Immunogenic Compositions and Vaccines Derived From Bacterial Surface Receptor Proteins

Abstract

The disclosure provides immunogenic compositions comprising a polypeptide comprising a C-lobe domain or an N-lobe domain of a HIBP surface receptor protein obtainable from or obtained from a Gram-negative bacterial species. The HIBP surface receptor proteins have been modified in such a manner that they are unable to bind host iron binding protein. Methods of making and using these immunogenic positions to prepare animal and human vaccines are also provided.

1 - 79 . (canceled) 
     
     
         80 . An isolated nucleic acid sequence encoding an immunogen comprising a Transferrin binding protein B (TbpB) from a Gram negative bacterial species, the TbpB comprising a C-lobe domain, or an N-lobe domain, wherein the C-lobe domain, or the N-lobe domain comprise a plurality of β-strands interspersed with a plurality of loop domains wherein at least one loop domain of the plurality of loop domains has been modified, and wherein the β-strands flanking the at least one modified loop domain are retained in unmodified form, wherein the TbpB polypeptide is modified in a such a manner that the value of the dissociation constant K d  of the binding interaction between the native host iron binding protein and the modified TbpB is at least 10× higher than the value of the dissociation constant K d  of the binding interaction between the native host iron binding protein and the native TbpB. 
     
     
         81 . An expression vector comprising as operably linked components:
 (i) a nucleic acid sequence capable or controlling expression in a host cell; and   (ii) the nucleic acid sequence of  claim 80 .   
     
     
         82 . The expression vector according to  claim 81 , wherein at least one loop domain has been modified in that one or more amino acids in the at least one loop domain have been removed or replaced. 
     
     
         83 . The expression vector according to  claim 81 , wherein the at least one loop domain has been modified in that it has been removed in its entirety. 
     
     
         84 . The expression vector according to  claim 82 , wherein the loop domain is replaced with a portion of an Integral Outer Membrane (IOM) polypeptide. 
     
     
         85 . The expression vector according to  claim 84 , wherein the IOM polypeptide is a Transferrin binding protein A (TbpA) polypeptide or a Lactoferrin binding protein A (LbpA) polypeptide. 
     
     
         86 . The expression vector according to  claims 82 , wherein the at least one loop domain is selected from any one of Loops L1 to Loops L32. 
     
     
         87 . The expression vector according to  claim 83 , wherein the at least one loop domain is selected from any one of Loops L1 to Loops L32. 
     
     
         88 . The expression vector according to  claim 86 , wherein the at least one loop domain is selected from any one of the Loops consisting of L1, L5, L8, L12, L18, L21, L23 and L27. 
     
     
         89 . The expression vector according to  claim 87 , wherein the at least one loop domain is selected from any one of the Loops consisting of L1, L5, L8, L12, L18, L21, L23 and L27. 
     
     
         90 . The expression vector according to  claim 81 , wherein the TbpB polypeptide is obtainable from a bacterial species belonging to the bacterial genus of  Actinobacillus, Neisseria, Haemophilus, Mannheimia, Histophilus, Pasteurella  or  Moraxella.    
     
     
         91 . The expression vector according to  claim 81 , wherein the C-lobe domain is a C-lobe domain selected from the group set forth in SEQ.ID NO: 6; SEQ.ID NO: 22; SEQ.ID NO: 34; SEQ.ID NO: 119; SEQ.ID NO: 125; SEQ.ID NO: 179 to SEQ.ID NO: 195; SEQ.ID NO: 213 to SEQ.ID NO: 218; SEQ.ID NO: 230; SEQ.ID NO: 232; SEQ.ID NO: 234 to SEQ.ID NO: 278; and SEQ.ID NO: 288 to SEQ.ID NO: 292. 
     
     
         92 . The expression vector according to  claim 82 , wherein the N-lobe domain is an N-lobe domain selected from the group set forth in SEQ.ID NO: 8; SEQ.ID NO: 10; SEQ.ID NO: 24; SEQ.ID NO: 26; SEQ.ID NO: 36; SEQ.ID NO: 38; SEQ.ID NO: 121; SEQ.ID NO: 127; SEQ.ID NO: 229; SEQ.ID NO: 231; and SEQ.ID NO: 233. 
     
     
         93 . The expression vector according to  claim 82 , wherein the immunogenic composition comprises any of the polypeptides set forth in SEQ.ID NO: 170; SEQ.ID NO: 172; SEQ.ID NO: 174; SEQ.ID NO; 176; SEQ.ID NO: 4; SEQ.ID NO: 14; SEQ.ID NO: 16; SEQ.ID NO: 18; SEQ.ID NO: 20; SEQ.ID NO: 30 and SEQ.ID NO: 32. 
     
     
         94 . The expression vector according to  claim 85 , wherein the TbpA and LbpA polypeptides are selected from SEQ.ID NO: 152 and SEQ.ID NO: 162. 
     
     
         95 . The expression vector according to  claim 85 , wherein the immunogenic composition comprises a polypeptide having the sequence set forth in SEQ.ID NO: 154; SEQ.ID NO: 156; SEQ.ID NO: 158; SEQ.ID NO: 160; SEQ.ID NO: 164, SEQ.ID NO: 166. 
     
     
         96 . A host cell containing the expression vector according to  claim 81 . 
     
     
         97 . A host cell containing the expression vector according to  claim 82 . 
     
     
         98 . A host cell containing the expression vector according to  claim 83 . 
     
     
         99 . A method for eliciting an immune response in a vertebrate subject, said method comprising administering to the subject the expression vector of  claim 81 .