Modulators of P-selectin glycoprotein ligand 1

Abstract

Multimeric compounds that bind to P-Selectin Glycoprotein 1 (PSGL-1) on the surface of T cells or natural killer (NK) cells can be used to induce T cell or NK cell depletion and/or to induce T cell or NK cell apoptosis. The multimeric compounds and methods of the invention can be used to control unwanted T cell- or NK cell-mediated immune responses in conditions such as inflammatory diseases, autoimmune diseases, transplant rejection, and allergic diseases.

What is claimed is:  
     
         1 . A method of preventing or reducing a T cell-mediated immune response in an individual, the method comprising: 
 selecting an individual diagnosed as having or as being at risk of acquiring a condition characterized by an excessive or unwanted T cell-mediated immune response; and    administering to the individual a multimeric compound that binds to at least two P-Selectin Glycoprotein Ligand 1 (PSGL-1) proteins on the surface of a T cell, wherein the multimeric compound comprises two polypeptide chains, each of the polypeptide chains comprising (i) a binding domain that binds to PSGL-1, and (ii) a heterologous amino acid sequence, wherein the polypeptide chains are linked via the heterologous amino acid sequence to form the multimeric compound,    wherein the binding of the multimeric compound to the at least two PSGL-1 proteins on the surface of the T cell induces a signal transduction pathway that results in the death of the T cell, thereby preventing or reducing a T cell-mediated immune response in the individual.    
     
     
         2 . The method of  claim 1 , wherein the multimeric compound is a homo-multimeric compound.  
     
     
         3 . The method of  claim 1 , wherein the multimeric compound is a hetero-multimeric compound.  
     
     
         4 . The method of  claim 1 , wherein the heterologous amino acid sequence comprises a cell surface receptor binding region.  
     
     
         5 . The method of  claim 1 , wherein the binding domain comprises a P-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         6 . The method of  claim 1 , wherein the binding domain comprises an E-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         7 . The method of  claim 1 , wherein the binding domain comprises an L-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         8 . The method of  claim 1 , wherein the binding domain comprises an antigen binding domain of an anti-PSGL-1 antibody or a fragment thereof.  
     
     
         9 . The method of  claim 1 , wherein the binding domain comprises a PSGL-1 binding polypeptide selected from a phage display library.  
     
     
         10 . The method of  claim 1 , wherein the polypeptide chains are covalently linked via the heterologous amino acid sequence to form the multimeric compound.  
     
     
         11 . The method of  claim 10 , wherein the covalent linkage is a disulfide linkage.  
     
     
         12 . The method of  claim 1 , wherein the heterologous amino acid sequence comprises an immunoglobulin heavy chain constant region.  
     
     
         13 . The method of  claim 1 , further comprising administering to the individual an agent that binds to the multimeric compound via the heterologous amino acid sequence and induces cross-linking of a plurality of PSGL-1 antigens on the surface of the T cell.  
     
     
         14 . The method of  claim 1 , comprising selecting an individual diagnosed as having an inflammatory disease.  
     
     
         15 . The method of  claim 1 , comprising selecting an individual diagnosed as having an autoimmune disease.  
     
     
         16 . The method of  claim 1 , comprising selecting an individual that has received or is expected to receive an allogeneic or xenogeneic transplant.  
     
     
         17 . The method of  claim 1 , comprising selecting an individual diagnosed as having an allergic disease.  
     
     
         18 . The method of  claim 1 , comprising selecting an individual diagnosed as having a T cell cancer.  
     
     
         19 . The method of  claim 1 , wherein the T cell is an activated T cell.  
     
     
         20 . The method of  claim 1 , wherein the method comprises detecting the number of T cells in a first biological sample taken from the individual before the administration of the multimeric compound and comparing the results with the number of T cells in a second biological sample taken from the individual after the administration of the multimeric compound.  
     
     
         21 . The method of  claim 1 , wherein the method comprises detecting a biological activity of T cells in a first biological sample taken from the individual before the administration of the multimeric compound and comparing the results with the biological activity of T cells in a second biological sample taken from the individual after the administration of the multimeric compound.  
     
     
         22 . The method of  claim 1 , wherein the administration results in the depletion of at least 10% of activated T cells in the individual.  
     
     
         23 . A method of inducing the death of a T cell or a natural killer (NK) cell, the method comprising: 
 providing a T cell or NK cell expressing PSGL-1 on its cell surface; and    contacting the T cell or NK cell with a multimeric compound that binds to at least two PSGL-1 proteins on the surface of the T cell or NK cell, wherein the multimeric compound comprises two polypeptide chains, each of the polypeptide chains comprising (i) a binding domain that binds to PSGL-1, and (ii) a heterologous amino acid sequence, wherein the polypeptide chains are linked via the heterologous amino acid sequence to form the multimeric compound,    wherein the binding of the multimeric compound to the at least two PSGL-1 proteins on the surface of the T cell or NK cell induces a signal transduction pathway that results in the death of the T cell or NK cell.    
     
     
         24 . The method of  claim 23 , wherein the multimeric compound is a homo-multimeric compound.  
     
     
         25 . The method of  claim 23 , wherein the multimeric compound is a hetero-multimeric compound.  
     
     
         26 . The method of  claim 23 , wherein the heterologous amino acid sequence comprises a cell surface receptor binding region.  
     
     
         27 . The method of  claim 23 , wherein the binding domain comprises a P-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         28 . The method of  claim 23 , wherein the binding domain comprises an E-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         29 . The method of  claim 23 , wherein the binding domain comprises an L-Selectin extracellular domain or a PSGL-1-binding fragment thereof.  
     
     
         30 . The method of  claim 23 , wherein the binding domain comprises an antigen binding domain of an anti-PSGL-1 antibody or a fragment thereof.  
     
     
         31 . The method of  claim 23 , wherein the binding domain comprises a PSGL-1 binding polypeptide selected from a phage display library.  
     
     
         32 . The method of  claim 23 , wherein the polypeptide chains are covalently linked via the heterologous amino acid sequence to form the multimeric compound.  
     
     
         33 . The method of  claim 32 , wherein the covalent linkage is a disulfide linkage.  
     
     
         34 . The method of  claim 23 , wherein the heterologous amino acid sequence comprises an immunoglobulin heavy chain constant region.  
     
     
         35 . The method of  claim 23 , further comprising contacting the multimeric compound an agent that binds to the multimeric compound via the heterologous amino acid sequence and induces cross-linking of a plurality of PSGL-1 antigens on the surface of the T cell.  
     
     
         36 . The method of  claim 23 , comprising inducing the death of an activated T cell.  
     
     
         37 . The method of  claim 23 , wherein the method comprises assessing the viability of the T cell or NK cell after the contacting with the multimeric compound.  
     
     
         38 . The method of  claim 23 , wherein the method comprises assessing a biological activity of the T cell or NK cell after the contacting with the multimeric compound.  
     
     
         39 . A kit comprising: 
 a multimeric compound that binds to at least two PSGL-1 proteins on the surface of a T cell, wherein the multimeric compound comprises two polypeptide chains, each of the polypeptide chains comprising (i) a binding domain that binds to PSGL-1, and (ii) a heterologous amino acid sequence, wherein the polypeptide chains are linked via the heterologous amino acid sequence to form the multimeric compound, wherein the binding of the multimeric compound to the at least two PSGL-1 proteins on the surface of the T cell induces a signal transduction pathway that results in the death of the T cell; and    instructions for use of the multimeric compound to treat inflammation, autoimmunity, transplant rejection, an allergic condition, or a T cell cancer.