Recombinant RSV G proteins and their use
Inventors
Assignees
US Department of Health and Human Services
Publication Number
US-11905313-B2
Publication Date
2024-02-20
Expiration Date
2038-11-27
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Abstract
Embodiments of a recombinant Respiratory Syncytial Virus (RSV) G ectodomain are provided. Also disclosed are nucleic acids encoding the RSV G ectodomain and methods of producing the RSV G ectodomain. Methods for inducing an immune response in a subject are also disclosed. In some embodiments, the method can be a method for inhibiting a RSV infection in a subject by administering an effective amount of the recombinant RSV G ectodomain to the subject to produce a protective immune response.
Core Innovation
The invention provides recombinant respiratory syncytial virus (RSV) G ectodomains and fragments thereof that elicit a neutralizing or protective immune response to RSV in mammalian subjects. These recombinant RSV G ectodomains have been modified to exclude the transmembrane domain and to remove glycosylation, improving properties such as solubility and production capacity, while retaining immunogenicity. A specific example includes a deletion of residues 172-186 with residues 171 and 187 linked by a peptide linker, resulting in immunogens that promote a Th1-biased immune response and inhibit disease, particularly in the lower respiratory tract.
The recombinant RSV G ectodomains lack glycosylation because they are produced in bacterial expression systems, and they are soluble in aqueous solution. The deletion of the central conserved domain (CCD) including residues 172-186 is shown not to significantly impact protective efficacy following immunization. Antigenic sites in the N-terminal and C-terminal domains flanking the CCD are immunogenic and contribute to protection. The recombinant RSV G ectodomains and fragments can be administered as immunogenic compositions optionally including adjuvants and can be linked to carriers to facilitate presentation. Methods include inducing an immune response in subjects by administration of these recombinant ectodomains or nucleic acid molecules encoding them to inhibit RSV infection or disease symptoms.
The background problem addressed is the lack of an effective vaccine against RSV, a virus causing severe respiratory disease in infants, the elderly, and immunocompromised individuals. Current passive immunization only partially prevents severe illness, and the virus causes repeated infections due to its antigenic variability and immune evasion. Thus, there was a need for safe, immunogenic RSV G-based vaccines that can induce protective immunity, particularly by targeting immunogenic regions other than or in addition to the central conserved domain.
Claims Coverage
The patent includes 28 claims encompassing recombinant RSV G ectodomains with specific deletions and modifications, nucleic acids encoding these ectodomains, vectors and viral vectors containing such nucleic acids, immunogenic compositions including these proteins or vectors, virus-like particles comprising the recombinant proteins, and methods of inducing immune responses or detecting RSV G-specific antibodies. The claim coverage spans from protein constructs to applications in vaccines and immunological assays.
Recombinant RSV G ectodomain with specific deletions and linkers
A recombinant RSV G ectodomain comprising deletions of residues 1-66 and 172-186 with residues 171 and 187 linked directly by a peptide bond or a peptide linker, excluding the transmembrane domain and cytosolic tail, where amino acid positions correspond to SEQ ID NO: 1.
Specific peptide linker between residues 171 and 187
Residues 171 and 187 of the RSV G ectodomain are linked by a glycine-serine peptide linker, specifically GGGGSGGGGS (SEQ ID NO: 5), to maintain protein structure and immunogenicity.
Recombinant RSV G ectodomains from different RSV strains
Expression of recombinant RSV G ectodomains from bovine RSV, human subtype A or B RSV G proteins containing the specified deletions and peptide linker with at least 90% amino acid identity to SEQ ID NO: 2 or SEQ ID NO: 11.
Non-glycosylated, soluble recombinant RSV G ectodomains
The recombinant RSV G ectodomain does not include glycosylation and is soluble due to lack of transmembrane domain and cytosolic tail.
Linkage to carriers and virus-like particles
The recombinant RSV G ectodomain can be linked to carriers to enhance immune presentation and incorporated into virus-like particles for vaccination.
Nucleic acids and expression vectors encoding recombinant RSV G ectodomains
Isolated nucleic acid molecules encoding the recombinant RSV G ectodomain operably linked to promoters, including RNA molecules, expression vectors, and viral vectors are claimed.
Immunogenic compositions including recombinant RSV G ectodomains and methods of use
Immunogenic compositions comprising the recombinant RSV G ectodomain, VLPs, nucleic acids or vectors encoding the ectodomain, optionally with additional RSV F protein, are included, along with methods of inducing immune responses that inhibit RSV infection and methods of detecting RSV G-specific antibodies using the recombinant ectodomain.
Membrane-anchored RSV G ectodomains linked to RSV G transmembrane domain and cytosolic tail
Recombinant RSV G ectodomains with deletion of residues 172-186 linked via peptide linker to an N-terminal RSV G transmembrane domain and cytosolic tail, with at least 90% identity to SEQ ID NO: 6 or SEQ ID NO: 15, which are not glycosylated, and included in virus-like particles.
The claims cover recombinant RSV G ectodomains with defined deletions and peptide linkers, nucleic acid constructs encoding them, various expression vectors and viral vectors, immunogenic compositions including these proteins or nucleic acids, virus-like particles comprising the constructs, and methods of immunization and antibody detection targeting RSV G protein. The inventive features address enhanced immunogenicity, solubility, production, and functional efficacy in eliciting immune responses against RSV.
Stated Advantages
The recombinant RSV G ectodomains have superior properties for production, including absence of glycosylation and transmembrane domain, which improve solubility and yield.
They promote a Th1-biased immune response, which is associated with effective and protective immunity against RSV infection.
The recombinant proteins induce protective immune responses that inhibit disease particularly in the lower respiratory tract, reducing viral loads and symptoms following RSV challenge.
Deletion of the central conserved domain does not significantly reduce protective efficacy, allowing construction of safer and more easily produced vaccine antigens.
Antigenic sites outside the central conserved domain contribute to protective immunity, broadening targets for vaccine design.
Documented Applications
Use as immunogens for inducing an immune response in subjects to inhibit or reduce the severity of RSV infection, particularly in infants, elderly, or at-risk populations.
Formulation into immunogenic compositions or vaccines, optionally including adjuvants or additional RSV antigens such as the F protein.
Use in virus-like particles to present recombinant RSV G ectodomains for vaccination purposes.
Use of recombinant RSV G ectodomains or encoding nucleic acids for prime-boost vaccination protocols involving protein and nucleic acid vaccines.
Use as probes in methods to detect antibodies that specifically bind to RSV G protein in biological samples to monitor immunization or infection status.
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