Drug – bio-affecting and body treating compositions – Antigen – epitope – or other immunospecific immunoeffector – Conjugate or complex
Reexamination Certificate
1998-03-23
2001-10-09
Le, Long V. (Department: 1641)
Drug, bio-affecting and body treating compositions
Antigen, epitope, or other immunospecific immunoeffector
Conjugate or complex
C424S178100, C424S193100, C424S197110, C424S146100, C424S196110, C424S201100, C424S202100, C424S203100, C424S280100, C424S256100, C424S244100, C424S236100, C424S240100, C424S239100, C424S085100, C424S085100, C424S093200, C530S403000, C530S806000, C530S404000, C530S405000, C530S406000, C530S409000, C530S411000, C530S391100, C435S188000, C435S961000, C435S964000, C436S543000
Reexamination Certificate
active
06299881
ABSTRACT:
BACKGROUND OF THE INVENTION
Vaccines have been very effective in protecting people from a wide variety of diseases, whether caused by viruses, bacteria, or fungi. The ability of vaccines to induce specific protection against such a wide range of pathogenic organisms results from their ability to stimulate specific humoral antibody responses, as well as cell-mediated responses. This invention relates to a process for preparing such vaccines, and particularly to a process for making conjugates that are used in preparing vaccines. Additionally, the process of the invention can be used to produce immunogens and other valuable immunological, therapeutic, or diagnostic reagents. The invention further relates to the vaccines, immunogens, and reagents produced from the conjugates made according to the invention, as well as to the use of these products.
It is often very desirable to induce immune responses against polysaccharides. For example, antibodies against a bacterial capsular polysaccharide can provide protection against that bacterium. Many polysaccharides, however, are poorly immunogenic, particularly in infants and young children. Furthermore, in both children and adults, there is usually no booster effect with repeated polysaccharide immunizations, and the principal antibody class is IgM. These features are all characteristic of so called “T cell independent” (“TI”) antigens.
In many cases, the immunogenicity of polysaccharides can be enhanced by covalently linking proteins or T cell epitope-containing peptides to the polysaccharide. Certain other components, such as lipids, fatty acids, lipopolysaccharides, and lipoproteins, also are known to enhance the immunogenicity of the polysaccharide. As described in the “dual conjugate” patent application of Mond and Lees, conjugation of a protein to a polysaccharide can enhance the immune response to the protein as well as to the polysaccharide. See U.S. Pat. No. 5,585,100; U.S. patent application Ser. No. 08/444,727 (filed May 19, 1995); and U.S. patent application Ser. No. 08/468,060 (filed Jun. 6, 1995). These patent applications each are entirely incorporated herein by reference. This effect also is described in A. Lees, et al., “Enhanced Immunogenicity of Protein-Dextran Conjugates: I. Rapid Stimulation of Enhanced Antibody Responses to Poorly Immunogenic Molecules,”
Vaccine,
Vol. 12, No. 13, (1994), pp. 1160-1166. This article is entirely incorporated herein by reference. In view of this potential for improving the immune response against polysaccharides, there is a need in the art for methods to covalently link proteins or other moieties to polysaccharides.
Ideally, the process of covalently linking moieties to a polysaccharide must be done in a way to maintain antigenicity of both the polysaccharide and protein components and to minimize damage to necessary epitopes of each component. Furthermore, the linkage should be stable. Therefore, there is a need for a mild and gentle means for coupling proteins, peptides, haptens, organic molecules, or other moieties to polysaccharides.
Vaccines are not the only products that can benefit from an improved procedure for coupling molecules together. For example, certain diagnostic or therapeutic reagents are produced by coupling polysaccharides, high molecular weight carbohydrates, and low molecular weight carbohydrates to solid phase materials (e.g., solid particles or surfaces). Thus, there is a need in the art for improved means for coupling polysaccharides, high molecular weight carbohydrates, and low molecular weight carbohydrates to solid phase materials.
Two main methods for coupling molecules together are used. In the first method, the means for coupling entails the crosslinking of a protein (or peptide or other moiety) directly to a polysaccharide (or some other moiety). Sometimes, however, a spacer molecule is needed between the coupled moieties, either to facilitate the chemical process and/or to enhance the immune response to the protein and/or the polysaccharide. In either method, it is usually necessary to activate or functionalize the polysaccharide before crosslinking occurs. Some methods of activating or functionalizing polysaccharides are described in W. E. Dick, et al., “Glycoconjugates of Bacterial Carbohydrate Antigens: A Survey and Consideration of Design and Preparation Factors,”
Conjugate Vaccines
(Eds. Cruse, et al.), Karger, Basel, 1989, Vol. 10, pp. 48-114. This excerpt is entirely incorporated herein by reference. Additional activation methods are described in R. W. Ellis, et al. (Editors),
Development and Clinical Uses of Haemophilus B Conjugate Vaccines
, Marcel Dekker, New York (1994), which book is entirely incorporated herein by reference.
One preferred method for activating polysaccharides is described in the CDAP patent applications of Lees, U.S. patent application Ser. No. 08/124,491 (filed Sep. 22, 1993, now abandoned); U.S. Pat. Nos. 5,651,971; 5,693,326; and U.S. patent application Ser. No. 08/482,666 (filed Jun. 7, 1995). These U.S. patents and patent applications each are entirely incorporated herein by reference. The use of CDAP also is described in Lees, et al., “Activation of Soluble Polysaccharides with 1-Cyano-4-Dimethylamino Pyridinium Tetrafluoroborate for Use in Protein-Polysaccharide Conjugate Vaccines and Immunological Reagents,”
Vaccine,
Vol. 14, No. 3 (1996), pp. 190-198. This article also is entirely incorporated herein by reference.
One specific method of preparing conjugates is through the condensation of amines (or hydrazides) and carboxyls to amides using carbodiimides. The carboxyl nucleophile reacts with the carbodiimide to form a highly reactive but unstable intermediate that can then either hydrolyze or react with an amine to form a stable amide bond. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (“EDC”) is a water soluble example of this class of carbodiimide reagent.
As one example of this reaction, Robbins describes functionalizing Haemophilus influenza (“PRP”) polysaccharide with hydrazides and condensing this functionalized material with carboxyls on tetanus toxoid. See C. Chu, et al.,
Infection and Immunity,
Vol. 40, 1983, beginning at pg. 245. Additionally, the coupling of a carboxylated polysaccharide to diptheria toxoid by this general process also is described by Robbins. See S. C. Szu, et al.,
Journal of Experimental Medicine,
Vol. 166, 1987, beginning at page 1510. These articles each are entirely incorporated herein by reference.
In general, however, there are a myriad of problems when one attempts to use carbodiimide for coupling multivalent ligands (e.g., proteins and polysaccharides) that contain both activatable groups and nucleophiles. The reaction is difficult to control, and it frequently leads to extensive homopolymerization, interchain crosslinking, and reduced antigenicity. A further problem is that the carboxyl-carbodiimide intermediate can undergo an O to N acyl shift, resulting in a stable, unreactive addition product that adds new epitopes to the protein (see G. T. Hermanson,
Bioconjugate Techniques,
Academic Press, San Diego, Calif., (1996), which document is entirely incorporated herein by reference).
Another method of forming conjugates is through the use of active ester intermediates. Reagents that form active ester intermediates include norborane, p-nitrobenzoic acid, NHS (N-hydroxysuccinimide), and S-NHS (sulfo-N-hydroxysuccinimide). NHS esters (or other suitable reagents) can react with nucleophiles like amines, hydrazides, and thiols. The reaction products of NHS esters with amines and hydrazides are particularly stable, forming an amide bond. NHS ester intermediates can be formed in a one step process using carbodiimide (to activate the carboxyls) and NHS (or S-NHS). In this process, NHS (or S-NHS), the carboxyl-containing component, and the amine-containing component are combined, and the carbodiimide is added thereto. Although coupling efficiency often is higher in this reaction than is the case when NHS is not present, problems, such as homopolymerization, interchain cross
Lees Andrew
Mond James J.
Cook Lisa J.
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Henry M. Jackson Foundation for the Advancement of Military Medi
Le Long V.
LandOfFree
Uronium salts for activating hydroxyls, carboxyls, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Uronium salts for activating hydroxyls, carboxyls, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Uronium salts for activating hydroxyls, carboxyls, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2596395