Monoclonal antibodies directed against the microtubule-associated protein tau and method of detecting the same

Abstract

A monoclonal antibody which forms an immunological complex with a phosphorylated epitope of an antigen belonging to human abnormally phosphorylated tau protein. The tau protein can be obtained from a brain homogenate, itslf isolated from the cerebral cortex of a patient having Alzheimer's disease. Further, a method of detecting the tau protein is claimed.

1 - 19 . (canceled)  
     
     
         20 . A peptide from 9 to 100 amino acids long, comprising the amino acid sequence YSSPGSPGT or YSSPGSPGT, phosphorylated at the positions marked with *, and wherein said peptide is able to form an immunological complex with the monoclonal antibody AT8 produced by the hybridoma deposited at the ECACC on Oct. 8, 1991 under No. 91100806.  
     
     
         21 . The peptide of  claim 20 , consisting of the amino acid sequence YSSPGSPGT or YSSPGSPGT, phosphorylated at the positions marked with *, and wherein said peptide is able to form an immunological complex with the monoclonal antibody AT8 produced by the hybridoma deposited at the ECACC on Oct. 8, 1991 under No. 91100806.  
     
     
         22 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), said method comprising the use of the phosphorylated peptide of  claim 20  as a standard.  
     
     
         23 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), wherein, for standard purposes, in a separate reaction, the phosphorylated peptide of  claim 20  is contacted with an antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex, and the phosphorylated peptide—antibody complex is detected.  
     
     
         24 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), comprising: 
 (a) contacting the sample with an antibody that forms an immunological complex with the phosphorylated peptide of  claim 20;  and    (b) detecting the complex formed between said antibody and the tau protein phosphorylated at Ser(199) and/or Ser(202); and    (c) contacting, in a separate reaction, for standard purposes, the phosphorylated peptide of  claim 20  with the antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex; and    (d) detecting the complex formed between said antibody and said phosphorylated peptide.    
     
     
         25 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), comprising: 
 (a) contacting the sample with an antibody that forms an immunological complex with the phosphorylated peptide of  claim 20;  and    (b) contacting the phosphorylated tau protein—antibody complex with a second antibody that binds an epitope on the phosphorylated peptide of  claim 20  that is different from phosphorylated Ser(199) and/or Ser(202); and    (c) detecting the complex formed between the first antibody, the tau protein phosphorylated at Ser(199) and/or Ser(202) and the second antibody; and    (d) contacting, in a separate reaction, for standard purposes, the phosphorylated peptide of  claim 20  with the antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex; and    (e) contacting, the phosphorylated peptide—antibody complex with the second antibody that binds an epitope on said phosphorylated peptide that is different from phosphorylated Ser(199) and/or Ser(202); and    (f) detecting the complex formed between said antibody, the phosphorylated peptide and the second antibody.    
     
     
         26 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), said method comprising the use of the phosphorylated peptide of  claim 20  for competition purposes.  
     
     
         27 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), wherein, for competition purposes, the phosphorylated peptide of  claim 20  is contacted with an antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex, and the phosphorylated peptide—antibody complex or the absence of a phosphorylated peptide—antibody complex is detected.  
     
     
         28 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), comprising: 
 (a) contacting the sample with an antibody that forms an immunological complex with the phosphorylated peptide of  claim 20;  and    (b) detecting the complex formed between said antibody and the tau protein phosphorylated at Ser(199) and/or Ser(202); and    (c) contacting, for competition purposes, the phosphorylated peptide of  claim 20  with the antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex; and    (d) detecting the complex formed between said antibody and said phosphorylated peptide or the absence of said complex.    
     
     
         29 . A method for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), comprising: 
 (a) contacting the sample with an antibody that forms an immunological complex with the phosphorylated peptide of  claim 20;  and    (b) contacting the phosphorylated tau protein—antibody complex with a second antibody that binds an epitope on the phosphorylated peptide of  claim 20  that is different from phosphorylated Ser(199) and/or Ser(202); and    (c) detecting the complex formed between the first antibody, the tau protein phosphorylated at Ser(199) and/or Ser(202) and the second antibody; and    (d) contacting, for competition purposes, the phosphorylated peptide of  claim 20  with the antibody that forms an immunological complex with said phosphorylated peptide under conditions suitable for producing a phosphorylated peptide—antibody complex; and    (e) contacting, the phosphorylated peptide—antibody complex with the second antibody that binds an epitope on said phosphorylated peptide that is different form phosphorylated Ser(199) and/or Ser(202); and    (f) detecting the complex formed between said first antibody, said phosphorylated peptide and said second antibody or the absence of said complex.    
     
     
         30 . A kit for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), said kit comprising the phosphorylated peptide of  claim 20  as a standard or competitor.  
     
     
         31 . A kit for the detection, in a sample, of tau protein phosphorylated at Ser(199) and/or Ser(202), said kit comprising the phosphorylated peptide of  claim 21  as a standard or competitor.