Anti-amyloid immunogenic compositions, methods and uses

Abstract

The present invention provides a recombinant immunogenic obtained by tandem multimerization of a B-cell epitope bearing fragment of Aβ42, within the active loop site of a carrier (display site), preferably bacterial thioredoxin (Trx). Polypeptides bearing multiple copies of Aβ42 fragments, preferably with an interposed amino acid linker, were constructed and injected into mice in combination with an adjuvant. Monoclonal antibodies were made which recognize the immunogenic construct comprising a carrier bearing at least one fragment of Aβ42 within an active loop site of the carrier. The elicited antibodies were found to selectively bind to fibrillar and/or oligomers Aβ within neuritic AD plaques.

1 . A monoclonal antibody which recognizes an immunogenic construct comprising a carrier bearing at least one fragment of Aβ42 within an active loop site of the carrier. 
     
     
         2 . The monoclonal antibody of  claim 1 , wherein the carrier is thioredoxin. 
     
     
         3 . The monoclonal antibody of  claim 2 , wherein the at least one Aβ42 fragment is selected from the group consisting of Aβ1-3, Aβ1-4 (SEQ ID NO: 3), Aβ1-5 (SEQ ID NO: 4), Aβ1-6 (SEQ ID NO: 5), Aβ1-7 (SEQ ID NO: 6), Aβ1-8 (SEQ ID NO: 7), Aβ1-9 (SEQ ID NO: 8), Aβ1-10 (SEQ ID NO: 9), Aβ1-11 (SEQ ID NO: 10), Aβ1-12 (SEQ ID NO: 11), Aβ1-13 (SEQ ID NO: 12), Aβ1-14 (SEQ ID NO: 13), and Aβ1-15 (SEQ ID NO: 14). 
     
     
         4 . The monoclonal antibody of  claim 3 , wherein said at least one Aβ42 fragment is Aβ1-15 (SEQ ID NO: 14). 
     
     
         5 . The monoclonal antibody of  claim 4 , wherein the Aβ1-15 (SEQ ID NO: 14) fragment is bound to the thioredoxin by means of an amino acid linker. 
     
     
         6 . The monoclonal antibody of  claim 5 , wherein the amino acid linker is Gly-Gly-Pro. 
     
     
         7 . The monoclonal antibody of  claim 4 , wherein the thioredoxin bears more than one said Aβ1-15 (SEQ ID NO: 14) fragment. 
     
     
         8 . The monoclonal antibody of  claim 7 , wherein the thioredoxin bears 4 to 16 said Aβ1-15 (SEQ ID NO: 14) fragments. 
     
     
         9 . The monoclonal antibody of  claim 8 , wherein the thioredoxin bears 4 said Aβ1-15 (SEQ ID NO: 14) fragments. 
     
     
         10 . The monoclonal antibody of  claim 7 , wherein each said Aβ1-15 (SEQ ID NO: 14) fragment is bound to the thioredoxin by means of the amino acid linker. 
     
     
         11 . The monoclonal antibody of  claim 10 , wherein the amino acid linker is Gly-Gly-Pro. 
     
     
         12 . A therapeutic agent for preventing or treating an amyloidogenic disease, said agent comprising the monoclonal antibody of  claim 1  as an active ingredient. 
     
     
         13 . The therapeutic agent of  claim 12 , wherein the amyloidogenic disease is Alzheimer's disease. 
     
     
         14 . A therapeutic agent for preventing or treating an amyloidogenic disease, said agent comprising the monoclonal antibody of  claim 9  as an active ingredient. 
     
     
         15 . The therapeutic agent of  claim 14 , wherein the amyloidogenic disease is Alzheimer's disease. 
     
     
         16 . A method for preparing an immunogenic construct comprising a carrier, said carrier bearing at least one fragment of Aβ42 within its active loop site, said method comprising:
 i) amplifying the carrier in a suitable bacterium,   ii) inserting the carrier in a suitable vector, said vector comprising a T7 promoter for the protein expression throughout the pET system;   iii) preparing an Aβ fragment DNA insert; and   iv) restricting and ligating the carrier-vector and the Aβ fragment DNA insert.   
     
     
         17 . The method of  claim 16 , wherein the carrier is thioredoxin. 
     
     
         18 . A method of  claim 16 , wherein the bacterium is  E. Coli.    
     
     
         19 . A method of  claim 16 , wherein the vector is pT7Kan-Trx.