses have raised concem about the potential for another coronavirus pandemic.
  • the high case-fatality rate, vaguely defined epidemiology, and absence of prophylactic or therapeutic measures against coronaviruses have created an urgent need for an effective vaccine and related therapeutic agents. Provided are methods, uses and articles of manufacture that meet such and other needs.
  • a protein comprising a plurality of recombinant polypeptides, each recombinant polypeptide comprising a surface antigen of a coronavirus linked to a C-terminal propeptide of collagen, wherein the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds.
  • recombinant subunit vaccines that comprise an ecto-domain (e.g., without transmembrane and cytoplasmic domains) of an S protein or its fragments from a coronavirus, such as SARS-CoV-2, which is fused in-frame to a C-propeptide of a collagen that is capable of forming disulfide bond-linked homo-trimer.
  • a coronavirus such as SARS-CoV-2
  • the resulting recombinant subunit vaccines such as an S-Trimer, can be expressed and purified from transfected cells, and are expected to be in native-like conformation in trimeric form.
  • the coronavirus is a Severe Acute Respiratory Syndrome (SARS) -coronavirus (SARS-CoV-1) , a SARS-coronavirus 2 (SARS-CoV-2) , a SARS-like coronavirus, a Middle East Respiratory Syndrome (MERS) -coronavirus (MERS-CoV) , a MERS-like coronavirus, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
  • SARS Severe Acute Respiratory Syndrome
  • SARS-CoV-1 Severe Acute Respiratory Syndrome
  • SARS-CoV-2 SARS-coronavirus 2
  • MERS-like coronavirus MERS-like coronavirus
  • NL63-CoV 229E-CoV
  • OC43-CoV HKU1-
  • the surface antigen can comprise a coronavirus spike (S) protein or a fragment or epitope thereof, wherein the epitope is optionally a linear epitope or a conformational epitope, and wherein the protein comprises three recombinant polypeptides.
  • S coronavirus spike
  • the surface antigen can comprise a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof.
  • the surface antigen can comprise a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof.
  • RBD receptor binding domain
  • RBM receptor binding motif
  • FP fusion peptide
  • HR1 heptad repeat 1
  • HR2 heptad repeat 2
  • the surface antigen can comprises a receptor binding domain (RBD) of the S protein.
  • RBD receptor binding domain
  • the surface antigen can comprise an S1 subunit and an S2 subunit of the S protein.
  • the surface antigen can be free of a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
  • the surface antigen can comprise a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
  • the surface antigen can be free of a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L, or can contain a mutated protease cleavage site that is not cleavable by the protease.
  • the surface antigen can be soluble or do not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
  • the surface antigens can be the same or different among the recombinant polypeptides of the protein.
  • the surface antigen can be directly fused to the C-terminal propeptide, or can be linked to the C-terminal propeptide via a linker, such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
  • a linker such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
  • the protein can be soluble or do not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
  • the protein can bind to a cell surface receptor of a subject, optionally wherein the subject is a mammal such as a primate, e.g., human.
  • the cell surface receptor can be angiotensin converting enzyme 2 (ACE2) , dipeptidyl peptidase 4 (DPP4) , dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin (DC-SIGN) , or liver/lymph node-SIGN (L-SIGN) .
  • ACE2 angiotensin converting enzyme 2
  • DPP4 dipeptidyl peptidase 4
  • DC-SIGN dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin
  • L-SIGN liver/lymph node-SIGN
  • the C-terminal propeptide can be of human collagen.
  • the C-terminal propeptide can comprise a C-terminal polypeptide of pro ⁇ 1 (I) , pro ⁇ 1 (II) , pro ⁇ 1 (III) , pro ⁇ 1 (V) , pro ⁇ 1 (XI) , pro ⁇ 2 (I) , pro ⁇ 2 (V) , pro ⁇ 2 (XI) , or pro ⁇ 3 (XI) , or a fragment thereof.
  • the C-terminal propeptides can be the same or different among the recombinant polypeptides.
  • the C-terminal propeptide can comprise any of SEQ ID NOs: 1-20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 3 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 4 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 7 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 12 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 15 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide can comprise SEQ ID NO: 3.
  • the C-terminal propeptide can comprise SEQ ID NO: 15.
  • the C-terminal propeptide can comprise SEQ ID NO: 20.
  • the C-terminal propeptide can comprise a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline, or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the surface antigen in each recombinant polypeptide can be in a prefusion conformation.
  • the surface antigen in each recombinant polypeptide can be in a postfusion conformation.
  • the surface antigen in each recombinant polypeptide can comprise any of SEQ ID NOs: 21-36 or an amino acid sequence at least 80%identical thereto.
  • the recombinant polypeptide can comprise any of SEQ ID NOs: 37-51 or an amino acid sequence at least 80%identical thereto.
  • an immunogen comprising a protein provided herein.
  • a protein nanoparticle comprising protein provided herein directly or indirectly linked to a nanoparticle.
  • a virus-like particle VLP comprising a protein provided herein.
  • an isolated nucleic acid encoding one, two, three or more of the recombinant polypeptides of the protein provided herein.
  • a polypeptide encoding the S protein peptide is fused in-frame to a polypeptide encoding the C-terminal propeptide of collagen.
  • the isolated nucleic acid provided herein is operably linked to a promoter.
  • the isolated nucleic acid provided herein is a DNA molecule. In some embodiments, the isolated nucleic acid provided herein is an RNA molecule, optionally an mRNA molecule such as a nucleoside-modified mRNA, a non-amplifying mRNA, a self-amplifying mRNA, or a trans-amplifying mRNA.
  • a vector comprising an isolated nucleic acid provided herein.
  • the vector is a viral vector.
  • a virus, a pseudovirus, or a cell comprising vector provided herein, optionally wherein the virus or cell has a recombinant genome.
  • an immunogenic composition comprising the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, or cell provided herein, and a pharmaceutically acceptable carrier.
  • a vaccine comprising an immunogenic composition provided herein and optionally an adjuvant, wherein the vaccine is optionally a subunit vaccine.
  • the vaccine is a prophylactic and/or therapeutic vaccine.
  • provided herein is a method of producing a protein, comprising: expressing the isolated nucleic acid or vector provided herein in a host cell to produce the protein as provided herein; and purifying the protein.
  • a protein produced by a method provided herein comprising: expressing the isolated nucleic acid or vector provided herein in a host cell to produce the protein as provided herein; and purifying the protein.
  • kits for generating an immune response to an S protein peptide or fragment or epitope thereof of a coronavirus in a subject comprising administering to the subject an effective amount of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine as provided herein to generate the immune response.
  • the method provided herein is for treating or preventing infection with the coronavirus.
  • generating the immune response inhibits or reduces replication of the coronavirus in the subject.
  • the immune response comprises a cell-mediated response and/or a humoral response, optionally comprising production of one or more neutralizing antibody, such as a polyclonal antibody or a monoclonal antibody.
  • the immune response is against the S protein peptide or fragment or epitope thereof of the coronavirus but not against the C-terminal propeptide.
  • the administering to the subject does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to one or more coronavirus.
  • the administering does not lead to antibody dependent enhancement (ADE) in the subject when subsequently exposed to one or more coronavirus.
  • the method further comprises a priming step and/or a boosting step.
  • the administering step is performed via topical, transdermal, subcutaneous, intradermal, oral, intranasal (e.g., intranasal spray) , intratracheal, sublingual, buccal, rectal, vaginal, inhaled, intravenous (e.g., intravenous injection) , intraarterial, intramuscular (e.g., intramuscular injection) , intracardiac, intraosseous, intraperitoneal, transmucosal, intravitreal, subretinal, intraarticular, peri-articular, local, or epicutaneous administration.
  • the effective amount is administered in a single dose or a series of doses separated by one or more interval.
  • the effective amount is administered without an adjuvant.
  • the effective amount is administered with an adjuvant.
  • kits for treating infectious diseases comprising administering to a subject an effective amount of a protein provided herein to generate in the subject a neutralizing antibody or neutralizing antisera to the coronavirus.
  • the subject is a mammal, optionally a human or a non-human primate.
  • the method further comprises isolating the neutralizing antibody or neutralizing antisera from the subject.
  • the method further comprises administering an effective amount of the isolated neutralizing antibody or neutralizing antisera to a human subject via passive immunization to prevent or treat an infection by the coronavirus.
  • the neutralizing antibody or neutralizing antisera to the coronavirus comprises polyclonal antibodies to the coronavirus S protein peptide or fragment or epitope thereof, optionally wherein the neutralizing antibody or neutralizing antisera is free or substantially free of antibodies to the C-terminal propeptide of collagen.
  • the neutralizing antibody comprises a monoclonal antibody to the coronavirus S protein peptide or fragment or epitope thereof, optionally wherein the neutralizing antibody is free or substantially free of antibodies to the C-terminal propeptide of collagen.
  • the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine provided herein is for use in inducing an immune response to a coronavirus in a subject, and/or in treating or preventing an infection by the coronavirus.
  • provided herein is use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine provided herein, for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
  • Also provided herein are methods for analyzing a sample comprising: contacting a sample with the protein provided herein, and detecting a binding between the protein and an analyte capable of specific binding to the S protein peptide or fragment or epitope thereof of the coronavirus.
  • the analyte is an antibody, a receptor, or a cell recognizing the S protein peptide or fragment or epitope thereof.
  • the binding indicates the presence of the analyte in the sample, and/or an infection by the coronavirus in a subject from which the sample is derived.
  • kits comprising the protein provided herein and a substrate, pad, or vial containing or immobilizing the protein, optionally wherein the kit is an ELISA or lateral flow assay kit.
  • FIG. 1 shows structural features of an exemplary soluble S-Trimer subunit vaccine for COVID-19.
  • A Schematic illustration of the structural domains of S-Trimer and
  • B its trimeric and covalently-linked three-dimensional conformation.
  • FIG. 2 shows high-level expression of an exemplary S-Trimer.
  • FIG. 3 shows the purification and characterization of an exemplary covalently linked S-Trimer.
  • S-Trimer was purified from the cleared cell cultured medium via a Protein A (PA) affinity chromatography and anion exchange column (Q) followed by ultra-filtration and diafiltration (UF/DF) to obtain the drug substance (DS) .
  • PA Protein A
  • UF/DF ultra-filtration and diafiltration
  • S-Trimer is a disulfide bond-linked trimer.
  • C The S-Trimer was purified to nearly homogeneity as judged by SEC-HPLC analysis, with some cleaved S1 being separated during the size exclusion chromatography.
  • D The receptor binding kinetics of S-Trimer to ACE2-Fc was assessed.
  • FIG. 4 shows an exemplary S-Trimer is highly glycosylated with N-linked glycans. The full-length S-Trimer, S2-Trimer and cleaved S1 before and after deglycosylation are indicated.
  • FIG. 5 shows Electron Micrographs (EM) of an exemplary S-Trimer and the predicted conformation of the S-Trimer (right cartoon) .
  • FIG. 6 shows the detection of S-specific antibodies and neutralizing antibodies from convalescent sera using an exemplary S-Trimer as an antigen.
  • FIG. 7A and FIG. 7B show the induction of antigen-specific antibodies and neutralizing antibodies, respectively, in rats, with an exemplary S-Trimer alone and without any adjuvant.
  • FIG. 7C shows induction of antigen-specific antibodies with an exemplary S-Trimer vaccine in mice, without adjuvant or with Alum as the adjuvant.
  • FIG. 8A shows the sequence of an exemplary SARS S fusion protein capable of self-trimerization upon expression (1504 aa) .
  • FIG. 8B shows the sequence of the exemplary SARS S fusion protein without a signal peptide at the N-terminus (1491 aa) .
  • FIG. 9A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa) .
  • FIG. 9B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
  • FIG. 10A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimefization upon expression (849 aa) .
  • FIG. 10B shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (992 aa) .
  • FIG. 11A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa, 986K/987V->986P/987P) .
  • FIG. 11B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
  • FIG. 12A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa, 685R->685A, 986K/987V->986P/987P) .
  • FIG. 12B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
  • FIG. 13 shows the structure and certain sequences of exemplary coronaviruses.
  • compositions, methods, and uses of fusion peptides and proteins comprising coronavirus viral antigens or immunogens for the treatment, e.g., prophylactic, therapeutic, of coronavirus infections.
  • compositions and methods of use of recombinant soluble surface antigens from RNA viruses in covalently linked trimeric forms are disclosed.
  • the resulting fusion proteins are secreted as disulfide bond-linked homo-trimers, which are more stable in structure, while preserving the conformations of native-like trimeric viral antigens, thereby can be used as more effective vaccines against these dangerous pathogens.
  • disclosed herein are methods for using viral antigen trimers as a vaccine or as part of a multivalent vaccine to prevent viral infections, without or with adjuvant, or with more than one adjuvant, optionally via either intra-muscular injections or intra-nasal administrations.
  • disclosed herein are methods for using viral antigen trimers as an antigen for diagnosis of viral infections through detection of antibodies, e.g., IgM or IgG, that recognize the viral antigen, such as neutralizing antibodies.
  • antibodies e.g., IgM or IgG
  • disclosed herein are methods for using viral antigen trimers as an antigen to generate polyclonal or monoclonal antibodies which can be used for passive immunization, e.g., neutralizing mAb for treating a coronavirus infection.
  • a viral antigen trimer as a vaccine or as part of a multivalent vaccine, wherein the vaccine comprises a plurality of trimeric subunit vaccines comprising viral antigens of the same protein of a virus or comprising viral antigens of two or more different proteins of one or more viruses or one or more strains of the same virus.
  • disclosed herein is a monovalent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a bi-valent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a tri-valent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a quadrivalent vaccine comprising a viral antigen trimer disclosed herein.
  • disclosed herein is a monovalent vaccine comprising an S-Trimer disclosed herein.
  • a bi-valent vaccine comprising an S-Trimer disclosed herein.
  • a bi-valent vaccine comprising at least one S-Trimer comprising a first S protein antigen and at least one S-Trimer comprising a second S protein antigen.
  • the first and second S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species.
  • a tri-valent vaccine comprising an S-Trimer disclosed herein.
  • a tri-valent vaccine comprising at least one S-Trimer comprising a first S protein antigen, at least one S-Trimer comprising a second S protein antigen, and at least one S-Trimer comprising a third S protein antigen.
  • the first, second and third S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two, three, or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species.
  • a quadrivalent vaccine comprising an S-Trimer disclosed herein.
  • quadrivalent vaccine comprising at least one S-Trimer comprising a first S protein antigen, at least one S-Trimer comprising a second S protein antigen, at least one S-Trimer comprising a third S protein antigen, and at least one S-Trimer comprising a fourth S protein antigen.
  • the first, second, third, and fourth S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two, three, four, or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species.
  • the proteins, including recombinant polypeptides and fusion proteins, comprising coronavirus viral antigens and immunogens provided herein are useful for effectively and safely treating (e.g., therapeutically, prophylactically) coronavirus infection.
  • the proteins comprising coronavirus viral antigens and immunogens provided herein treat coronavirus infection without meditated vaccine-induced disease enhancement (VED) and/or antibody dependent enhancement (ADE) .
  • VED vaccine-induced disease enhancement
  • AD antibody dependent enhancement
  • the proteins comprising coronavirus viral antigens and immunogens provided herein are easily produced, and demonstrate stability under high stress conditions such as, e.g., high temperature, extreme pH, and high and low osmolality.
  • the proteins and immunogenic compositions provided herein circumvent and satisfy the issues of production, stability, safety, and efficacy that have hindered coronavirus vaccine development.
  • the coronavirus viral antigens and immunogens provided herein include the coronavirus Spike (S) protein or peptide, particularly SARS-CoV or SARS-CoV-2 S proteins.
  • S coronavirus Spike
  • SARS-CoV and SARS-CoV-2 S proteins are composed of trimers of S protein, which belongs to a group of class I viral fusion glycoproteins that also includes HIV glycoprotein 160 (Env) , influenza haemagglutinin (HA) , paramyxovirus F and Ebola virus glycoprotein.
  • the SARS-CoV and SARS-CoV-2 S proteins each encodes a surface glycoprotein precursor, and the amino terminus and most of the protein is predicted to be on the outside of the cell surface or the virus particles.
  • the S protein comprises a signal peptide located at the N terminus, an extracellular domain, a transmembrane domain and an intracellular domain.
  • the S protein of SARS-CoV and SARS-CoV-2 can be cleaved into the S1 and S2 subunits by proteases.
  • SARS-CoV-2 contains a furin-like cleavage site that is lacking in the other SARS-like CoVs.
  • the recombinant S ectodomain trimer comprises recombinant S ectodomain protomers from an alphacoronavirus, such as NL63-CoV or 229E-CoV.
  • the recombinant S ectodomain trimers comprise S ectodomain protomers from a betacoronavirus, such as OC43-CoV, SARS-CoV, SARS-CoV-2, MERS-CoV, HKU1-CoV, WIV1-CoV, mouse hepatitis virus (MHV) , or HKU9-CoV.
  • coronaviruses including SARS-CoV-2, all each has a trimeric surface antigen on its viral envelopes to gain entry into different host cells via specific cell surface receptors during infections.
  • SARS-CoV-2 uses its trimeric viral surface antigen S protein to enter host cells of respiratory systems in mammals upon binding to its specific cell surface receptor ACE2.
  • the prerequisite for generating an effective recombinant subunit vaccine is to be able to create a viral S antigen that is native-like, and in particular, to maintain its trimeric conformation in order to evoke sufficient amount of antibodies that could bind to the receptor binding domain (RBD) of the viral S protein, thereby preventing the virus from binding to ACE2 receptor, thus abolishing viral infections.
  • RBD receptor binding domain
  • the protein comprising a coronavirus viral antigen or immunogen e.g., SARS-CoV or SARS-CoV-2 S protein peptide
  • an immune response e.g., an immune response to the SARS-CoV or SARS-CoV-2 S protein peptide.
  • the immune response inhibits or reduces replication of a coronavirus in a subject, e.g., a patient.
  • the immune response includes production of one or more neutralizing antibodies, such as polyclonal and/or monoclonal antibodies.
  • the neutralizing antibodies inhibit or reduce replication of a coronavirus in a subject, e.g., a patient.
  • administration of the protein, for example as an immunogenic composition, to the subject does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to a coronavirus.
  • ADE antibody dependent enhancement
  • the protein comprising a coronavirus viral antigen and immunogen is used as a vaccine.
  • the coronavirus viral antigen and immunogen e.g., SARS-CoV or SARS-CoV-2 S protein peptide
  • the protein or peptide to which the coronavirus viral antigen or immunogen is linked is capable of associating, e.g., covalently or non-covalently linking, with proteins or peptides, such as proteins or peptides of fusion proteins or recombinant polypeptides.
  • the protein or peptide to which the coronavirus viral antigen or immunogen is linked is a multimerization domain.
  • the coronavirus viral antigen and immunogen e.g., coronavirus S protein peptide
  • the protein provided herein comprises recombinant polypeptides containing coronavirus viral antigens and immunogens, e.g., coronavirus S protein peptides or a fragment or epitope thereof, linked to a C-terminal propeptide of collagen.
  • the propeptide of collagen is derived from the human C-propeptide of ⁇ 1 collagen and is capable self-trimerization upon expression.
  • linking the coronavirus viral antigen and immunogen, e.g., coronavirus S protein peptide, to a propeptide of collagen, e.g., at the C-terminal of propeptide of collagen aids in the ability of the protein to generate an immune response.
  • the creation of the recombinant protein may preserve the tertiary and quaternary structures of the coronavirus S protein peptide, which may be important for the stability of the native conformation of the coronavirus S protein peptide, and in turn the availability of antigenic sites on the surface of the protein capable of eliciting an immune response, e.g., neutralizing antibodies.
  • linking of the coronavirus S protein peptide to a protein or peptide capable of self-trimerization allows the aggregation of the recombinant proteins, thus mimicking the native homotrimeric structure of the coronavirus S protein peptides on the viral envelope.
  • the protein provided herein comprises a plurality of self-trimerized coronavirus S protein peptide and propeptide of collagen recombinant polypeptides.
  • the trimeric nature of the recombinant proteins aids in the stability of the protein.
  • the trimefic nature of the recombinant proteins aids in the ability of the protein to generate an immune response.
  • the trimeric nature of the recombinant proteins and/or a macrostructure of a plurality of self-trimerized recombinant proteins aids in the ability of the protein to generate an immune response.
  • immunogenic compositions comprising the proteins provided herein, methods of producing proteins provided herein, methods of treating subjects with proteins and compositions provided herein, and kits.
  • the proteins provided herein comprise coronavirus viral antigens and immunogens.
  • the coronavirus viral antigens and immunogens contemplated herein are capable of promoting or stimulating a cell-mediated response and/or a humoral response.
  • the response e.g., cell-mediated or humoral response, comprises the production of antibodies, e.g., neutralizing antibodies.
  • the coronavirus viral antigen or immunogen is an coronavirus S protein peptide.
  • Coronavirus is a family of positive-sense, single-stranded RNA viruses that are known to cause severe respiratory illness. Viruses currently known to infect human from the coronavirus family are from the alphacoronavirus and betacoronavirus genera. Additionally, it is believed that the gammacoronavirus and deltacoronavirus genera may infect humans in the future.
  • betacoronaviruses include Middle East respiratory syndrome coronavirus (MERS-CoV) , Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) , Human coronavirus HKU1 (HKU1-CoV) , Human coronavirus OC43 (OC43-CoV) , Murine Hepatitis Virus (MHV-CoV) , Bat SARS-like coronavirus WIV 1 (WIV 1-CoV) , and Human coronavirus HKU9 (HKU9-CoV) .
  • MERS-CoV Middle East respiratory syndrome coronavirus
  • SARS-CoV Severe Acute Respiratory Syndrome coronavirus
  • HKU1-CoV Human coronavirus HKU1
  • OC43-CoV Human coronavirus OC43
  • MHV-CoV Murine Hepatitis Virus
  • WIV 1-CoV Bat SARS-like coronavirus WIV 1
  • HKU9-CoV Human coronavirus
  • Non-limiting examples of alphacoronaviruses include human coronavirus 229E (229E-CoV) , human coronavirus NL63 (NL63-CoV) , porcine epidemic diarrhea virus (PEDV) , and Transmissible gastroenteritis coronavirus (TGEV) .
  • a non-limiting example of a deltacoronaviruses is the Swine Delta Coronavirus (SDCV) .
  • a list of Severe acute respiratory syndrome-related coronavirus is disclosed herein:
  • Taiwan TC1 SARS coronavirus Taiwan TC1
  • Taiwan TC2 SARS coronavirus Taiwan TC2
  • Taiwan TC3 SARS coronavirus Taiwan TC3
  • SARS CoV-2 strains are shown in the table below.
  • the coronavirus viral genome is capped, polyadenylated, and covered with nucleocapsid proteins.
  • the coronavirus virion includes a viral envelope containing type I fusion glycoproteins referred to as the spike (S) protein.
  • S spike
  • Most coronaviruses have a common genome organization with the replicase gene included in the 5'-portion of the genome, and structural genes included in the 3'-portion of the genome.
  • Coronavirus Spike (S) protein is class I fusion glycoprotein initially synthesized as a precursor protein. Individual precursor S polypeptides form a homotrimer and undergo glycosylation within the Golgi apparatus as well as processing to remove the signal peptide, and cleavage by a cellular protease to generate separate S1 and S2 polypeptide chains, which remain associated as S1/S2 protomers within the homotrimer and is therefore a trimer of heterodimers.
  • the S1 subunit is distal to the virus membrane and contains the receptor-binding domain (RBD) that mediates virus attachment to its host receptor.
  • RBD receptor-binding domain
  • the S2 subunit contains fusion protein machinery, such as the fusion peptide, two heptad-repeat sequences (HR1 and HR2) and a central helix typical of fusion glycoproteins, a transmembrane domain, and the cytosolic tail domain.
  • fusion protein machinery such as the fusion peptide, two heptad-repeat sequences (HR1 and HR2) and a central helix typical of fusion glycoproteins, a transmembrane domain, and the cytosolic tail domain.
  • the coronavirus viral antigen or immunogen is a coronavirus S protein peptide in a prefusion conformation, which is a structural conformation adopted by the ectodomain of the coronavirus S protein following processing into a mature coronavirus S protein in the secretory system, and prior to triggering of the fusogenic event that leads to transition of coronavirus S to the postfusion conformation.
  • the three-dimensional structure of an exemplary coronavirus S protein (HKU1-CoV) in a prefusion conformation is provided in Kirchdoerfer et al., “Pre-fusion structure of a human coronavirus spike protein, ” Nature, 531: 118-121, 2016.
  • the coronavirus viral antigen or immunogen comprises one or more amino acid substitutions, deletions, or insertions compared to a native coronavirus S sequence that provide for increased retention of the prefusion conformation compared to coronavirus S ectodomain trimers formed from a corresponding native coronavirus S sequence.
  • the “stabilization” of the prefusion conformation by the one or more amino acid substitutions, deletions, or insertions can be, for example, energetic stabilization (for example, reducing the energy of the prefusion conformation relative to the post-fusion open conformation) and/or kinetic stabilization (for example, reducing the rate of transition from the prefusion conformation to the postfusion conformation) .
  • stabilization of the coronavirus S ectodomain trimer in the prefusion conformation can include an increase in resistance to denaturation compared to a corresponding native coronavirus S sequence.
  • Methods of determining if a coronavirus S ectodomain trimer is in the prefusion conformation are provided herein, and include (but are not limited to) negative-stain electron microscopy and antibody binding assays using a prefusion-conformation-specific antibody.
  • the coronavirus viral antigen or immunogen is a fragment of an S protein peptide.
  • the antigen or immunogen is an epitope of an S protein peptide.
  • Epitopes include antigenic determinant chemical groups or peptide sequences on a molecule that are antigenic, such that they elicit a specific immune response, for example, an epitope is the region of an antigen to which B and/or T cells respond.
  • An antibody can bind to a particular antigenic epitope, such as an epitope on coronavirus S ectodomain.
  • Epitopes can be formed both from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary folding of a protein.
  • the coronavirus epitope is a linear epitope. In some embodiments, the coronavirus epitope is a conformational epitope. In some embodiments, the coronavirus epitope is a neutralizing epitope site. In some embodiments, all neutralizing epitopes of the coronavirus S protein peptide or fragment thereof are present as the antigen or immunogen.
  • the viral antigen or immunogen is a fragment of an S protein peptide
  • only a single subunit of the S protein peptide is present, and that single subunit of the S protein peptide is trimerized.
  • the viral antigen or immunogen comprises a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof.
  • the viral antigen or immunogen comprises a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof.
  • the viral antigen or immunogen comprises a receptor binding domain (RBD) of the S protein.
  • the viral antigen or immunogen comprises an S1 subunit and an S2 subunit of the S protein.
  • the viral antigen or immunogen comprises an S1 subunit of the S protein but not an S2 subunit.
  • the viral antigen or immunogen comprises an S2 subunit of the S protein but not an S1 subunit. In some embodiments, the viral antigen or immunogen is free of a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
  • TM transmembrane
  • CP cytoplasm
  • the viral antigen or immunogen comprises a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, or cathepsin L.
  • the viral antigen or immunogen is free of a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, or cathepsin L, or contains a mutated protease cleavage site that is not cleavable by the protease.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 21. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 21.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 22. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 22.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 23. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 23.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 24:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 85:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 35:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 67:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 86:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 68:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 69:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 87:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 70:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 71:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 88:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 72:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 73:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 89:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 74:
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 25. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 25.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 26. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 26.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 27. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 27.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 28. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 28.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 29. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 29.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 30. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 30.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 31. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 31.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 32. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 32.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 33. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 33.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 34. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 34.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 35. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 35.
  • the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 36. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 36.
  • the coronavirus viral antigen or immunogen comprises an S protein peptide that is soluble.
  • the soluble S protein peptide lacks a TM domain peptide and a CP domain peptide.
  • the soluble S protein peptide does not bind to a lipid bilayer, such as a membrane or viral envelope.
  • the S protein peptide is produced from a nucleic acid sequence that has been codon optimized. In some embodiments, the S protein peptide is produced from a nucleic acid sequence that has not been codon optimized.
  • the viral antigen or immunogen as referred to herein can include recombinant polypeptides or fusion peptides comprising said viral antigen or immunogen.
  • the terms viral antigen or immunogen may be used to refer to proteins comprising recombinant receptors comprising a coronavirus viral antigen or immunogen.
  • the coronavirus viral antigen or immunogen is a coronavirus protein peptide as provided herein.
  • coronavirus viral antigens and immunogens provided herein can be combined, e.g., linked, to other proteins or peptides to form recombinant polypeptides, including fusion peptides.
  • individual recombinant polypeptides e.g., monomers
  • association of the individual recombinant polypeptide monomers occurs via covalent interactions.
  • association of the individual recombinant polypeptide monomers occurs via non-covalent interactions.
  • the interaction is effected by the protein or peptide to which the coronavirus viral antigen or immunogen, e.g., S protein peptide, is linked.
  • the coronavirus viral antigen or immunogen e.g., S protein peptide
  • the protein or peptide to which it will be linked can be selected such that the native homotrimeric structure of the glycoprotein is preserved. This can be advantageous for evoking a strong and effective immunogenic response to the S protein peptide.
  • the recombinant polypeptide comprising an S protein peptide described herein, e.g., see Section I is referred to herein alternatively as a recombinant S antigen, recombinant S immunogen, or a recombinant S protein.
  • the recombinant polypeptides or multimerized recombinant polypeptides thereof aggregate or can be aggregated to form a protein or a complex comprising a plurality of coronavirus viral antigen and/or immunogen recombinant polypeptides. Formation of such proteins may be advantageous for generating a strong and effective immunogenic response to the coronavirus viral antigens and/or immunogens.
  • formation of a protein comprising a plurality of recombinant polypeptides, and thus a plurality of coronavirus viral antigens, e.g., coronavirus S protein peptides, may preserve the tertiary and/or quaternary structures of the viral antigen, allowing an immune response to be mounted against the native structure.
  • the aggregation may confer structural stability of the coronavirus viral antigen or immunogen, which in turn can afford access to potentially antigenic sites capable of promoting an immune response.
  • the coronavirus viral antigen or immunogen can be linked at their C-terminus (C-terminal linkage) to a trimerization domain to promote trimerization of the monomers.
  • the trimerization stabilizes the membrane proximal aspect of the coronavirus viral antigen or immunogen, e.g., coronavirus S protein peptide, in a trimeric configuration.
  • Non-limiting examples of exogenous multimerization domains that promote stable trimers of soluble recombinant proteins include: the GCN4 leucine zipper (Harbury et al. 1993 Science 262: 1401-1407) , the trimerization motif from the lung surfactant protein (Hoppe et al. 1994 FEBS Lett 344: 191-195) , collagen (McAlinden et al. 2003 J Biol Chem 278: 42200-42207) , and the phage T4 fibritin Foldon (Miroshnikov et al.
  • any of which can be linked to a coronavirus viral antigen or immunogen described herein (e.g., by linkage to the C-terminus of an S peptide) to promote trimerization of the recombinant viral antigen or immunogen.
  • one or more peptide linkers can be used to link the recombinant viral antigen or immunogen to the multimerization domain.
  • the trimer can include any of the stabilizing mutations provided herein (or combinations thereof) as long as the recombinant viral antigen or immunogen trimer retains the desired properties (e.g., the prefusion conformation) .
  • a desired trimerizing protein moiety for biologic drug designs should satisfy the following criteria. Ideally it should be part of a naturally secreted protein, like immunoglobulin Fc, that is also abundant (non-toxic) in the circulation, human in origin (lack of immunogenicity) , relatively stable (long half-life) and capable of efficient self-trimerization which is strengthened by inter-chain covalent disulfide bonds so the trimerized coronavirus viral antigens or immunogens are structurally stable.
  • a naturally secreted protein like immunoglobulin Fc, that is also abundant (non-toxic) in the circulation, human in origin (lack of immunogenicity) , relatively stable (long half-life) and capable of efficient self-trimerization which is strengthened by inter-chain covalent disulfide bonds so the trimerized coronavirus viral antigens or immunogens are structurally stable.
  • Collagen is a family of fibrous proteins that are the major components of the extracellular matrix. It is the most abundant protein in mammals, constituting nearly 25%of the total protein in the body. Collagen plays a major structural role in the formation of bone, tendon, skin, cornea, cartilage, blood vessels, and teeth.
  • the fibrillar types of collagen I, II, III, IV, V, and XI are all synthesized as larger trimeric precursors, called procollagens, in which the central uninterrupted triple-helical domain consisting of hundreds of “G-X-Y” repeats (or glycine repeats) is flanked by non-collagenous domains (NC) , the N-propeptide and the C-propeptide.
  • NC non-collagenous domains
  • Both the C-and N-terminal extensions are processed proteolytically upon secretion of the procollagen, an event that triggers the assembly of the mature protein into collagen fibrils which forms an insoluble cell matrix.
  • BMP-1 is a protease that recognizes a specific peptide sequence of procollagen near the junction between the glycine repeats and the C-prodomain of collagens and is responsible for the removal of the propeptide.
  • the shed trimeric C-propeptide of type I collagen is found in human sera of normal adults at a concentration in the range of 50-300 ng/mL, with children having a much higher level which is indicative of active bone formation.
  • C-propeptide of type I collagen In people with familial high serum concentration of C-propeptide of type I collagen, the level could reach as high as 1-6 ⁇ g/mL with no apparent abnormality, suggesting the C-propeptide is not toxic.
  • Structural study of the trimeric C-propeptide of collagen suggested that it is a tri-lobed structure with all three subunits coming together in a junction region near their N-termini to connect to the rest of the procollagen molecule.
  • Such geometry in projecting proteins to be fused in one direction is similar to that of Fc dimer.
  • Type I, IV, V and XI collagens are mainly assembled into heterotrimeric forms consisting of either two ⁇ -1 chains and one ⁇ -2 chain (for Type I, IV, V) , or three different a chains (for Type XI) , which are highly homologous in sequence.
  • the type II and III collagens are both homotrimers of ⁇ -1 chain.
  • type I collagen the most abundant form of collagen, stable ⁇ (I) homotrimer is also formed and is present at variable levels in different tissues. Most of these collagen C-propeptide chains can self-assemble into homotrimers, when over-expressed alone in a ceil.
  • Non-collagenous proteins such as cytokines and growth factors, also have been fused to the N-termini of either pro-collagens or mature collagens to allow new collagen matrix formation, which is intended to allow slow release of the noncollagenous proteins from the cell matrix.
  • the C-propeptides are required to be cleaved before recombinant collagen fibril assembly into an insoluble cell matrix.
  • collagen in a recombinant polypeptide as described herein thus has many advantages, including: (1) collagen is the most abundant protein secreted in the body of a mammal, constituting nearly 25%of the total proteins in the body; (2) the major forms of collagen naturally occur as trimeric helixes, with their globular C-propeptides being responsible for the initiating of trimerization; (3) the trimeric C-propeptide of collagen proteolytically released from the mature collagen is found naturally at sub microgram/mL level in the blood of mammals and is not known to be toxic to the body; (4) the linear triple helical region of collagen can be included as a linker with predicted spacing per resi due, or excluded as part of the fusion protein so the di stance between a protein to be trimerized and the C-propeptide of collagen can be precisely adjusted to achieve an optimal biological activity; (5) the recognition site of BMP1 which cleaves the C-propeptide off the pro-collagen can be mutated or deleted to prevent the disruption of a
  • the C-propeptide of collagen to which the coronavirus viral antigen and immunogen e.g., S protein peptide, enables the recombinant production of soluble, covalently-linked homotrimeric fusion proteins.
  • the coronavirus viral antigen or immunogen is linked to a C-terminal propeptide of collagen to form a recombinant polypeptide.
  • the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds.
  • the recombinant proteins form trimers.
  • the coronavirus viral antigen or immunogen is an S protein peptide as described in Section I.
  • the C-terminal propeptide is of human collagen. In some embodiments, the C-terminal propeptide comprises a C-terminal polypeptide of pro ⁇ 1 (I) , pro ⁇ 1 (II) , pro ⁇ 1 (III) , pro ⁇ 1 (V) , pro ⁇ 1 (XI) , pro ⁇ 2 (I) , pro ⁇ 2 (V) , pro ⁇ 2 (XI) , or pro ⁇ 3 (XI) , or a fragment thereof. In some embodiments, the C-terminal propeptide is or comprises a C-terminal polypeptide of pro ⁇ 1 (I) .
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 1. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 1. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 2. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 2. In some embodiments, the C-terminal propeptide is or is the amino acid sequence set forth by SEQ ID NO: 3.
  • the C-terminal propeptide exhibits an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 3.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 4.
  • the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 4.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 5. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 5. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 6. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 6. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 7.
  • the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 7. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 8. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 8.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 9. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 9. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 10. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 10. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 11.
  • the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 11. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 12. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 12.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 13:
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 14. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 14.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 15:
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 16. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 16.
  • the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 17. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 17. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 18. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 18. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 19.
  • the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 19. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 20. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 20.
  • the C-terminal propeptide can comprise a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20, wherein X and Y are independently any amino acid, or an amino acid sequence at least 85%, 90%, 92%, 95%, or 97%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • X and Y are independently proline or hydroxyproline.
  • the recombinant polypeptides form a trimer resulting in a homotrimer of S protein peptides.
  • the S protein peptides of the trimerized recombinant polypetides are in a prefusion conformation.
  • the S protein peptides of the trimerized recombinant polypetides are in a postfusion conformation.
  • the confirmation state allows for access to different antigenic sites on the S protein peptides.
  • the antigenic sites are epitopes, such as linear epitopes or conformational epitopes.
  • trimerized recombinant polypeptides include individual recombinant polypeptides comprising the same viral antigen or immunogen. In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides each comprising a different viral antigen or immunogen from the other recombinant polypeptides. In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides wherein one of the individual recombinant polypeptides comprises a viral antigen or immunogen different from the other recombinant polypeptides.
  • trimerized recombinant polypeptides include individual recombinant polypeptides wherein two of the individual recombinant polypeptides comprise the same viral antigen or immunogen, and the viral antigen or immunogen is different from the viral antigen or immunogen comprised in the remaining recombinant polypeptide.
  • the recombinant polypeptide comprises any coronavirus viral antigen or immunogen described in Section I. In some embodiments, the recombinant polypeptide comprises any coronavirus viral antigen or immunogen described in Section I linked, as described herein, to the C-terminal propeptide of collagen as described herein.
  • the immunogen comprises a recombinant SARS-CoV or SARS-CoV-2 S ectodomain trimer comprising protomers comprising one or more (such as two, for example two consecutive) proline substitutions at or near the boundary between a HR1 domain and a central helix domain that stabilize the S ectodomain trimer in the prefusion conformation.
  • the one or more (such as two, for example two consecutive) proline substitutions that stabilize the S ectodomain in the prefusion conformation are located between a position 15 amino acids N-terminal of a C-terminal residue of the HR1 and a position 5 amino acids C-terminal of a N-terminal residue of the central helix.
  • the one or more (such as two, for example two consecutive) proline substitutions stabilize the coronavirus (e.g., SARS-CoV or SARS-CoV-2) S ectodomain trimer in the prefusion conformation.
  • the SARS-CoV-2 S protein peptide comprises 986K/987V to 986P/987P mutations.
  • the recombinant coronavirus e.g., SARS-CoV or SARS-CoV-2
  • S ectodomain trimer stabilized in the prefusion conformation comprises single-chain S ectodomain protomers comprising mutations to the S1/S2 and/or S2′protease cleavage sites to prevent protease cleavage at these sites.
  • the SARS-CoV-2 S protein peptide comprises a 685R to 685A mutation. Exemplary protease cleavage sites for various viruses are shown below:
  • the protomers of the recombinant coronavirus e.g., SARS-CoV or SARS-CoV-2
  • S ectodomain trimer stabilized in the prefusion conformation by the one or more proline substitutions comprises additional modifications for stabilization in the prefusion conformation, such as a mutation at a protease cleavage site to prevent protease cleavage.
  • the ectodomain comprises a signal peptide (SP) , which is removed during cellular processing; an N-terminal domain (NTD) ; a receptor binding domain (RBD) ; one or more S1/S2 cleavage sites; a fusion peptide (FP) ; internal fusion peptide (IFP) ; heptad repeat 1/2 (HR1/2) , and the transmembrane domain (TM) .
  • SP signal peptide
  • NTD N-terminal domain
  • RBD receptor binding domain
  • FP fusion peptide
  • IFP internal fusion peptide
  • HR1/2 heptad repeat 1/2
  • TM transmembrane domain
  • Additoinal sequences can be found at ncbi. nlm. nih. gov/genbank/sars-cov-2-seqs/, including the pneumonia virus isolate Wuhan-Hu-1, complete genome.
  • the protomers of the pre fusion-stabilized SARS-CoV-2 S ectodomain trimer can have a C-terminal residue (which can be linked to a trimerization domain, or a transmembrane domain, for example) of the C-terminal residue of the NTD, the RBD, S1 (at either the S1/S2 site 1, or S1/S2 site 2) , FP, IFP, HR1, HR2, or the ectodomain.
  • the position numbering of the S protein may vary between SARS-CoV stains, but the sequences can be aligned to determine relevant structural domains and cleavage sites.
  • the recombinant polypeptide is or comprises an NTD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an RBD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an NTD peptide and an RBD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an S1 domain peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an S2 domain peptide of SARS-CoV or SARS-CoV-2 S protein.
  • SARS-CoV-1 S recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 56 (1491 aa) :
  • SARS-CoV-1 S recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 57 (1504 aa) :
  • SARS-CoV-2 S recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 58 (1509 aa) :
  • SARS-CoV-2 S recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 59 (1522 aa) :
  • SARS-CoV-2 S2 (cleavage at S1/S2, site 1) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 60:
  • SARS-CoV-2 S2 (cleavage at S1/S2, site 2) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 61:
  • SARS-CoV-2 S2 (cleavage at S2') recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 62:
  • SARS-CoV-2 S (986K/987V->986P/987P) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 63 (1509 aa) :
  • SARS-CoV-2 S (986K/987V->986P/987P) recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 64 (1522 aa) :
  • SARS-CoV-2 S (685R->685A, 986K/987V->986P/987P) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 65 (1509 aa) :
  • SARS-CoV-2 S (685R->685A, 986K/987V->986P/987P) recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 66 (1522 aa) :
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 37.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 37.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 38. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 38.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 39. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 39.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 40. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 40.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 41.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 41.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 42. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 42.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 43.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 43.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 44. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 44.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 45. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 45.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 46.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 46.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 47.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 47.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 48. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 48.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 49. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 49.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 50. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 50.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 51.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 51.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 56.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 56.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 57.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 57.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 58.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 58.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 59.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 59.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 60.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 60.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 61.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 61.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 62.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 62.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 63.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 63.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 64.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 64.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 65.
  • the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 65.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 66. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 66.
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 75:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 90:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 76:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 77:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 91:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 78:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 79:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 92:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 80:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 81:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 93:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 82:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 83:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 94:
  • the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 84:
  • the recombinant polypeptides provided herein associate not only to form trimers, but can also aggregate or be aggregated to generate proteins comprising a plurality of recombinant polypeptides.
  • the proteins formed have macrostructures.
  • the macrostructure may confer structural stability of the coronavirus viral antigen or immunogen recombinant polypeptides, which in turn can afford access to potentially antigenic sites capable of promoting an immune response.
  • the trimerized recombinant polypeptides aggregate to form a protein containing a plurality of trimerized recombinant polypeptides. In some embodiments, the plurality of trimerized recombinant polypeptides forms a protein having a macrostructure.
  • the proteins described herein comprising a plurality of recombinant polypeptides are an immunogen. In some embodiments, the proteins described herein comprising a plurality of recombinant polypeptides are comprised in a nanoparticle. For example, in some embodiments, the proteins are linked directly to a nanoparticle, e.g., protein nanoparticle. In some embodiments, the proteins are linked indirectly to a nanoparticle. In some embodiments, the proteins described herein comprising a plurality of recombinant polypeptides are comprised in virus-like particle (VLP) .
  • VLP virus-like particle
  • polynucleotides encoding the coronavirus antigens or immunogens and recombinant polypeptides provided herein, and vectors for genetically engineering cells to express such coronavirus antigens or immunogens and recombinant polypeptides.
  • polynucleotides that encode recombinant polypeptides provided herein.
  • the polynucleotide contains a single nucleic acid sequence, such as a nucleic acid sequence encoding a recombinant polypeptide.
  • the polynucleotide contains a first nucleic acid sequence encoding a recombinant polypeptide a particular coronavirus viral antigen or immunogen and a second nucleic acid sequence encoding a recombinant polypeptide comprising a different coronavirus viral antigen or immunogen.
  • the polynucleotide encoding the recombinant polypeptide contains at least one promoter that is operatively linked to control expression of the recombinant polypeptide. In some embodiments, the polynucleotide contains two, three, or more promoters operatively linked to control expression of the recombinant polypeptide.
  • the polynucleotide contains two or more nucleic acid coding sequences, such as a sequences encoding recombinant polypeptides comprising different coronavirus viral antigens or immunogens
  • at least one promoter is operatively linked to control expression of the two or more nucleic acid sequences.
  • the polynucleotide contains two, three, or more promoters operatively linked to control expression of the recombinant polypeptides.
  • expression of the recombinant polypeptide (s) is inducible or conditional.
  • the polynucleotide encoding the recombinant polypeptide (s) contains a conditional promoter, enhancer, or transactivator.
  • the conditional promoter, enhancer, or transactivator is an inducible promoter, enhancer, or transactivator or a repressible promoter, enhancer, or transactivator.
  • an inducible or conditional promoter can be used to restrict expression of the recombinant polypeptides to a specific microenvironment.
  • expression driven by the inducible or conditional promoter is regulated by exposure to an exogenous agent, such as heat, radiation, or drug.
  • the polynucleotide may further include a nucleic acid sequence encoding a peptide between the one or more nucleic acid sequences.
  • the nucleic acid positioned between the nucleic acid sequences encodes a peptide that separates the translation products of the nucleic acid sequences during or after translation.
  • the peptide contains an internal ribosome entry site (IRES) , a self-cleaving peptide, or a peptide that causes ribosome skipping, such as a T2A peptide.
  • IRS internal ribosome entry site
  • the polynucleotide encoding the recombinant polypeptide (s) is introduced into a composition containing cultured cells (e.g., host cells) , such as by retroviral transduction, transfection, or transformation. In some embodiments, this can allow for expression (e.g., production) of the recombinant polypeptides. In some embodiments, the expressed recombinant polypeptides are purified.
  • the polynucleotide (nucleic acid molecule) provided herein encodes an coronavirus viral antigen or immunogen as described herein. In some embodiments, the polynucleotide (nucleic acid molecule) provided herein encodes a recombinant polypeptide comprising coronavirus viral antigen or immunogen, e.g., coronavirus S protein peptide, as described herein.
  • vectors or constructs containing nucleic acid molecules as described herein contain one or more promoters operatively linked to the nucleic acid molecule encoding the recombinant polypeptide to drive expression thereof.
  • the promoter is operatively linked to one or more than one nucleic acid molecule, e.g., nucleic acid molecule encoding recombinant polypeptides containing different coronavirus viral antigens or immunogens.
  • the vector is a viral vector. In some embodiments the viral vector is a retroviral vector. In some embodiments, the retroviral vector is a lentiviral vector. In some embodiments, the retroviral vector is a gammaretroviral vector.
  • the vector or construct includes a single promoter that drives the expression of one or more nucleic acid molecules of the polynucleotide.
  • promoters can be multicistronic (bicistronic or tricistronic, see e.g., U.S. Patent No. 6,060,273) .
  • transcription units can be engineered as a bicistronic unit containing an IRES (internal ribosome entry site) , which allows coexpression of gene products (e.g., encoding different recombinant polypeptides) by a message from a single promoter.
  • IRES internal ribosome entry site
  • the vectors provided herein are bicistronic, allowing the vector to contain and express two nucleic acid sequences. In some embodiments, the vectors provided herein are tricistronic, allowing the vector to contain and express three nucleic acid sequences.
  • a single promoter directs expression of an RNA that contains, in a single open reading frame (ORF) , two or three genes (e.g. encoding the chimeric signaling receptor and encoding a recombinant receptor) separated from one another by sequences encoding a self-cleavage peptide (e.g., 2A sequences) or a protease recognition site (e.g., furin) .
  • the ORF thus encodes a single polypeptide, which, either during (in the case of 2A) or after translation, is processed into the individual proteins.
  • the peptide such as T2A
  • T2A can cause the ribosome to skip (ribosome skipping) synthesis of a peptide bond at the C-terminus of a 2A element, leading to separation between the end of the 2A sequence and the next peptide downstream (see, for example, de Felipe. Genetic Vaccines and Ther. 2: 13 (2004) and deFelipe et al. Traffic 5: 616-626 (2004) ) .
  • Many 2A elements are known in the art.
  • Examples of 2A sequences that can be used in the methods and nucleic acids disclosed herein include, without limitation, 2A sequences from the foot-and-mouth disease virus (F2A) , equine rhinitis A virus (E2A) , Thosea asigna virus (T2A) , and porcine teschovirus-1 (P2A) as described in U.S. Patent Publication No. 20070116690.
  • F2A foot-and-mouth disease virus
  • E2A equine rhinitis A virus
  • T2A Thosea asigna virus
  • P2A porcine teschovirus-1
  • the vector is comprised in a virus.
  • the virus is a pseudovirus.
  • the virus is a viral-like particle.
  • the vector is comprised in a cell.
  • the virus or cell in which the vector is comprised contains a recombinant genome.
  • Immunogenic compositions comprising a disclosed immunogen (e.g., a disclosed recombinant coronavirus S antigen or nucleic acid molecule encoding a protomer of disclosed recombinant coronavirus S antigen) and a pharmaceutically acceptable carrier are also provided.
  • the immunogenic composition comprises trimerized recombinant polypeptides provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a protein comprising a plurality of trimerized recombinant polypeptides provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition a protein nanoparticle provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a VLP as provided herein, and optionally a pharmaceutically acceptable cartier.
  • the immunogenic composition comprises an isolated nucleic acid provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a vector as provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a virus as provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a pseudovirus provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition comprises a cell as provided herein, and optionally a pharmaceutically acceptable carrier.
  • the immunogenic composition such as described herein, is a vaccine.
  • the vaccine is a prophylactic vaccine.
  • the vaccine is a therapeutic vaccine.
  • the vaccine is a prophylactic vaccine and a therapeutic vaccine.
  • Such pharmaceutical compositions can be administered to subjects by a variety of administration modes known to the person of ordinary skill in the art, for example, intramuscular, intradermal, subcutaneous, intravenous, intra-arterial, intra-articular, intraperitoneal, intranasal, sublingual, tonsillar, oropharyngeal, or other parenteral and mucosal routes.
  • pharmaceutical compositions including one or more of the disclosed immunogens are immunogenic compositions. Actual methods for preparing administrable compositions will be known or apparent to those skilled in the art and are described in more detail in such publications as Remingtons Pharmaceutical Sciences, 19th Ed., Mack Publishing Company, Easton, Pa., 1995.
  • an immunogen e.g., recombinant coronavirus S antigen, e.g., trimer, protein, described herein can be formulated with pharmaceutically acceptable carriers to help retain biological activity while also promoting increased stability during storage within an acceptable temperature range.
  • Potential carriers include, but are not limited to, physiologically balanced culture medium, phosphate buffer saline solution, water, emulsions (e.g., oil/water or water/oil emulsions) , various types of wetting agents, cryoprotective additives or stabilizers such as proteins, peptides or hydrolysates (e.g., albumin, gelatin) , sugars (e.g., sucrose, lactose, sorbitol) , amino acids (e.g., sodium glutamate) , or other protective agents.
  • the resulting aqueous solutions may be packaged for use as is or lyophilized. Lyophilized preparations are combined with a sterile solution prior to administration for either single or multiple dosing.
  • Formulated compositions may contain a bacteriostat to prevent or minimize degradation during storage, including but not limited to effective concentrations (usually 1%w/v) of benzyl alcohol, phenol, m-cresol, chlorobutanol, methylparaben, and/or propylparaben.
  • a bacteriostat may be contraindicated for some patients; therefore, a lyophilized formulation may be reconstituted in a solution either containing or not containing such a component.
  • the immunogenic compositions of the disclosure can contain as pharmaceutically acceptable vehicles substances as required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents and the like, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, and triethanolamine oleate.
  • the immunogenic composition may optionally include an adjuvant to enhance an immune response of the host.
  • Suitable adjuvants are, for example, toil-like receptor agonists, alum, AlPO 4 , alhydrogel, Lipid-A and derivatives or variants thereof, oil-emulsions, saponins, neutral liposomes, liposomes containing the vaccine and cytokines, non-ionic block copolymers, and chemokines.
  • Non-ionic block polymers containing polyoxyethylene (POE) and polyxylpropylene (POP) such as POE-POP-POE block copolymers, MPL TM (3-O-deacylated monophosphoryl lipid A; Corixa, Hamilton, Ind. ) and IL-12 (Genetics Institute, Cambridge, Mass.
  • the immunogenic compositions of the disclosure may include or be administered with more than one adjuvant.
  • the immunogenic compositions of the disclosure may include or be administered with two adjuvants.
  • the immunogenic compositions of the disclosure may include or be administered with a plurality of adjuvants.
  • a vaccine e.g., comprising an immunogenic composition provided herein, may include or be administered in combination with a plurality of adjuvants.
  • a composition including a recombinant coronavirus S antigen as described herein, e.g., trimer or protein can be can be administered simultaneously (typically separately) or sequentially with other vaccines recommended by the Advisory Committee on Immunization Practices (ACIP; cdc. gov/vaccines/acip/index. html) for the targeted age group (e.g., infants from approximately one to six months of age) , such as an influenza vaccine or a varicella zoster vaccine.
  • ACIP Advisory Committee on Immunization Practices
  • a disclosed immunogen including a recombinant coronavirus S antigen described herein may be administered simultaneously or sequentially with vaccines against, for example, hepatitis B (HepB) , diphtheria, tetanus and pertussis (DTaP) , pneumococcal bacteria (PCV) , Haemophilus influenzae type b (Hib) , polio, influenza and rotavirus.
  • HepB hepatitis B
  • DTaP diphtheria, tetanus and pertussis
  • PCV pneumococcal bacteria
  • Hib Haemophilus influenzae type b
  • polio influenza and rotavirus.
  • Multivalent or combination vaccines provide protection against multiple pathogens.
  • multivalent vaccines can protect against multiple strains of the same pathogen.
  • multivalent vaccines protect against multiple pathogens, such as the combination vaccine Tdap, which protects against strains of tentus, pertussis, and diphtheria.
  • Multivalent vaccines are highly desirable to minimize the number of immunizations required to confer protection against multiple pathogens or pathogenic strains, to reduce administration costs, and to increase coverage rates. This can be particularly useful, for example, when vaccinating babies or children.
  • the vaccine e.g., comprising an immunogenic composition described herein
  • the antigenic material for incorporation into the multivalent vaccine compositions of the invention is derived from coronavirus strains or types, for examples as described herein (see, e.g., Section I) .
  • Antigens for incorporation into the multivalent vaccine compositions of the invention may be derived from one strain of coronavirus or multiple strains, for example, between two and five strains, in order to provide a broader spectrum of protection.
  • antigens for incorporation into the multivalent vaccine compositions of the invention are derived from multiple strains of coronavirus.
  • Other useful antigens include live, attenuated and inactivated viruses such as inactivated polio virus (Jiang et al., J. Biol. Stand., (1986) 14: 103-9) , attenuated strains of Hepatitis A virus (Bradley et al., J. Med. Virol., (1984) 14: 373-86) , attenuated measles virus (James et al., N. Engl. J. Med., (1995) 332: 1262-6) , and epitopes of pertussis virus (for example, ACEL-IMUNErM acellular DTP, Wyeth-Lederle Vaccines and Pediatrics) .
  • inactivated polio virus Japanese polio virus
  • attenuated strains of Hepatitis A virus Bradley et al., J. Med. Virol., (1984) 14: 373-86
  • attenuated measles virus James
  • the vaccine provided herein is a universal vaccine.
  • a universal vaccine is a vaccine which protects against multiple strains of the same virus, such as multiple strains of coronavirus. Development of an effective universal coronavirus vaccine would reduce cost and labor, e.g., with seasonal vaccine formulation, and allow for more robust pandemic preparedness.
  • a universal vaccine is one comprised of multiple epitopes derived from distinct viral strains. In some aspects, a universal vaccine is comprised of a single epitope that is conserved across distinct viral strains. For example, a universal vaccine can be based on the relatively conserved domain (s) of the S protein,
  • the composition can be provided as a sterile composition.
  • the pharmaceutical composition typically contains an effective amount of a disclosed immunogen and can be prepared by conventional techniques.
  • the amount of immunogen in each dose of the immunogenic composition is selected as an amount which induces an immune response without significant, adverse side effects.
  • the composition can be provided in unit dosage form for use to induce an immune response in a subject.
  • a unit dosage form contains a suitable single preselected dosage for administration to a subject, or suitable marked or measured multiples of two or more preselected unit dosages, and/or a metering mechanism for administering the unit dose or multiples thereof.
  • the composition further includes an adjuvant.
  • the disclosed immunogens can be administered to a subject to induce an immune response to the corresponding coronavirus S antigen in the subject.
  • the subject is a human.
  • the immune response can be a protective immune response, for example a response that inhibits subsequent infection with the corresponding coronavirus. Elicitation of the immune response can also be used to treat or inhibit infection and illnesses associated with the corresponding coronavirus.
  • a subject can be selected for treatment that has, or is at risk for developing infection with the coronavirus, for example because of exposure or the possibility of exposure to the coronavirus.
  • the subject can be monitored for infection or symptoms associated with coronavirus, or both.
  • Typical subjects intended for treatment with the therapeutics and methods of the present disclosure include humans, as well as non-human primates and other animals.
  • accepted screening methods are employed to determine risk factors associated with a targeted or suspected disease or condition, or to determine the status of an existing disease or condition in a subject.
  • These screening methods include, for example, conventional work-ups to determine environmental, familial, occupational, and other such risk factors that may be associated with the targeted or suspected disease or condition, as well as diagnostic methods, such as various ELISA and other immunoassay methods to detect and/or characterize coronavirus infection.
  • diagnostic methods such as various ELISA and other immunoassay methods to detect and/or characterize coronavirus infection.
  • the administration of a disclosed immunogen can be for prophylactic or therapeutic purpose.
  • the disclosed therapeutic agents are provided in advance of any symptom, for example, in advance of infection.
  • the prophylactic administration of the disclosed therapeutic agents serves to prevent or ameliorate any subsequent infection.
  • the disclosed therapeutic agents are provided at or after the onset of a symptom of disease or infection, for example, after development of a symptom of infection with coronavirus corresponding to the coronavirus S antigen, or after diagnosis with the coronavirus infection.
  • the therapeutic agents can thus be provided prior to the anticipated exposure to coronavirus so as to attenuate the anticipated severity, duration or extent of an infection and/or associated disease symptoms, after exposure or suspected exposure to the virus, or after the actual initiation of an infection.
  • the immunogens described herein, and immunogenic compositions thereof, are provided to a subject in an amount effective to induce or enhance an immune response against the coronavirus S antigen in the subject, preferably a human.
  • the actual dosage of disclosed immunogen will vary according to factors such as the disease indication and particular status of the subject (for example, the subject's age, size, fitness, extent of symptoms, susceptibility factors, and the like) , time and route of administration, other drugs or treatments being administered concurrently, as well as the specific pharmacology of the composition for eliciting the desired activity or biological response in the subject. Dosage regimens can be adjusted to provide an optimum prophylactic or therapeutic response.
  • An immunogenic composition including one or more of the disclosed immunogens can be used in coordinate (or prime-boost) vaccination protocols or combinatorial formulations.
  • novel combinatorial immunogenic compositions and coordinate immunization protocols employ separate immunogens or formulations, each directed toward eliciting an anti-viral immune response, such as an immune response to coronavirus S antigen.
  • Separate immunogenic compositions that elicit the anti-viral immune response can be combined in a polyvalent immunogenic composition administered to a subject in a single immunization step, or they can be administered separately (in monovalent immunogenic compositions) in a coordinate (or prime-boost) immunization protocol.
  • each boost can be a different disclosed immunogen.
  • the boost may be the same immunogen as another boost, or the prime.
  • the prime and boost can be administered as a single dose or multiple doses, for example two doses, three doses, four doses, five doses, six doses or more can be administered to a subject over days, weeks or months.
  • Multiple boosts can also be given, such one to five (e.g., 1, 2, 3, 4 or 5 boosts) , or more.
  • Different dosages can be used in a series of sequential immunizations. For example a relatively large dose in a primary immunization and then a boost with relatively smaller doses.
  • the boost can be administered about two, about three to eight, or about four, weeks following the prime, or about several months after the prime. In some embodiments, the boost can be administered about 5, about 6, about 7, about 8, about 10, about 12, about 18, about 24, months after the prime, or more or less time after the prime. Periodic additional boosts can also be used at appropriate time points to enhance the subject's “immune memory. ”
  • the adequacy of the vaccination parameters chosen, e.g., formulation, dose, regimen and the like, can be determined by taking aliquots of serum from the subject and assaying antibody titers during the course of the immunization program.
  • the clinical condition of the subject can be monitored for the desired effect, e.g., prevention of infection or improvement in disease state (e.g., reduction in viral load) . If such monitoring indicates that vaccination is sub-optimal, the subject can be boosted with an additional dose of immunogenic composition, and the vaccination parameters can be modified in a fashion expected to potentiate the immune response.
  • the prime-boost method can include DNA-primer and protein-boost vaccination protocol to a subject.
  • the method can include two or more administrations of the nucleic acid molecule or the protein.
  • each human dose will comprise 1-1000 ⁇ g of protein, such as from about 1 ⁇ g to about 100 ⁇ g, for example, from about 1 ⁇ g to about 50 ⁇ g, such as about 1 ⁇ g, about 2 ⁇ g, about 5 ⁇ g, about 10 ⁇ g, about 15 ⁇ g, about 20 ⁇ g, about 25 ⁇ g, about 30 ⁇ g, about 40 ⁇ g, or about 50 ⁇ g.
  • the amount utilized in an immunogenic composition is selected based on the subject population (e.g., infant or elderly) .
  • An optimal amount for a particular composition can be ascertained by standard studies involving observation of antibody titers and other responses in subjects.
  • a therapeutically effective amount of a disclosed immunogen such as a disclosed recombinant coronavirus S antigen, e.g., trimer, protein, , viral vector, or nucleic acid molecule in a immunogenic composition, can include an amount that is ineffective at eliciting an immune response by administration of a single dose, but that is effective upon administration of multiple dosages, for example in a prime-boost administration protocol.
  • the immune system of the subject Upon administration of a disclosed immunogen of this disclosure, the immune system of the subject typically responds to the immunogenic composition by producing antibodies specific for the coronavirus S protein peptide included in the immunogen. Such a response signifies that an immunologically effective dose was delivered to the subject.
  • the antibody response of a subject will be determined in the context of evaluating effective dosages/immunization protocols. In most instances it will be sufficient to assess the antibody titer in serum or plasma obtained from the subject. Decisions as to whether to administer booster inoculations and/or to change the amount of the therapeutic agent administered to the individual can be at least partially based on the antibody titer level.
  • the antibody titer level can be based on, for example, an immunobinding assay which measures the concentration of antibodies in the serum which bind to an antigen including, for example, the recombinant coronavirus S antigen, e.g., an S-Trimer.
  • coronavirus infection does not need to be completely eliminated or reduced or prevented for the methods to be effective.
  • elicitation of an immune response to a coronavirus with one or more of the disclosed immunogens can reduce or inhibit infection with the coronavirus by a desired amount, for example, by at least 10%, at least 20%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or even at least 100% (elimination or prevention of detectable infected cells) , as compared to infection with the coronavirus in the absence of the immunogen.
  • coronavirus replication can be reduced or inhibited by the disclosed methods. Coronavirus replication does not need to be completely eliminated for the method to be effective.
  • the immune response elicited using one or more of the disclosed immunogens can reduce replication of the corresponding coronavirus by a desired amount, for example, by at least 10%, at least 20%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or even at least 100% (elimination or prevention of detectable replication of the coronavirus) , as compared to replication of the coronavirus in the absence of the immune response.
  • the disclosed immunogen is administered to the subject simultaneously with the administration of the adjuvant. In other embodiments, the disclosed immunogen is administered to the subject after the administration of the adjuvant and within a sufficient amount of time to induce the immune response.
  • nucleic acids are direct immunization with plasmid DNA, such as with a mammalian expression plasmid.
  • Immunization by nucleic acid constructs is well known in the art and taught, for example, in U.S. Pat. No. 5,643,578 (which describes methods of immunizing vertebrates by introducing DNA encoding a desired antigen to elicit a cell-mediated or a humoral response) , and U.S. Pat. Nos. 5,593,972 and 5,817,637 (which describe operably linking a nucleic acid sequence encoding an antigen to regulatory sequences enabling expression) .
  • 5,880,103 describes several methods of delivery of nucleic acids encoding immunogenic peptides or other antigens to an organism.
  • the methods include liposomal delivery of the nucleic acids (or of the synthetic peptides themselves) , and immune-stimulating constructs, or ISCOMS TM , negatively charged cage-like structures of 30-40 nm in size formed spontaneously on mixing cholesterol and Quil A TM (saponin) .
  • Protective immunity has been generated in a variety of experimental models of infection, including toxoplasmosis and Epstein-Barr virus-induced tumors, using ISCOMS TM as the delivery vehicle for antigens (Mowat and Donachie, Immunol. Today 12: 383, 1991) .
  • Doses of antigen as low as 1 ⁇ g encapsulated in ISCOMS TM have been found to produce Class I mediated CTL responses (Takahashi et al., Nature 344: 873, 1990) .
  • a plasmid DNA vaccine is used to express a disclosed immunogen in a subject.
  • a nucleic acid molecule encoding a disclosed immunogen can be administered to a subject to induce an immune response to the coronavirus S antigen.
  • the nucleic acid molecule can be included on a plasmid vector for DNA immunization, such as the pVRC8400 vector (described in Barouch et al., J. Virol, 79, 8828-8834, 2005, which is incorporated by reference herein) .
  • a disclosed recombinant coronavirus S antigen e.g., trimer, protein
  • Recombinant vaccinia virus, adeno-associated virus (AAV) , herpes virus, retrovirus, cytogmeglo virus or other viral vectors can be used to express the peptide or protein, thereby eliciting a CTL response.
  • AAV adeno-associated virus
  • herpes virus herpes virus
  • retrovirus cytogmeglo virus or other viral vectors
  • vaccinia vectors and methods useful in immunization protocols are described in U.S. Pat. No. 4,722,848.
  • BCG Bacillus Calmette Guerin
  • provides another vector for expression of the peptides see Stover, Nature 351: 456-460, 1991.
  • a nucleic acid encoding a disclosed recombinant coronavirus S antigen is introduced directly into cells.
  • the nucleic acid can be loaded onto gold microspheres by standard methods and introduced into the skin by a device such as Bio-Rad′s HELIOS TM Gene Gun.
  • the nucleic acids can be “naked, ” consisting of plasmids under control of a strong promoter.
  • the DNA is injected into muscle, although it can also be injected directly into other sites. Dosages for injection are usually around 0.5 ⁇ g/kg to about 50 mg/kg, and typically are about 0.005 mg/kg to about 5 mg/kg (see, e.g., U.S. Pat. No. 5,589,466) .
  • the nucleic acid can be loaded onto gold microspheres by standard methods and introduced into the skin by a device such as Bio-Rad's HELIOS TM Gene Gun.
  • the nucleic acids can be “naked, ” consisting of plasmids under control of a strong promoter.
  • the DNA is injected into muscle, although it can also be injected directly into other sites. Dosages for injection are usually around 0.5 ⁇ g/kg to about 50 mg/kg, and typically are about 0.005 mg/kg to about 5 mg/kg (see, e.g., U.S. Pat. No. 5,589,466) .
  • an mRNA-based immunization protocol can be used to deliver a nucleic acid encoding a disclosed recombinant coronavirus S antigen directly into cells.
  • nucleic acid-based vaccines based on mRNA may provide a potent altemative to the previously mentioned approaches.
  • mRNA vaccines preclude safety concerns about DNA integration into the host genome and can be directly translated in the host cell cytoplasm.
  • the simple cell-free, in vitro synthesis of RNA avoids the manufacturing complications associated with viral vectors.
  • RNA-based vaccination Two exemplary forms of RNA-based vaccination that can be used to deliver a nucleic acid encoding a disclosed recombinant coronavirus S antigen include conventional non-amplifying mRNA immunization (see, e.g., Petsch et al., “Protective efficacy of in vitro synthesized, specific mRNA vaccines against influenza A virus infection, ” Nature biotechnology, 30 (12) : 1210-6, 2012) and self-amplifying mRNA immunization (see, e.g., Geall et al., “Nonviral delivery of self-amplifying RNA vaccines, ” PNAS, 109 (36) : 14604-14609, 2012; Magini et al., “Self-Amplifying mRNA Vaccines Expressing Multiple conserveed Influenza Antigens Confer Protection against Homologous and Heterosubtypic Viral Challenge, ” PLoS One, 11 (8)
  • administration of a therapeutically effective amount of one or more of the disclosed immunogens to a subject induces a neutralizing immune response in the subject.
  • serum can be collected from the subject at appropriate time points, frozen, and stored for neutralization testing.
  • Methods to assay for neutralization activity are known to the person of ordinary skill in the art and are further described herein, and include, but are not limited to, plaque reduction neutralization (PRNT) assays, microneutralization assays, flow cytometry based assays, single-cycle infection assays.
  • PRNT plaque reduction neutralization
  • the serum neutralization activity can be assayed using a panel of coronavirus pseudoviruses.
  • administration of a therapeutically effective amount of one or more of the disclosed immunogens to a subject induces a neutralizing immune response in the subject.
  • serum can be collected from the subject at appropriate time points, frozen, and stored for neutralization testing.
  • Methods to assay for neutralization activity are known to the person of ordinary skill in the art and are further described herein, and include, but are not limited to, plaque reduction neutralization (PRNT) assays, microneutralization assays, flow cytometry based assays, single-cycle infection assays.
  • PRNT plaque reduction neutralization
  • the serum neutralization activity can be assayed using a panel of coronavirus pseudoviruses.
  • the articles of manufacture may include a container and a label or package insert on or associated with the container.
  • Suitable containers include, for example, bottles, vials, syringes, test tubes, IV solution bags, etc.
  • the containers may be formed from a variety of materials such as glass or plastic.
  • the container has a sterile access port.
  • Exemplary containers include an intravenous solution bags, vials, including those with stoppers pierceable by a needle for injection.
  • the article of manufacture or kit may further include a package insert indicating that the compositions can be used to treat a particular condition such as a condition described herein (e.g., coronavirus infection) .
  • a condition described herein e.g., coronavirus infection
  • the article of manufacture or kit may further include another or the same container comprising a pharmaceutically-acceptable buffer. It may further include other materials such as other buffers, diluents, filters, needles, and/or syringes.
  • the label or package insert may indicate that the composition is used for treating an coronavirus infection in an individual.
  • the label or a package insert which is on or associated with the container, may indicate directions for reconstitution and/or use of the formulation.
  • the label or package insert may further indicate that the formulation is useful or intended for subcutaneous, intravenous, or other modes of administration for treating or preventing a coronavirus infection in an individual.
  • the container in some embodiments holds a composition which is by itself or combined with another composition effective for treating, preventing and/or diagnosing the condition.
  • the article of manufacture or kit may include (a) a first container with a composition contained therein (i.e., first medicament) , wherein the composition includes the immunogenic composition or protein or recombinant polypeptide thereof; and (b) a second container with a composition contained therein (i.e., second medicament) , wherein the composition includes a further agent, such as an adjuvant or otherwise therapeutic agent, and which article or kit further comprises instructions on the label or package insert for treating the subject with the second medicament, in an effective amount.
  • a further agent such as an adjuvant or otherwise therapeutic agent
  • polypeptide and “protein” are used interchangeably to refer to a polymer of amino acid residues, and are not limited to a minimum length.
  • Polypeptides including the provided receptors and other polypeptides, e.g., linkers or peptides, may include amino acid residues including natural and/or non-natural amino acid residues.
  • the terms also include post-expression modifications of the polypeptide, for example, glycosylation, sialylation, acetylation, and phosphorylation.
  • the polypeptides may contain modifications with respect to a native or natural sequence, as long as the protein maintains the desired activity. These modifications may be deliberate, as through site-directed mutagenesis, or may be accidental, such as through mutations of hosts which produce the proteins or errors due to PCR amplification.
  • a “subject” is a mammal, such as a human or other animal, and typically is human.
  • the subject e.g., patient, to whom the agent or agents, cells, cell populations, or compositions are administered, is a mammal, typically a primate, such as a human.
  • the primate is a monkey or an ape.
  • the subject can be male or female and can be any suitable age, including infant, juvenile, adolescent, adult, and geriatric subjects.
  • the subject is a non-primate mammal, such as a rodent.
  • treatment refers to complete or partial amelioration or reduction of a disease or condition or disorder, or a symptom, adverse effect or outcome, or phenotype associated therewith. Desirable effects of treatment include, but are not limited to, preventing occurrence or recurrence of disease, alleviation of symptoms, diminishment of any direct or indirect pathological consequences of the disease, preventing metastasis, decreasing the rate of disease progression, amelioration or palliation of the disease state, and remission or improved prognosis. The terms do not imply complete curing of a disease or complete elimination of any symptom or effect (s) on all symptoms or outcomes.
  • delay development of a disease means to defer, hinder, slow, retard, stabilize, suppress and/or postpone development of the disease (such as cancer) .
  • This delay can be of varying lengths of time, depending on the history of the disease and/or individual being treated.
  • sufficient or significant delay can, in effect, encompass prevention, in that the individual does not develop the disease.
  • a late stage cancer such as development of metastasis, may be delayed.
  • Preventing includes providing prophylaxis with respect to the occurrence or recurrence of a disease in a subject that may be predisposed to the disease but has not yet been diagnosed with the disease.
  • the provided cells and compositions are used to delay development of a disease or to slow the progression of a disease.
  • to “suppress” a function or activity is to reduce the function or activity when compared to otherwise same conditions except for a condition or parameter of interest, or alternatively, as compared to another condition.
  • cells that suppress tumor growth reduce the rate of growth of the tumor compared to the rate of growth of the tumor in the absence of the cells.
  • an “effective amount” of an agent e.g., a pharmaceutical formulation, cells, or composition, in the context of administration, refers to an amount effective, at dosages/amounts and for periods of time necessary, to achieve a desired result, such as a therapeutic or prophylactic result.
  • a “therapeutically effective amount” of an agent refers to an amount effective, at dosages and for periods of time necessary, to achieve a desired therapeutic result, such as for treatment of a disease, condition, or disorder, and/or pharmacokinetic or pharmacodynamic effect of the treatment.
  • the therapeutically effective amount may vary according to factors such as the disease state, age, sex, and weight of the subject, and the populations of cells administered.
  • the provided methods involve administering the cells and/or compositions at effective amounts, e.g., therapeutically effective amounts.
  • prophylactically effective amount refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired prophylactic result. Typically but not necessarily, since a prophylactic dose is used in subjects prior to or at an earlier stage of disease, the prophylactically effective amount will be less than the therapeutically effective amount. In the context of lower tumor burden, the prophylactically effective amount in some aspects will be higher than the therapeutically effective amount.
  • composition refers to any mixture of two or more products, substances, or compounds, including cells. It may be a solution, a suspension, liquid, powder, a paste, aqueous, non-aqueous or any combination thereof.
  • vector refers to a nucleic acid molecule capable of propagating another nucleic acid to which it is linked.
  • the term includes the vector as a self-replicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced.
  • Certain vectors are capable of directing the expression of nucleic acids to which they are operatively linked. Such vectors are referred to herein as “expression vectors. ”
  • Embodiment 1 A protein comprising a plurality of recombinant polypeptides, each recombinant polypeptide comprising a surface antigen of a coronavirus linked to a C-terminal propeptide of collagen, wherein the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds.
  • Embodiment 2 The protein of embodiment 1, wherein the coronavirus is a Severe Acute Respiratory Syndrome (SARS) -coronavirus (SARS-CoV) , a SARS-coronavirus 2 (SARS-CoV-2) , a SARS-like coronavirus, a Middle East Respiratory Syndrome (MERS) -coronavirus (MERS-CoV) , a MERS-like coronavirus, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
  • SARS Severe Acute Respiratory Syndrome
  • SARS-CoV Severe Acute Respiratory Syndrome
  • SARS-CoV-2 SARS-coronavirus 2
  • MERS Middle East Respiratory Syndrome
  • MERS-like coronavirus NL63-CoV, 229E-CoV, OC
  • Embodiment 3 The protein of embodiment 1 or 2, wherein the surface antigen comprises a coronavirus spike (S) protein or a fragment or epitope thereof, wherein the epitope is optionally a linear epitope or a conformational epitope, and wherein the protein comprises three recombinant polypeptides.
  • S coronavirus spike
  • the epitope is optionally a linear epitope or a conformational epitope
  • the protein comprises three recombinant polypeptides.
  • Embodiment 4 The protein of embodiment 3, wherein the surface antigen comprises a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof.
  • Embodiment 5 The protein of embodiment 3, wherein the surface antigen comprises a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof.
  • RBD receptor binding domain
  • RBM receptor binding motif
  • FP fusion peptide
  • HR1 heptad repeat 1
  • HR2 heptad repeat 2
  • Embodiment 6 The protein of any of embodiments 3-5, wherein the surface antigen comprises a receptor binding domain (RBD) of the S protein.
  • RBD receptor binding domain
  • Embodiment 7 The protein of any of embodiments 3-6, wherein the surface antigen comprises an S1 subunit and an S2 subunit of the S protein.
  • Embodiment 8 The protein of any of embodiments 3-7, wherein the surface antigen does not comprise a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
  • TM transmembrane
  • CP cytoplasm
  • Embodiment 9 The protein of any of embodiments 3-8, wherein the surface antigen comprises a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
  • Embodiment 10 The protein of any of embodiments 3-8, wherein the surface antigen does not comprise a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
  • Embodiment 11 The protein of any of embodiments 1-10, wherein the surface antigen is soluble or does not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
  • a lipid bilayer e.g., a membrane or viral envelope.
  • Embodiment 12 The protein of any of embodiments 1-11, wherein the surface antigens are the same or different among the recombinant polypeptides of the protein.
  • Embodiment 13 The protein of any of embodiments 1-12, wherein the surface antigen is directly fused to the C-terminal propeptide, or is linked to the C-terminal propeptide via a linker, such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
  • a linker such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
  • Embodiment 14 The protein of any of embodiments 1-13, which is soluble or does not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
  • a lipid bilayer e.g., a membrane or viral envelope.
  • Embodiment 15 The protein of any of embodiments 1-14, wherein the protein is capable of binding to a cell surface receptor of a subject, optionally wherein the subject is a mammal such as a primate, e.g., human.
  • Embodiment 16 The protein of embodiment 15, wherein the cell surface receptor is angiotensin converting enzyme 2 (ACE2) , dipeptidyl peptidase 4 (DPP4) , dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin (DC-SIGN) , or liver/lymph node-SIGN (L-SIGN) .
  • ACE2 angiotensin converting enzyme 2
  • DPP4 dipeptidyl peptidase 4
  • DC-SIGN dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin
  • L-SIGN liver/lymph node-SIGN
  • Embodiment 17 The protein of any of embodiments 1-16, wherein the C-terminal propeptide is of human collagen.
  • Embodiment 18 The protein of any of embodiments 1-17, wherein the C-terminal propeptide comprises a C-terminal polypeptide of pro ⁇ 1 (I) , pro ⁇ 1 (II) , pro ⁇ 1 (III) , pro ⁇ 1 (V) , pro ⁇ 1 (XI) , pro ⁇ 2 (I) , pro ⁇ 2 (V) , pro ⁇ 2 (XI) , or pro ⁇ 3 (XI) , or a fragment thereof.
  • Embodiment 19 The protein of any of embodiments 1-18, wherein the C-terminal propeptides are the same or different among the recombinant polypeptides.
  • Embodiment 20 The protein of any of embodiments 1-19, wherein the C-terminal propeptide comprises any of SEQ ID NOs: 1-20 and 52-55 an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 21 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 3 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 22 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 4 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 23 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 7 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 24 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 12 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 25 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 15 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 26 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 27 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 52 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 28 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 54 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 29 The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 55 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 30 The protein of any of embodiments 1-29, wherein the C-terminal propeptide comprises a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20 and 52-55, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline, or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • the C-terminal propeptide comprises a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20 and 52-55, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline, or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
  • Embodiment 31 The protein of any of embodiments 1-30, wherein the surface antigen in each recombinant polypeptide is in a prefusion conformation or a postfusion conformation.
  • Embodiment 32 The protein of any of embodiments 1-31, wherein the surface antigen in each recombinant polypeptide comprises any of SEQ ID NOs: 21-36 or an amino acid sequence at least 80%identical thereto.
  • Embodiment 33 The protein of any of embodiments 1-32, wherein the recombinant polypeptide comprises any of SEQ ID NOs: 37-51 and 56-66 or an amino acid sequence at least 80%identical thereto.
  • Embodiment 34 An immunogen comprising the protein of any of embodiments 1-33.
  • Embodiment 35 A protein nanoparticle comprising the protein of any of embodiments 1-33 directly or indirectly linked to a nanoparticle.
  • Embodiment 36 A virus-like particle (VLP) comprising the protein of any of embodiments 1-33.
  • VLP virus-like particle
  • Embodiment 37 An isolated nucleic acid encoding one, two, three or more of the recombinant polypeptides of the protein of any of embodiments 1-33.
  • Embodiment 38 The isolated nucleic acid of embodiment 37, wherein a polypeptide encoding the surface antigen is fused in-frame to a polypeptide encoding the C-terminal propeptide of collagen.
  • Embodiment 39 The isolated nucleic acid of embodiment 37 or 38, which is operably linked to a promoter.
  • Embodiment 40 The isolated nucleic acid of any of embodiments 37-39, which is a DNA molecule.
  • Embodiment 41 The isolated nucleic acid of any of embodiments 37-39, which is an RNA molecule, optionally an mRNA molecule such as a nucleoside-modified mRNA, a non-amplifying mRNA, a self-amplifying mRNA, or a trans-amplifying mRNA.
  • RNA molecule optionally an mRNA molecule such as a nucleoside-modified mRNA, a non-amplifying mRNA, a self-amplifying mRNA, or a trans-amplifying mRNA.
  • Embodiment 42 A vector comprising the isolated nucleic acid of any of embodiments 37-41.
  • Embodiment 43 The vector of embodiment 42, which is a viral vector.
  • Embodiment 44 A virus, a pseudovirus, or a cell comprising the vector of embodiment 42 or 43, optionally wherein the virus or cell has a recombinant genome.
  • Embodiment 45 An immunogenic composition comprising the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, or cell of any one of embodiments 1-44, and a pharmaceutically acceptable carrier.
  • Embodiment 46 A vaccine comprising the immunogenic composition of embodiment 45 and optionally an adjuvant, wherein the vaccine is optionally a subunit vaccine, and/or optionally wherein the vaccines is a prophylactic and/or therapeutic vaccine.
  • Embodiment 47 The vaccine of embodiment 46, wherein the vaccine comprises a plurality of different adjuvants.
  • Embodiment 48 A method of producing a protein, comprising: expressing the isolated nucleic acid or vector of any one of embodiments 37-43 in a host cell to produce the protein of any of embodiments 1-33; and purifying the protein.
  • Embodiment 49 The protein produced by the method of embodiment 48.
  • Embodiment 50 A method for generating an immune response to a surface antigen of a coronavirus in a subject, comprising administering to the subject an effective amount of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49 to generate the immune response.
  • Embodiment 51 The method of embodiment 50, for treating or preventing infection with the coronavirus.
  • Embodiment 52 The method of embodiment 50 or 51, wherein generating the immune response inhibits or reduces replication of the coronavirus in the subject.
  • Embodiment 53 The method of any of embodiments 50-52, wherein the immune response comprises a cell-mediated response and/or a humoral response, optionally comprising production of one or more neutralizing antibody, such as a polyclonal antibody or a monoclonal antibody.
  • the immune response comprises a cell-mediated response and/or a humoral response, optionally comprising production of one or more neutralizing antibody, such as a polyclonal antibody or a monoclonal antibody.
  • Embodiment 54 The method of any of embodiments 50-53, wherein the immune response is against the surface antigen of the coronavirus but not against the C-terminal propeptide.
  • Embodiment 55 The method of any of embodiments 50-54, wherein the administering does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to one or more coronavirus.
  • ADE antibody dependent enhancement
  • Embodiment 56 The method of any of embodiments 50-55, wherein the administering does not lead to antibody dependent enhancement (ADE) in the subject when subsequently exposed to one or more coronavirus.
  • ADE antibody dependent enhancement
  • Embodiment 57 The method of any of embodiments 50-56, further comprising a priming step and/or a boosting step.
  • Embodiment 58 The method of any of embodiments 50-57, wherein the administering step is performed via topical, transdermal, subcutaneous, intradermal, oral, intranasal (e.g., intranasal spray) , intratracheal, sublingual, buccal, rectal, vaginal, inhaled, intravenous (e.g., intravenous injection) , , intraarterial, intramuscular (e.g., intramuscular injection) , intracardiac, intraosseous, intraperitoneal, transmucosal, intravitreal, subretinal, intraarticular, peri-articular, local, or epicutaneous administration.
  • intravenous e.g., intravenous injection
  • intraarterial intramuscular
  • intramuscular injection e.g., intramuscular injection
  • intracardiac intraosseous
  • intraperitoneal transmucosal
  • intravitreal subretinal
  • intraarticular peri-articular
  • local or
  • Embodiment 59 The method of any of embodiments 50-58, wherein the effective amount is administered in a single dose or a series of doses separated by one or more interval.
  • Embodiment 60 The method of any of embodiments 50-59, wherein the effective amount is administered without an adjuvant.
  • Embodiment 61 The method of any of embodiments 50-59, wherein the effective amount is administered with an adjuvant or a plurality of adjuvants.
  • Embodiment 62 A method comprising administering to a subject an effective amount of the protein of any one of embodiments 1-33 to generate in the subject a neutralizing antibody or neutralizing antisera to the coronavirus.
  • Embodiment 63 The method of embodiment 62, wherein the subject is a mammal, optionally a human or a non-human primate.
  • Embodiment 64 The method of embodiment 62 or 63, further comprising isolating the neutralizing antibody or neutralizing antisera from the subject.
  • Embodiment 65 The method of embodiment 64, further comprising administering an effective amount of the isolated neutralizing antibody or neutralizing antisera to a human subject via passive immunization to prevent or treat an infection by the coronavirus.
  • Embodiment 66 The method of any of embodiments 62-65, wherein the neutralizing antibody or neutralizing antisera comprises polyclonal antibodies to the coronavirus surface antigen, optionally wherein the neutralizing antibody or neutralizing antisera is free or substantially free of antibodies to the C-terminal propeptide of collagen.
  • Embodiment 67 The method of any of embodiments 62-65, wherein the neutralizing antibody comprises a monoclonal antibody to the coronavirus surface antigen, optionally wherein the neutralizing antibody is free or substantially free of antibodies to the C-terminal propeptide of collagen.
  • Embodiment 68 The protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for use in inducing an immune response to a coronavirus in a subject, and/or in treating or preventing an infection by the coronavirus.
  • Embodiment 69 Use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
  • Embodiment 70 Use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for the manufacture of a medicament or a prophylactic for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
  • Embodiment 71 A method for analyzing a sample, comprising: contacting a sample with the protein of any of embodiments 1-33, and detecting a binding between the protein and an analyte capable of specific binding to the surface antigen of the coronavirus.
  • Embodiment 72 The method of embodiment 71, wherein the analyte is an antibody, a receptor, or a cell recognizing the surface antigen.
  • Embodiment 73 The method of embodiment 71 or 72, wherein the binding indicates the presence of the analyte in the sample, and/or an infection by the coronavirus in a subject from which the sample is derived.
  • Embodiment 74 A kit comprising the protein of any of embodiments 1-33 and a substrate, pad, or vial containing or immobilizing the protein, optionally wherein the kit is an ELISA or lateral flow assay kit.
  • Example 1 Generation of recombinant disulfide-bond linked SARS-CoV-2 S-Trimer fusion protein as a subunit vaccine.
  • Secreted forms of recombinant disulfide bond-linked polypeptides comprising SARS-CoV-2 protein peptides fused to a trimerization domain as candidate protein subunit vaccines were generated.
  • the complete ecto-domain of the native spike protein (S) from SARS-CoV2, including its signal peptide (SP) , S1 and S2 domains was fused in-frame at the C-terminus to a mammalian expression vector that encoded human C-propeptide of ⁇ 1 collagen, to enable expression of a secreted and trimeric S-Trimer fusion antigen, e.g., as shown in FIG. 1.
  • FIG. 2 High-level expression of S-Trimer fusion protein was shown in FIG. 2.
  • S-Trimers were then purified and characterized.
  • S-Trimer was purified from the cleared cell cultured medium via a Protein A (PA) affinity chromatography and anion exchange column (Q) followed by ultra-filtration and diafiltration (UF/DF) to obtain the drug substance (DS) , as shown in FIG. 3A.
  • PA Protein A
  • UF/DF ultra-filtration and diafiltration
  • the S-Trimer is a disulfide bond-linked trimer.
  • Four ⁇ g of highly purified native-like S-Trimer was analyzed by a 6%SDS-PAGEs under non-reducing and reducing conditions as indicated and stained with Coomassie Blue.
  • the S-Trimer was purified to nearly homogeneity as judged by SEC-HPLC analysis, with some cleaved S1 being separated during the size exclusion chromatography, as shown in FIG. 3C.
  • the molecular weight of S-Trimer was estimated to be 660 Kda.
  • FIG. 3D the receptor binding kinetics of S-Trimer to ACE2-Fc was assessed by Fortebio biolayer interferometry measurements using a protein A sensor.
  • the S-Trimers were highly glycosylated with N-linked glycans. Highly purified S-Trimer before and after digestion with either endoglycanase F (PNGase F) alone or PNGase F plus endo-O-glycosidase to remove N-and O-linked glycans, and analyzed by an 8%reducing SDS-PAGE and stained with Coomassie Blue. The full-length S-Trimer, S2-Trimer and cleaved S1 before and after deglycosylation were as indicated in FIG. 4. Highly purified S-Trimers were visualized by negative EM using FEI Tecnai spirit electron microscopy, with the predicted conformation of S-Trimer shown in FIG. 5.
  • Example 2 Functional characterization of recombinant pol. ypeptides comprising S-Trimer protein peptides
  • FIG. 7A and FIG. 7B show the induction of antigen-specific antibodies and neutralizing antibodies, respectively, in rats with S-Trimer alone (30 micrograms) and without any adjuvant. Similar to data shown in human in FIG. 6, these results show that antigen-specific antibodies as well as neutralizing antibodies were induced with the S-Trimer vaccine. Similarly, immunogenicity of the S-Trimer was shown in mice. Balb-c mice grouped in 6 were immunized twice at Day 1 and Day 14 with either 3 micrograms of S-Trimer alone or S-Trimer + Alum as an adjuvant. The antisera collected at Day 28 were analyzed with S-Trimer to determine the antibody titers (FIG. 7C) .

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Abstract

The present invention provides a complex of coronavirus antigens joined by in-frame fusion to a C-terminal portion of a collagen to form a disulfide bond-linked trimeric fusion protein. Also provided herein are methods for preventing the infection or producing the recombinant peptides and diagnostic methods.

Description

CORONAVIRUS VACCINE COMPOSITIONS, METHODS, AND USES THEREOF Field
The present disclosure relates in some aspects to immunogenic compositions including recombinant peptides and proteins comprising coronavirus viral antigens and immunogens, e.g., coronavirus S protein peptides, for treating or preventing a coronavirus infection.
Background
Coronaviruses are enveloped, positive-sense single-stranded RNA viruses. They have the largest genomes (26-32 kb) among known RNA viruses, and are phylogenetically divided into four genera (α, β, γ, δ) , with betacoronaviruses further subdivided into four lineages (A, B, C, D) . Coronaviruses infect a wide range of avian and mammalian species, including humans. Human coronaviruses may circulate annually in humans and generally cause mild respiratory diseases, although severity can be greater in infants, elderly, and the immunocompromised. In contrast, certain other coronaviruses, including the Middle East respiratory syndrome coronavirus (MERS-CoV) , the severe acute respiratory syndrome coronavirus (SARS-CoV-1) , and the most recent 2019 new coronavirus (2019-nCoV) , also known as CoVID-19 or SARS-CoV-2, are highly pathogenic and the pandemic has left millions of people infected and led to hundreds of thousands of deaths world wide. The high pathogenicity and airbome transmissibility of these coronaviruses have raised concem about the potential for another coronavirus pandemic. The high case-fatality rate, vaguely defined epidemiology, and absence of prophylactic or therapeutic measures against coronaviruses have created an urgent need for an effective vaccine and related therapeutic agents. Provided are methods, uses and articles of manufacture that meet such and other needs.
Summary
In some embodiments, disclosed herein is a protein comprising a plurality of recombinant polypeptides, each recombinant polypeptide comprising a surface antigen of a coronavirus linked to a C-terminal propeptide of collagen, wherein the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds.
In some embodiments, disclosed herein are recombinant subunit vaccines that comprise an ecto-domain (e.g., without transmembrane and cytoplasmic domains) of an S protein or its  fragments from a coronavirus, such as SARS-CoV-2, which is fused in-frame to a C-propeptide of a collagen that is capable of forming disulfide bond-linked homo-trimer. The resulting recombinant subunit vaccines, such as an S-Trimer, can be expressed and purified from transfected cells, and are expected to be in native-like conformation in trimeric form. This solves the problems of mis-folding of a viral antigen often encountered when it is expressed as a recombinant peptide or protein in soluble forms without the transmembrane and/or cytoplasmic domains. Such mis-folded viral antigens do not faithfully preserve the native viral antigen conformation, and often fail to evoke neutralizing antibodies.
In some embodiments, the coronavirus is a Severe Acute Respiratory Syndrome (SARS) -coronavirus (SARS-CoV-1) , a SARS-coronavirus 2 (SARS-CoV-2) , a SARS-like coronavirus, a Middle East Respiratory Syndrome (MERS) -coronavirus (MERS-CoV) , a MERS-like coronavirus, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
In any of the preceding embodiments, the surface antigen can comprise a coronavirus spike (S) protein or a fragment or epitope thereof, wherein the epitope is optionally a linear epitope or a conformational epitope, and wherein the protein comprises three recombinant polypeptides.
In any of the preceding embodiments, the surface antigen can comprise a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof.
In any of the preceding embodiments, the surface antigen can comprise a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof.
In any of the preceding embodiments, the surface antigen can comprises a receptor binding domain (RBD) of the S protein.
In any of the preceding embodiments, the surface antigen can comprise an S1 subunit and an S2 subunit of the S protein.
In any of the preceding embodiments, the surface antigen can be free of a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
In any of the preceding embodiments, the surface antigen can comprise a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
In any of the preceding embodiments, the surface antigen can be free of a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L, or can contain a mutated protease cleavage site that is not cleavable by the protease.
In any of the preceding embodiments, the surface antigen can be soluble or do not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
In any of the preceding embodiments, the surface antigens can be the same or different among the recombinant polypeptides of the protein.
In any of the preceding embodiments, the surface antigen can be directly fused to the C-terminal propeptide, or can be linked to the C-terminal propeptide via a linker, such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
In any of the preceding embodiments, the protein can be soluble or do not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
In any of the preceding embodiments, the protein can bind to a cell surface receptor of a subject, optionally wherein the subject is a mammal such as a primate, e.g., human.
In any of the preceding embodiments, the cell surface receptor can be angiotensin converting enzyme 2 (ACE2) , dipeptidyl peptidase 4 (DPP4) , dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin (DC-SIGN) , or liver/lymph node-SIGN (L-SIGN) .
In any of the preceding embodiments, the C-terminal propeptide can be of human collagen.
In any of the preceding embodiments, the C-terminal propeptide can comprise a C-terminal polypeptide of proα1 (I) , proα1 (II) , proα1 (III) , proα1 (V) , proα1 (XI) , proα2 (I) , proα2 (V) , proα2 (XI) , or proα3 (XI) , or a fragment thereof.
In any of the preceding embodiments, the C-terminal propeptides can be the same or different among the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise any of SEQ ID NOs: 1-20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 3 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 4 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 7 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 12 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 15 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments the C-terminal propeptide can comprise SEQ ID NO: 3.
In any of the preceding embodiments, the C-terminal propeptide can comprise SEQ ID NO: 15.
In any of the preceding embodiments, the C-terminal propeptide can comprise SEQ ID NO: 20.
In any of the preceding embodiments, the C-terminal propeptide can comprise a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20,  wherein X and Y and independently any amino acid and optionally proline or hydroxyproline, or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
In any of the preceding embodiments, the surface antigen in each recombinant polypeptide can be in a prefusion conformation.
In any of the preceding embodiments, the surface antigen in each recombinant polypeptide can be in a postfusion conformation.
In any of the preceding embodiments, the surface antigen in each recombinant polypeptide can comprise any of SEQ ID NOs: 21-36 or an amino acid sequence at least 80%identical thereto.
In any of the preceding embodiments, the recombinant polypeptide can comprise any of SEQ ID NOs: 37-51 or an amino acid sequence at least 80%identical thereto.
Also provided herein is an immunogen comprising a protein provided herein. Provided herein is a protein nanoparticle comprising protein provided herein directly or indirectly linked to a nanoparticle. Provided herein is a virus-like particle (VLP) comprising a protein provided herein.
Also provided herein is an isolated nucleic acid encoding one, two, three or more of the recombinant polypeptides of the protein provided herein. In some embodiments, a polypeptide encoding the S protein peptide is fused in-frame to a polypeptide encoding the C-terminal propeptide of collagen. In some embodiments, the isolated nucleic acid provided herein is operably linked to a promoter.
In some embodiments, the isolated nucleic acid provided herein is a DNA molecule. In some embodiments, the isolated nucleic acid provided herein is an RNA molecule, optionally an mRNA molecule such as a nucleoside-modified mRNA, a non-amplifying mRNA, a self-amplifying mRNA, or a trans-amplifying mRNA.
Also provided herein is a vector comprising an isolated nucleic acid provided herein. In some embodiments, the vector is a viral vector.
In some aspects, provided herein is a virus, a pseudovirus, or a cell comprising vector provided herein, optionally wherein the virus or cell has a recombinant genome. In some aspects, provided herein is an immunogenic composition comprising the protein, immunogen, protein  nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, or cell provided herein, and a pharmaceutically acceptable carrier.
Also provided herein is a vaccine comprising an immunogenic composition provided herein and optionally an adjuvant, wherein the vaccine is optionally a subunit vaccine. In some embodiments, the vaccine is a prophylactic and/or therapeutic vaccine.
In some aspects, provided herein is a method of producing a protein, comprising: expressing the isolated nucleic acid or vector provided herein in a host cell to produce the protein as provided herein; and purifying the protein. Provided herein is a protein produced by a method provided herein.
Provided herein are methods for generating an immune response to an S protein peptide or fragment or epitope thereof of a coronavirus in a subject, comprising administering to the subject an effective amount of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine as provided herein to generate the immune response. In some embodiments, the method provided herein is for treating or preventing infection with the coronavirus. In some embodiments, generating the immune response inhibits or reduces replication of the coronavirus in the subject. In some embodiments, the immune response comprises a cell-mediated response and/or a humoral response, optionally comprising production of one or more neutralizing antibody, such as a polyclonal antibody or a monoclonal antibody. In some embodiments, the immune response is against the S protein peptide or fragment or epitope thereof of the coronavirus but not against the C-terminal propeptide. In some embodiments, the administering to the subject does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to one or more coronavirus. In some embodiments, the administering does not lead to antibody dependent enhancement (ADE) in the subject when subsequently exposed to one or more coronavirus. In some embodiments, the method further comprises a priming step and/or a boosting step. In some embodiments, the administering step is performed via topical, transdermal, subcutaneous, intradermal, oral, intranasal (e.g., intranasal spray) , intratracheal, sublingual, buccal, rectal, vaginal, inhaled, intravenous (e.g., intravenous injection) , intraarterial, intramuscular (e.g., intramuscular injection) , intracardiac, intraosseous, intraperitoneal, transmucosal, intravitreal, subretinal, intraarticular, peri-articular, local, or  epicutaneous administration. In some embodiments, the effective amount is administered in a single dose or a series of doses separated by one or more interval. In some embodiments, the effective amount is administered without an adjuvant. In some embodiments, the effective amount is administered with an adjuvant.
Provided herein are methods comprising administering to a subject an effective amount of a protein provided herein to generate in the subject a neutralizing antibody or neutralizing antisera to the coronavirus. In some embodiments, the subject is a mammal, optionally a human or a non-human primate. In some embodiments, the method further comprises isolating the neutralizing antibody or neutralizing antisera from the subject. In some embodiments, the method further comprises administering an effective amount of the isolated neutralizing antibody or neutralizing antisera to a human subject via passive immunization to prevent or treat an infection by the coronavirus. In some embodiments, the neutralizing antibody or neutralizing antisera to the coronavirus comprises polyclonal antibodies to the coronavirus S protein peptide or fragment or epitope thereof, optionally wherein the neutralizing antibody or neutralizing antisera is free or substantially free of antibodies to the C-terminal propeptide of collagen. In some embodiments, the neutralizing antibody comprises a monoclonal antibody to the coronavirus S protein peptide or fragment or epitope thereof, optionally wherein the neutralizing antibody is free or substantially free of antibodies to the C-terminal propeptide of collagen.
In some aspects, the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine provided herein, is for use in inducing an immune response to a coronavirus in a subject, and/or in treating or preventing an infection by the coronavirus.
In some aspects, provided herein is use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine provided herein, for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus. In some aspects, provided herein is use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine provided herein, for the manufacture of a medicament or a  prophylactic for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
Also provided herein are methods for analyzing a sample, comprising: contacting a sample with the protein provided herein, and detecting a binding between the protein and an analyte capable of specific binding to the S protein peptide or fragment or epitope thereof of the coronavirus. In some embodiments, the analyte is an antibody, a receptor, or a cell recognizing the S protein peptide or fragment or epitope thereof. In some embodiments, the binding indicates the presence of the analyte in the sample, and/or an infection by the coronavirus in a subject from which the sample is derived.
Provided herein are kits comprising the protein provided herein and a substrate, pad, or vial containing or immobilizing the protein, optionally wherein the kit is an ELISA or lateral flow assay kit.
Brief Description of the Drawings
FIG. 1 shows structural features of an exemplary soluble S-Trimer subunit vaccine for COVID-19. (A) Schematic illustration of the structural domains of S-Trimer and (B) its trimeric and covalently-linked three-dimensional conformation.
FIG. 2 shows high-level expression of an exemplary S-Trimer. The full-length S-Trimer and partially cleaved forms at S1/S2 furin site, namely the S2-Trimer and the cleaved S1 fragment, are indicated.
FIG. 3 shows the purification and characterization of an exemplary covalently linked S-Trimer. (A) S-Trimer was purified from the cleared cell cultured medium via a Protein A (PA) affinity chromatography and anion exchange column (Q) followed by ultra-filtration and diafiltration (UF/DF) to obtain the drug substance (DS) . (B) S-Trimer is a disulfide bond-linked trimer. (C) The S-Trimer was purified to nearly homogeneity as judged by SEC-HPLC analysis, with some cleaved S1 being separated during the size exclusion chromatography. (D) The receptor binding kinetics of S-Trimer to ACE2-Fc was assessed.
FIG. 4 shows an exemplary S-Trimer is highly glycosylated with N-linked glycans. The full-length S-Trimer, S2-Trimer and cleaved S1 before and after deglycosylation are indicated.
FIG. 5 shows Electron Micrographs (EM) of an exemplary S-Trimer and the predicted conformation of the S-Trimer (right cartoon) .
FIG. 6 shows the detection of S-specific antibodies and neutralizing antibodies from convalescent sera using an exemplary S-Trimer as an antigen.
FIG. 7A and FIG. 7B show the induction of antigen-specific antibodies and neutralizing antibodies, respectively, in rats, with an exemplary S-Trimer alone and without any adjuvant. FIG. 7C shows induction of antigen-specific antibodies with an exemplary S-Trimer vaccine in mice, without adjuvant or with Alum as the adjuvant.
FIG. 8A shows the sequence of an exemplary SARS S fusion protein capable of self-trimerization upon expression (1504 aa) . FIG. 8B shows the sequence of the exemplary SARS S fusion protein without a signal peptide at the N-terminus (1491 aa) .
FIG. 9A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa) . FIG. 9B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
FIG. 10A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimefization upon expression (849 aa) .
FIG. 10B shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (992 aa) .
FIG. 11A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa, 986K/987V->986P/987P) . FIG. 11B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
FIG. 12A shows the sequence of an exemplary SARS-CoV-2 S fusion protein capable of self-trimerization upon expression (1522 aa, 685R->685A, 986K/987V->986P/987P) . FIG. 12B shows the sequence of the exemplary SARS-CoV-2 S fusion protein without a signal peptide at the N-terminus (1509 aa) .
FIG. 13 shows the structure and certain sequences of exemplary coronaviruses.
Detailed Description
Provided herein are immunogenic compositions, methods, and uses of fusion peptides and proteins comprising coronavirus viral antigens or immunogens for the treatment, e.g., prophylactic, therapeutic, of coronavirus infections. In some embodiments, compositions and methods of use of recombinant soluble surface antigens from RNA viruses in covalently linked trimeric forms are disclosed. In some embodiments, the resulting fusion proteins are secreted as disulfide bond-linked homo-trimers, which are more stable in structure, while preserving the conformations of native-like trimeric viral antigens, thereby can be used as more effective vaccines against these dangerous pathogens.
In some embodiments, disclosed herein are methods for using viral antigen trimers as a vaccine or as part of a multivalent vaccine to prevent viral infections, without or with adjuvant, or with more than one adjuvant, optionally via either intra-muscular injections or intra-nasal administrations.
In some embodiments, disclosed herein are methods for using viral antigen trimers as an antigen for diagnosis of viral infections through detection of antibodies, e.g., IgM or IgG, that recognize the viral antigen, such as neutralizing antibodies.
In some embodiments, disclosed herein are methods for using viral antigen trimers as an antigen to generate polyclonal or monoclonal antibodies which can be used for passive immunization, e.g., neutralizing mAb for treating a coronavirus infection.
In some embodiments, disclosed herein is a viral antigen trimer as a vaccine or as part of a multivalent vaccine, wherein the vaccine comprises a plurality of trimeric subunit vaccines comprising viral antigens of the same protein of a virus or comprising viral antigens of two or more different proteins of one or more viruses or one or more strains of the same virus.
In some embodiments, disclosed herein is a monovalent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a bi-valent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a tri-valent vaccine comprising a viral antigen trimer disclosed herein. In some embodiments, disclosed herein is a quadrivalent vaccine comprising a viral antigen trimer disclosed herein.
In some embodiments, disclosed herein is a monovalent vaccine comprising an S-Trimer disclosed herein. In some embodiments, disclosed herein is a bi-valent vaccine comprising an S-Trimer disclosed herein. In some embodiments, disclosed herein is a bi-valent vaccine comprising at least one S-Trimer comprising a first S protein antigen and at least one S-Trimer comprising a second S protein antigen. In some embodiments, the first and second S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species. In some embodiments, disclosed herein is a tri-valent vaccine comprising an S-Trimer disclosed herein. In some embodiments, disclosed herein is a tri-valent vaccine comprising at least one S-Trimer comprising a first S protein antigen, at least one S-Trimer comprising a second S protein antigen, and at least one S-Trimer comprising a third S protein antigen. In some embodiments, the first, second and third S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two, three, or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species. In some embodiments, disclosed herein is a quadrivalent vaccine comprising an S-Trimer disclosed herein. In some embodiments, disclosed herein is quadrivalent vaccine comprising at least one S-Trimer comprising a first S protein antigen, at least one S-Trimer comprising a second S protein antigen, at least one S-Trimer comprising a third S protein antigen, and at least one S-Trimer comprising a fourth S protein antigen. In some embodiments, the first, second, third, and fourth S protein antigens are from the same S protein of one or more virus species or strains/subtypes, or from two, three, four, or more different S proteins of one or more virus species or one or more strains/subtypes of the same virus species.
The proteins, including recombinant polypeptides and fusion proteins, comprising coronavirus viral antigens and immunogens provided herein are useful for effectively and safely treating (e.g., therapeutically, prophylactically) coronavirus infection. For example, the proteins comprising coronavirus viral antigens and immunogens provided herein treat coronavirus infection without meditated vaccine-induced disease enhancement (VED) and/or antibody dependent enhancement (ADE) . In addition, the proteins comprising coronavirus viral antigens and immunogens provided herein are easily produced, and demonstrate stability under high stress conditions such as, e.g., high temperature, extreme pH, and high and low osmolality. Thus, the  proteins and immunogenic compositions provided herein circumvent and satisfy the issues of production, stability, safety, and efficacy that have hindered coronavirus vaccine development.
In some aspects, the coronavirus viral antigens and immunogens provided herein include the coronavirus Spike (S) protein or peptide, particularly SARS-CoV or SARS-CoV-2 S proteins. The spikes of SARS-CoV and SARS-CoV-2 are composed of trimers of S protein, which belongs to a group of class I viral fusion glycoproteins that also includes HIV glycoprotein 160 (Env) , influenza haemagglutinin (HA) , paramyxovirus F and Ebola virus glycoprotein. The SARS-CoV and SARS-CoV-2 S proteins each encodes a surface glycoprotein precursor, and the amino terminus and most of the protein is predicted to be on the outside of the cell surface or the virus particles. The S protein comprises a signal peptide located at the N terminus, an extracellular domain, a transmembrane domain and an intracellular domain. Similarly to other coronaviruses, the S protein of SARS-CoV and SARS-CoV-2 can be cleaved into the S1 and S2 subunits by proteases. In particular, SARS-CoV-2 contains a furin-like cleavage site that is lacking in the other SARS-like CoVs.
In some embodiments, provided herein are recombinant S ectodomain trimers. In some embodiments, the recombinant S ectodomain trimer comprises recombinant S ectodomain protomers from an alphacoronavirus, such as NL63-CoV or 229E-CoV. In some embodiments, the recombinant S ectodomain trimers comprise S ectodomain protomers from a betacoronavirus, such as OC43-CoV, SARS-CoV, SARS-CoV-2, MERS-CoV, HKU1-CoV, WIV1-CoV, mouse hepatitis virus (MHV) , or HKU9-CoV.
Similar to other enveloped RNA viruses such as HIV, RSV and Influenza, coronaviruses including SARS-CoV-2, all each has a trimeric surface antigen on its viral envelopes to gain entry into different host cells via specific cell surface receptors during infections. Like SARS-CoV-1, SARS-CoV-2 uses its trimeric viral surface antigen S protein to enter host cells of respiratory systems in mammals upon binding to its specific cell surface receptor ACE2. The prerequisite for generating an effective recombinant subunit vaccine is to be able to create a viral S antigen that is native-like, and in particular, to maintain its trimeric conformation in order to evoke sufficient amount of antibodies that could bind to the receptor binding domain (RBD) of the viral S protein, thereby preventing the virus from binding to ACE2 receptor, thus abolishing viral infections.
In some embodiments, the protein comprising a coronavirus viral antigen or immunogen, e.g., SARS-CoV or SARS-CoV-2 S protein peptide, is capable of generating an immune response, e.g., an immune response to the SARS-CoV or SARS-CoV-2 S protein peptide. In some embodiments, the immune response inhibits or reduces replication of a coronavirus in a subject, e.g., a patient. In some embodiments, the immune response includes production of one or more neutralizing antibodies, such as polyclonal and/or monoclonal antibodies. In some embodiments, the neutralizing antibodies inhibit or reduce replication of a coronavirus in a subject, e.g., a patient. In some embodiments, administration of the protein, for example as an immunogenic composition, to the subject does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to a coronavirus. In some aspects, the protein comprising a coronavirus viral antigen and immunogen is used as a vaccine.
In some embodiments, the coronavirus viral antigen and immunogen, e.g., SARS-CoV or SARS-CoV-2 S protein peptide, is linked to a protein or peptide to form a fusion protein or recombinant polypeptide. In some embodiments, the protein or peptide to which the coronavirus viral antigen or immunogen is linked is capable of associating, e.g., covalently or non-covalently linking, with proteins or peptides, such as proteins or peptides of fusion proteins or recombinant polypeptides. Thus, in some cases, the protein or peptide to which the coronavirus viral antigen or immunogen is linked is a multimerization domain.
In some embodiments, the coronavirus viral antigen and immunogen, e.g., coronavirus S protein peptide, is linked to a propeptide of collagen, e.g., at the C-terminal of propeptide of collagen, to form a fusion peptide or recombinant polypeptide. Thus, in some embodiments, the protein provided herein comprises recombinant polypeptides containing coronavirus viral antigens and immunogens, e.g., coronavirus S protein peptides or a fragment or epitope thereof, linked to a C-terminal propeptide of collagen. In some embodiments, the propeptide of collagen is derived from the human C-propeptide of α1 collagen and is capable self-trimerization upon expression.
In some embodiments, linking the coronavirus viral antigen and immunogen, e.g., coronavirus S protein peptide, to a propeptide of collagen, e.g., at the C-terminal of propeptide of collagen, aids in the ability of the protein to generate an immune response. For example, the creation of the recombinant protein may preserve the tertiary and quaternary structures of the  coronavirus S protein peptide, which may be important for the stability of the native conformation of the coronavirus S protein peptide, and in turn the availability of antigenic sites on the surface of the protein capable of eliciting an immune response, e.g., neutralizing antibodies. Additionally, linking of the coronavirus S protein peptide to a protein or peptide capable of self-trimerization allows the aggregation of the recombinant proteins, thus mimicking the native homotrimeric structure of the coronavirus S protein peptides on the viral envelope.
In some embodiments, linking the coronavirus S protein peptide to a C-terminal propeptide of collagen results in self-trimerized recombinant polypeptides. In some embodiments, the protein provided herein comprises a plurality of self-trimerized coronavirus S protein peptide and propeptide of collagen recombinant polypeptides. In some embodiments, the trimeric nature of the recombinant proteins aids in the stability of the protein. In some embodiments, the trimefic nature of the recombinant proteins aids in the ability of the protein to generate an immune response. In some embodiments, the trimeric nature of the recombinant proteins and/or a macrostructure of a plurality of self-trimerized recombinant proteins aids in the ability of the protein to generate an immune response.
Also provided herein are immunogenic compositions comprising the proteins provided herein, methods of producing proteins provided herein, methods of treating subjects with proteins and compositions provided herein, and kits.
All publications, including patent documents, scientific articles and databases, referred to in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were individually incorporated by reference. If a definition set forth herein is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporated by reference, the definition set forth herein prevails over the definition that is incorporated herein by reference. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.
I. Viral Antigens and Immunogens
The proteins provided herein comprise coronavirus viral antigens and immunogens. The coronavirus viral antigens and immunogens contemplated herein are capable of promoting or  stimulating a cell-mediated response and/or a humoral response. In some embodiments, the response, e.g., cell-mediated or humoral response, comprises the production of antibodies, e.g., neutralizing antibodies. In some embodiments, the coronavirus viral antigen or immunogen is an coronavirus S protein peptide.
Coronavirus is a family of positive-sense, single-stranded RNA viruses that are known to cause severe respiratory illness. Viruses currently known to infect human from the coronavirus family are from the alphacoronavirus and betacoronavirus genera. Additionally, it is believed that the gammacoronavirus and deltacoronavirus genera may infect humans in the future. Non-limiting examples of betacoronaviruses include Middle East respiratory syndrome coronavirus (MERS-CoV) , Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) , Human coronavirus HKU1 (HKU1-CoV) , Human coronavirus OC43 (OC43-CoV) , Murine Hepatitis Virus (MHV-CoV) , Bat SARS-like coronavirus WIV 1 (WIV 1-CoV) , and Human coronavirus HKU9 (HKU9-CoV) . Non-limiting examples of alphacoronaviruses include human coronavirus 229E (229E-CoV) , human coronavirus NL63 (NL63-CoV) , porcine epidemic diarrhea virus (PEDV) , and Transmissible gastroenteritis coronavirus (TGEV) . A non-limiting example of a deltacoronaviruses is the Swine Delta Coronavirus (SDCV) .
A list of Severe acute respiratory syndrome-related coronavirus is disclosed herein:
■  Bat coronavirus Cp/Yunnan2011
■  Bat coronavirus RaTG13
■  Bat coronavirus Rp/Shaanxi2011
○  Bat SARS coronavirus HKU3
■  Bat SARS coronavirus HKU3-1
■  Bat SARS coronavirus HKU3-10
■  Bat SARS coronavirus HKU3-11
■  Bat SARS coronavirus HKU3-12
■  Bat SARS coronavirus HKU3-13
■  Bat SARS coronavirus HKU3-2
■  Bat SARS coronavirus HKU3-3
■  Bat SARS coronavirus HKU3-4
■  Bat SARS coronavirus HKU3-5
■  Bat SARS coronavirus HKU3-6
■  Bat SARS coronavirus HKU3-7
■  Bat SARS coronavirus HKU3-8
■  Bat SARS coronavirus HKU3-9
■  Bat SARS coronavirus Rp1
■  Bat SARS coronavirus Rp2
○  Bat SARS CoV Rfl/2004
■  Bat CoV 273/2005
○  Bat SARS CoV Rm1/2004
■  Bat CoV 279/2005
■  Bat SARS CoV Rp3/2004
■  Bat SARS-like coronavirus
■  Bat SARS-like coronavirus Rs3367
■  Bat SARS-like coronavirus RsSHC014
■  Bat SARS-like coronavirus WIV1
■  Bat SARS-like coronavirus YNLF_31C
■  Bat SARS-like coronavirus YNLF_34C
■  BtRf-BetaCoV/HeB2013
■  BtRf-BetaCoV/JL2012
■  BtRf-BetaCoV/SX2013
■  BtRs-BetaCoV/GX2013
■  BtRs-BetaCoV/HuB2013
■  BtRs-BetaCoV/YN2013
■  Civet SARS CoV 007/2004
■  Civet SARS CoV SZ16/2003
■  Civet SARS CoV SZ3/2003
○  recombinant SARSr-CoV
■  SARS coronavirus ExoN1
■  SARS coronavirus MA15
■  SARS coronavirus MA15 ExoN1
■  SARS coronavirus wtic-MB
■  Rhinolophus affinis coronavirus
■  SARS bat coronavirus
■  SARS coronavirus A001
■  SARS coronavirus A013
■  SARS coronavirus A021
■  SARS coronavirus A022
■  SARS coronavirus A030
■  SARS coronavirus A031
■  SARS coronavirus AS
■  SARS coronavirus B012
■  SARS coronavirus B024
■  SARS coronavirus B029
■  SARS coronavirus B033
■  SARS coronavirus B039
■  SARS coronavirus B040
■  SARS coronavirus BJ01
■  SARS coronavirus BJ02
■  SARS coronavirus BJ03
■  SARS coronavirus BJ04
■  SARS coronavirus BJ162
■  SAKS coronavirus BJ182-12
■  SARS coronavirus BJ182-4
■  SARS coronavirus BJ182-8
■  SAKS coronavirus BJ182a
■  SARS coronavirus BJ182b
■  SARS coronavirus BJ202
■  SARS coronavirus BJ2232
■  SAKS coronavirus BJ302
■  SARS coronavirus C013
■  SAKS coronavirus C014
■  SARS coronavirus C017
■  SAKS coronavirus C018
■  SARS coronavirus C019
■  SARS coronavirus C025
■  SARS coronavirus C028
■  SAKS coronavirus C029
■  SARS Coronavirus CDC#200301157
■  SARS coronavirus civet010
■  SARS coronavirus civet014
■  SARS coronavirus civet019
■  SARS coronavirus civet020
■  SAKS coronavirus CS21
■  SARS coronavirus CS24
■  SARS coronavirus CUHK-AG01
■  SARS coronavirus CUHK-AG02
■  SARS coronavirus CUHK-AG03
■  SARS coronavirus CUHK-L2
■  SARS coronavirus CUHK-Su10
■  SARS coronavirus CUHK-W1
■  SAKS coronavirus cw037
■  SARS coronavirus cw049
■  SARS coronavirus ES191
■  SARS coronavirus ES260
■  SARS coronavirus FRA
○  SARS coronavirus Frankfurt 1
■  SARS coronavirus Frankfurt1-v01
■  SARS coronavirus GD01
■  SARS coronavirus GD03T0013
■  SARS coronavirus GD322
■  SAKS coronavirus GD69
■  SARS coronavirus GDH-BJH01
■  SAKS coronavirus GZ-A
■  SARS coronavirus GZ-B
■  SARS coronavirus GZ-C
■  SARS coronavirus GZ-D
■  SARS coronavirus GZ02
■  SARS coronavirus GZ0401
■  SARS coronavirus GZ0402
■  SARS coronavirus GZ0403
■  SARS coronavirus GZ43
■  SARS coronavirus GZ50
■  SARS coronavirus GZ60
■  SARS coronavirus HB
■  SARS coronavirus HC/SZ/61/03
■  SARS coronavirus HGZ8L1-A
■  SARS coronavirus HGZ8L1-B
■  SARS coronavirus HGZ8L2
■  SARS coronavirus HHS-2004
■  SARS coronavirus HKU-36871
■  SARS coronavirus HKU-39849
■  SARS coronavirus HKU-65806
■  SARS coronavirus HKU-66078
■  SARS coronavirus Hong Kong/03/2003
■  SARS coronavirus HPZ-2003
■  SARS coronavirus HSR 1
■  SARS coronavirus HSZ-A
■  SARS coronavirus HSZ-Bb
■  SARS coronavirus HSZ-Bc
■  SARS coronavirus HSZ-Cb
■  SARS coronavirus HSZ-Cc
■  SARS coronavirus HSZ2-A
■  SARS coronavirus HZS2-Bb
■  SARS coronavirus HZS2-C
■  SARS coronavirus HZS2-D
■  SARS coronavirus HZS2-E
■  SARS coronavirus HZS2-Fb
■  SARS coronavirus HZS2-Fc
■  SARS coronavirus JMD
■  SARS coronavirus LC1
■  SARS coronavirus LC2
■  SARS coronavirus LC3
■  SARS coronavirus LC4
■  SARS coronavirus LC5
■  SARS coronavirus LLJ-2004
■  SARS coronavirus NS-1
■  SARS coronavirus P2
■  SARS coronavirus PC4-115
■  SARS coronavirus PC4-127
■  SARS coronavirus PC4-13
■  SARS coronavirus PC4-136
■  SARS coronavirus PC4-137
■  SARS coronavirus PC4-145
■  SARS coronavirus PC4-199
■  SARS coronavirus PC4-205
■  SARS coronavirus PC4-227
■  SARS coronavirus PC4-241
■  SARS coronavirus PUMC01
■  SARS coronavirus PUMC02
■  SARS coronavirus PUMC03
■  SARS coronavirus Rs 672/2006
■  SARS coronavirus sf098
■  SARS coronavirus sf099
■  SARS coronavirus ShanghaiQXC1
■  SARS coronavirus ShanghaiQXC2
■  SARS coronavirus Shanhgai LY
■  SARS coronavirus Sin0409
■  SARS coronavirus Sin2500
■  SARS coronavirus Sin2677
■  SARS coronavirus Sin2679
■  SARS coronavirus Sin2748
■  SARS coronavirus Sin2774
■  SARS coronavirus Sin3408
■  SARS coronavirus Sin3408L
■  SARS coronavirus Sin3725V
■  SARS coronavirus Sin3765V
■  SARS coronavirus Sin842
■  SARS coronavirus Sin845
■  SARS coronavirus Sin846
■  SARS coronavirus Sin847
■  SARS coronavirus Sin848
■  SARS coronavirus Sin849
■  SARS coronavirus Sin850
■  SARS coronavirus Sin852
■  SARS coronavirus Sin WNV
■  SARS coronavirus Sino1-11
■  SARS coronavirus Sino3-11
■  SARS coronavirus SinP1
■  SARS coronavirus SinP2
■  SARS coronavirus SinP3
■  SARS coronavirus SinP4
■  SARS coronavirus SinP5
■  SARS coronavirus SoD
■  SARS coronavirus SZ1
■  SARS coronavirus SZ13
■  SARS coronavirus Taiwan
■  SARS coronavirus Taiwan JC-2003
■  SARS coronavirus Taiwan TC1
■  SARS coronavirus Taiwan TC2
■  SARS coronavirus Taiwan TC3
■  SARS coronavirus TJ01
■  SARS coronavirus TJF
■  SARS coronavirus Tor2
○  SARS coronavirus TW
■  SARS coronavirus TW-GD1
■  SARS coronavirus TW-GD2
■  SARS coronavirus TW-GD3
■  SARS coronavirus TW-GD4
■  SARS coronavirus TW-GD5
■  SARS coronavirus TW-HP1
■  SARS coronavirus TW-HP2
■  SARS coronavirus TW-HP3
■  SARS coronavirus TW-HP4
■  SARS coronavirus TW-JC2
■  SARS coronavirus TW-KC1
■  SARS coronavirus TW-KC3
■  SARS coronavirus TW-PH1
■  SARS coronavirus TW-PH2
■  SARS coronavirus TW-YM1
■  SARS coronavirus TW-YM2
■  SARS coronavirus TW-YM3
■  SARS coronavirus TW-YM4
■  SARS coronavirus TW1
■  SARS coronavirus TW10
■  SARS coronavirus TW11
■  SARS coronavirus TW2
■  SARS coronavirus TW3
■  SARS coronavirus TW4
■  SARS coronavirus TW5
■  SARS coronavirus TW6
■  SARS coronavirus TW7
■  SARS coronavirus TW8
■  SARS coronavirus TW9
■  SARS coronavirus TWC
■  SARS coronavirus TWC2
■  SARS coronavirus TWC3
■  SARS coronavirus TWH
■  SARS coronavirus TWJ
■  SARS coronavirus TWK
■  SARS coronavirus TWS
■  SARS coronavirus TWY
■  SARS coronavirus Urbani
■  SARS coronavirus Vietnam
■ S ARS coronavirus WF188
■  SARS coronavirus WH20
■  SARS coronavirus WHU
■  SARS coronavirus xw002
■  SARS coronavirus ZJ01
■  SARS coronavirus ZJ02
■  SARS coronavirus ZJ0301
■  SARS coronavirus ZMY 1
■  SARS coronavirus ZS-A
■  SARS coronavirus ZS-B
■  SARS coronavirus ZS-C
■  SARS-related bat coronavirus RsSHC014
■  SARS-related betacoronavirus Rp3/2004
■  Severe acute respiratory syndrome coronavirus 2
Exemplary SARS CoV-2 strains are shown in the table below.
Figure PCTCN2021087066-appb-000001
The coronavirus viral genome is capped, polyadenylated, and covered with nucleocapsid proteins. The coronavirus virion includes a viral envelope containing type I fusion glycoproteins referred to as the spike (S) protein. Most coronaviruses have a common genome organization with the replicase gene included in the 5'-portion of the genome, and structural genes included in the 3'-portion of the genome.
Coronavirus Spike (S) protein is class I fusion glycoprotein initially synthesized as a precursor protein. Individual precursor S polypeptides form a homotrimer and undergo glycosylation within the Golgi apparatus as well as processing to remove the signal peptide, and cleavage by a cellular protease to generate separate S1 and S2 polypeptide chains, which remain associated as S1/S2 protomers within the homotrimer and is therefore a trimer of heterodimers. The S1 subunit is distal to the virus membrane and contains the receptor-binding domain (RBD) that mediates virus attachment to its host receptor. The S2 subunit contains fusion protein machinery, such as the fusion peptide, two heptad-repeat sequences (HR1 and HR2) and a central helix typical of fusion glycoproteins, a transmembrane domain, and the cytosolic tail domain.
In some cases, the coronavirus viral antigen or immunogen is a coronavirus S protein peptide in a prefusion conformation, which is a structural conformation adopted by the ectodomain of the coronavirus S protein following processing into a mature coronavirus S protein in the secretory system, and prior to triggering of the fusogenic event that leads to transition of coronavirus S to the postfusion conformation. The three-dimensional structure of an exemplary coronavirus S protein (HKU1-CoV) in a prefusion conformation is provided in Kirchdoerfer et al., “Pre-fusion structure of a human coronavirus spike protein, ” Nature, 531: 118-121, 2016.
In some cases, the coronavirus viral antigen or immunogen comprises one or more amino acid substitutions, deletions, or insertions compared to a native coronavirus S sequence that provide for increased retention of the prefusion conformation compared to coronavirus S ectodomain trimers formed from a corresponding native coronavirus S sequence. The “stabilization” of the prefusion conformation by the one or more amino acid substitutions, deletions, or insertions can be, for example, energetic stabilization (for example, reducing the energy of the prefusion conformation relative to the post-fusion open conformation) and/or kinetic stabilization (for example, reducing the rate of transition from the prefusion conformation to the postfusion  conformation) . Additionally, stabilization of the coronavirus S ectodomain trimer in the prefusion conformation can include an increase in resistance to denaturation compared to a corresponding native coronavirus S sequence. Methods of determining if a coronavirus S ectodomain trimer is in the prefusion conformation are provided herein, and include (but are not limited to) negative-stain electron microscopy and antibody binding assays using a prefusion-conformation-specific antibody.
In some cases, the coronavirus viral antigen or immunogen is a fragment of an S protein peptide. In some embodiments, the antigen or immunogen is an epitope of an S protein peptide. Epitopes include antigenic determinant chemical groups or peptide sequences on a molecule that are antigenic, such that they elicit a specific immune response, for example, an epitope is the region of an antigen to which B and/or T cells respond. An antibody can bind to a particular antigenic epitope, such as an epitope on coronavirus S ectodomain. Epitopes can be formed both from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary folding of a protein. In some embodiments, the coronavirus epitope is a linear epitope. In some embodiments, the coronavirus epitope is a conformational epitope. In some embodiments, the coronavirus epitope is a neutralizing epitope site. In some embodiments, all neutralizing epitopes of the coronavirus S protein peptide or fragment thereof are present as the antigen or immunogen.
In some cases, for example when the viral antigen or immunogen is a fragment of an S protein peptide, only a single subunit of the S protein peptide is present, and that single subunit of the S protein peptide is trimerized. In some embodiments, the viral antigen or immunogen comprises a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof. In some embodiments, the viral antigen or immunogen comprises a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof. In some embodiments, the viral antigen or immunogen comprises a receptor binding domain (RBD) of the S protein. In some embodiments, the viral antigen or immunogen comprises an S1 subunit and an S2 subunit of the S protein. In some embodiments, the viral antigen or immunogen comprises an S1 subunit of the S protein but not an S2 subunit. In some embodiments, the viral antigen or immunogen comprises an S2 subunit of the S protein but not an S1 subunit. In  some embodiments, the viral antigen or immunogen is free of a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
In some embodiments, the viral antigen or immunogen comprises a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, or cathepsin L.
In some embodiments, the viral antigen or immunogen is free of a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, or cathepsin L, or contains a mutated protease cleavage site that is not cleavable by the protease.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 21. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 21.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 22. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 22.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 23. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 23.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 24:
Figure PCTCN2021087066-appb-000002
Figure PCTCN2021087066-appb-000003
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 85:
Figure PCTCN2021087066-appb-000004
Figure PCTCN2021087066-appb-000005
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 35:
Figure PCTCN2021087066-appb-000006
Figure PCTCN2021087066-appb-000007
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 67:
Figure PCTCN2021087066-appb-000008
Figure PCTCN2021087066-appb-000009
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 86:
Figure PCTCN2021087066-appb-000010
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 68:
Figure PCTCN2021087066-appb-000011
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 69:
Figure PCTCN2021087066-appb-000012
Figure PCTCN2021087066-appb-000013
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 87:
Figure PCTCN2021087066-appb-000014
Figure PCTCN2021087066-appb-000015
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 70:
Figure PCTCN2021087066-appb-000016
Figure PCTCN2021087066-appb-000017
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 71:
Figure PCTCN2021087066-appb-000018
Figure PCTCN2021087066-appb-000019
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 88:
Figure PCTCN2021087066-appb-000020
Figure PCTCN2021087066-appb-000021
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 72:
Figure PCTCN2021087066-appb-000022
Figure PCTCN2021087066-appb-000023
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 73:
Figure PCTCN2021087066-appb-000024
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 89:
Figure PCTCN2021087066-appb-000025
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 74:
Figure PCTCN2021087066-appb-000026
Figure PCTCN2021087066-appb-000027
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 25. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 25.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 26. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 26.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 27. In some embodiments, the viral antigen or immunogen comprises an amino  acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 27.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 28. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 28.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 29. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 29.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 30. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 30.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 31. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 31.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 32. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 32.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 33. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 33.
In some embodiments the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 34. In some embodiments, the viral antigen or immunogen comprises an amino  acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 34.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 35. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 35.
In some embodiments, the viral antigen or immunogen comprises the sequence set forth in SEQ ID NO: 36. In some embodiments, the viral antigen or immunogen comprises an amino acid sequence having at least or about 80%, 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 36.
In some embodiments, the coronavirus viral antigen or immunogen comprises an S protein peptide that is soluble. In some embodiments, the soluble S protein peptide lacks a TM domain peptide and a CP domain peptide. In some embodiments, the soluble S protein peptide does not bind to a lipid bilayer, such as a membrane or viral envelope.
In some embodiments, the S protein peptide is produced from a nucleic acid sequence that has been codon optimized. In some embodiments, the S protein peptide is produced from a nucleic acid sequence that has not been codon optimized.
In some embodiments, the viral antigen or immunogen as referred to herein can include recombinant polypeptides or fusion peptides comprising said viral antigen or immunogen. The terms viral antigen or immunogen may be used to refer to proteins comprising recombinant receptors comprising a coronavirus viral antigen or immunogen. In certain cases, the coronavirus viral antigen or immunogen is a coronavirus protein peptide as provided herein.
II. Recombinant Peptides and Proteins
It is contemplated that the coronavirus viral antigens and immunogens provided herein, e.g., S protein peptides (see, Section I) , can be combined, e.g., linked, to other proteins or peptides to form recombinant polypeptides, including fusion peptides. In some embodiments, individual recombinant polypeptides (e.g., monomers) provided herein associate to form multimers, e.g., trimers, of recombinant polypeptides. In some embodiments, association of the individual recombinant polypeptide monomers occurs via covalent interactions. In some embodiments,  association of the individual recombinant polypeptide monomers occurs via non-covalent interactions. In some embodiments, the interaction, e.g., covalent or non-covalent, is effected by the protein or peptide to which the coronavirus viral antigen or immunogen, e.g., S protein peptide, is linked. In some embodiments, for example when the coronavirus viral antigen or immunogen is an S protein peptide as described herein, the protein or peptide to which it will be linked can be selected such that the native homotrimeric structure of the glycoprotein is preserved. This can be advantageous for evoking a strong and effective immunogenic response to the S protein peptide. For example, preservation and/or maintenance of the native conformation of the coronavirus viral antigens or immunogens (e.g., S protein peptide) may improve or allow access to antigenic sites capable to generating an immune response. In some cases, the recombinant polypeptide comprising an S protein peptide described herein, e.g., see Section I, is referred to herein alternatively as a recombinant S antigen, recombinant S immunogen, or a recombinant S protein.
It is further contemplated that in some cases, the recombinant polypeptides or multimerized recombinant polypeptides thereof aggregate or can be aggregated to form a protein or a complex comprising a plurality of coronavirus viral antigen and/or immunogen recombinant polypeptides. Formation of such proteins may be advantageous for generating a strong and effective immunogenic response to the coronavirus viral antigens and/or immunogens. For instance, formation of a protein comprising a plurality of recombinant polypeptides, and thus a plurality of coronavirus viral antigens, e.g., coronavirus S protein peptides, may preserve the tertiary and/or quaternary structures of the viral antigen, allowing an immune response to be mounted against the native structure. In some cases, the aggregation may confer structural stability of the coronavirus viral antigen or immunogen, which in turn can afford access to potentially antigenic sites capable of promoting an immune response.
1. FUSION PEPTIDES AND RECOMBINANT POL YPEPTIDES
In some embodiments, the coronavirus viral antigen or immunogen can be linked at their C-terminus (C-terminal linkage) to a trimerization domain to promote trimerization of the monomers. In some embodiments, the trimerization stabilizes the membrane proximal aspect of the coronavirus viral antigen or immunogen, e.g., coronavirus S protein peptide, in a trimeric configuration.
Non-limiting examples of exogenous multimerization domains that promote stable trimers of soluble recombinant proteins include: the GCN4 leucine zipper (Harbury et al. 1993 Science 262: 1401-1407) , the trimerization motif from the lung surfactant protein (Hoppe et al. 1994 FEBS Lett 344: 191-195) , collagen (McAlinden et al. 2003 J Biol Chem 278: 42200-42207) , and the phage T4 fibritin Foldon (Miroshnikov et al. 1998 Protein Eng 11: 329-414) , any of which can be linked to a coronavirus viral antigen or immunogen described herein (e.g., by linkage to the C-terminus of an S peptide) to promote trimerization of the recombinant viral antigen or immunogen.
In some embodiments, one or more peptide linkers (such as a gly-ser linker, for example, a 10 amino acid glycine-serine peptide linker) can be used to link the recombinant viral antigen or immunogen to the multimerization domain. The trimer can include any of the stabilizing mutations provided herein (or combinations thereof) as long as the recombinant viral antigen or immunogen trimer retains the desired properties (e.g., the prefusion conformation) .
To be therapeutically feasible, a desired trimerizing protein moiety for biologic drug designs should satisfy the following criteria. Ideally it should be part of a naturally secreted protein, like immunoglobulin Fc, that is also abundant (non-toxic) in the circulation, human in origin (lack of immunogenicity) , relatively stable (long half-life) and capable of efficient self-trimerization which is strengthened by inter-chain covalent disulfide bonds so the trimerized coronavirus viral antigens or immunogens are structurally stable.
Collagen is a family of fibrous proteins that are the major components of the extracellular matrix. It is the most abundant protein in mammals, constituting nearly 25%of the total protein in the body. Collagen plays a major structural role in the formation of bone, tendon, skin, cornea, cartilage, blood vessels, and teeth. The fibrillar types of collagen I, II, III, IV, V, and XI are all synthesized as larger trimeric precursors, called procollagens, in which the central uninterrupted triple-helical domain consisting of hundreds of “G-X-Y” repeats (or glycine repeats) is flanked by non-collagenous domains (NC) , the N-propeptide and the C-propeptide. Both the C-and N-terminal extensions are processed proteolytically upon secretion of the procollagen, an event that triggers the assembly of the mature protein into collagen fibrils which forms an insoluble cell matrix. BMP-1 is a protease that recognizes a specific peptide sequence of procollagen near the  junction between the glycine repeats and the C-prodomain of collagens and is responsible for the removal of the propeptide. The shed trimeric C-propeptide of type I collagen is found in human sera of normal adults at a concentration in the range of 50-300 ng/mL, with children having a much higher level which is indicative of active bone formation. In people with familial high serum concentration of C-propeptide of type I collagen, the level could reach as high as 1-6 μg/mL with no apparent abnormality, suggesting the C-propeptide is not toxic. Structural study of the trimeric C-propeptide of collagen suggested that it is a tri-lobed structure with all three subunits coming together in a junction region near their N-termini to connect to the rest of the procollagen molecule. Such geometry in projecting proteins to be fused in one direction is similar to that of Fc dimer.
Type I, IV, V and XI collagens are mainly assembled into heterotrimeric forms consisting of either two α-1 chains and one α-2 chain (for Type I, IV, V) , or three different a chains (for Type XI) , which are highly homologous in sequence. The type II and III collagens are both homotrimers of α-1 chain. For type I collagen, the most abundant form of collagen, stable α (I) homotrimer is also formed and is present at variable levels in different tissues. Most of these collagen C-propeptide chains can self-assemble into homotrimers, when over-expressed alone in a ceil. Although the N-propeptide domains are synthesized first, molecular assembly into trimeric collagen begins with the in-register association of the C-propeptides. It is believed the C-propeptide complex is stabilized by the formation of interchain disulfide bonds, but the necessity of disulfide bond formation for proper chain registration is not clear. The triple helix of the glycine repeats and is then propagated from the associated C-termini to the N-termini in a zipper-like manner. This knowledge has led to the creation of non-natural types of collagen matrix by swapping the C-propeptides of different collagen chains using recombinant DNA technology. Non-collagenous proteins, such as cytokines and growth factors, also have been fused to the N-termini of either pro-collagens or mature collagens to allow new collagen matrix formation, which is intended to allow slow release of the noncollagenous proteins from the cell matrix. However, under both circumstances, the C-propeptides are required to be cleaved before recombinant collagen fibril assembly into an insoluble cell matrix.
Although, other protein trimerization domains, such as those from GCN4 from yeast fibritin from bacteria phage T4 and aspartate transcarbamoylase of Escherichia coli, have been  described previously to allow trimerization of heterologous proteins, none of these trimerizing proteins are human in nature, nor are they naturally secreted proteins. As such, any trimeric fusion proteins would have to be made intracellularly, which not only may fold incorrectly for naturally secreted proteins such as soluble receptors, but also make purification of such fusion proteins from thousands of other intracellular proteins difficult. Moreover, the fatal drawback of using such non-human protein trimerization domains (e.g. from yeast, bacteria phage and bacteria) for trimeric biologic drug design is their presumed immunogenicity in the human body, rendering such fusion proteins ineffective shortly after injecting them into the human body.
The use of collagen in a recombinant polypeptide as described herein thus has many advantages, including: (1) collagen is the most abundant protein secreted in the body of a mammal, constituting nearly 25%of the total proteins in the body; (2) the major forms of collagen naturally occur as trimeric helixes, with their globular C-propeptides being responsible for the initiating of trimerization; (3) the trimeric C-propeptide of collagen proteolytically released from the mature collagen is found naturally at sub microgram/mL level in the blood of mammals and is not known to be toxic to the body; (4) the linear triple helical region of collagen can be included as a linker with predicted 
Figure PCTCN2021087066-appb-000028
spacing per resi due, or excluded as part of the fusion protein so the di stance between a protein to be trimerized and the C-propeptide of collagen can be precisely adjusted to achieve an optimal biological activity; (5) the recognition site of BMP1 which cleaves the C-propeptide off the pro-collagen can be mutated or deleted to prevent the disruption of a trimeric fusion protein; (6) the C-propeptide domain self-trimerizes via disulfide bonds and it provides a universal affinity tag, which can be used for purification of any secreted fusion proteins created. In some embodiments, the C-propeptide of collagen to which the coronavirus viral antigen and immunogen, e.g., S protein peptide, enables the recombinant production of soluble, covalently-linked homotrimeric fusion proteins.
In some embodiments, the coronavirus viral antigen or immunogen is linked to a C-terminal propeptide of collagen to form a recombinant polypeptide. In some embodiments, the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds. In some embodiments, the recombinant proteins form trimers. In some embodiments, the coronavirus viral antigen or immunogen is an S protein peptide as described in Section I.
In some embodiments, the C-terminal propeptide is of human collagen. In some embodiments, the C-terminal propeptide comprises a C-terminal polypeptide of proα1 (I) , proα1 (II) , proα1 (III) , proα1 (V) , proα1 (XI) , proα2 (I) , proα2 (V) , proα2 (XI) , or proα3 (XI) , or a fragment thereof. In some embodiments, the C-terminal propeptide is or comprises a C-terminal polypeptide of proα1 (I) .
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 1. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 1. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 2. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 2. In some embodiments, the C-terminal propeptide is or is the amino acid sequence set forth by SEQ ID NO: 3. In some embodiments, the C-terminal propeptide exhibits an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 3. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 4. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 4.
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 5. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 5. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 6. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 6. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 7. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 7. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 8. In some embodiments, the C-terminal propeptide is an amino  acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 8.
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 9. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 9. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 10. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 10. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 11. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 11. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 12. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 12.
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 13:
Figure PCTCN2021087066-appb-000029
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 14. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 14.
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 15:
Figure PCTCN2021087066-appb-000030
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 16. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 16.
In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 17. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 17. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 18. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 18. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 19. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 19. In some embodiments, the C-terminal propeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 20. In some embodiments, the C-terminal propeptide is an amino acid sequence having at least or about 85%, 90%, 92%, 95%, or 97%sequence identity to sequence of SEQ ID NO: 20.
In any of the preceding embodiments, the C-terminal propeptide can comprise a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20, wherein X and Y are independently any amino acid, or an amino acid sequence at least 85%, 90%,  92%, 95%, or 97%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides. In some embodiments, X and Y are independently proline or hydroxyproline.
In some cases where an S protein peptide is linked to the C-terminal propeptide to form the recombinant polypeptide, the recombinant polypeptides form a trimer resulting in a homotrimer of S protein peptides. In some embodiments, the S protein peptides of the trimerized recombinant polypetides are in a prefusion conformation. In some embodiments, the S protein peptides of the trimerized recombinant polypetides are in a postfusion conformation. In some embodiments, the confirmation state allows for access to different antigenic sites on the S protein peptides. In some embodiments, the antigenic sites are epitopes, such as linear epitopes or conformational epitopes. An advantage of having a trimerized recombinant polypeptides as described is that an immune response can be mounted against a variety of potential and diverse antigenic sites.
In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides comprising the same viral antigen or immunogen. In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides each comprising a different viral antigen or immunogen from the other recombinant polypeptides. In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides wherein one of the individual recombinant polypeptides comprises a viral antigen or immunogen different from the other recombinant polypeptides. In some embodiments, trimerized recombinant polypeptides include individual recombinant polypeptides wherein two of the individual recombinant polypeptides comprise the same viral antigen or immunogen, and the viral antigen or immunogen is different from the viral antigen or immunogen comprised in the remaining recombinant polypeptide.
In some embodiments, the recombinant polypeptide comprises any coronavirus viral antigen or immunogen described in Section I. In some embodiments, the recombinant polypeptide comprises any coronavirus viral antigen or immunogen described in Section I linked, as described herein, to the C-terminal propeptide of collagen as described herein.
In some embodiments, the immunogen comprises a recombinant SARS-CoV or SARS-CoV-2 S ectodomain trimer comprising protomers comprising one or more (such as two, for  example two consecutive) proline substitutions at or near the boundary between a HR1 domain and a central helix domain that stabilize the S ectodomain trimer in the prefusion conformation. In some such embodiments, the one or more (such as two, for example two consecutive) proline substitutions that stabilize the S ectodomain in the prefusion conformation are located between a position 15 amino acids N-terminal of a C-terminal residue of the HR1 and a position 5 amino acids C-terminal of a N-terminal residue of the central helix.
In some embodiments, the one or more (such as two, for example two consecutive) proline substitutions stabilize the coronavirus (e.g., SARS-CoV or SARS-CoV-2) S ectodomain trimer in the prefusion conformation. In some embodiments, the SARS-CoV-2 S protein peptide comprises 986K/987V to 986P/987P mutations.
In some embodiments, the recombinant coronavirus (e.g., SARS-CoV or SARS-CoV-2) S ectodomain trimer stabilized in the prefusion conformation comprises single-chain S ectodomain protomers comprising mutations to the S1/S2 and/or S2′protease cleavage sites to prevent protease cleavage at these sites. In some embodiments, the SARS-CoV-2 S protein peptide comprises a 685R to 685A mutation. Exemplary protease cleavage sites for various viruses are shown below:
Coronavirus S1/S2, site 1 S1/S2, site 2 S2’
2019-nCoV SPRRAR↓SVAS IAY↓TMS SKPSKR↓SF
CoV-ZX21 TASILR↓STGQ IAY↓TMS SKPsKR↓SF
Bat-AC45 TASILR↓STGQ IAY↓TMS SKPSKR↓SF
SARS-CoV TVSLLR↓STGQ IAY↓TMS LKPTKR↓SF
BM48-31 SSTLVR↓SGGH LAY↓TMS LKPTKR↓SF
HKU9-1 ADSLPR↓LQLV VNY↓DPL GATTYR↓SA
MERS-CoV TPRSCR↓SVPG   GSRSAR↓SA
HKU1 SRRKRR↓SISA   CGSSSR↓SF
HCoV-OC43 KNRRSR↓GAITT   SKASSR↓SA
HCoV-229E IAVQPR↓NVSYD   SRVAGR↓SA
HCoV-NL63 IPVRPR↓NSSDN   SRIAGR↓SA
In some embodiments, the protomers of the recombinant coronavirus (e.g., SARS-CoV or SARS-CoV-2) S ectodomain trimer stabilized in the prefusion conformation by the one or more proline substitutions (such as 986P/987P substitutions) comprises additional modifications for stabilization in the prefusion conformation, such as a mutation at a protease cleavage site to prevent protease cleavage.
With reference to the SARS-CoV-2 S protein sequence provided as SEQ ID NO: 23 and shown in FIG. 13, the ectodomain comprises a signal peptide (SP) , which is removed during cellular processing; an N-terminal domain (NTD) ; a receptor binding domain (RBD) ; one or more S1/S2 cleavage sites; a fusion peptide (FP) ; internal fusion peptide (IFP) ; heptad repeat 1/2 (HR1/2) , and the transmembrane domain (TM) . Exemplary sources of the sequence can be found at https: //www. ncbi. nlm. nih. gov/nuccore/MN908947.3, https: //www. ncbi. nlm. nih. gov/nuccore/MN908947, ncbi. nim. nih. gov/nuccore/MN908947.2. Additoinal sequences can be found at ncbi. nlm. nih. gov/genbank/sars-cov-2-seqs/, including the pneumonia virus isolate Wuhan-Hu-1, complete genome.
In some embodiments, the protomers of the pre fusion-stabilized SARS-CoV-2 S ectodomain trimer can have a C-terminal residue (which can be linked to a trimerization domain, or a transmembrane domain, for example) of the C-terminal residue of the NTD, the RBD, S1 (at either the S1/S2 site 1, or S1/S2 site 2) , FP, IFP, HR1, HR2, or the ectodomain. The position numbering of the S protein may vary between SARS-CoV stains, but the sequences can be aligned to determine relevant structural domains and cleavage sites. It will be appreciated that a few residues (such as up to 10) on the N and C-terminal ends of any of the ectodomain fragment can be removed or modified in the disclosed immunogens without decreasing the utility of the S ectodomain trimer as an immunogen.
In some embodiments, the recombinant polypeptide is or comprises an NTD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an RBD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an NTD peptide and an RBD peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an S1 domain peptide of SARS-CoV or SARS-CoV-2 S protein. In some embodiments, the recombinant polypeptide is or comprises an S2 domain peptide of SARS-CoV or SARS-CoV-2 S protein.
An exemplary SARS-CoV-1 S recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 56 (1491 aa) :
Figure PCTCN2021087066-appb-000031
Figure PCTCN2021087066-appb-000032
An exemplary SARS-CoV-1 S recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 57 (1504 aa) :
Figure PCTCN2021087066-appb-000033
Figure PCTCN2021087066-appb-000034
An exemplary SARS-CoV-2 S recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 58 (1509 aa) :
Figure PCTCN2021087066-appb-000035
Figure PCTCN2021087066-appb-000036
An exemplary SARS-CoV-2 S recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 59 (1522 aa) :
Figure PCTCN2021087066-appb-000037
Figure PCTCN2021087066-appb-000038
An exemplary SARS-CoV-2 S2 (cleavage at S1/S2, site 1) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 60:
Figure PCTCN2021087066-appb-000039
Figure PCTCN2021087066-appb-000040
An exemplary SARS-CoV-2 S2 (cleavage at S1/S2, site 2) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 61:
Figure PCTCN2021087066-appb-000041
An exemplary SARS-CoV-2 S2 (cleavage at S2') recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 62:
Figure PCTCN2021087066-appb-000042
Figure PCTCN2021087066-appb-000043
An exemplary SARS-CoV-2 S (986K/987V->986P/987P) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 63 (1509 aa) :
Figure PCTCN2021087066-appb-000044
Figure PCTCN2021087066-appb-000045
An exemplary SARS-CoV-2 S (986K/987V->986P/987P) recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 64 (1522 aa) :
Figure PCTCN2021087066-appb-000046
Figure PCTCN2021087066-appb-000047
An exemplary SARS-CoV-2 S (685R->685A, 986K/987V->986P/987P) recombinant polypeptide without a signal peptide is provided in SEQ ID NO: 65 (1509 aa) :
Figure PCTCN2021087066-appb-000048
Figure PCTCN2021087066-appb-000049
An exemplary SARS-CoV-2 S (685R->685A, 986K/987V->986P/987P) recombinant polypeptide with a signal peptide is provided in SEQ ID NO: 66 (1522 aa) :
Figure PCTCN2021087066-appb-000050
Figure PCTCN2021087066-appb-000051
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 37. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 37.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 38. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 38.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 39. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 39.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 40. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 40.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 41. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,  89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 41.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 42. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 42.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 43. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 43.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 44. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 44.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 45. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 45.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 46. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 46.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 47. In some embodiments, the recombinant polypeptide is an  amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 47.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 48. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 48.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 49. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 49.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 50. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 50.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 51. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 51.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 56. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 56.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 57. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 57.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 58. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 58.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 59. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 59.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 60. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 60.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 61. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 61.
In some embodiments the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 62. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,  89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 62.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 63. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 63.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 64. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 64.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 65. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 65.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 66. In some embodiments, the recombinant polypeptide is an amino acid sequence having at least or about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to sequence of SEQ ID NO: 66.
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 75:
Figure PCTCN2021087066-appb-000052
Figure PCTCN2021087066-appb-000053
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 90:
Figure PCTCN2021087066-appb-000054
Figure PCTCN2021087066-appb-000055
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 76:
Figure PCTCN2021087066-appb-000056
Figure PCTCN2021087066-appb-000057
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 77:
Figure PCTCN2021087066-appb-000058
Figure PCTCN2021087066-appb-000059
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 91:
Figure PCTCN2021087066-appb-000060
Figure PCTCN2021087066-appb-000061
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 78:
Figure PCTCN2021087066-appb-000062
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 79:
Figure PCTCN2021087066-appb-000063
Figure PCTCN2021087066-appb-000064
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 92:
Figure PCTCN2021087066-appb-000065
Figure PCTCN2021087066-appb-000066
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 80:
Figure PCTCN2021087066-appb-000067
Figure PCTCN2021087066-appb-000068
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 81:
Figure PCTCN2021087066-appb-000069
Figure PCTCN2021087066-appb-000070
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 93:
Figure PCTCN2021087066-appb-000071
Figure PCTCN2021087066-appb-000072
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 82:
Figure PCTCN2021087066-appb-000073
Figure PCTCN2021087066-appb-000074
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 83:
Figure PCTCN2021087066-appb-000075
Figure PCTCN2021087066-appb-000076
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 94:
Figure PCTCN2021087066-appb-000077
Figure PCTCN2021087066-appb-000078
In some embodiments, the recombinant polypeptide is or comprises the amino acid sequence set forth by SEQ ID NO: 84:
Figure PCTCN2021087066-appb-000079
Figure PCTCN2021087066-appb-000080
As indicated above, in some embodiments, the recombinant polypeptides provided herein associate not only to form trimers, but can also aggregate or be aggregated to generate proteins comprising a plurality of recombinant polypeptides. In some embodiments, the proteins formed have macrostructures. In some cases, the macrostructure may confer structural stability of the coronavirus viral antigen or immunogen recombinant polypeptides, which in turn can afford access to potentially antigenic sites capable of promoting an immune response.
In some embodiments, the trimerized recombinant polypeptides aggregate to form a protein containing a plurality of trimerized recombinant polypeptides. In some embodiments, the plurality of trimerized recombinant polypeptides forms a protein having a macrostructure.
In some embodiments, the proteins described herein comprising a plurality of recombinant polypeptides are an immunogen. In some embodiments, the proteins described herein comprising a plurality of recombinant polypeptides are comprised in a nanoparticle. For example, in some embodiments, the proteins are linked directly to a nanoparticle, e.g., protein nanoparticle. In some embodiments, the proteins are linked indirectly to a nanoparticle.. In some embodiments, the proteins described herein comprising a plurality of recombinant polypeptides are comprised in virus-like particle (VLP) .
2. POL YNUCLEOTIDES AND VECTORS
Also provided are polynucleotides (nucleic acid molecules) encoding the coronavirus antigens or immunogens and recombinant polypeptides provided herein, and vectors for genetically  engineering cells to express such coronavirus antigens or immunogens and recombinant polypeptides.
In some embodiments, provided are polynucleotides that encode recombinant polypeptides provided herein. In some aspects, the polynucleotide contains a single nucleic acid sequence, such as a nucleic acid sequence encoding a recombinant polypeptide. In other instances, the polynucleotide contains a first nucleic acid sequence encoding a recombinant polypeptide a particular coronavirus viral antigen or immunogen and a second nucleic acid sequence encoding a recombinant polypeptide comprising a different coronavirus viral antigen or immunogen.
In some embodiments, the polynucleotide encoding the recombinant polypeptide contains at least one promoter that is operatively linked to control expression of the recombinant polypeptide. In some embodiments, the polynucleotide contains two, three, or more promoters operatively linked to control expression of the recombinant polypeptide.
In some embodiments, for example when the polynucleotide contains two or more nucleic acid coding sequences, such as a sequences encoding recombinant polypeptides comprising different coronavirus viral antigens or immunogens, at least one promoter is operatively linked to control expression of the two or more nucleic acid sequences. In some embodiments, the polynucleotide contains two, three, or more promoters operatively linked to control expression of the recombinant polypeptides.
In some embodiments, expression of the recombinant polypeptide (s) is inducible or conditional. Thus, in some aspects, the polynucleotide encoding the recombinant polypeptide (s) contains a conditional promoter, enhancer, or transactivator. In some such aspects, the conditional promoter, enhancer, or transactivator is an inducible promoter, enhancer, or transactivator or a repressible promoter, enhancer, or transactivator. For example, in some embodiments, an inducible or conditional promoter can be used to restrict expression of the recombinant polypeptides to a specific microenvironment. In some embodiments, expression driven by the inducible or conditional promoter is regulated by exposure to an exogenous agent, such as heat, radiation, or drug.
In cases where the polynucleotide contains more than one nucleic acid sequence encoding a recombinant polypeptide, the polynucleotide may further include a nucleic acid sequence encoding a peptide between the one or more nucleic acid sequences. In some cases, the  nucleic acid positioned between the nucleic acid sequences encodes a peptide that separates the translation products of the nucleic acid sequences during or after translation. In some embodiments, the peptide contains an internal ribosome entry site (IRES) , a self-cleaving peptide, or a peptide that causes ribosome skipping, such as a T2A peptide.
In some embodiments, the polynucleotide encoding the recombinant polypeptide (s) is introduced into a composition containing cultured cells (e.g., host cells) , such as by retroviral transduction, transfection, or transformation. In some embodiments, this can allow for expression (e.g., production) of the recombinant polypeptides. In some embodiments, the expressed recombinant polypeptides are purified.
In some embodiments, the polynucleotide (nucleic acid molecule) provided herein encodes an coronavirus viral antigen or immunogen as described herein. In some embodiments, the polynucleotide (nucleic acid molecule) provided herein encodes a recombinant polypeptide comprising coronavirus viral antigen or immunogen, e.g., coronavirus S protein peptide, as described herein.
Also provided are vectors or constructs containing nucleic acid molecules as described herein. In some embodiments, the vectors or constructs contain one or more promoters operatively linked to the nucleic acid molecule encoding the recombinant polypeptide to drive expression thereof. In some embodiments, the promoter is operatively linked to one or more than one nucleic acid molecule, e.g., nucleic acid molecule encoding recombinant polypeptides containing different coronavirus viral antigens or immunogens.
In some embodiments, the vector is a viral vector. In some embodiments the viral vector is a retroviral vector. In some embodiments, the retroviral vector is a lentiviral vector. In some embodiments, the retroviral vector is a gammaretroviral vector.
In some embodiments, the vector or construct includes a single promoter that drives the expression of one or more nucleic acid molecules of the polynucleotide. In some embodiments, such promoters can be multicistronic (bicistronic or tricistronic, see e.g., U.S. Patent No. 6,060,273) . For example, in some embodiments, transcription units can be engineered as a bicistronic unit containing an IRES (internal ribosome entry site) , which allows coexpression of gene products (e.g., encoding different recombinant polypeptides) by a message from a single promoter. In some  embodiments, the vectors provided herein are bicistronic, allowing the vector to contain and express two nucleic acid sequences. In some embodiments, the vectors provided herein are tricistronic, allowing the vector to contain and express three nucleic acid sequences.
In some embodiments, a single promoter directs expression of an RNA that contains, in a single open reading frame (ORF) , two or three genes (e.g. encoding the chimeric signaling receptor and encoding a recombinant receptor) separated from one another by sequences encoding a self-cleavage peptide (e.g., 2A sequences) or a protease recognition site (e.g., furin) . The ORF thus encodes a single polypeptide, which, either during (in the case of 2A) or after translation, is processed into the individual proteins. In some cases, the peptide, such as T2A, can cause the ribosome to skip (ribosome skipping) synthesis of a peptide bond at the C-terminus of a 2A element, leading to separation between the end of the 2A sequence and the next peptide downstream (see, for example, de Felipe. Genetic Vaccines and Ther. 2: 13 (2004) and deFelipe et al. Traffic 5: 616-626 (2004) ) . Many 2A elements are known in the art. Examples of 2A sequences that can be used in the methods and nucleic acids disclosed herein include, without limitation, 2A sequences from the foot-and-mouth disease virus (F2A) , equine rhinitis A virus (E2A) , Thosea asigna virus (T2A) , and porcine teschovirus-1 (P2A) as described in U.S. Patent Publication No. 20070116690.
In some embodiments, the vector is comprised in a virus. In some embodiments, the virus is a pseudovirus. In some embodiments, the virus is a viral-like particle. In some embodiments, the vector is comprised in a cell. In some embodiments, the virus or cell in which the vector is comprised contains a recombinant genome.
III. Immunogenic Compositions and Formulations
Immunogenic compositions comprising a disclosed immunogen (e.g., a disclosed recombinant coronavirus S antigen or nucleic acid molecule encoding a protomer of disclosed recombinant coronavirus S antigen) and a pharmaceutically acceptable carrier are also provided. In some embodiments, the immunogenic composition comprises trimerized recombinant polypeptides provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a protein comprising a plurality of trimerized recombinant polypeptides provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition a protein nanoparticle provided herein, and optionally  a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a VLP as provided herein, and optionally a pharmaceutically acceptable cartier. In some embodiments, the immunogenic composition comprises an isolated nucleic acid provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a vector as provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a virus as provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a pseudovirus provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition comprises a cell as provided herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the immunogenic composition, such as described herein, is a vaccine. In some embodiments, the vaccine is a prophylactic vaccine. In some embodiments, the vaccine is a therapeutic vaccine. In some embodiments, the vaccine is a prophylactic vaccine and a therapeutic vaccine. Such pharmaceutical compositions can be administered to subjects by a variety of administration modes known to the person of ordinary skill in the art, for example, intramuscular, intradermal, subcutaneous, intravenous, intra-arterial, intra-articular, intraperitoneal, intranasal, sublingual, tonsillar, oropharyngeal, or other parenteral and mucosal routes. In several embodiments, pharmaceutical compositions including one or more of the disclosed immunogens are immunogenic compositions. Actual methods for preparing administrable compositions will be known or apparent to those skilled in the art and are described in more detail in such publications as Remingtons Pharmaceutical Sciences, 19th Ed., Mack Publishing Company, Easton, Pa., 1995.
Thus, an immunogen, e.g., recombinant coronavirus S antigen, e.g., trimer, protein, described herein can be formulated with pharmaceutically acceptable carriers to help retain biological activity while also promoting increased stability during storage within an acceptable temperature range. Potential carriers include, but are not limited to, physiologically balanced culture medium, phosphate buffer saline solution, water, emulsions (e.g., oil/water or water/oil emulsions) , various types of wetting agents, cryoprotective additives or stabilizers such as proteins, peptides or hydrolysates (e.g., albumin, gelatin) , sugars (e.g., sucrose, lactose, sorbitol) , amino acids (e.g., sodium glutamate) , or other protective agents. The resulting aqueous solutions may be packaged for  use as is or lyophilized. Lyophilized preparations are combined with a sterile solution prior to administration for either single or multiple dosing.
Formulated compositions, especially liquid formulations, may contain a bacteriostat to prevent or minimize degradation during storage, including but not limited to effective concentrations (usually 1%w/v) of benzyl alcohol, phenol, m-cresol, chlorobutanol, methylparaben, and/or propylparaben. A bacteriostat may be contraindicated for some patients; therefore, a lyophilized formulation may be reconstituted in a solution either containing or not containing such a component.
The immunogenic compositions of the disclosure can contain as pharmaceutically acceptable vehicles substances as required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents and the like, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, and triethanolamine oleate. The immunogenic composition may optionally include an adjuvant to enhance an immune response of the host. Suitable adjuvants are, for example, toil-like receptor agonists, alum, AlPO 4, alhydrogel, Lipid-A and derivatives or variants thereof, oil-emulsions, saponins, neutral liposomes, liposomes containing the vaccine and cytokines, non-ionic block copolymers, and chemokines. Non-ionic block polymers containing polyoxyethylene (POE) and polyxylpropylene (POP) , such as POE-POP-POE block copolymers, MPL TM (3-O-deacylated monophosphoryl lipid A; Corixa, Hamilton, Ind. ) and IL-12 (Genetics Institute, Cambridge, Mass. ) , among many other suitable adjuvants well known in the art, may be used as an adjuvant (Newman et al., 1998, Critical Reviews in Therapeutic Drug Carrier Systems 15: 89-142) . These adjuvants have the advantage in that they help to stimulate the immune system in a non-specific way, thus enhancing the immune response to a pharmaceutical product. In some embodiments, the immunogenic compositions of the disclosure may include or be administered with more than one adjuvant. In some embodiments, the immunogenic compositions of the disclosure may include or be administered with two adjuvants. In some embodiments, the immunogenic compositions of the disclosure may include or be administered with a plurality of adjuvants. For example, in some cases, a vaccine, e.g., comprising an immunogenic composition provided herein, may include or be administered in combination with a plurality of adjuvants.
In some instances it may be desirable to combine a disclosed immunogen, with other pharmaceutical products (e.g., vaccines) which induce protective responses to other agents. For example, a composition including a recombinant coronavirus S antigen as described herein, e.g., trimer or protein, can be can be administered simultaneously (typically separately) or sequentially with other vaccines recommended by the Advisory Committee on Immunization Practices (ACIP; cdc. gov/vaccines/acip/index. html) for the targeted age group (e.g., infants from approximately one to six months of age) , such as an influenza vaccine or a varicella zoster vaccine. As such, a disclosed immunogen including a recombinant coronavirus S antigen described herein may be administered simultaneously or sequentially with vaccines against, for example, hepatitis B (HepB) , diphtheria, tetanus and pertussis (DTaP) , pneumococcal bacteria (PCV) , Haemophilus influenzae type b (Hib) , polio, influenza and rotavirus.
Multivalent or combination vaccines provide protection against multiple pathogens. In some aspects, multivalent vaccines can protect against multiple strains of the same pathogen. In some aspects, multivalent vaccines protect against multiple pathogens, such as the combination vaccine Tdap, which protects against strains of tentus, pertussis, and diphtheria. Multivalent vaccines are highly desirable to minimize the number of immunizations required to confer protection against multiple pathogens or pathogenic strains, to reduce administration costs, and to increase coverage rates. This can be particularly useful, for example, when vaccinating babies or children.
In some embodiments, the vaccine, e.g., comprising an immunogenic composition described herein, is a multivalent vaccine. In some embodiments, the antigenic material for incorporation into the multivalent vaccine compositions of the invention is derived from coronavirus strains or types, for examples as described herein (see, e.g., Section I) . Antigens for incorporation into the multivalent vaccine compositions of the invention may be derived from one strain of coronavirus or multiple strains, for example, between two and five strains, in order to provide a broader spectrum of protection. In one embodiment, antigens for incorporation into the multivalent vaccine compositions of the invention are derived from multiple strains of coronavirus. Other useful antigens include live, attenuated and inactivated viruses such as inactivated polio virus (Jiang et al., J. Biol. Stand., (1986) 14: 103-9) , attenuated strains of Hepatitis A virus (Bradley et al.,  J. Med. Virol., (1984) 14: 373-86) , attenuated measles virus (James et al., N. Engl. J. Med., (1995) 332: 1262-6) , and epitopes of pertussis virus (for example, ACEL-IMUNErM acellular DTP, Wyeth-Lederle Vaccines and Pediatrics) .
In some aspects, the vaccine provided herein is a universal vaccine. In some embodiments, a universal vaccine is a vaccine which protects against multiple strains of the same virus, such as multiple strains of coronavirus. Development of an effective universal coronavirus vaccine would reduce cost and labor, e.g., with seasonal vaccine formulation, and allow for more robust pandemic preparedness.
In some aspects, a universal vaccine is one comprised of multiple epitopes derived from distinct viral strains. In some aspects, a universal vaccine is comprised of a single epitope that is conserved across distinct viral strains. For example, a universal vaccine can be based on the relatively conserved domain (s) of the S protein,
In some embodiments, the composition can be provided as a sterile composition. The pharmaceutical composition typically contains an effective amount of a disclosed immunogen and can be prepared by conventional techniques. Typically, the amount of immunogen in each dose of the immunogenic composition is selected as an amount which induces an immune response without significant, adverse side effects. In some embodiments, the composition can be provided in unit dosage form for use to induce an immune response in a subject. A unit dosage form contains a suitable single preselected dosage for administration to a subject, or suitable marked or measured multiples of two or more preselected unit dosages, and/or a metering mechanism for administering the unit dose or multiples thereof. In other embodiments, the composition further includes an adjuvant.
IV. Methods of Inducing an Immune Response
The disclosed immunogens (e.g., recombinant coronavirus S antigen, e.g., an S-Trimer or an S protein described herein, a nucleic acid molecule (such as an RNA molecule) or vector encoding a protomer of a disclosed recombinant coronavirus S antigen, or a protein nanoparticle or virus like particle comprising a disclosed recombinant coronavirus S antigen) can be administered to a subject to induce an immune response to the corresponding coronavirus S antigen in the subject. In a particular example, the subject is a human. The immune response can be a protective immune  response, for example a response that inhibits subsequent infection with the corresponding coronavirus. Elicitation of the immune response can also be used to treat or inhibit infection and illnesses associated with the corresponding coronavirus.
A subject can be selected for treatment that has, or is at risk for developing infection with the coronavirus, for example because of exposure or the possibility of exposure to the coronavirus. Following administration of a disclosed immunogen, the subject can be monitored for infection or symptoms associated with coronavirus, or both.
Typical subjects intended for treatment with the therapeutics and methods of the present disclosure include humans, as well as non-human primates and other animals. To identify subjects for prophylaxis or treatment according to the methods of the disclosure, accepted screening methods are employed to determine risk factors associated with a targeted or suspected disease or condition, or to determine the status of an existing disease or condition in a subject. These screening methods include, for example, conventional work-ups to determine environmental, familial, occupational, and other such risk factors that may be associated with the targeted or suspected disease or condition, as well as diagnostic methods, such as various ELISA and other immunoassay methods to detect and/or characterize coronavirus infection. These and other routine methods allow the clinician to select patients in need of therapy using the methods and pharmaceutical compositions of the disclosure. In accordance with these methods and principles, a composition can be administered according to the teachings herein, or other conventional methods, as an independent prophylaxis or treatment program, or as a follow-up, adjunct or coordinate treatment regimen to other treatments.
The administration of a disclosed immunogen, e.g., coronavirus S antigen, e.g., trimer, protein, can be for prophylactic or therapeutic purpose. When provided prophylactically, the disclosed therapeutic agents are provided in advance of any symptom, for example, in advance of infection. The prophylactic administration of the disclosed therapeutic agents serves to prevent or ameliorate any subsequent infection. When provided therapeutically, the disclosed therapeutic agents are provided at or after the onset of a symptom of disease or infection, for example, after development of a symptom of infection with coronavirus corresponding to the coronavirus S antigen, or after diagnosis with the coronavirus infection. The therapeutic agents can thus be provided prior to the anticipated exposure to coronavirus so as to attenuate the anticipated severity,  duration or extent of an infection and/or associated disease symptoms, after exposure or suspected exposure to the virus, or after the actual initiation of an infection.
The immunogens described herein, and immunogenic compositions thereof, are provided to a subject in an amount effective to induce or enhance an immune response against the coronavirus S antigen in the subject, preferably a human. The actual dosage of disclosed immunogen will vary according to factors such as the disease indication and particular status of the subject (for example, the subject's age, size, fitness, extent of symptoms, susceptibility factors, and the like) , time and route of administration, other drugs or treatments being administered concurrently, as well as the specific pharmacology of the composition for eliciting the desired activity or biological response in the subject. Dosage regimens can be adjusted to provide an optimum prophylactic or therapeutic response.
An immunogenic composition including one or more of the disclosed immunogens can be used in coordinate (or prime-boost) vaccination protocols or combinatorial formulations. In certain embodiments, novel combinatorial immunogenic compositions and coordinate immunization protocols employ separate immunogens or formulations, each directed toward eliciting an anti-viral immune response, such as an immune response to coronavirus S antigen. Separate immunogenic compositions that elicit the anti-viral immune response can be combined in a polyvalent immunogenic composition administered to a subject in a single immunization step, or they can be administered separately (in monovalent immunogenic compositions) in a coordinate (or prime-boost) immunization protocol.
There can be several boosts, and each boost can be a different disclosed immunogen. In some examples that the boost may be the same immunogen as another boost, or the prime. The prime and boost can be administered as a single dose or multiple doses, for example two doses, three doses, four doses, five doses, six doses or more can be administered to a subject over days, weeks or months. Multiple boosts can also be given, such one to five (e.g., 1, 2, 3, 4 or 5 boosts) , or more. Different dosages can be used in a series of sequential immunizations. For example a relatively large dose in a primary immunization and then a boost with relatively smaller doses.
In some embodiments, the boost can be administered about two, about three to eight, or about four, weeks following the prime, or about several months after the prime. In some  embodiments, the boost can be administered about 5, about 6, about 7, about 8, about 10, about 12, about 18, about 24, months after the prime, or more or less time after the prime. Periodic additional boosts can also be used at appropriate time points to enhance the subject's “immune memory. ” The adequacy of the vaccination parameters chosen, e.g., formulation, dose, regimen and the like, can be determined by taking aliquots of serum from the subject and assaying antibody titers during the course of the immunization program. In addition, the clinical condition of the subject can be monitored for the desired effect, e.g., prevention of infection or improvement in disease state (e.g., reduction in viral load) . If such monitoring indicates that vaccination is sub-optimal, the subject can be boosted with an additional dose of immunogenic composition, and the vaccination parameters can be modified in a fashion expected to potentiate the immune response.
In some embodiments, the prime-boost method can include DNA-primer and protein-boost vaccination protocol to a subject. The method can include two or more administrations of the nucleic acid molecule or the protein.
For protein therapeutics, typically, each human dose will comprise 1-1000 μg of protein, such as from about 1 μg to about 100 μg, for example, from about 1 μg to about 50 μg, such as about 1 μg, about 2 μg, about 5 μg, about 10 μg, about 15 μg, about 20 μg, about 25 μg, about 30 μg, about 40 μg, or about 50 μg.
The amount utilized in an immunogenic composition is selected based on the subject population (e.g., infant or elderly) . An optimal amount for a particular composition can be ascertained by standard studies involving observation of antibody titers and other responses in subjects. It is understood that a therapeutically effective amount of a disclosed immunogen, such as a disclosed recombinant coronavirus S antigen, e.g., trimer, protein, , viral vector, or nucleic acid molecule in a immunogenic composition, can include an amount that is ineffective at eliciting an immune response by administration of a single dose, but that is effective upon administration of multiple dosages, for example in a prime-boost administration protocol.
Upon administration of a disclosed immunogen of this disclosure, the immune system of the subject typically responds to the immunogenic composition by producing antibodies specific for the coronavirus S protein peptide included in the immunogen. Such a response signifies that an immunologically effective dose was delivered to the subject.
In some embodiments, the antibody response of a subject will be determined in the context of evaluating effective dosages/immunization protocols. In most instances it will be sufficient to assess the antibody titer in serum or plasma obtained from the subject. Decisions as to whether to administer booster inoculations and/or to change the amount of the therapeutic agent administered to the individual can be at least partially based on the antibody titer level. The antibody titer level can be based on, for example, an immunobinding assay which measures the concentration of antibodies in the serum which bind to an antigen including, for example, the recombinant coronavirus S antigen, e.g., an S-Trimer.
The coronavirus infection does not need to be completely eliminated or reduced or prevented for the methods to be effective. For example, elicitation of an immune response to a coronavirus with one or more of the disclosed immunogens can reduce or inhibit infection with the coronavirus by a desired amount, for example, by at least 10%, at least 20%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or even at least 100% (elimination or prevention of detectable infected cells) , as compared to infection with the coronavirus in the absence of the immunogen. In additional examples, coronavirus replication can be reduced or inhibited by the disclosed methods. Coronavirus replication does not need to be completely eliminated for the method to be effective. For example, the immune response elicited using one or more of the disclosed immunogens can reduce replication of the corresponding coronavirus by a desired amount, for example, by at least 10%, at least 20%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or even at least 100% (elimination or prevention of detectable replication of the coronavirus) , as compared to replication of the coronavirus in the absence of the immune response.
In some embodiments, the disclosed immunogen is administered to the subject simultaneously with the administration of the adjuvant. In other embodiments, the disclosed immunogen is administered to the subject after the administration of the adjuvant and within a sufficient amount of time to induce the immune response.
One approach to administration of nucleic acids is direct immunization with plasmid DNA, such as with a mammalian expression plasmid. Immunization by nucleic acid constructs is well known in the art and taught, for example, in U.S. Pat. No. 5,643,578 (which describes methods  of immunizing vertebrates by introducing DNA encoding a desired antigen to elicit a cell-mediated or a humoral response) , and U.S. Pat. Nos. 5,593,972 and 5,817,637 (which describe operably linking a nucleic acid sequence encoding an antigen to regulatory sequences enabling expression) . U.S. Pat. No. 5,880,103 describes several methods of delivery of nucleic acids encoding immunogenic peptides or other antigens to an organism. The methods include liposomal delivery of the nucleic acids (or of the synthetic peptides themselves) , and immune-stimulating constructs, or ISCOMS TM, negatively charged cage-like structures of 30-40 nm in size formed spontaneously on mixing cholesterol and Quil A TM (saponin) . Protective immunity has been generated in a variety of experimental models of infection, including toxoplasmosis and Epstein-Barr virus-induced tumors, using ISCOMS TM as the delivery vehicle for antigens (Mowat and Donachie, Immunol. Today 12: 383, 1991) . Doses of antigen as low as 1 μg encapsulated in ISCOMS TM have been found to produce Class I mediated CTL responses (Takahashi et al., Nature 344: 873, 1990) .
In some embodiments, a plasmid DNA vaccine is used to express a disclosed immunogen in a subject. For example, a nucleic acid molecule encoding a disclosed immunogen can be administered to a subject to induce an immune response to the coronavirus S antigen. In some embodiments, the nucleic acid molecule can be included on a plasmid vector for DNA immunization, such as the pVRC8400 vector (described in Barouch et al., J. Virol, 79, 8828-8834, 2005, which is incorporated by reference herein) .
In another approach to using nucleic acids for immunization, a disclosed recombinant coronavirus S antigen, e.g., trimer, protein, can be expressed by attenuated viral hosts or vectors or bacterial vectors. Recombinant vaccinia virus, adeno-associated virus (AAV) , herpes virus, retrovirus, cytogmeglo virus or other viral vectors can be used to express the peptide or protein, thereby eliciting a CTL response. For example, vaccinia vectors and methods useful in immunization protocols are described in U.S. Pat. No. 4,722,848. BCG (Bacillus Calmette Guerin) provides another vector for expression of the peptides (see Stover, Nature 351: 456-460, 1991) .
In one embodiment, a nucleic acid encoding a disclosed recombinant coronavirus S antigen is introduced directly into cells. For example, the nucleic acid can be loaded onto gold microspheres by standard methods and introduced into the skin by a device such as Bio-Rad′s HELIOS TM Gene Gun. The nucleic acids can be “naked, ” consisting of plasmids under control of a  strong promoter. Typically, the DNA is injected into muscle, although it can also be injected directly into other sites. Dosages for injection are usually around 0.5 μg/kg to about 50 mg/kg, and typically are about 0.005 mg/kg to about 5 mg/kg (see, e.g., U.S. Pat. No. 5,589,466) .
For example, the nucleic acid can be loaded onto gold microspheres by standard methods and introduced into the skin by a device such as Bio-Rad's HELIOS TM Gene Gun. The nucleic acids can be “naked, ” consisting of plasmids under control of a strong promoter. Typically, the DNA is injected into muscle, although it can also be injected directly into other sites. Dosages for injection are usually around 0.5 μg/kg to about 50 mg/kg, and typically are about 0.005 mg/kg to about 5 mg/kg (see, e.g., U.S. Pat. No. 5,589,466) .
In another embodiment, an mRNA-based immunization protocol can be used to deliver a nucleic acid encoding a disclosed recombinant coronavirus S antigen directly into cells. In some embodiments, nucleic acid-based vaccines based on mRNA may provide a potent altemative to the previously mentioned approaches. mRNA vaccines preclude safety concerns about DNA integration into the host genome and can be directly translated in the host cell cytoplasm. Moreover, the simple cell-free, in vitro synthesis of RNA avoids the manufacturing complications associated with viral vectors. Two exemplary forms of RNA-based vaccination that can be used to deliver a nucleic acid encoding a disclosed recombinant coronavirus S antigen include conventional non-amplifying mRNA immunization (see, e.g., Petsch et al., “Protective efficacy of in vitro synthesized, specific mRNA vaccines against influenza A virus infection, ” Nature biotechnology, 30 (12) : 1210-6, 2012) and self-amplifying mRNA immunization (see, e.g., Geall et al., “Nonviral delivery of self-amplifying RNA vaccines, ” PNAS, 109 (36) : 14604-14609, 2012; Magini et al., “Self-Amplifying mRNA Vaccines Expressing Multiple Conserved Influenza Antigens Confer Protection against Homologous and Heterosubtypic Viral Challenge, ” PLoS One, 11 (8) : e0161193, 2016; and Brito et al., “Self-amplifying mRNA vaccines, ” Adv Genet., 89: 179-233, 2015) .
In some embodiments, administration of a therapeutically effective amount of one or more of the disclosed immunogens to a subject induces a neutralizing immune response in the subject. To assess neutralization activity, following immunization of a subject, serum can be collected from the subject at appropriate time points, frozen, and stored for neutralization testing. Methods to assay for neutralization activity are known to the person of ordinary skill in the art and  are further described herein, and include, but are not limited to, plaque reduction neutralization (PRNT) assays, microneutralization assays, flow cytometry based assays, single-cycle infection assays. In some embodiments, the serum neutralization activity can be assayed using a panel of coronavirus pseudoviruses.
In some embodiments, administration of a therapeutically effective amount of one or more of the disclosed immunogens to a subject induces a neutralizing immune response in the subject. To assess neutralization activity, following immunization of a subject, serum can be collected from the subject at appropriate time points, frozen, and stored for neutralization testing. Methods to assay for neutralization activity are known to the person of ordinary skill in the art and are further described herein, and include, but are not limited to, plaque reduction neutralization (PRNT) assays, microneutralization assays, flow cytometry based assays, single-cycle infection assays. In some embodiments, the serum neutralization activity can be assayed using a panel of coronavirus pseudoviruses.
V. ARTICLES OF MANUFACTURE OR KITS
Also provided are articles of manufacture or kits containing the provided recombinant polypeptide, proteins, and immunogenic compositions. The articles of manufacture may include a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, test tubes, IV solution bags, etc. The containers may be formed from a variety of materials such as glass or plastic. In some embodiments, the container has a sterile access port. Exemplary containers include an intravenous solution bags, vials, including those with stoppers pierceable by a needle for injection. The article of manufacture or kit may further include a package insert indicating that the compositions can be used to treat a particular condition such as a condition described herein (e.g., coronavirus infection) . Alternatively, or additionally, the article of manufacture or kit may further include another or the same container comprising a pharmaceutically-acceptable buffer. It may further include other materials such as other buffers, diluents, filters, needles, and/or syringes.
The label or package insert may indicate that the composition is used for treating an coronavirus infection in an individual. The label or a package insert, which is on or associated with the container, may indicate directions for reconstitution and/or use of the formulation. The label or  package insert may further indicate that the formulation is useful or intended for subcutaneous, intravenous, or other modes of administration for treating or preventing a coronavirus infection in an individual.
The container in some embodiments holds a composition which is by itself or combined with another composition effective for treating, preventing and/or diagnosing the condition. The article of manufacture or kit may include (a) a first container with a composition contained therein (i.e., first medicament) , wherein the composition includes the immunogenic composition or protein or recombinant polypeptide thereof; and (b) a second container with a composition contained therein (i.e., second medicament) , wherein the composition includes a further agent, such as an adjuvant or otherwise therapeutic agent, and which article or kit further comprises instructions on the label or package insert for treating the subject with the second medicament, in an effective amount.
Definitions
Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art.
The terms “polypeptide” and “protein” are used interchangeably to refer to a polymer of amino acid residues, and are not limited to a minimum length. Polypeptides, including the provided receptors and other polypeptides, e.g., linkers or peptides, may include amino acid residues including natural and/or non-natural amino acid residues. The terms also include post-expression modifications of the polypeptide, for example, glycosylation, sialylation, acetylation, and phosphorylation. In some aspects, the polypeptides may contain modifications with respect to a native or natural sequence, as long as the protein maintains the desired activity. These modifications may be deliberate, as through site-directed mutagenesis, or may be accidental, such as through mutations of hosts which produce the proteins or errors due to PCR amplification.
As used herein, a “subject” is a mammal, such as a human or other animal, and typically is human. In some embodiments, the subject, e.g., patient, to whom the agent or agents, cells, cell populations, or compositions are administered, is a mammal, typically a primate, such as a human. In some embodiments, the primate is a monkey or an ape. The subject can be male or female and can be any suitable age, including infant, juvenile, adolescent, adult, and geriatric subjects. In some embodiments, the subject is a non-primate mammal, such as a rodent.
As used herein, “treatment” (and grammatical variations thereof such as “treat” or “treating” ) refers to complete or partial amelioration or reduction of a disease or condition or disorder, or a symptom, adverse effect or outcome, or phenotype associated therewith. Desirable effects of treatment include, but are not limited to, preventing occurrence or recurrence of disease, alleviation of symptoms, diminishment of any direct or indirect pathological consequences of the disease, preventing metastasis, decreasing the rate of disease progression, amelioration or palliation of the disease state, and remission or improved prognosis. The terms do not imply complete curing of a disease or complete elimination of any symptom or effect (s) on all symptoms or outcomes.
As used herein, “delaying development of a disease” means to defer, hinder, slow, retard, stabilize, suppress and/or postpone development of the disease (such as cancer) . This delay can be of varying lengths of time, depending on the history of the disease and/or individual being treated. In some embodiments, sufficient or significant delay can, in effect, encompass prevention, in that the individual does not develop the disease. For example, a late stage cancer, such as development of metastasis, may be delayed.
“Preventing, ” as used herein, includes providing prophylaxis with respect to the occurrence or recurrence of a disease in a subject that may be predisposed to the disease but has not yet been diagnosed with the disease. In some embodiments, the provided cells and compositions are used to delay development of a disease or to slow the progression of a disease.
As used herein, to “suppress” a function or activity is to reduce the function or activity when compared to otherwise same conditions except for a condition or parameter of interest, or alternatively, as compared to another condition. For example, cells that suppress tumor growth reduce the rate of growth of the tumor compared to the rate of growth of the tumor in the absence of the cells.
An “effective amount” of an agent, e.g., a pharmaceutical formulation, cells, or composition, in the context of administration, refers to an amount effective, at dosages/amounts and for periods of time necessary, to achieve a desired result, such as a therapeutic or prophylactic result.
A “therapeutically effective amount” of an agent, e.g., a pharmaceutical formulation or cells, refers to an amount effective, at dosages and for periods of time necessary, to achieve a desired therapeutic result, such as for treatment of a disease, condition, or disorder, and/or pharmacokinetic or pharmacodynamic effect of the treatment. The therapeutically effective amount may vary according to factors such as the disease state, age, sex, and weight of the subject, and the populations of cells administered. In some embodiments, the provided methods involve administering the cells and/or compositions at effective amounts, e.g., therapeutically effective amounts.
A “prophylactically effective amount” refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired prophylactic result. Typically but not necessarily, since a prophylactic dose is used in subjects prior to or at an earlier stage of disease, the prophylactically effective amount will be less than the therapeutically effective amount. In the context of lower tumor burden, the prophylactically effective amount in some aspects will be higher than the therapeutically effective amount.
The term “about” as used herein refers to the usual error range for the respective value readily known to the skilled person in this technical field. Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se.
As used herein, the singular forms “a, ” “an, ” and “the” include plural referents unless the context clearly dictates otherwise. For example, “a” or “an” means “at least one” or “one or more. ” 
Throughout this disclosure, various aspects of the claimed subject matter are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the claimed subject matter. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, where a range of values is provided, it is understood that each intervening  value, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the claimed subject matter. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the claimed subject matter, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the claimed subject matter. This applies regardless of the breadth of the range.
As used herein, a composition refers to any mixture of two or more products, substances, or compounds, including cells. It may be a solution, a suspension, liquid, powder, a paste, aqueous, non-aqueous or any combination thereof.
The term “vector, ” as used herein, refers to a nucleic acid molecule capable of propagating another nucleic acid to which it is linked. The term includes the vector as a self-replicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced. Certain vectors are capable of directing the expression of nucleic acids to which they are operatively linked. Such vectors are referred to herein as “expression vectors. ” 
Exemplary Embodiments
Embodiment 1. A protein comprising a plurality of recombinant polypeptides, each recombinant polypeptide comprising a surface antigen of a coronavirus linked to a C-terminal propeptide of collagen, wherein the C-terminal propeptides of the recombinant polypeptides form inter-polypeptide disulfide bonds.
Embodiment 2. The protein of embodiment 1, wherein the coronavirus is a Severe Acute Respiratory Syndrome (SARS) -coronavirus (SARS-CoV) , a SARS-coronavirus 2 (SARS-CoV-2) , a SARS-like coronavirus, a Middle East Respiratory Syndrome (MERS) -coronavirus (MERS-CoV) , a MERS-like coronavirus, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
Embodiment 3. The protein of  embodiment  1 or 2, wherein the surface antigen comprises a coronavirus spike (S) protein or a fragment or epitope thereof, wherein the epitope is  optionally a linear epitope or a conformational epitope, and wherein the protein comprises three recombinant polypeptides.
Embodiment 4. The protein of embodiment 3, wherein the surface antigen comprises a signal peptide, an S1 subunit peptide, an S2 subunit peptide, or any combination thereof.
Embodiment 5. The protein of embodiment 3, wherein the surface antigen comprises a signal peptide, a receptor binding domain (RBD) peptide, a receptor binding motif (RBM) peptide, a fusion peptide (FP) , a heptad repeat 1 (HR1) peptide, or a heptad repeat 2 (HR2) peptide, or any combination thereof.
Embodiment 6. The protein of any of embodiments 3-5, wherein the surface antigen comprises a receptor binding domain (RBD) of the S protein.
Embodiment 7. The protein of any of embodiments 3-6, wherein the surface antigen comprises an S1 subunit and an S2 subunit of the S protein.
Embodiment 8. The protein of any of embodiments 3-7, wherein the surface antigen does not comprise a transmembrane (TM) domain peptide and/or a cytoplasm (CP) domain peptide.
Embodiment 9. The protein of any of embodiments 3-8, wherein the surface antigen comprises a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
Embodiment 10. The protein of any of embodiments 3-8, wherein the surface antigen does not comprise a protease cleavage site, wherein the protease is optionally furin, trypsin, factor Xa, thrombin, or cathepsin L.
Embodiment 11. The protein of any of embodiments 1-10, wherein the surface antigen is soluble or does not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
Embodiment 12. The protein of any of embodiments 1-11, wherein the surface antigens are the same or different among the recombinant polypeptides of the protein.
Embodiment 13. The protein of any of embodiments 1-12, wherein the surface antigen is directly fused to the C-terminal propeptide, or is linked to the C-terminal propeptide via a linker, such as a linker comprising glycine-X-Y repeats, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline.
Embodiment 14. The protein of any of embodiments 1-13, which is soluble or does not directly bind to a lipid bilayer, e.g., a membrane or viral envelope.
Embodiment 15. The protein of any of embodiments 1-14, wherein the protein is capable of binding to a cell surface receptor of a subject, optionally wherein the subject is a mammal such as a primate, e.g., human.
Embodiment 16. The protein of embodiment 15, wherein the cell surface receptor is angiotensin converting enzyme 2 (ACE2) , dipeptidyl peptidase 4 (DPP4) , dendritic cell-specific intercellular adhesion molecule-3-grabbing non integrin (DC-SIGN) , or liver/lymph node-SIGN (L-SIGN) .
Embodiment 17. The protein of any of embodiments 1-16, wherein the C-terminal propeptide is of human collagen.
Embodiment 18. The protein of any of embodiments 1-17, wherein the C-terminal propeptide comprises a C-terminal polypeptide of proα1 (I) , proα1 (II) , proα1 (III) , proα1 (V) , proα1 (XI) , proα2 (I) , proα2 (V) , proα2 (XI) , or proα3 (XI) , or a fragment thereof.
Embodiment 19. The protein of any of embodiments 1-18, wherein the C-terminal propeptides are the same or different among the recombinant polypeptides.
Embodiment 20. The protein of any of embodiments 1-19, wherein the C-terminal propeptide comprises any of SEQ ID NOs: 1-20 and 52-55 an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 21. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 3 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 22. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 4 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 23. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 7 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 24. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 12 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 25. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 15 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 26. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 20 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 27. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 52 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 28. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 54 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 29. The protein of any of embodiments 1-20, wherein the C-terminal propeptide comprises SEQ ID NO: 55 or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 30. The protein of any of embodiments 1-29, wherein the C-terminal propeptide comprises a sequence comprising glycine-X-Y repeats linked to the N-terminus of any of SEQ ID NOs: 1-20 and 52-55, wherein X and Y and independently any amino acid and optionally proline or hydroxyproline, or an amino acid sequence at least 90%identical thereto capable of forming inter-polypeptide disulfide bonds and trimerizing the recombinant polypeptides.
Embodiment 31. The protein of any of embodiments 1-30, wherein the surface antigen in each recombinant polypeptide is in a prefusion conformation or a postfusion conformation.
Embodiment 32. The protein of any of embodiments 1-31, wherein the surface antigen in each recombinant polypeptide comprises any of SEQ ID NOs: 21-36 or an amino acid sequence at least 80%identical thereto.
Embodiment 33. The protein of any of embodiments 1-32, wherein the recombinant polypeptide comprises any of SEQ ID NOs: 37-51 and 56-66 or an amino acid sequence at least 80%identical thereto.
Embodiment 34. An immunogen comprising the protein of any of embodiments 1-33.
Embodiment 35. A protein nanoparticle comprising the protein of any of embodiments 1-33 directly or indirectly linked to a nanoparticle.
Embodiment 36. A virus-like particle (VLP) comprising the protein of any of embodiments 1-33.
Embodiment 37. An isolated nucleic acid encoding one, two, three or more of the recombinant polypeptides of the protein of any of embodiments 1-33.
Embodiment 38. The isolated nucleic acid of embodiment 37, wherein a polypeptide encoding the surface antigen is fused in-frame to a polypeptide encoding the C-terminal propeptide of collagen.
Embodiment 39. The isolated nucleic acid of embodiment 37 or 38, which is operably linked to a promoter.
Embodiment 40. The isolated nucleic acid of any of embodiments 37-39, which is a DNA molecule.
Embodiment 41. The isolated nucleic acid of any of embodiments 37-39, which is an RNA molecule, optionally an mRNA molecule such as a nucleoside-modified mRNA, a non-amplifying mRNA, a self-amplifying mRNA, or a trans-amplifying mRNA.
Embodiment 42. A vector comprising the isolated nucleic acid of any of embodiments 37-41.
Embodiment 43. The vector of embodiment 42, which is a viral vector.
Embodiment 44. A virus, a pseudovirus, or a cell comprising the vector of embodiment 42 or 43, optionally wherein the virus or cell has a recombinant genome.
Embodiment 45. An immunogenic composition comprising the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, or cell of any one of embodiments 1-44, and a pharmaceutically acceptable carrier.
Embodiment 46. A vaccine comprising the immunogenic composition of embodiment 45 and optionally an adjuvant, wherein the vaccine is optionally a subunit vaccine, and/or optionally wherein the vaccines is a prophylactic and/or therapeutic vaccine.
Embodiment 47. The vaccine of embodiment 46, wherein the vaccine comprises a plurality of different adjuvants.
Embodiment 48. A method of producing a protein, comprising: expressing the isolated nucleic acid or vector of any one of embodiments 37-43 in a host cell to produce the protein of any of embodiments 1-33; and purifying the protein.
Embodiment 49. The protein produced by the method of embodiment 48.
Embodiment 50. A method for generating an immune response to a surface antigen of a coronavirus in a subject, comprising administering to the subject an effective amount of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49 to generate the immune response.
Embodiment 51. The method of embodiment 50, for treating or preventing infection with the coronavirus.
Embodiment 52. The method of embodiment 50 or 51, wherein generating the immune response inhibits or reduces replication of the coronavirus in the subject.
Embodiment 53. The method of any of embodiments 50-52, wherein the immune response comprises a cell-mediated response and/or a humoral response, optionally comprising production of one or more neutralizing antibody, such as a polyclonal antibody or a monoclonal antibody.
Embodiment 54. The method of any of embodiments 50-53, wherein the immune response is against the surface antigen of the coronavirus but not against the C-terminal propeptide.
Embodiment 55. The method of any of embodiments 50-54, wherein the administering does not lead to antibody dependent enhancement (ADE) in the subject due to prior exposure to one or more coronavirus.
Embodiment 56. The method of any of embodiments 50-55, wherein the administering does not lead to antibody dependent enhancement (ADE) in the subject when subsequently exposed to one or more coronavirus.
Embodiment 57. The method of any of embodiments 50-56, further comprising a priming step and/or a boosting step.
Embodiment 58. The method of any of embodiments 50-57, wherein the administering step is performed via topical, transdermal, subcutaneous, intradermal, oral, intranasal (e.g., intranasal spray) , intratracheal, sublingual, buccal, rectal, vaginal, inhaled, intravenous (e.g., intravenous injection) , , intraarterial, intramuscular (e.g., intramuscular injection) , intracardiac, intraosseous, intraperitoneal, transmucosal, intravitreal, subretinal, intraarticular, peri-articular, local, or epicutaneous administration.
Embodiment 59. The method of any of embodiments 50-58, wherein the effective amount is administered in a single dose or a series of doses separated by one or more interval.
Embodiment 60. The method of any of embodiments 50-59, wherein the effective amount is administered without an adjuvant.
Embodiment 61. The method of any of embodiments 50-59, wherein the effective amount is administered with an adjuvant or a plurality of adjuvants.
Embodiment 62. A method comprising administering to a subject an effective amount of the protein of any one of embodiments 1-33 to generate in the subject a neutralizing antibody or neutralizing antisera to the coronavirus.
Embodiment 63. The method of embodiment 62, wherein the subject is a mammal, optionally a human or a non-human primate.
Embodiment 64. The method of embodiment 62 or 63, further comprising isolating the neutralizing antibody or neutralizing antisera from the subject.
Embodiment 65. The method of embodiment 64, further comprising administering an effective amount of the isolated neutralizing antibody or neutralizing antisera to a human subject via passive immunization to prevent or treat an infection by the coronavirus.
Embodiment 66. The method of any of embodiments 62-65, wherein the neutralizing antibody or neutralizing antisera comprises polyclonal antibodies to the coronavirus surface antigen,  optionally wherein the neutralizing antibody or neutralizing antisera is free or substantially free of antibodies to the C-terminal propeptide of collagen.
Embodiment 67. The method of any of embodiments 62-65, wherein the neutralizing antibody comprises a monoclonal antibody to the coronavirus surface antigen, optionally wherein the neutralizing antibody is free or substantially free of antibodies to the C-terminal propeptide of collagen.
Embodiment 68. The protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for use in inducing an immune response to a coronavirus in a subject, and/or in treating or preventing an infection by the coronavirus.
Embodiment 69. Use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
Embodiment 70. Use of the protein, immunogen, protein nanoparticle, VLP, isolated nucleic acid, vector, virus, pseudovirus, cell, immunogenic composition, or vaccine of any one of embodiments 1-47 and 49, for the manufacture of a medicament or a prophylactic for inducing an immune response to a coronavirus in a subject, and/or for treating or preventing an infection by the coronavirus.
Embodiment 71. A method for analyzing a sample, comprising: contacting a sample with the protein of any of embodiments 1-33, and detecting a binding between the protein and an analyte capable of specific binding to the surface antigen of the coronavirus.
Embodiment 72. The method of embodiment 71, wherein the analyte is an antibody, a receptor, or a cell recognizing the surface antigen.
Embodiment 73. The method of embodiment 71 or 72, wherein the binding indicates the presence of the analyte in the sample, and/or an infection by the coronavirus in a subject from which the sample is derived.
Embodiment 74. A kit comprising the protein of any of embodiments 1-33 and a substrate, pad, or vial containing or immobilizing the protein, optionally wherein the kit is an ELISA or lateral flow assay kit.
Examples
The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention.
Example 1: Generation of recombinant disulfide-bond linked SARS-CoV-2 S-Trimer fusion  protein as a subunit vaccine.
Secreted forms of recombinant disulfide bond-linked polypeptides comprising SARS-CoV-2 protein peptides fused to a trimerization domain as candidate protein subunit vaccines were generated. In one example, the complete ecto-domain of the native spike protein (S) from SARS-CoV2, including its signal peptide (SP) , S1 and S2 domains, was fused in-frame at the C-terminus to a mammalian expression vector that encoded human C-propeptide of α1 collagen, to enable expression of a secreted and trimeric S-Trimer fusion antigen, e.g., as shown in FIG. 1.
High-level expression of S-Trimer fusion protein was shown in FIG. 2. An 8%SDS-PAGE analysis of S-Trimer expression from a fed-batch serum-free CHO cell culture in a 10L bioreactor. 10 μL of cell-free conditioned medium from Day 6 to Day 11 were analyzed under reducing condition followed by Coomassie Blue staining. A highly purified S-Trimer was loaded on the gel as a reference standard (Std) . The full-length S-Trimer and partially cleaved forms at S1/S2 furin site were as indicated.
Covalently linked S-Trimers were then purified and characterized. S-Trimer was purified from the cleared cell cultured medium via a Protein A (PA) affinity chromatography and anion exchange column (Q) followed by ultra-filtration and diafiltration (UF/DF) to obtain the drug substance (DS) , as shown in FIG. 3A. Four μg of purified protein was analyzed against starting cell culture medium feed by an 8%reducing SDS-PAGE and stained with Coomassie Blue. The S-Trimer was partially cleaved at the S1/S2 furin cleavage site, but the cleaved S1 subunit appeared to be bound to the S-Trimer since it was co-purified with the S-Trimer. As shown in FIG. 3B, the S-Trimer is a disulfide bond-linked trimer. Four μg of highly purified native-like S-Trimer was  analyzed by a 6%SDS-PAGEs under non-reducing and reducing conditions as indicated and stained with Coomassie Blue. The S-Trimer was purified to nearly homogeneity as judged by SEC-HPLC analysis, with some cleaved S1 being separated during the size exclusion chromatography, as shown in FIG. 3C. The molecular weight of S-Trimer was estimated to be 660 Kda. In FIG. 3D, the receptor binding kinetics of S-Trimer to ACE2-Fc was assessed by Fortebio biolayer interferometry measurements using a protein A sensor.
The S-Trimers were highly glycosylated with N-linked glycans. Highly purified S-Trimer before and after digestion with either endoglycanase F (PNGase F) alone or PNGase F plus endo-O-glycosidase to remove N-and O-linked glycans, and analyzed by an 8%reducing SDS-PAGE and stained with Coomassie Blue. The full-length S-Trimer, S2-Trimer and cleaved S1 before and after deglycosylation were as indicated in FIG. 4. Highly purified S-Trimers were visualized by negative EM using FEI Tecnai spirit electron microscopy, with the predicted conformation of S-Trimer shown in FIG. 5.
Example 2: Functional characterization of recombinant pol. ypeptides comprising S-Trimer  protein peptides
Sera from multiple patients who had recently recovered from COVID-19 were analyzed with S-Trimer as an antigen to determine S-specific antibody titers (FIG. 6, Left Panel) and neutralizing antibody levels via inhibition of S-Trimer binding to ACE2 receptor (FIG. 6, Right Panel) . The results show that S-specific antibodies and neutralizing antibodies were successfully detected from convalescent sera using S-Trimer as an antigen.
To further evaluate the immunogenicity and protective efficacy of exemplary recombinant polypeptides generated as described in Example 1, FIG. 7A and FIG. 7B show the induction of antigen-specific antibodies and neutralizing antibodies, respectively, in rats with S-Trimer alone (30 micrograms) and without any adjuvant. Similar to data shown in human in FIG. 6, these results show that antigen-specific antibodies as well as neutralizing antibodies were induced with the S-Trimer vaccine. Similarly, immunogenicity of the S-Trimer was shown in mice. Balb-c mice grouped in 6 were immunized twice at Day 1 and Day 14 with either 3 micrograms of S-Trimer alone or S-Trimer + Alum as an adjuvant. The antisera collected at Day 28 were analyzed with S-Trimer to determine the antibody titers (FIG. 7C) .
The present invention is not intended to be limited in scope to the particular disclosed embodiments, which are provided, for example, to illustrate various aspects of the invention. Various modifications to the compositions and methods described will become apparent from the description and teachings herein. Such variations may be practiced without departing from the true scope and spirit of the disclosure and are intended to fall within the scope of the present disclosure.
SEQUENCES
Figure PCTCN2021087066-appb-000081
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Figure PCTCN2021087066-appb-000091
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Figure PCTCN2021087066-appb-000098
Figure PCTCN2021087066-appb-000099
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Claims (45)

  1. A method for preventing infection by a coronavirus in a mammal, comprising immunizing a mammal with an effective amount of a recombinant subunit vaccine comprising a soluble coronavirus viral surface antigen joined by in-frame fusion to a C-terminal portion of a collagen to form a disulfide bond-linked trimeric fusion protein.
  2. The method of claim 1, wherein the coronavirus is a Severe Acute Respiratory Syndrome (SARS) -coronavirus (SARS-CoV) , a SARS-coronavirus 2 (SARS-CoV-2) , a SARS-like coronavirus, a Middle East Respiratory Syndrome (MERS) -coronavirus (MERS-CoV) , a MERS-like coronavirus, NL63-CoV, 229E-CoV, OC43-CoV, HKU1-CoV, WIV1-CoV, MHV, HKU9-CoV, PEDV-CoV, or SDCV.
  3. The method of claim 1 or 2, wherein the coronavirus viral surface antigen comprises a coronavirus spike (S) protein or a fragment or epitope thereof.
  4. The method of any of claims 1-3, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) ectodomain peptide or a fragment or epitope thereof.
  5. The method of any of claims 1-4, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) N-terminal domain (NTD) peptide or a fragment or epitope thereof.
  6. The method of any of claims 1-5, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) receptor binding domain (RBD) peptide or a fragment or epitope thereof.
  7. The method of any of claims 1-6, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) S1 peptide or a fragment or epitope thereof.
  8. The method of any of claims 1-7, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) S2 peptide or a fragment or epitope thereof.
  9. The method of any of claims 1-8, wherein the coronavirus viral surface antigen comprises a SARS-CoV-2 spike (S) ectodomain peptide or a fragment or epitope thereof having a mutation.
  10. The method of claim 9, wherein the mutation comprises 685R-＞685A.
  11. The method of claim 9 or 10, wherein the mutation comprises 986K-＞986P.
  12. The method of any of claims 9-11, wherein the mutation comprises 987V-＞987P.
  13. The method of any of claims 1-12, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 56 or 57.
  14. The method of any of claims 1-13, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 58 or 59.
  15. The method of any of claims 1-14, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 41 or 42.
  16. The method of any of claims 1-15, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 43 or 44.
  17. The method of any of claims 1-16, wherein the fusion protein comprises a sequence set forth in any of SEQ ID NOs: 60-62.
  18. The method of any of claims 1-17, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 63 or 64.
  19. The method of any of claims 1-18, wherein the fusion protein comprises a sequence set forth in SEQ ID NO: 65 or 66.
  20. The method of any of claims 1-19, wherein the fusion protein comprises a first sequence set forth in any of SEQ ID NOs: 21-36 linked to a second sequence set forth in any of  SEQ ID NOs: 1-20 and 52-55, wherein the C terminus of the first sequence is directly or indirectly linked to the N terminus of the second sequence.
  21. The method of any of claims 1-20, wherein the recombinant subunit vaccine is administered via intramuscular injection.
  22. The method of any of claim 1-21, wherein the recombinant subunit vaccine is administered via intra-nasai spray.
  23. The method of any of claims 1-22, wherein the recombinant subunit vaccine is administered in a single dose or a series of doses separated by intervals of weeks or months.
  24. The method of any of claims 1-23, wherein the recombinant subunit vaccine is administered without adjuvant.
  25. The method of any of claims 1-23, wherein the recombinant subunit vaccine is administered with an adjuvant.
  26. The method of any of claims 1-23, wherein the recombinant subunit vaccine is administered with more than one adjuvant.
  27. A method for detecting antibodies to a coronavirus from sera of a mammal comprising the step of contacting the sera with a soluble coronavirus viral surface antigen joined by in-frame fusion to a C-terminal portion of collagen to form a disulfide bond-linked trimeric fusion protein.
  28. The method of claim 27, wherein the soluble coronavirus viral surface antigen is an S protein or peptide.
  29. A method of using a recombinant subunit vaccine comprising a soluble surface antigen from a coronavirus, which is joined by in-frame fusion to a C-terminal portion of collagen to form a disulfide bond-linked trimeric fusion protein, the method comprising: immunize a  mammal, purifying the neutralizing antibody generated, and treating patients infected by the said coronavirus via passive immunization using said neutralizing antibody.
  30. The method of claim 29, wherein the neutralizing antibody comprises polyclonal antibodies.
  31. The method of claim 29, wherein the neutralizing antibody is a monoclonal antibody.
  32. The method of claim 29, wherein the neutralizing antibody is a monoclonal antibody to an S protein or peptide.
  33. The method of claim 29, wherein the neutralizing antibody is a monoclonal antibody to an S protein of SARS-CoV-2.
  34. The method of claim 29, wherein the neutralizing antibody is a monoclonal antibody to an S protein of SARS-CoV-1.
  35. The method of claim 29, wherein the neutralizing antibody is a monoclonal antibody to an S protein of MERS.
  36. A complex comprising a recombinant polypeptide selected from the group consisting of SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, and SEQ ID NO: 94.
  37. A complex comprising a trimer of a recombinant polypeptide selected from the group consisting of SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, and SEQ ID NO: 94, wherein the recombinant polypeptides are trimerized via inter-polypeptide disulfide bonds to form the trimer.
  38. An immunogenic composition comprising a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 75, a trimer of a recombinant polypeptide  comprising the sequence set forth in SEQ ID NO: 76, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 77, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 78, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 79, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 80, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 81, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 82, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 83, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 84, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 90, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 91, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 92, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 93, a trimer of a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 94, or a combination of any two or more of the trimers.
  39. The immunogenic composition of claim 38, comprising the trimer of the recombinant polypeptide having the sequence set forth in SEQ ID NO: 75 and the trimer of the recombinant polypeptide having the sequence set forth in SEQ ID NO: 77.
  40. A method for generating an immune response to a surface antigen of a coronavirus in a subject, comprising administering to the subject an effective amount of a complex comprising a recombinant polypeptide selected from the group consisting of SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, and SEQ ID NO: 94.
  41. A method for generating an immune response to a surface antigen of a coronavirus in a subject,
    wherein the surface antigen comprises an S protein or antigenic fragment thereof, and
    the method comprises administering to the subject an effective amount of a complex comprising a recombinant polypeptide selected from the group consisting of SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, and SEQ ID NO: 94.
  42. A method for generating an immune response to a surface antigen of a coronavirus in a subject,
    wherein the surface antigen comprises a sequence selected from the group consisting of SEQ ID NO: 24, SEQ ID NO: 67, SEQ ID NO: 69, SEQ ID NO: 71, and SEQ ID NO: 73, and
    the method comprises administering to the subject an effective amount of a complex comprising a recombinant polypeptide selected from the group consisting of SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, and SEQ ID NO: 94.
  43. A method for generating an immune response to a surface antigen of a coronavirus in a subject,
    wherein the surface antigen comprises an S protein or antigenic fragment thereof of the coronavirus and optionally the sequence set forth in SEQ ID NO: 24, and
    the method comprises administering to the subject an effective amount of a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 77, SEQ ID NO: 78, or SEQ ID NO: 91.
  44. A method for generating an immune response to a surface antigen of a coronavirus in a subject,
    wherein the surface antigen comprises an S protein or antigenic fragment thereof, and
    the method comprises administering to the subject an effective amount of a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 75, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 76, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID  NO: 77, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 78, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 79, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 80, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 81, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 82, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 83, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 84, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 90, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 91, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 92, a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 93, or a complex comprising a recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 94, or a combination of any two or more of the complexes.
  45. The method of claim 44, wherein the method comprises administering to the subject an effective amount of the complex comprising the recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 75, SEQ ID NO: 90, and/or SEQ ID NO: 76, and an effective amount of the complex comprising the recombinant polypeptide comprising the sequence set forth in SEQ ID NO: 77, SEQ ID NO: 91, and/or SEQ ID NO: 78.
PCT/CN2021/087066 2020-06-10 2021-04-13 Coronavirus vaccine compositions, methods, and uses thereof WO2021249012A1 (en)

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