Recombinant prefusion RSV F proteins and uses thereof
Inventors
Chen, Lei • Zhang, Baoshan • Kwong, Peter D. • Corti, Davide • Lanzavecchia, Antonio • Taylor, Geraldine
Assignees
Institute for Research in Biomedicine IRB • Pirbright Institute • US Department of Health and Human Services
Publication Number
US-11084850-B2
Publication Date
2021-08-10
Expiration Date
2037-12-15
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Abstract
The present invention provides immunogens comprising a recombinant Respiratory Syncytial Virus (RSV) F protein stabilized in a prefusion conformation and nucleic acids encoding such immunogens. In particular the present invention provides polypeptides, polynucleotides, compositions, and uses thereof for eliciting an immune response to bovine respiratory syncytial virus (bRSV). Methods for generating an immune response in a subject are also disclosed. In some embodiments, the method is a method for treating or preventing a RSV infection in a subject by administering a therapeutically effective amount of the antigen to the subject.
Core Innovation
The invention provides immunogens comprising recombinant Respiratory Syncytial Virus (RSV) F proteins stabilized in a prefusion conformation and nucleic acids encoding such immunogens to elicit an immune response to bovine respiratory syncytial virus (bRSV). The recombinant RSV F protein includes F1 and F2 polypeptides characterized by substitutions that form non-natural disulfide bonds and cavity-filling amino acid substitutions. The recombinant proteins specifically bind to RSV F prefusion-specific antibodies and lack a pep27 polypeptide.
The problem addressed is the lack of effective vaccines against RSV, particularly for bRSV in cattle. Current vaccines suffer drawbacks including low immunogenicity in the presence of maternal antibodies, potential disease enhancement, and limited efficacy. Moreover, there is a need for stable RSV F protein immunogens in a prefusion conformation that elicit potent neutralizing antibody responses and avoid vaccine-associated disease enhancement. The invention aims to provide improved vaccines that induce high-titer neutralizing responses, protect from viral replication, lung inflammation, and clinical disease signs, while avoiding disease enhancement.
Claims Coverage
The claims include one independent claim directed to an immunogen with specific mutations that stabilize the RSV F protein in a prefusion conformation, and related dependent claims covering preferred features, nucleic acids, vectors, host cells, particles, and compositions.
Immunogen comprising recombinant RSV F protein stabilized in prefusion conformation
An immunogen comprising a recombinant RSV F protein or fragment thereof that specifically binds to an RSV F prefusion-specific antibody; comprising F1 and F2 polypeptides of any RSV F protein with the following substitutions: (i) S155C and S290C forming a non-natural disulfide bond; (ii) one or both of position S190 and V207 substituted by amino acids F, L, W, Y, H, or M; and (iii) a pair of substitutions forming a non-natural disulfide bond from the group Q98C/Q361C, A149C/Y458C, N183GC/N428C, N88C/N254C, E92C/N254C, or S238C/Q279C; wherein the protein does not comprise a pep27 polypeptide; and wherein the protein comprises specific amino acid segments corresponding to SEQ ID NOs 31 or 32 as defined.
Sequence identity to native bovine RSV F protein
The F1 and F2 polypeptides of the recombinant RSV F protein or fragment thereof share at least 80% sequence identity with the F1 and F2 polypeptides, respectively, of a native bovine RSV F protein, preferably set forth in SEQ ID NOs: 1-9.
Presence of key antigenic sites and epitopes
The recombinant RSV F protein or fragment comprises (i) antigenic site Ø that specifically binds prefusion-specific antibodies and includes residues 62-69 and 196-209; (ii) an epitope recognized by AM14 antibody comprising residues L160, N183, N426, R429, H514, and H515; and/or (iii) an epitope recognized by MPE8 antibody comprising residues T50, D310, L305, G307, and I309 of a native bovine RSV F protein.
Linkage of F2 and F1 polypeptides by linker or direct connection
The F2 polypeptide and the F1 polypeptide are linked by a heterologous peptide linker or are directly linked.
Linkage to a trimerization domain
The recombinant RSV F protein is linked to a trimerization domain, preferably a foldon domain, promoting trimer formation.
Preferred embodiments including foldon domain and defined amino acid spans
The immunogen comprises or consists of F2 (amino acids 26-103 or 26-105), F1 (amino acids 106-474 or 108-476), and a foldon domain (amino acids 475-513 or 477-515) directly linked to the C-terminus of F1 polypeptide, as defined in SEQ ID NOs 31 and 32.
Virus-like particles and protein nanoparticles comprising the immunogen
Virus-like particles and protein nanoparticles comprising the recombinant RSV F immunogen stabilized in prefusion conformation.
Nucleic acid molecules, vectors and host cells encoding or comprising the immunogen
Nucleic acid molecules comprising polynucleotides encoding the immunogen or particles, vectors comprising such nucleic acids, and isolated host cells comprising the nucleic acid molecules or vectors.
Pharmaceutical compositions comprising the immunogen, particles, nucleic acids, vectors or host cells
Pharmaceutical compositions comprising the immunogen, virus-like particles, protein nanoparticles, nucleic acids encoding the immunogen or particles, vectors comprising the nucleic acids, or host cells comprising the nucleic acids or vectors, together with pharmaceutically acceptable carriers.
The claims cover an immunogen comprising a recombinant bovine RSV F protein stabilized in the prefusion conformation by defined cysteine substitutions forming non-natural disulfide bonds and cavity-filling mutations, that specifically binds RSV prefusion-specific antibodies, lacks pep27 polypeptide, and comprises defined amino acid regions. Dependent claims provide preferred features including sequence identity, antigenic sites, polypeptide linkage, trimerization domains, and specific amino acid sequence embodiments. Claims also cover virus-like particles, protein nanoparticles, nucleic acids, vectors, host cells, and pharmaceutical compositions comprising the immunogen.
Stated Advantages
The vaccine induces high-titer neutralizing responses and protection from viral replication, lung inflammation, and clinical signs of disease.
It avoids vaccine-associated disease enhancement.
The immunogens have excellent stability (physical properties) and high immunogenicity.
Provides an improved animal model authentically representing natural RSV infection and vaccine responses.
Documented Applications
Eliciting an immune response to RSV F in a subject, in particular in cattle, preferably a Th1 immune response.
Treatment or prevention of RSV infection in a subject, particularly bovine respiratory syncytial virus infection in cattle.
Use as vaccine compositions to reduce or prevent infection with RSV and pathological response following infection.
Production of antigen-specific immunodiagnostic reagents to detect or isolate RSV F binding antibodies in subjects.
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