Polysaccharide and uses thereof
Provided herein is a novel E. coli O polysaccharide, O25B. Also provided herein are prokaryotic host cells comprising enzymes (e.g., glycosyltransferases) used in O25B production. The host cells provided herein produce O25B bioconjugates, wherein said bioconjugates comprise O25B linked to a carrier protein. Further provided herein are compositions, e.g., pharmaceutical compositions, comprising O25B and/or bioconjugates comprising O25B. Such compositions can be used as vaccines against infection with ExPEC, and may further comprise one or more additional bioconjugates.
1. A composition comprising a bioconjugate of an E. coli O25B antigen covalently coupled to a carrier protein, (ii) a bioconjugate of an E. coli O1A antigen covalently coupled to a carrier protein, (iii) a bioconjugate of an E. coli O2 antigen covalently coupled to a carrier protein, and (iv) a bioconjugate of an O6 antigen covalently coupled to a carrier protein,
wherein the E. coli O25B antigen comprises the structure of Formula O25B′:
wherein n is an integer between 1 and 30.
2. The composition of claim 1 , wherein the O1A antigen, O6 antigen, and O2 antigen comprise the following formulas, respectively:
3. The composition of claim 1 , wherein the E. coli O25B antigen is covalently bound to an Asn residue in the carrier protein.
4. The composition of claim 1 , wherein (i) the E. coli O1A antigen is covalently bound to an Asn residue of the carrier protein, (ii) the E. coli O2 antigen is covalently bound to an Asn residue of the carrier protein, and (iii) the E. coli O6 antigen is covalently bound to an Asn residue of the carrier protein.
5. The composition of claim 1 , wherein the carrier protein is selected from the group consisting of detoxified Exotoxin A of P. aeruginosa (EPA), CRM197, maltose binding protein (MBP). Diphtheria toxoid, Tetanus toxoid, detoxified hemolysin A of S. aureus , clumping factor A, clumping factor B, E. coli Emil, E. coli FimH, E. coli heat labile enterotoxin, detoxified variants of E. coli heat labile enterotoxin, Cholera toxin B subunit (CTB), cholera toxin, detoxified variants of cholera toxin, E. coli Sat protein, the passenger domain of E. coli Sat protein, Streptococcus pneumoniae Pneumolysin and detoxified variants thereof, C. jejuni AcrA, and C. jejuni natural glycoproteins.
6. The composition of claim 5 , wherein the carrier protein is detoxified EPA.
7. The composition of claim 3 , wherein the Asn residue of the carrier protein is positioned in the consensus sequence Asp(Glu)-X-Asn-Z-Ser(Thr), wherein X and Z are independently selected from any natural amino acid except Pro (SEQ ID NO:15).
8. A composition comprising a bioconjugate of an E. coli O25B antigen covalently bound to an Asn residue of detoxified Exotoxin A of P. aeruginosa (EPA), (ii) a bioconjugate of an E. coli O1A antigen covalently bound to an Asn residue of detoxified EPA, (iii) a bioconjugate of an E. coli O2 antigen covalently bound to an Asn residue of detoxified EPA, and (iv) a bioconjugate of an O6 antigen covalently bound to an Asn residue of detoxified EPA,
wherein the E. coli O25B antigen comprises the structure of Formula O25B′:
wherein n is an integer between 1 and 30.
9. The composition of claim 8 , wherein the O1A antigen, O6 antigen, and O2 antigen comprise the following formulas, respectively:
10. An immunogenic composition comprising (i) a bioconjugate of an E. coli O25B antigen covalently bound to an Asn residue of detoxified Exotoxin A of P. aeruginosa (EPA), (ii) a bioconjugate of an E. coli O1A antigen covalently bound to an Asn residue of detoxified EPA, (iii) a bioconjugate of an E. coli O2 antigen covalently bound to an Asn residue of detoxified EPA, and (iv) a bioconjugate of an O6 antigen covalently bound to an Asn residue of detoxified EPA,
wherein the E. coli O25B antigen, O1A antigen, O6 antigen, and O2 antigen comprise the following formulas, respectively:
wherein n is an integer between 1 and 30.
11. A method for (i) vaccinating a subject against extra-intestinal pathogenic Escherichia coli , (ii) inducing an immune response in a subject against extra-intestinal pathogenic Escherichia coli , or (iii) inducing the production of opsonophagocytic antibodies in a subject that are specific to extra-intestinal pathogenic Escherichia coli , wherein the method comprises administering to the subject an effective amount of the composition of claim 1 .
12. The method of claim 11 , wherein the subject is at risk of developing a urinary tract infection.
13. The method of claim 11 , wherein the subject is at risk of developing bacteremia.
14. The method of claim 11 , wherein the subject is at risk of developing sepsis.
15. A method for (i) vaccinating a subject against extra-intestinal pathogenic Escherichia coli , (ii) inducing an immune response in a subject against extra-intestinal pathogenic Escherichia coli , or (iii) inducing the production of opsonophagocytic antibodies in a subject that are specific to extra-intestinal pathogenic Escherichia coli , wherein the method comprises administering to the subject an effective amount of the composition of claim 2 .
16. A method for (i) vaccinating a subject against extra-intestinal pathogenic Escherichia coli , (ii) inducing an immune response in a subject against extra-intestinal pathogenic Escherichia coli , or (iii) inducing the production of opsonophagocytic antibodies in a subject that are specific to extra-intestinal pathogenic Escherichia coli , wherein the method comprises administering to the subject an effective amount of the composition of claim 8 .
17. The method of claim 16 , wherein the subject is at risk of developing a urinary tract infection, bacteremia, or sepsis.
18. A method for (i) vaccinating a subject against extra-intestinal pathogenic Escherichia coli , (ii) inducing an immune response in a subject against extra-intestinal pathogenic Escherichia coli , or (iii) inducing the production of opsonophagocytic antibodies in a subject that are specific to extra-intestinal pathogenic Escherichia coli , wherein the method comprises administering to the subject an effective amount of the composition of claim 9 .
19. The method of claim 18 , wherein the subject is at risk of developing urinary tract infection, bacteremia, or sepsis.
20. A method of inducing an immune response in a subject against extra-intestinal pathogenic Escherichia coli , wherein the method comprises administering an effective amount of the immunogenic composition of claim 10 .