1444827-18-2

Upstream product

• 920958-49-2 benzyl-(5-hydroxy-pentyl)-carbamic acid benzyl ester 
• 1444827-17-1 (2-methyl-5-tert-butylphenyl) 2,3-di-O-benzoyl-4-O-benzyl-α-L-rhamnopyranosyl-(1→3)-2-O-benzoyl-4,6-di-O-benzyl-1-thio-β-D-glucopyranoside 

Relevant academic research and scientific papers

OLIGOSACCHARIDES AND OLIGOSACCHARIDE-PROTEIN CONJUGATES DERIVED FROM CLOSTRIDIUM DIFFICILE POLYSACCARIDE PS-I, METHODS OF SYNTHESIS AND USES THEREOF, IN PARTICULAR AS VACCINES AND DIAGNOSTIC TOOLS

The invention relates to a synthetic oligosaccharide representing part of the repeating unit of the Clostridium difficile glycopolymer PS-I and having the sequence of the pentasaccharide a-L-Rhap- ( 1→3 ) -β-D-Glcp- ( 1→4 ) - [a-L-Rhap- ( 1→3 ] -a-D-Glcp- ( 1→2 ) -a-D-Glcp or a synthetic fragment or derivative thereof. Preferably, the claimed synthetic oligosaccharide bears at least one linker L for conjugation to a carrier protein or for immobilization on a surface. Further aspects of the invention relate to advantageous methods for synthesizing said synthetic oligosaccharide and oligosaccharide-protein conjugate as well as to uses thereof, in particular as vaccines and diagnostic tools.

Immunological evaluation of a synthetic clostridium difficile oligosaccharide conjugate vaccine candidate and identification of a minimal epitope

Clostridium difficile is the cause of emerging nosocomial infections that result in abundant morbidity and mortality worldwide. Thus, the development of a vaccine to kill the bacteria to prevent this disease is highly desirable. Several recently identified bacterial surface glycans, such as PS-I and PS-II, are promising vaccine candidates to preclude C. difficile infection. To circumvent difficulties with the generation of natural PS-I due to its low expression levels in bacterial cultures, improved chemical synthesis protocols for the pentasaccharide repeating unit of PS-I and oligosaccharide substructures were utilized to produce large quantities of well-defined PS-I related glycans. The analysis of stool and serum samples obtained from C. difficile patients using glycan microarrays of synthetic oligosaccharide epitopes revealed humoral immune responses to the PS-I related glycan epitopes. Two different vaccine candidates were evaluated in the mouse model. A synthetic PS-I repeating unit CRM197 conjugate was immunogenic in mice and induced immunoglobulin class switching as well as affinity maturation. Microarray screening employing PS-I repeating unit substructures revealed the disaccharide Rha-(1→3)-Glc as a minimal epitope. A CRM197-Rha-(1→3)-Glc disaccharide conjugate was able to elicit antibodies recognizing the C. difficile PS-I pentasaccharide. We herein demonstrate that glycan microarrays exposing defined oligosaccharide epitopes help to determine the minimal immunogenic epitopes of complex oligosaccharide antigens. The synthetic PS-I pentasaccharide repeating unit as well as the Rha-(1→3)-Glc disaccharide are promising novel vaccine candidates against C. difficile that are currently in preclinical evaluation.