Diagnosis and treatment of alzheimer's disease

Abstract

Methods are provided for the prevention, treatment and diagnosis of Alzheimer's disease, based on the glycosylation pattern of amyloid-beta peptides in body fluids and tissues.

1 . A method for diagnosing or prognosing Alzheimer's disease in a subject, or determining whether a subject is at increased risk of developing Alzheimer's disease, comprising:
 a. determining the amounts of Abeta peptide with O-linked Tyr10 glycosylation in a sample; and   b. comparing said level to a reference value representing a known disease or health status, wherein a varied level in said sample relative to a said reference value representing a known health status indicates a diagnosis, or prognosis, or increased risk of Alzheimer's disease.   
     
     
         2 . The method according to  claim 1 , wherein step a) comprises determining the amount of Abeta peptide with O-linked Tyr10 glycosylation relative to unglycosylated Abeta peptide. 
     
     
         3 . The method according to  claim 1 , wherein step a) comprises determining the amount of unglycosylated Abeta peptide relative to the total amount of Abeta peptide for indirect determination of Tyr10 glycosylated Abeta amount. 
     
     
         4 . The method according to  claim 1  wherein said sample is selected from the group consisting of cerebrospinal fluid, serum, urine, whole blood, lymphatic fluid, plasma, saliva, cells, tissue, and material secreted by cells or tissues cultured in vitro. 
     
     
         5 . The method according to  claim 1  wherein said determination of the level of O-linked glycosylation at Tyr10 of Abeta or APP is performed by a method or combination of methods selected from the group consisting of Enzyme-linked immunosorbent assays (ELISAs) Plasmon-enhanced colorimetric ELISA or other single molecule immunoassays using fluorescent lipid vesicles as enhancer elements, mass spectrometry (MS), positron emission tomography-computed tomography (PET), magnetic resonance imaging (MRI), immunosorbent assays, Radioimmunoassays (RIAs), lectin based assays, immunohistochemistry (IHC) methods, western blotting (WB), flow cytometry and similar sorbent-based assays, metabolic, enzymatic or chemical labeling with either isotopic, radioactive, fluorescent or chemically reactive monosaccharides or their precursors, liquid chromatography based methods or direct chemical reactions with either isotopic, radioactive, fluorescent or chemically reactive reagents with constituent monosaccharides or their precursors of the Tyr10 glycosylation of Abeta. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . The method according to  claim 5  wherein the ELISA comprises the steps of
 a. contacting a sample with a capture ligand under conditions that allow the target molecule to bind to the capture ligand; 
 b. subsequently contacting the capture ligand:target molecule complex with a detection ligand; 
 c. detecting the detection ligand using a detectable label conjugated to a binding moiety with affinity for the detection ligand, and 
 d. determining the level of the level of O-linked glycosylation at Tyr10 on Abeta by quantifying the detectable label. 
 
     
     
         9 . The method of  claim 8  wherein the capture ligand has affinity for a substance selected from the group consisting of the Abeta peptide and the O-linked glycosylation at Tyr10 peptide, and the detection ligand has affinity for a substance selected from the group consisting of the O-linked glycosylation at Tyr10 and the Abeta peptide. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 8  wherein either the capture ligand or the detection ligand has affinity for the combination of O-glycosylation at Tyr10 on Abeta and Abeta peptide backbone. 
     
     
         12 - 14 . (canceled) 
     
     
         15 . The method according to  claim 8  wherein the capture ligand of step a) is an anti-amyloid beta antibody. 
     
     
         16 - 17 . (canceled) 
     
     
         18 . The method according to claim  17  wherein the binding ligand is biotin; the capture ligand is the anti-human amyloid beta (N) 82E1 mouse IgG monoclonal antibody; the detectable label conjugated to a moiety with affinity for the binding ligand is peroxidase conjugated to streptavidin; and the quantifying of the detectable label is done by optically reading the signal output generated by a peroxidase-TMB reaction at 450 nm. 
     
     
         19 . The method of claim  17  wherein the capture ligand has affinity for the combination of O-glycosylation at Tyr10 on Abeta and Abeta peptide backbone. 
     
     
         20 . A kit for performing the method of  claim 1  comprising a substance selected from the group consisting of a capture ligand having affinity for the Abeta peptide and a detection ligand having affinity for the O-linked glycosylation at Tyr 10. 
     
     
         21 - 22 . (canceled) 
     
     
         23 . The method according to  claim 1  comprising the steps:
 a. Enrichment of Abeta peptides carrying the O-linked glycosylation on Tyr10 from a sample, 
 b. Separation of Abeta peptides using liquid chromatography, 
 c. Identification of Abeta peptide fragments by mass spectrometry and 
 d. Determination of the level of O-linked glycosylation at Tyr10 of Abeta. 
 
     
     
         24 - 27 . (canceled) 
     
     
         28 . A method of generating antibodies, comprising using one or more Tyr10 glycosylated Abeta peptides or Tyr10 glycosylated APP. 
     
     
         29 . An antibody or antibody-like molecule against one or more Tyr′ 0 glycosylated Abeta peptides or Tyr10 glycosylated APP. 
     
     
         30 . The antibody according to  claim 29  wherein the antibody is against a Tyr10 glycosylated Abeta peptide comprising SEQ ID 7. 
     
     
         31 . The method of  claim 5  for determination of the level of glycosylation at Tyr10 on Abeta or APP, comprising using an antibody against one or more Tyr10 glycosylated Abeta peptides or Tyr10 glycosylated APP. 
     
     
         32 - 37 . (canceled) 
     
     
         38 . The method according to  claim 5 , wherein the method is selected from the group consisting of ELISAs, Plasmon-enhanced colorimetric ELISA and other single molecule immunoassays using fluorescent lipid vesicles as enhancer elements and mass spectrometry. 
     
     
         39 . The method according to  claim 28 , wherein the one or more Tyr10 glycosylated Abeta peptides or Tyr10 glycosylated APP comprises SEQ ID 7.