Methods for preparing complex multivalent immunogenic conjugates
View Patent ↗Methods for preparing complex multivalent immunogenic conjugates that include simultaneously reacting a plurality or immunogenic-distinct polysaccharides with at least one protein to make the complex multivalent immunogenic conjugates. The simultaneous reaction involves reaction of a hydrazide group on one reactant with an aldehyde or cyanate ester group on the other reactant.
1. A method for making a complex multivalent immunogenic conjugate, comprising:
reacting a protein with 1-amino-2,3-propanediol (APDO) in the presence of 1-[3-(dimethylamino)propyl]-3-ethyl carbodiimide hydrochloride at a pH of from about 5.5 to about 7 resulting in a solution of an APDO-modified protein;
reacting the APDO-modified protein with an oxidizing agent resulting in a solution of an aldehyde-activated protein;
contacting a mixture of a plurality of hydrazide-activated immunogenic-distinct polysaccharides with the aldehyde-activated protein at a pH of about 5 to about 8 such that the plurality of hydrazide-activated immunogenic-distinct polysaccharides simultaneously react with at least one aldehyde-activated protein resulting in a complex multivalent conjugate that includes at least one C═N double bond formed between each attached immunogenic-distinct polysaccharide and the protein; and
reducing all of the C═N double bonds of the complex multivalent conjugate to C—N bonds resulting in a complex multivalent immunogenic conjugate product.
2. The method of claim 1 , wherein the protein is reacted with APDO at a pH of about 5.5 to about 6.5.
3. The method of claim 1 , wherein the protein is reacted with APDO at a pH of about 6 to about 7.
4. A method for preparing a hydrazide-activated protein, comprising:
reacting a protein with hydrazine, carbohydrazide, hydrazine chloride, a dihydrazide, or a mixture thereof in the presence of (i) a carbodiimide and (ii) at least one other amino acid, wherein the amino acid is selected from at least one of lysine, arginine, histidine, glycine, serine, threonine, glutamic acid or cysteine.
5. The method of claim 4 , wherein the carbodiimide is 1-[3-(dimethylamino)propyl]-3-ethyl carbodiimide hydrochloride.
6. The method of claim 4 , wherein the at least one hydrazide-activated protein is soluble at neutral pH.
7. The method of claim 1 , wherein the plurality of immunogenic-distinct polysaccharides includes at least one pneumococcal polysaccharide, at least one meningococcal polysaccharide, and at least one Haemophilus influenzae type b polysaccharide.
8. The method of claim 1 , wherein the complex multivalent immunogenic conjugate comprises a structure having a plurality of immunogenic-distinct polysaccharides conjugated to a single protein construct.
9. The method of claim 1 , wherein the complex multivalent immunogenic conjugate has a structure comprising:
wherein P′ is a carrier protein; and PS′, PS 2 , and PS 3 are each immunogenic-distinct polysaccharides that are covalently attached to P 1 .
10. The method of claim 4 , wherein the protein comprises an inactivated bacterial toxin selected from diphtheria toxoid, CRM 197 , tetanus toxoid, pertussis toxoid, E. coli LT, E. coli ST, or exotoxin A from Pseudomonas aeruginosa.
11. The method of claim 4 , wherein the protein comprises a protein selected from outer membrane complex c (OMPC), porin, transferrin binding protein, pneumococcal surface protein A (PspA), pneumococcal adhesin protein (PsaA), pneumococcal surface protein BVH-3, pneumococcal surface protein BVH-11, protective antigen (PA) of Bacillus anthracis , detoxified edema factor (EF) of Bacillus anthracis , lethal factor (LF) of Bacillus anthracis , ovalbumin, keyhole limpet hemocyanin (KLH), human serum albumin, bovine serum albumin (BSA) or purified protein derivative of tuberculin (PPD).