Antibodies against CTLA4 and uses therefor

Abstract

The invention provides an antibody-toxic moiety conjugates comprising an antibody that specifically recognizes a molecule expressed on the surface of a T cell which is expressed only on T cells and is only expressed transiently on T cells upon T cell activation. Preferably, the T cell molecule is CTLA4. The invention further provides anti-CTLA4 antibodies and humanized forms thereof.

1 - 15 . (canceled)  
     
     
         16 . A method of modulating the immune response comprising contacting a cell with an antibody-toxic moiety conjugate comprising an antibody that specifically recognizes a molecule expressed only on activated T cells and a toxic moiety, and further wherein the antibody is specifically reactive with CTLA4.  
     
     
         17 . The method of  claim 16 , wherein the antibody-toxic moiety conjugate is administered to a subject and the step of contacting is performed in vivo.  
     
     
         18 . The method of  claim 17 , wherein the subject is suffering from a disorder or condition that would benefit from downmodulation of an ongoing immune response wherein the disorder or condition is selected from the group consisting of: 
 an autoimmune disorder, an immune response to a graft, an allergic response, an immune response to a therapeutic protein.    
     
     
         19 . The method of  claim 16 , wherein the step of contacting is performed in vitro.  
     
     
         20 . (canceled)  
     
     
         21 . A method of modulating the immune response comprising contacting a cell with an antibody specifically reactive with human CTLA 4 .  
     
     
         22 . The method of  claim 21  wherein the antibody comprises an amino acid sequence shown in SEQ ID NO: 10.  
     
     
         23 . A method of downmodulating the immune response comprising contacting a cell with an antibody-toxic moiety conjugate, wherein the antibody specifically recognizes CTLA4.  
     
     
         24 . The method of  claim 21  wherein the antibody comprises an amino acid sequence shown in SEQ ID NO:8.