Chlamydia oligosaccharides

Abstract

Mannose-containing, branched oligosaccharides mediate binding of chlamydia to mammalian cells. The “high mannose-type” glycan was found to block adhesion of chlamydiae to mammalian cells and thus to inhibit infectivity. The glycan and its mimetics, including multivalent derivatives, can be used as agents for treatment or prevention of chlamydia-based human diseases.

We claim:  
     
         1 . A composition comprising a carbohydrate, or a derivative thereof, wherein said carbohydrate comprises at least five mannose residues; wherein said carbohydrate comprises a branched trimannosyl core, wherein a mannose residue optionally is bonded thereto; wherein said carbohydrate comprises at least three branches and each branch terminates in a mannose residue; and wherein said carbohydrate or derivative is present in an amount which inhibits binding of chlamydia to a mammalian cell, and a biologically acceptable carrier, diluent or excipient.  
     
     
         2 . The composition of  claim 1 , wherein said carbohydrate comprises at least six mannose residues.  
     
     
         3 . The composition of  claim 2 , wherein said carbohydrate comprises at least seven mannose residues.  
     
     
         4 . The composition of  claim 3 , wherein said carbohydrate comprises at least eight residues.  
     
     
         5 . The composition of  claim 1 , wherein trimannosyl core is linked to chitobiose.  
     
     
         6 . The composition of  claim 5 , wherein said chitobiose is linked to an asparagine.  
     
     
         7 . The composition of  claim 1 , wherein said carbohydrate has at least three branches.  
     
     
         8 . The composition of  claim 1 , wherein said carbohydrate has at least four branches.  
     
     
         9 . A method of inhibiting binding of chlamydia to a mammalian cell comprising exposing said chlamydia to a carbohydrate, or a derivative thereof, wherein said carbohydrate comprises at least five mannose residues; wherein said carbohydrate comprises a branched trimannosyl core, wherein a mannose residue optionally is bonded thereto; wherein said carbohydrate comprises at least three branches and each branch terminates in a mannose residue; and wherein said carbohydrate or derivative is present in an amount which inhibits binding of chlamydia to a mammalian cell.  
     
     
         10 . An isolated Chlamydia carbohydrate comprising at least five mannose residues; wherein said carbohydrate comprises a branched trimannosyl core, wherein a mannose residue optionally is bonded thereto; and wherein said carbohydrate comprises at least three branches and each branch terminates in a mannose residue.  
     
     
         11 . A multivalent carbohydrate comprising two or more carbohydrates linked to a carrier, wherein said carbohydrate comprises at least five mannose residues; wherein said carbohydrate comprises a branched trimannosyl core, wherein a mannose residue optionally is bonded thereto; and wherein said carbohydrate comprises at least three branches and each branch terminates in a mannose residue.