Induced internalization of surface receptors

Abstract

Disclosed is a hetero-bifunctional ligand for use in inducing internalization of a target receptor. The hetero-bifunctional ligand includes a target receptor-binding agent that specifically binds the target receptor linked to an internalizing receptor-binding agent that specifically binds to an internalizing receptor, where the two binding agents are non-identical. Also disclosed is a method of inducing the internalization of a target receptor on a cell. The method includes contacting a cell with a hetero-bifunctional ligand, where binding of the hetero-bifunctional ligand induces internalization of a target receptor of the cell. Also disclosed is a method of treating a disease or condition associated with a target receptor using the disclosed hetero-bifunctional ligand and pharmaceutical compositions including a hetero-bifunctional ligand.

We claim: 
     
         1 . A hetero-bifunctional ligand for use in inducing internalization of a target receptor, comprising:
 a target receptor-binding agent that specifically binds the target receptor;   a heterologous internalizing receptor-binding agent that specifically binds to an internalizing receptor, wherein binding of the hetero-bifunctional ligand to the internalizing receptor on a cell induces internalization of the internalizing receptor and wherein the target receptor-binding agent and the internalizing receptor-binding agent are not identical; and   a linker linking the target receptor-binding agent to the internalizing receptor-binding agent, wherein the linker has a length sufficient to allow the hetero-bifunctional ligand to bind to the target receptor and the internalizing receptor on the cell.   
     
     
         2 . The hetero-bifunctional ligand of  claim 1 , wherein the internalizing receptor-binding agent and the target receptor-binding agent do not specifically bind the same receptor. 
     
     
         3 . The hetero-bifunctional ligand of  claim 1 , wherein the linker is a heterologous linker. 
     
     
         4 . The hetero-bifunctional ligand of  claim 1 , wherein the target receptor-binding agent comprises an antibody or a small molecule that specifically binds the target receptor. 
     
     
         5 . The hetero-bifunctional ligand of  claim 1 , wherein the target receptor-binding agent is a target receptor ligand. 
     
     
         6 . The hetero-bifunctional ligand of  claim 1 , wherein the internalizing receptor comprises a scavenger receptor, low density lipoprotein (LDL) receptor, a heat shock protein receptor or a transferrin receptor. 
     
     
         7 . The hetero-bifunctional ligand of  claim 1 , wherein the target receptor-binding agent is a ligand or antibody for a CCR5 or CXCR4 receptor or vascular endothelial growth factor-A (VEGF-A). 
     
     
         8 . The hetero-bifunctional ligand of  claim 1 , wherein the internalizing receptor-binding agent is Acetylated-LDL, a sulfated polysaccharide, or an oligonucleotide. 
     
     
         9 . A method of inducing internalization of a target receptor on a cell, comprising:
 contacting the cell with an effective amount of the hetero-bifunctional ligand of  claim 1 .   
     
     
         10 . A pharmaceutical composition, comprising a therapeutically effective amount of the hetero-bifunctional ligand of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         11 . The hetero-bifunctional ligand of  claim 1 , for use in treating or inhibiting HIV infection, wherein the target receptor-binding agent specifically binds to a target receptor used by HIV to bind or gain entry into a cell. 
     
     
         12 . The hetero-bifunctional ligand of  claim 7 , wherein the ligand for the CCR5 or CXCR4 receptor comprises a chemokine. 
     
     
         13 . A pharmaceutical composition comprising a therapeutically effective amount of the hetero-bifunctional ligand of  claim 11  and a pharmaceutically acceptable carrier. 
     
     
         14 . A method of treating or inhibiting an HIV infection, comprising administering a therapeutically effective amount of the pharmaceutical composition of  claim 13  to a subject having or suspected of having an HIV infection, wherein the hetero-bifunctional ligand present in the pharmaceutical composition binds to the CCR5 or the CXCR4 receptor and induces the internalization of the CCR5 or the CXCR4 receptor, thereby treating or inhibiting the HIV infection. 
     
     
         15 . The hetero-bifunctional ligand of  claim 1 , for use in inhibiting angiogenesis, wherein the target receptor binding agent comprises VEGF-A and the internalizing receptor-binding agent comprises acetylated-LDL or an oligonucleotide. 
     
     
         16 . A pharmaceutical composition comprising a therapeutically effective amount of the hetero-bifunctional ligand of  claim 15  and a pharmaceutically acceptable carrier. 
     
     
         17 . A method of inhibiting angiogenesis, comprising administering a therapeutically effective amount of the pharmaceutical composition of  claim 16  to a subject, wherein the hetero-bifunctional ligand present in the pharmaceutical composition binds to the VEGF-A receptor and induces the internalization of the receptor, thereby inhibiting angiogenesis. 
     
     
         18 . The hetero-bifunctional ligand of  claim 1 , wherein the target receptor comprises neuropilin-1, neuropilin-2, a vascular endothelial growth factor (VEGF) receptor, an interleukin receptor, an interferon receptor, a receptor tyrosine kinase receptor, or a chemokine receptor.