Islet cell antigen 1851

Abstract

A mammalian islet cell antigen polypeptide involved in the development of insulin-dependent diabetes mellitus (IDDM) is disclosed. This islet cell antigen polypeptide, 1851, was found to contain regions of homology to the protein tyrosine phosphatase family. Methods for diagnosis and treatment, including use in immunoprecipitation assays and the induction of immune tolerance using the recombinant mammalian polypeptides and antibodies specific to mammalian islet cell antigen 1851 polypeptides are presented.

We claim:  
     
         1 . An isolated polynucleotide comprising a DNA segment encoding a mammalian islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) a polypeptide of SEQ ID NO:16 from Leu, amino acid residue 636 to Gln, amino acid residue 1012:    b) a polypeptide of SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818; and    c) allelic variants of (a) or (b) 
 wherein the polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM.  
   
     
     
         2 . An isolated polynucleotide according to  claim 1 , wherein said isolated polynucleotide encodes a mammalian islet cell antigen polypeptide selected from the group consisting of: 
 a) a polypeptide of SEQ ID NO:16 from Phe, amino acid residue 612 to Gln, amino acid residue 1012;    b) a polypeptide of SEQ ID NO:22 from Phe, amino acid residue 418 to Gln, amino acid residue 818; and    c) allelic variants of (a) or (b).    
     
     
         3 . An isolated polynucleotide according to  claim 1 , wherein said isolated polynucleotide encodes a mammalian islet cell antigen polypeptide selected from the group consisting of: 
 a) a polypeptide of SEQ ID NO:16 from Ala, amino acid residue 1 to Gln, amino acid residue 1012;    b) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1 to Gln, amino acid residue 818; and    c) allelic variants of (a) or (b).    
     
     
         4 . An isolated polynucleotide according to  claim 1 , wherein said isolated polynucleotide is a DNA molecule selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ ID NO:15 from nucleotide 1909 to nucleotide 3039;    b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1325 to nucleotide 2455;    c) allelic variants of (a) or (b); and    d) complements of polynucleotide molecules that specifically hybridize to (a), (b) or (c).    
     
     
         5 . An isolated polynucleotide according to  claim 1 , wherein said isolated polynucleotide is a DNA molecule selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ ID NO:15 from nucleotide 1837 to nucleotide 3039;    b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 2 to nucleotide 2455;    c) allelic variants of (a) or (b); and    d) complements of polynucleotide molecules that specifically hybridize to (a), (b) or (c).    
     
     
         6 . An isolated polynucleotide according to  claim 1 , wherein said isolated polynucleotide is a DNA molecule selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ ID NO:15 from nucleotide 4 to nucleotide 3039;    b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1254 to nucleotide 2455;    c) allelic variants of (a) or (b); and    d) complements of polynucleotide molecules that specifically hybridize to (a), (b) or (c).    
     
     
         7 . An isolated polynucleotide according to  claim 1  which encodes a full length mammalian islet cell antigen polypeptide comprising the sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         8 . An isolated polynucleotide comprising a DNA segment encoding a mammalian islet cell antigen polypeptide according to  claim 1 , wherein said mammalian islet cell antigen polypeptide is a primate islet cell antigen polypeptide.  
     
     
         9 . A DNA construct comprising a first DNA segment encoding a human islet cell antigen polypeptide operably linked to additional DNA segments required for the expression of said first DNA segment, wherein said first DNA segment encodes a human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c) 
 wherein said mammalian islet cell antigen polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM.  
   
     
     
         10 . A DNA construct according to  claim 9  herein said first DNA segment comprises a nucleotide sequence selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ. ID NO:21 from nucleotide 1325 to nucleotide 2455;  
 b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1253 to nucleotide 2455;  
 c) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 2 to nucleotide 2455;  
 d) naturally occurring allelic variants of (a), (b) or (c); and  
 e) complements of polynucleotide molecules that specifically hybridize to (a), (b), (c) or (d).  
 
     
     
         11 . A DNA construct according to  claim 9 , wherein said first segment encodes a full length mammalian islet cell antigen comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         12 . A DNA construct comprising a first DNA segment encoding a mammalian islet cell antigen according to  claim 9 , wherein said mammalian islet cell antigen polypeptide is a primate islet cell antigen polypeptide.  
     
     
         13 . A host cell containing a DNA construct comprising a first DNA segment encoding a mammalian islet cell antigen polypeptide operably linked to additional DNA segments required for the expression of said first DNA segment, wherein said first DNA segment encodes a human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c) 
 wherein said mammalian islet cell antigen polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM.  
   
     
     
         14 . A host cell according to  claim 13 , wherein said first DNA segment comprises a nucleotide sequence selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1325 to nucleotide 2455;    b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1253 to nucleotide 2455;    c) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 2 to nucleotide 2455;    d) naturally occurring allelic variants of (a), (b) or (c); and    e) complements of polynucleotide molecules that specifically hybridize to (a), (b), (c) or (d).    
     
     
         15 . A host cell according to  claim 13 , wherein said first DNA segment encodes a full length mammalian islet cell antigen polypeptide comprising the sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         16 . A host cell containing a DNA construct comprising a first DNA segment encoding a mammalian islet cell antigen polypeptide according to  claim 13 , wherein said mammalian islet cell antigen polypeptide is a primate islet cell antigen polypeptide.  
     
     
         17 . An isolated mammalian islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c) 
 wherein said mammalian islet cell antigen polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM.  
   
     
     
         18 . An isolated mammalian islet cell antigen polypeptide according to  claim 17 , wherein said isolated mammalian islet cell antigen polypeptide is a full length mammalian islet cell antigen polypeptide comprising the sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         19 . An isolated mammalian islet cell antigen polypeptide according to  claim 17 , wherein said mammalian islet cell antigen polypeptide is a primate islet cell antigen polypeptide.  
     
     
         20 . A method for producing a mammalian islet cell antigen polypeptide comprising the steps of: 
 culturing a host cell containing a DNA construct comprising a first DNA segment operably linked to additional DNA segments required for the expression of said first DNA segment, wherein said first DNA segment encodes a human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;  
 b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;  
 c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and  
 d) allelic variants of (a), (b) or (c) 
 wherein said mammalian islet cell antigen polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM; and  
 
   isolating said mammalian islet cell antigen polypeptide.    
     
     
         21 . A method for producing a mammalian islet cell antigen polypeptide according to  claim 20 , wherein said first DNA segment comprises a nucleotide sequence selected from the group consisting of: 
 a) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1325 to nucleotide 2455;    b) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 1253 to nucleotide 2455;    c) a DNA molecule comprising the coding sequence of SEQ ID NO:21 from nucleotide 2 to nucleotide 2455;    d) naturally occurring allelic variants of (a), (b) or (c); and    e) complements of polynucleotide molecules that specifically hybridize to (a), (b), (c) or (d).    
     
     
         22 . A method for producing a mammalian islet cell antigen polypeptide according to  claim 20 , wherein said first DNA segment encodes a full length mammalian islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         23 . A method for producing a human islet cell antigen polypeptide according to  claim 20 , wherein said host cell is a bacterial cell or a cultured human cell.  
     
     
         24 . A method for determining the presence of an autoantibody to a human islet cell antigen polypeptide in a biological sample comprising the steps of: 
 contacting a biological sample with a human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;  
 b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;  
 c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and  
 d) allelic variants of (a), (b) or (c), 
 under conditions conducive to immune complex formation, and  
 
   detecting the presence of immune complex formation between said human islet cell antigen polypeptide and said autoantibody to a human islet cell antigen, thereby determining the presence of an autoantibody to said human islet cell antigen in said biological sample.    
     
     
         25 . The method of determining the presence of an autoantibody to a human islet cell antigen polypeptide according to  claim 24 , wherein said human islet cell antigen polypeptide is detectably labeled.  
     
     
         26 . A method of determining the presence of an autoantibody to a human islet cell antigen polypeptide according to  claim 24 , wherein said human islet cell antigen polypeptide is a full length human islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         27 . A method for predicting the clinical course of IDDM in a patient comprising: 
 testing a biological sample from a patient for the presence of human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;  
 b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;  
 c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and  
 d) allelic variants of (a), (b) or (c), wherein said polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM and  
   classifying said patient for clinical course of diabetes based on the presence or absence of mammalian islet cell antigen polypeptides in said sample.    
     
     
         28 . A method for predicting the clinical course of IDDM according to  claim 27 , wherein said patient is further tested for one or more additional predictive markers associated with risk of or protection from IDDM.  
     
     
         29 . A method for predicting the clinical course of IDDM according to  claim 27 , wherein said predictive marker is an autoantibody to an antigen selected from the group consisting of GAD65, IA-2/ICA512, or insulin.  
     
     
         30 . A method for predicting the clinical course of IDDM according to  claim 27 , wherein said predictive marker is a genotype selected from the group consisting of HLA DR and HLA DQ.  
     
     
         31 . A method for predicting the clinical course of IDDM according to  claim 27 , wherein said predictive marker is a polymorphic region in the 5′ flanking region of a human insulin gene.  
     
     
         32 . A method of predicting the clinical course of IDDM according to  claim 27 , wherein said human islet cell antigen polypeptide is a full length human islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         33 . A method of treating a patient to prevent an autoimmune response to a human islet cell antigen polypeptide, the method comprising inducing immunological tolerance in said patient by administering a human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c), 
 that specifically binds a human islet cell antigen receptor on immature or mature T or B lymphocytes.  
   
     
     
         34 . A method of treating a patient to prevent an autoimmune response to a human islet cell antigen polypeptide according to  claim 33 , wherein said human islet cell antigen polypeptide is a full length human islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         35 . A probe which comprises an oligonucleotide of at least about 16 nucleotides, wherein said oligonucleotide is at least 85% identical to a sequence of the human islet cell antigen DNA sequence of SEQ ID NOs: 15 or 21.  
     
     
         36 . An isolated antibody which specifically binds to a human islet cell antigen polypeptide, wherein said human islet cell antigen polypeptide comprising an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c).    
     
     
         37 . An isolated antibody according to  claim 36 , wherein said isolated antibody is a monoclonal antibody.  
     
     
         38 . An isolated antibody according to  claim 36 , wherein said human islet cell antigen polypeptide is a full length human islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         39 . A hybridoma which produces a monoclonal antibody which specifically binds to a human islet cell antigen polypeptide, wherein said human islet cell antigen polypeptide comprises an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c).    
     
     
         40 . A hybridoma according to  claim 39 , wherein said human islet cell antigen polypeptide is a full length human islet cell antigen polypeptide comprising the amino acid sequence of SEQ ID NO:22 from Leu, amino acid residue 442 to Arg, amino acid residue 738.  
     
     
         41 . A diagnostic kit for use in detecting an autoantibody to pancreatic β-islet cells, comprising a container containing a human islet cell antigen polypeptide wherein said human islet cell antigen polypeptide comprises an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;  
 b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;  
 c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and  
 d) allelic variants of (a), (b) or (c), 
 wherein said polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM, and one or more containers containing additional reagents.  
 
 
     
     
         42 . A pharmaceutical composition which comprises a human islet cell antigen polypeptide, wherein said human islet cell antigen polypeptide comprises an amino acid sequence selected from the group consisting of: 
 a) SEQ ID NO:22 from Leu, amino acid residue 442 to Gln, amino acid residue 818;    b) SEQ ID NO:22 from Phe, amino acid residue 418, to Gln, amino acid residue 818;    c) a polypeptide of SEQ ID NO:22 from His, amino acid residue 1, to Gln, amino acid residue 818; and    d) allelic variants of (a), (b) or (c), wherein said polypeptide forms an immune complex with an autoantibody from a patient at risk of or predisposed to develop IDDM in combination with a pharmaceutically acceptable carrier or vehicle.    
     
     
         43 . A method for monitoring the disease state in a patient comprising: 
 testing a biological sample from a patient for the presence of mammalian islet cell antigen post-translationally modified polypeptides;    determining the concentration of said polypeptides; and    correlating levels of said polypeptides in said sample with the disease state in a patient.    
     
     
         44 . A method for monitoring the disease state in a patient according to  claim 43  wherein said human islet cell antigen post-translationally modified polypeptide comprise the sequence of SEQ ID NO:22 from His, amino acid residue 1 to Glu, amino acid residue 227.  
     
     
         45 . A method for monitoring the disease state in a patient according to  claim 43  wherein said biological sample is plasma or serum.  
     
     
         46 . A method for monitoring the disease state in a patient comprising: 
 exposing T cells to islet cell antigen 1851 peptides;    detecting T cell reactivity; and    correlating T cell reactivity with disease state.    
     
     
         47 . A method for monitoring the disease state according to  claim 46  wherein said T cells are from peripheral blood mononuclear cells from a prediabetic patient.  
     
     
         48 . A method for monitoring the disease state according to  claim 46  wherein said disease state is conversion from prediabetes to diabetes.