Methods of modulating CD200 receptors

Abstract

Provided are methods for modulating activity of the immune system using agonists or antagonists of a CD200 receptor. Also provided are methods of treatment and diagnosis of immune disorders.

What is claimed is:  
     
         1 . A method of modulating the activity of a cell comprising contacting the cell with a binding composition derived from the antigen binding site of an antibody that specifically binds to CD200Ra (SEQ ID NOs:2 or 6), or an antigenic fragment thereof.  
     
     
         2 . The method of  claim 1 , wherein the cell is a mast cell.  
     
     
         3 . The method of  claim 1 , wherein the modulating: 
 a) inhibits cell activity; or    b) stimulates cell activity.    
     
     
         4 . The method of  claim 1 , wherein the modulating inhibits cell activity and the binding composition comprises an agonist of CD200Ra (SEQ ID NOs:2 or 6).  
     
     
         5 . The method of  claim 1 , wherein the modulating increases cell activity and the binding composition comprises an antagonist of CD200Ra (SEQ ID NOs:2 or 6).  
     
     
         6 . The method of  claim 1 , wherein the binding composition comprises: 
 a) a humanized antibody;    b) a monoclonal antibody;    c) a polyclonal antibody;    d) an Fab fragment;    e) an F(ab′) 2  fragment;    f) a peptide mimetic of an antibody; or    g) a detectable label.    
     
     
         7 . The method of  claim 1 , further comprising contacting the cell with an agent that enhances expression of CD200Ra (SEQ ID NOs:2 or 6), or an antigenic fragment thereof.  
     
     
         8 . A method of treating a subject suffering from an immune condition comprising treating with or administering the binding composition of  claim 1 .  
     
     
         9 . The method of  claim 8 , wherein the binding composition comprises an agonist or antagonist of CD200Ra (SEQ ID NOs:2 or 6).  
     
     
         10 . The method of  claim 8 , wherein the immune condition is: 
 a) an inflammatory condition; or    b) an autoimmune condition.    
     
     
         11 . The method of  claim 8 , wherein the immune condition is: 
 a) rheumatoid arthritis;    b) endotoxemia;    c) psoriasis; or    d) allergy.    
     
     
         12 . The method of  claim 8 , wherein the immune condition is: 
 a) an infection; or    b) a cancerous condition.    
     
     
         13 . The method of  claim 8 , wherein the binding composition is administered in conjunction with an agent that specifically enhances expression of CD200Ra (SEQ ID NOs:2 or 6), or an antigenic fragment thereof.  
     
     
         14 . A method of diagnosing an immune disorder comprising contacting a sample with a binding composition of  claim 1  and determining the modulation of cell activity.  
     
     
         15 . The method of  claim 14 , wherein the modulation is: 
 a) inhibition; or    b) activation.    
     
     
         16 . The method of  claim 14 , wherein the contacting is in vitro.