Pre-fusion rsv f antigens

Abstract

The invention relates to pre-fusion RSV F protein and polypeptides that contain one or more amino acid mutations that stabilize the pre-fusion conformation or destabilize the post-fusion conformation. The invention also relates to methods for inducing an immune response to pre-fusion RSV F.

1 . A pre-fusion respiratory syncytial virus (RSV) F polypeptide, having an HRA region (residues 137-239 of reference RSV F protein of SEQ ID NO:1) and a DIII region (residues 51-98 and 206-308 of reference RSV F protein of SEQ ID NO:1) wherein a cysteine residue is introduced into the HRA region and is introduced into the DIII region not more than about 10 A away from the cysteine residue introduced into the HRA region, and a disulfide bond is formed between the introduced cysteine residue in the HRA region and the introduced cysteine residue in the DIII region that prevents a post-fusion HRA-HRB six-helix bundle from forming, thus stabilizing the pre-fusion RSV F polypeptide. 
     
     
         2 . The pre-fusion RSV F polypeptide of  claim 1  wherein the prefusion RSV F polypeptide is a soluble ectodomain of RSV F. 
     
     
         3 . The pre-fusion RSV F polypeptide of  claim 1 , further comprising a heterologous oligomerization domain, an epitope, or a signal peptide. 
     
     
         4 . The pre-fusion RSV F polypeptide of  claim 3  comprising a heterologous oligomerization domain, wherein said heterologous oligomerization domain is a trimerization domain. 
     
     
         5 . The pre-fusion RSV F polypeptide of  claim 4  wherein the trimerization domain is selected from the group consisting of: influenza hemagglutinin, trimerizing sequence from bacteriophage T4 fibritin (“foldon”), SARS spike, HN gp41, NadA, modified GCN4, GCN4 or ATCase. 
     
     
         6 . The pre-fusion RSV F polypeptide of  claim 5 , wherein said heterologous oligomerization domain is the foldon. 
     
     
         7 . An immunogenic composition comprising the pre-fusion RSV F polypeptide of  claim 1 . 
     
     
         8 . The immunogenic composition of  claim 7 , further comprising an adjuvant. 
     
     
         9 . The immunogenic composition of  claim 8 , wherein the adjuvant is selected from the group consisting of: an aluminum salt, a squalene-in-water emulsion, a benzonaphthyridine compound, a phospholipid compound, a small molecule immunopotentiator and combinations of any of the foregoing. 
     
     
         10 . An isolated nucleic acid encoding the pre-fusion RSV F polypeptide of  claim 1 . 
     
     
         11 . The isolated nucleic acid of  claim 10 , which is a self-replicating RNA molecule. 
     
     
         12 . An immunogenic composition comprising the self-replicating RNA molecule of  claim 11  and a delivery system selected from liposomes, non-toxic and biodegradable polymer molecules and cationic submicron oil-in-water emulsions.