Antibodies for cancer therapy and diagnosis

Abstract

The present application describes a method for making antibodies which can be used for cancer diagnosis or therapy. The application also discloses a method for identifying an antigen which is differentially expressed on the surface of two or more distinct cell populations. The application additionally describes human antibodies directed against decay accelerating factor (DAF), as well as therapeutic compositions comprising such antibodies. Moreover, the application discloses a method of treating lung cancer with antibodies directed against DAF.

1 . A method for making an antibody against an antigen which is shared by a cancer cell and a non-cancer cell comprising the following steps:
 (a) counter-selecting antibody phage from a naïve antibody phage library using a live non-cancer cell;   (b) subsequently binding the antibody phage to a live cancer cell;   (c) selecting an antibody phage or antibody which binds selectively to the live cancer cell; and   (d) identifying an antigen to which the antibody phage or antibody binds.   
     
     
         2 . The method of  claim 1  wherein the mean number of antigen molecules per cancer cell is greater than the mean number of antigen molecules per non-cancer cell. 
     
     
         3 . The method of  claim 2  wherein the mean number of antigen molecules per cancer cell is about two fold to about 1000 fold greater than the mean number of antigen molecules per non-cancer cell. 
     
     
         4 . The method of  claim 2  wherein the mean number of antigen molecules per cancer cell is about five fold to about 100 fold greater than the mean number of antigen molecules per non-cancer cell. 
     
     
         5 . The method of  claim 1  wherein the non-cancer cell is of the same tissue-type as the cancer cell. 
     
     
         6 . The method of  claim 1  wherein the cancer cell is a lung cancer cell. 
     
     
         7 . The method of  claim 1  wherein the antibody phage library comprises from about 10 9  to about 10 15  antibody phage. 
     
     
         8 . The method of  claim 1  further comprising expression cloning the antigen. 
     
     
         9 . The method of  claim 1  wherein the cancer cell is from a cancer cell line. 
     
     
         10 . The method of  claim 1  further comprising comparing binding of the antibody phage or antibody to a cancer cell and a non-cancer cell. 
     
     
         11 . The method of  claim 1  further comprising detaching the cancer cell from a surface to which the cancer cell is adhered using a solution which does not include any protease. 
     
     
         12 . The method of  claim 1  wherein the solution comprises EDTA for detaching the cancer cell.