Rsv f protein compositions and methods for making same

Abstract

The present invention relates to immunogenic compositions comprising RSV F protein, methods for preparing compositions that contain RSV F protein ecto-domain polypeptides, and to certain engineered RSV F proteins and nucleic acids that encode the engineered RSV F proteins. Compositions prepared using the methods can contain RSV F protein ecto-domain polypeptides in a predominant or single desired form and conformation. The invention also relates to methods for inducing an immune response to RSV F.

1 .- 6 . (canceled) 
     
     
         7 . A method of making a cleaved respiratory syncytial virus (RSV)-F protein, the method comprising:
 a) providing uncleaved RSV-F protein ectodomain polypeptides containing one or more protease cleavage sites that, when cleaved, produce F1 and F2 fragments; and   b) cleaving the uncleaved RSV-F protein ectodomain polypeptides with a protease or proteases that recognize the protease cleavage site or sites,   wherein the F2 fragment lacks a transmembrane domain and a cytoplasmic tail, and wherein the F2 fragment comprises a trimerizing sequence from bacteriophage T4 fibritin.   
     
     
         8 . The method of  claim 7 , wherein the trimerizing sequence comprises the amino acid sequence of SEQ ID NO: 19. 
     
     
         9 . The method of  claim 7 , wherein the trimerizing sequence comprises amino acid residues 3-29 of SEQ ID NO: 19. 
     
     
         10 . The method of  claim 7 , wherein the cleaved RSV-F protein does not comprise a p27 region. 
     
     
         11 . The method of  claim 7 , wherein the uncleaved RSV-F protein is of a RSV A subgroup. 
     
     
         12 . The method of  claim 7 , wherein the uncleaved RSV-F protein is of a RSV B subgroup. 
     
     
         13 . The method of  claim 7 , wherein step b) occurs within a host cell. 
     
     
         14 . The method of  claim 13 , further comprising culturing the host cell and recovering the cleaved RSV-F protein from a culture media.