Targeted heterologous antigen presentation on calicivirus virus-like particles

Abstract

The present invention provides particle-forming chimeric proteins comprising a Calicivirus capsid protein and one or more heterologous antigen sequences. In particular, the present invention discloses engineered Calicivirus capsid protein sequences containing heterologous epitopes fused at internal locations such that the modified capsid proteins retain the ability to form virus-like particles when expressed in host cells. Virus-like particles comprising the chimeric proteins and vaccine formulations are also described.

1 - 38 . (canceled) 
     
     
         39 . A method for identifying one or more epitopes that elicit an immunologic response, the method comprising screening a library of epitopes present on at least one chimeric protein, wherein the chimeric protein comprises a Calicivirus capsid protein having a P2 domain and a plurality of heterologous epitopes, wherein the heterologous epitopes are inserted into the P2 domain of said capsid protein, and wherein the chimeric protein is capable of forming virus-like particles (VLPs) when expressed in a host cell. 
     
     
         40 . The method of  claim 39 , wherein the heterologous epitopes are inserted into at least one solvent-exposed loop of the P2 domain. 
     
     
         41 . The method of  claim 39 , wherein the Calicivirus is a Norovirus. 
     
     
         42 . The method of  claim 41 , wherein the Norovirus is a Genogroup I or Genogroup II Norovirus. 
     
     
         43 . The method of  claim 42 , wherein the Norovirus is a Genogroup I, genotype 1 Norovirus or a Genogroup II, genotype 4 Norovirus. 
     
     
         44 . The method of  claim 39 , wherein the capsid protein is VP1. 
     
     
         45 . The method of  claim 39 , wherein the capsid protein has an amino acid sequence according to SEQ ID NO: 1. 
     
     
         46 . The method of  claim 39 , wherein the capsid protein is a composite capsid protein derived from two or more circulating strains of Norovirus. 
     
     
         47 . The method of  claim 46 , wherein the composite capsid protein has an amino acid sequence of SEQ ID NO: 2. 
     
     
         48 . The method of  claim 39 , wherein the heterologous epitopes are derived from one or more viruses selected from the group consisting of rota virus, respiratory syncytial virus, parainfluenza virus, and metaneumovirus. 
     
     
         49 . A chimeric protein comprising a Calicivirus capsid protein having a P2 domain and at least one heterologous sequence, wherein said heterologous sequence comprises a high-affinity binding site for a foreign antigen, wherein said heterologous sequence is inserted into said P2 domain of said capsid protein, and wherein said chimeric protein is capable of forming virus-like particles when expressed in a host cell. 
     
     
         50 . The chimeric protein of  claim 49 , wherein the high-affinity binding site is a short linear binding motif, a leucine zipper, an epitope, a paratrope, an antigen-binding site of an antibody that binds to the foreign antigen, or a binding region of a protein that interacts with the foreign antigen. 
     
     
         51 . The chimeric protein of  claim 50 , wherein the binding region that interacts with the foreign antigen is a receptor. 
     
     
         52 . The chimeric protein of  claim 49 , wherein the heterologous epitopes are inserted into at least one solvent-exposed loop of the P2 domain. 
     
     
         53 . The chimeric protein of  claim 49 , wherein the Calicivirus is a Norovirus. 
     
     
         54 . The chimeric protein of  claim 53 , wherein the Norovirus is a Genogroup I or Genogroup II Norovirus. 
     
     
         55 . The chimeric protein of  claim 54 , wherein the Norovirus is a Genogroup I, genotype 1 Norovirus or a Genogroup II, genotype 4 Norovirus. 
     
     
         56 . The chimeric protein of  claim 49 , wherein the capsid protein is VP1. 
     
     
         57 . The chimeric protein of  claim 49 , wherein the capsid protein has an amino acid sequence according to SEQ ID NO: 1. 
     
     
         58 . The chimeric protein of  claim 49 , wherein the capsid protein is a composite capsid protein derived from two or more circulating strains of Norovirus. 
     
     
         59 . The chimeric protein of  claim 49 , wherein the composite capsid protein has an amino acid sequence of SEQ ID NO: 2.