Antibodies specific for osteoprotegerin binding proteins and method of use

Abstract

A novel polypeptide, oseteoprotegerin binding protein, involved in osteolcast maturation has been identified based upon its affinity for osteoprotegerin. Nucleic acid sequences encoding the polypeptide, or a fragment, analog or derivative thereof, vectors and host cells for production, methods of preparing osteoprotegerin binding protein, and binding assays are also described. Compositions and methods for the treatment of bone diseases such as osteoporosis, bone loss due to arthritis or metastasis, hypercalcemia, and Paget's disease are also provided.

What is claimed is:  
     
         1 . An isolated nucleic acid encoding an osteoprotegerin binding protein selected from the group consisting of: 
 a) the nucleic acid sequence as in FIG. 1 (SEQ ID NO:______);    b) nucleic acids which hybridize to the polypeptide coding regions as shown in FIG. 1 (SEQ ID NO:______) and remain hybridized under high stringency conditions; and    c) nucleic acids which are degenerate to the nucleic acids of (a) or (b).    
     
     
         2 . The nucleic acid of  claim 1  which is cDNA, genomic DNA, synthetic DNA or RNA.  
     
     
         3 . A polypeptide encoded by the nucleic acid of  claim 1 .  
     
     
         4 . The nucleic acid of  claim 1  including one or more codons preferred for  Escherichia coli  expression.  
     
     
         5 . The nucleic acid of  claim 1  having a detectable label attached thereto.  
     
     
         6 . The nucleic acid of  claim 1  comprising the polypeptide-coding region of residues 1-316 as shown in FIG. 1 (SEQ ID NO:______).  
     
     
         7 . A nucleic acid encoding a polypeptide having the amino acid sequence of residues 1-316 or residues 70-316 as shown in FIG. 1 (SEQ ID NO:______).  
     
     
         8 . An expression vector comprising the nucleic acid of  claim 1 .  
     
     
         9 . The expression vector of  claim 8  wherein the nucleic acid comprises the polypeptide-encoding region as shown in FIG. 1 (SEQ ID NO:______).  
     
     
         10 . A host cell transformed or transfected with the expression vector of  claim 8 .  
     
     
         11 . The host cell of  claim 10  which is a eucaryotic or procaryotic cell.  
     
     
         12 . The host cell of  claim 11  which is  Escherichia coli.    
     
     
         13 . A process for the production of an osteoprotegerin binding protein comprising: 
 growing under suitable nutrient conditions host cells transformed or transfected with the nucleic acid of  claim 1;  and    isolating the polypeptide product of the expression of the nucleic acid.    
     
     
         14 . A polypeptide produced by the process of  claim 13 .  
     
     
         15 . A purified and isolated osteoprotegerin binding protein, or fragment, analog, or derivative thereof.  
     
     
         16 . The protein of  claim 15  which is a human osteoprotegerin.  
     
     
         17 . The protein of  claim 15  having the amino acid sequence as shown in FIG. 1 (SEQ ID NO:______).  
     
     
         18 . The protein of  claim 15  which has been covalently modified with a water-soluble polymer.  
     
     
         19 . The protein of  claim 18  wherein the polymer is polyethylene glycol.  
     
     
         20 . The protein of  claim 15  which is a soluble osteoprotegerin binding protein.  
     
     
         21 . The protein of  claim 20  having the amino acid sequence from residues 70-316 inclusive as shown in FIG. 1 (SEQ ID NO:______), or a fragment, analog, or derivative thereof.  
     
     
         22 . An antibody or fragment thereof which specifically binds an osteoprotegerin binding protein.  
     
     
         23 . The antibody of  claim 22  which is a monoclonal antibody.  
     
     
         24 . A method for detecting the presence of an osteoprotegerin binding protein in a biological sample comprising: 
 incubating the sample with the antibody of  claim 22  under conditions that allow binding of the antibody to the osteoprotegerin binding protein; and    detecting the bound antibody.    
     
     
         25 . A method for detecting the presence of osteoprotegerin in a biological sample comprising: 
 incubating the sample with an osteoprotegerin binding protein under conditions that allow binding of the protein to osteoprotegerin; and    measuring the bound osteoprotegerin binding protein.    
     
     
         26 . A method to assess the ability of a candidate compound to bind to an osteoprotegerin binding protein comprising: 
 incubating the osteoprotegerin binding protein with the candidate compound under conditions that allow binding; and    measuring the bound compound.    
     
     
         27 . The method of  claim 26  wherein the compound is an agonist or an antagonist of an osteoprotegerin binding protein.  
     
     
         28 . A method of regulating expression of an osteoprotegerin binding protein in an animal comprising administering to the animal a nucleic acid complementary to the nucleic acids as shown in FIG. 1 (SEQ ID NO:______).  
     
     
         29 . A pharmaceutical composition comprising a therapeutically effective amount of an osteoprotegerin binding protein in a pharmaceutically acceptable carrier, adjuvant, solubilizer, stabilizer and/or anti-oxidant.  
     
     
         30 . The composition of  claim 29  wherein the osteoprotegerin binding protein is a human osteoprotegerin binding protein.  
     
     
         31 . A method of treating bone disease in a mammal comprising administering a therapeutically effective amount of a modulator of an osteoprotegerin binding protein.  
     
     
         32 . The method of  claim 31  wherein the modulator is a soluble form of an osteoprotegerin binding protein.  
     
     
         33 . The method of  claim 32  wherein the modulator is an antibody, or fragment thereof, which specifically binds an osteoprotegerin binding protein.