Methods and molecules useful for identifying molecules that bind LFA-1 and for determining receptor occupancy

Abstract

The present invention relates generally to a method for identifying molecules that bind the R7.1 epitope of LFA-1 or bind LFA-1 such that the R7.1 epitope is modified. The present invention further relates to a method for determining occupancy of the LFA-1 receptor by molecules that bind to the R7.1 epitope or bind LFA-1 such that the R7.1 epitope is modified after administration to a subject. The present invention further relates to molecules useful in the methods of the invention.

What is claimed is:  
     
         1 . A method for identifying a molecule that binds or modifies the R7.1 epitope of LFA-1 comprising: 
 (a) incubating a cell that expresses LFA-1 with a first test molecule and a second molecule that specifically binds the R7.1 epitope of LFA-1 or binds LFA-1 such that the R7.1 epitope is modified; and    (b) detecting the second molecule;    wherein a decrease in binding of the second molecule indicates binding of the first test molecule.    
     
     
         2 . A method for identifying a molecule that binds or modifies the R7.1 epitope of LFA-1 comprising: 
 (a) incubating purified LFA-1 that expresses LFA-1 with a first test molecule and a second molecule that specifically binds the R7.1 epitope of LFA-1 or binds LFA-1 such that the R7.1 epitope is modified; and    (b) detecting the second molecule,    wherein a decrease in binding of the second molecule indicates binding of the first test molecule.    
     
     
         3 . The method according to  claim 1  wherein the second molecule is a compound of the formula I.  
     
     
         4 . The method according to  claim 2  wherein the second molecule is a compound of the formula I.  
     
     
         5 . The method according to  claim 1  wherein the second molecule is a compound of the formula II.  
     
     
         6 . The method according to  claim 2  wherein the second molecule is a compound of the formula II.  
     
     
         7 . The method according to  claim 1  wherein the second molecule is a compound of the formula III.  
     
     
         8 . The method according to  claim 2  wherein the second molecule is a compound of the formula III.  
     
     
         9 . A method for identifying a molecule that specifically binds or modifies the R7.1 epitope of LFA-1 comprising: 
 (a) incubating a cell that expresses LFA-1 (i) a first test molecule, (ii) a second molecule that specifically binds the R7.1 epitope of LFA-1 or binds LFA-1 such that the R7.1 epitope is modified, and (iii) a third labeled molecule, wherein the third labeled molecule binds the second molecule; and    (b) detecting the third labeled molecule bound to the second molecule;    wherein a decrease in binding of the second molecule indicates binding of the first test molecule.    
     
     
         10 . A method for identifying a molecule that specifically binds or modifies the R7.1 epitope of LFA-1 comprising: 
 (a) incubating purified LFA-1 that expresses LFA-1 with (i) a first test molecule, (ii) a second molecule that specifically binds the R7.1 epitope of LFA-1 or binds LFA-1 such that the R7.1 epitope is modified, and (iii) a third labeled molecule, wherein the third labeled molecule binds the second molecule; and    (b) detecting the third labeled molecule bound to the second molecule;    wherein a decrease in binding of the second molecule indicates binding of the first test molecule.    
     
     
         11 . The method according to any of claims  1 ,  2 ,  9 , or  10  wherein the molecule that specifically binds or modifies the R7.1 epitope is a monoclonal antibody or a fragment thereof.  
     
     
         12 . The method according to  claim 11  wherein the monoclonal antibody is R7.1.  
     
     
         13 . The method according to any one of claims  1 - 10  wherein the labeled molecule is labeled with a fluorescent compound.