Nogo receptor-mediated blockade of axonal growth

Abstract

Disclosed are NgR proteins and biologically active Nogo (ligand) protein fragments. Also disclosed are compositions and methods for modulating the expression or activity of the Nogo and NgR protein. Also disclosed are peptides which block Nogo-mediated inhibition of axonal extension. The compositions and methods of the invention are useful in the treatment of cranial or cerebral trauma, spinal cord injury, stroke or a demyelinating disease.

1 - 43 . (canceled) 
     
     
         44 . An isolated polynucleotide comprising a first nucleic acid encoding a fragment of the polypeptide of SEQ ID NO:2, or a variant thereof, wherein said polypeptide inhibits NOGO-receptor-mediated neurite outgrowth inhibition. 
     
     
         45 . The polynucleotide of  claim 44 , wherein said polypeptide is selected from the group consisting of (a) amino acids 27 to 309 of SEQ ID NO:2, (b) amino acids 27-445 of SEQ ID NO:2, (c) amino acids 1 to 348 of SEQ ID NO:2, and (d) amino acids 1-309 of SEQ ID NO:2. 
     
     
         46 . The polynucleotide of  claim 45 , further comprising a second nucleic acid encoding a heterologous polypeptide fused to said polypeptide. 
     
     
         47 . A vector comprising the polynucleotide of  claim 44 . 
     
     
         48 . The vector of  claim 47 , wherein said polynucleotide is operably linked to one or more expression control elements. 
     
     
         49 . An isolated host cell comprising the polynucleotide of  claim 44 . 
     
     
         50 . The host cell of  claim 49 , wherein said polynucleotide is operably linked to one or more expression control elements. 
     
     
         51 . A method for producing a polypeptide comprising culturing the host cell of  claim 49  under conditions suitable for expression of the polypeptide and recovering the polypeptide from the culture medium. 
     
     
         52 . An isolated antibody which specifically binds to a polypeptide encoded by the polynucleotide of  claim 45  or antigen-binding fragment of said antibody wherein said antibody or antibody fragment inhibits NOGO-receptor-mediated neurite outgrowth inhibition. 
     
     
         53 . The antibody of  claim 52 , wherein said antibody or antigen binding fragment thereof is selected from the group consisting of a polyclonal antibody, a monoclonal antibody, a human antibody, a humanized antibody, a chimeric antibody, an Fab fragment, an Fab′ fragment and an F(ab′)2 fragment. 
     
     
         54 . A method of producing the antibody of  claim 52  comprising (a) immunizing a mammalian subject with a NgR polypeptide; and (b) recovering said antibody. 
     
     
         55 . A method of inhibiting CNS myelin-mediated neurite outgrowth inhibition or promoting axonal regeneration comprising contacting a neuron with a Nogo receptor (NgR) antagonist selected from the group consisting of: (a) an isolated NgR polypeptide; and (b) an antibody or antigen binding fragment thereof that binds a NgR polypeptide; wherein said NgR antagonist inhibits CNS myelin-induced neurite outgrowth inhibition or promotes axonal regeneration. 
     
     
         56 . The method of  claim 55 , wherein said neuron is a mammalian cell. 
     
     
         57 . The method of  claim 56 , wherein said mammalian cell is a human cell. 
     
     
         58 . A method of promoting neurite outgrowth or axonal regeneration in a mammal comprising administering to a mammal in need thereof an effective amount of a Nogo receptor (NgR) antagonist, wherein said NgR antagonist is selected from the group consisting of:
 (a) an isolated NgR polypeptide; and   (b) an antibody or antigen binding fragment thereof that binds a NgR polypeptide; wherein said NgR antagonist inhibits CNS myelin-induced neurite outgrowth inhibition or promotes axonal regeneration.   
     
     
         59 . A method of treating a central nervous system disease, disorder or injury in a mammal, comprising administering to a mammal in need thereof an effective amount of a NgR antagonist selected from the group consisting of: (a) an isolated NgR polypeptide; and
 (b) an antibody or antigen binding fragment thereof that binds a NgR polypeptide; wherein said NgR antagonist inhibits CNS myelin-induced neurite outgrowth inhibition or promotes axonal regeneration.   
     
     
         60 . The method of  claim 59 , wherein said central nervous system disease, disorder or injury is selected from the group consisting of cranial or cerebral trauma, spinal cord injury, stroke, multiple sclerosis, monophasic demyelination, encephalomyelitis, multifocal leukoencephalopathy, panencephalitis, Marchiafava-Bignami disease, pontine myelinolysis, adrenoleukodystrophy, Pelizaeus-Merzbacher disease, Spongy degeneration, Alexander's disease, Canavan's disease, metachromatic leukodystrophy, and Krabbe's disease. 
     
     
         61 . A method for identifying a molecule that decreases Nogo-dependent inhibition of axonal growth, the method comprising: (a) providing a Nogo polypeptide and a NgR polypeptide; (b) contacting the NgR polypeptide with a candidate molecule; and (c) detecting a decrease in binding of the Nogo polypeptide to the NgR in the presence of the candidate molecule, as compared to the binding of the Nogo polypeptide to the NgR in the absence of the candidate molecule, and wherein said Nogo-dependent inhibition of axonal growth is decreased in the presence of said candidate molecule. 
     
     
         62 . A method of identifying an agent which modulates Nogo receptor protein expression comprising the steps of: (a) providing a cell expressing a Nogo receptor protein; (b) contacting the cell with a candidate agent; and (c) detecting an increase or decrease in the level of Nogo receptor protein expression in the presence of the candidate agent relative to the level of Nogo receptor protein expression in the absence of the candidate agent.