Compositions and methods for preparing
View Patent ↗The present invention relates to immunogenic conjugates comprising S. aureus serotype 5 and 8 capsular polysaccharides conjugated to carrier proteins and methods for their preparation and use. Methods for making the immunogenic conjugates of the invention involve covalent conjugation of the capsular polysaccharides with the carrier proteins using conjugation chemistry involving either 1,1-carboyl-di-1,2,4-triazole (CDT) or 3-(2-pyridyldithio)-propionyl hydrazide (PDPH).
1. An immunogenic polysaccharide-protein conjugate comprising an isolated Staphylococcus aureus capsular polysaccharide conjugated to a carrier protein, wherein the polysaccharide has a molecular weight of between 70 kDa and 300 kDa, wherein the conjugate has a molecular weight range of between about 600 kDa and about 2800 kDa, and wherein the conjugate comprises a one-carbon or zero-carbon linker between the polysaccharide and the carrier protein.
2. The immunogenic conjugate of claim 1 , wherein the immunogenic conjugate has a molecular weight of between 595 kDa and 1708 kDa.
3. The immunogenic conjugate of claim 1 , wherein the polysaccharide has a molecular weight range of between 70 kDa and 150 kDa.
4. An immunogenic polysaccharide-protein conjugate comprising an isolated Staphylococcus aureus capsular polysaccharide conjugated to a carrier protein, wherein the polysaccharide has a molecular weight of between 70 kDa and 300 kDa, wherein the conjugate has a molecular weight range of between 500 kDa and 2500 kDa, and wherein the conjugate comprises a one-carbon or zero-carbon linker between the polysaccharide and the carrier protein.
5. The immunogenic conjugate of claim 1 , wherein the polysaccharide has a degree of O-acetylation between 10-100%.
6. The immunogenic conjugate of claim 5 , wherein the polysaccharide has a degree of O-acetylation between 50-100%.
7. The immunogenic conjugate of claim 6 , wherein the polysaccharide has a degree of O-acetylation between 75-100%.
8. The immunogenic conjugate of claim 1 , wherein the carrier protein is CRM197.
9. The immunogenic conjugate of claim 8 , wherein the CRM197 is covalently linked to the polysaccharide through a carbamate linkage, an amide linkage, or both.
10. The immunogenic conjugate of claim 9 , wherein the molar ratio of the conjugated lysines in the CRM197 to the CRM197 is about 10:1 to about 25:1.
11. The immunogenic conjugate of claim 9 , wherein at least one covalent linkage between CRM197 and polysaccharide occurs at least at every 5 to 10 saccharide repeat units of the polysaccharide.
12. The immunogenic conjugate of claim 11 , wherein at least one linkage between CRM197 and polysaccharide occurs at every 5 saccharide repeat units of the polysaccharide.
13. The immunogenic conjugate of claim 9 , wherein the CRM197 comprises 5 to 23 lysines covalently linked to the polysaccharide.
14. The immunogenic conjugate of claim 13 , wherein the CRM197 comprises 5 to 15 lysines covalently linked to the polysaccharide.
15. An immunogenic composition comprising the immunogenic conjugate of claim 1 and at least one of an adjuvant, diluent, or carrier.
16. A method of inducing an immune response against Staphylococcus aureus in a subject comprising administering to the subject an immunologically effective amount of the immunogenic composition of claim 15 .
17. A method of reducing a Staphylococcal infection, disease or condition associated with a Staphylococcus bacteria in a subject, the method comprising the step of administering an immunologically effective amount of the immunogenic composition of claim 15 to the subject.
18. The immunogenic conjugate of claim 1 , wherein the capsular polysaccharide is a serotype 5 or a serotype 8 capsular polysaccharide.
19. An immunogenic polysaccharide-protein conjugate comprising an isolated Staphylococcus aureus capsular polysaccharide conjugated to a carrier protein, wherein the polysaccharide has a molecular weight of between 70 kDa and 300 kDa, wherein the conjugate has a molecular weight range of between 1600 kDa and 3000 kDa, and wherein the conjugate comprises a one-carbon or zero-carbon linker between the polysaccharide and the carrier protein.
20. The immunogenic conjugate of claim 13 , wherein the CRM197 comprises 18 to 22 lysines covalently linked to the polysaccharide.
21. The immunogenic conjugate of claim 1 , wherein the conjugate has a molecular weight range of between 1533 kDa and 2656 kDa.
22. The immunogenic conjugate of claim 1 , wherein the conjugate has a molecular weight range of between about 1300 kDa and about 2600 kDa.
23. The method of claim 17 , wherein the infection, disease or condition is selected from the group consisting of invasive Staphylococcus aureus disease, sepsis and carriage.
24. The method of claim 17 , wherein the method comprises the step of administering the immunologically effective amount of the immunogenic composition to the subject prior to a surgical procedure.
25. The immunogenic composition of claim 15 , wherein the capsular polysaccharide is a serotype 5 or a serotype 8 capsular polysaccharide.
26. The immunogenic composition of claim 25 , wherein the composition comprises less than 30% free serotype 5 or serotype 8 polysaccharide compared to the total amount of serotype 5 or serotype 8 polysaccharide.
27. The immunogenic composition of claim 26 , wherein the composition comprises less than 20% free serotype 5 or serotype 8 polysaccharide compared to the total amount of serotype 5 or serotype 8 polysaccharide.