Compositions and methods for modulating blood-brain barrier transport

Abstract

This invention provides conjugates of therapeutic or active agents with melanotransferrin or with other ligands of a melanotransferrin receptor, melanotransferrin receptor modulators, and related compositions and methods for modulating blood-brain barrier transport by providing methods of screening and selecting such conjugates, ligands, and modulators in vitro and in vivo, and methods of use of such conjugates, modulators and ligands in diagnosis and the treatment of diseases, including particularly diseases of the central nervous system or lysosomal storage diseases.

What is claimed is:  
     
         1 . A method for identifying a compound that modulates the transcytosis or endocytosis of melanotransferrin or a melanotransferrin conjugate with an active agent, said method comprising: 
 contacting melanotransferrin (“MTf”) and said MTf-receptor (“MTf-R”) with said compound; and    determining the functional effect of said compound.    
     
     
         2 . The method of  claim 1  wherein said compound has neurological activity.  
     
     
         3 . The method of  claim 2  wherein the neurological activity is treatment, prophylaxis or diagnosis of a neurological disorder.  
     
     
         4 . The use of  claim 2  wherein the neurological activity is to reduce an undesirable side-effect of a therapeutic agent.  
     
     
         5 . The use of  claim 3  wherein the neurological activity is modulation of the uptake of melanotransferrin conjugated therapeutic agents into the brain.  
     
     
         6 . The method of  claim 1  wherein the method is a high throughput screening assay.  
     
     
         7 . A method of modulating a melanotransferrin receptor (“MTf-R”), said method comprising: contacting said MTf-R with a compound identified using the method of  claim 1 .  
     
     
         8 . A method of treating a neurological disorder in a patient, said method comprising administering to said patient a therapeutically effective amount of a compound identified using the method of  claim 1 .  
     
     
         9  A method of  claim 1 , wherein the MTf-R is LRP or LRP1B.  
     
     
         10  The method of  claim 1 , wherein the compound is a endogenous human MTf-R ligand.  
     
     
         11 . The method of  claim 1 , wherein the MTf-R is human.  
     
     
         12 . A method of  claim 1 , wherein the compound is lactoferrin or RAP.  
     
     
         13 . A method for increasing the uptake of a melanotransferrin conjugated therapeutic agent into the brain of a patient, said method comprising administering a modulator of MTf-R biological activity and said melanotransferrin conjugated therapeutic agent.  
     
     
         14 . The method of  claim 13  wherein said modulator of MTf-R biological activity and said melanotransferrin conjugated therapeutic agent are administered contemporaneously.  
     
     
         15 . The method of  claim 9  wherein said modulator of MTf-R biological activity and said melanotransferrin conjugated therapeutic agent are administered sequentially.  
     
     
         16 . A method of reducing the uptake of a melanotransferrin conjugated therapeutic agent into the brain of a patient, said method comprising administering a modulator of MTf-R biological activity either contemporaneously or sequentially with a melanotransferrin conjugated therapeutic agent.  
     
     
         17 . The method of  claim 13  wherein the modulator is first identified according to the method of  claim 1 .  
     
     
         18 . A modulator of MTf-R biological activity, said modulator identified using the method of  claim 1 .  
     
     
         19 . The modulator of  claim 18  wherein said modulator is useful for reducing a neurological side-effect of a therapeutic agent.  
     
     
         20 . A method of identifying a compound that modulates melanotransferrin-mediated (“MTf-mediated) iron uptake, said method comprising: contacting a cell expressing MTf on its surface with said compound in the presence of MTf bound to iron (“halo-MTf”) and in the absence of transferrin; and determining the amount of iron uptake into said cell.  
     
     
         21 . The method of  claim 20 , wherein said compound increases the amount of iron uptake into said cell.  
     
     
         22 . The method of  claim 20 , wherein said compound decreases the amount of iron uptake into said cell.  
     
     
         23 . The method of  claim 20 , wherein MTf-R is LRP1 or LRP1B.  
     
     
         24 . The method of  claim 23 , wherein the LRP1B is human.  
     
     
         25 . A conjugate of an LRP1B receptor ligand with an active agent, wherein the ligand is not selected from the group comprising p97, lactoferrin, transferrin RAP, or fragments thereof.  
     
     
         26 . A conjugate of  claim 25 , wherein the conjugate is a fusion protein.  
     
     
         27 . A conjugate of  claim 25 , wherein the active agent is an enzyme.  
     
     
         28 . A cojugate of  claim 27 , wherein the enzyme is an enzyme deficient in a lysosomal storage disease.