ErbB3 ANTIBODIES

Abstract

Antibodies are disclosed which bind to ErbB3 protein and further possess any one or more of the following properties: an ability to reduce heregulin-induced formation of an ErbB2-ErbB3 protein complex in a cell which expresses ErbB2 and ErbB3; the ability to increase the binding affinity of heregulin for ErbB3 protein; and the characteristic of reducing heregulin-induced ErbB2 activation in a cell which expresses ErbB2 and ErbB3.

1 . An antibody which binds to ErbB3 protein and reduces heregulin-induced formation of an ErbB2-ErbB3 protein complex in a cell which expresses ErbB2 and ErbB3, wherein the antibody is conjugated to a cytotoxic agent. 
     
     
         2 . The antibody of  claim 1  which further increases the binding affinity of heregulin for ErbB3 protein. 
     
     
         3 . The antibody of  claim 1  which further reduces heregulin-induced ErbB2 activation in the cell. 
     
     
         4 . The antibody of  claim 1  which is a monoclonal antibody. 
     
     
         5 . The antibody of  claim 1  which is humanized. 
     
     
         6 . The antibody of  claim 1  which is human. 
     
     
         7 . The antibody of  claim 1  which is an antibody fragment. 
     
     
         8 . The antibody fragment of  claim 7  which is a Fab. 
     
     
         9 . The antibody of  claim 1  which is labelled. 
     
     
         10 . The antibody of  claim 1  which is immobilized on a solid phase. 
     
     
         11 . (canceled) 
     
     
         12 . An antibody which binds to ErbB3 protein and reduces heregulin-induced ErbB2 activation in a cell which expresses ErbB2 and ErbB3. 
     
     
         13 . An antibody which binds to ErbB3 protein and reduces heregulin binding thereto. 
     
     
         14 . The antibody of  claim 13  which further reduces heregulin-induced ErbB2 activation in a cell which expresses ErbB2 and ErbB3 
     
     
         15 . The antibody of  claim 1  which binds to the epitope bound by the 8B8 antibody. 
     
     
         16 . The antibody of  claim 1  which has the complementarity determining regions of the 8B8 antibody. 
     
     
         17 . A composition comprising the antibody of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         18 . A cell line which produces the antibody of  claim 1 . 
     
     
         19 . The cell line of  claim 18  which is a hybridoma cell line producing the 8B8 antibody. 
     
     
         20 . A method for determining the presence of ErbB3 protein comprising exposing a cell suspected of containing the ErbB3 protein to the antibody of  claim 1  and determining binding of said antibody to the cell. 
     
     
         21 . A kit comprising the antibody of  claim 1  and instructions for using the antibody to detect the ErbB3 protein. 
     
     
         22 . The antibody of  claim 1 , wherein the cytotoxic agent is selected from the group consisting of a toxin, chemotherapeutic agent, and radioactive isotope. 
     
     
         23 . The antibody of  claim 1 , wherein the cytotoxic agent is a toxin. 
     
     
         24 . The antibody of  claim 22  or  23 , wherein the toxin is an enzymatically active toxin, or fragment thereof. 
     
     
         25 . The antibody of  claim 24 , wherein the enzymatically active toxin is of bacterial origin. 
     
     
         26 . The antibody of  claim 24 , wherein the enzymatically active toxin is of fungal origin. 
     
     
         27 . The antibody of  claim 24 , wherein the enzymatically active toxin is of plant origin. 
     
     
         28 . The antibody of  claim 24 , wherein the enzymatically active toxin is of animal origin. 
     
     
         29 . The antibody of  claim 22 , wherein the cytotoxic agent is a chemotherapeutic agent. 
     
     
         30 . The antibody of  claim 22 , wherein the cytotoxic agent is a radioactive isotope.