Methods for selecting binders by phage display and masked selection

Abstract

The present invention relates to methods for selecting binders by phage display and masked selection. More particularly, the present invention relates to a method for selecting a plurality of binders specific for at least one relevant target comprising screening a phage binder library of binders against the relevant target in the presence of a plurality of binders obtained from a library of binders directed against at least one irrelevant target and positively selecting the binders that are specific for the at least one relevant target.

1 . (canceled) 
     
     
         2 . A method for selecting a plurality of binders specific for a cell surface protein comprising:
 i) providing a cell that was genetically transformed so as to express at its surface the cell surface protein;   ii) building a binder library by using peripheral blood mononuclear cells (PBMCs) obtained from at least one animal immunized with the cell of step i);   iii) producing a phage binder library by infecting the binder library of step ii) with a helper phage;   iv) performing with the phage binder library of step ii) at least one round of selection against the cell of step i) that was not genetically transformed;   v) producing soluble binders with selected clones obtained at step iv).   vi) performing with the phage binder library of step iii) at least one round of selection against the cell of step i) in the presence of an excess of binders produced by step vi); and   vii) cloning and recovering the binders from the clones selected at step vi).   
     
     
         3 . (canceled) 
     
     
         4 . A method for selecting a plurality of binders with cancer specificity comprising:
 i) building a binder library by using peripheral blood mononuclear cells (PBMCs) obtained from at least one animal immunized with a mixture of cancer biopsy lysates;   ii) producing a phage binder library by infecting the binder library of step i) with a helper phage;.   iii) performing with the phage binder library of step ii) at least one round of selection against a mixture of normal biopsy lysate;   iv) producing soluble binders with selected clones obtained at step iii);   v) performing with the phage binder library of step ii) at least one round of selection against the mixture of cancer biopsy lysates in the presence of an excess of binders produced by step iv); and   vi) cloning and recovering the binders from the clones selected at step v).   
     
     
         5 . A method for selecting a plurality of binders with cancer specificity comprising:
 i) building a binder library by using peripheral blood mononuclear cells (PBMCs) obtained from at least one animal immunized with a mixture of cancer cell lines.;   ii) producing a phage binder library by infecting the binder library of step i) with a helper phage;   iii) performing with the phage binder library of step ii) at least one round of selection against a normal cell line;   iv) producing soluble binders with selected clones obtained at step   v) performing with the phage binder library of step ii) at least one round of selection against the mixture of cancer cell lines in the presence of an excess of binders produced by step iv); and   vi) cloning and recovering the binders from the clones selected at step v).   
     
     
         6 . The method of  claim 2 , further comprising sequencing the binders from the clones selected at step vi). 
     
     
         7 . The method of  claim 4 , further comprising sequencing the binders from the clones selected at step vi). 
     
     
         8 . The method of  claim 5 , further comprising sequencing the binders from the clones selected at step vi).