Vector for efficient selection and/or maturation of an antibody and uses thereof

Abstract

It is described a vector suitable for efficient selection and/or maturation of a recombinant antibody characterized in that it contains at least one element able to reduce the expression level and/or has an improved efficiency of display of said recombinant antibody.

The invention claimed is: 
     
       1. An isolated or purified vector suitable for efficient selection and affinity maturation of a recombinant antibody, the recombinant antibody having a leader peptide and being encoded by a recombinant antibody coding sequence, wherein
 the vector comprises a leader sequence encoding a leader peptide expressed with the recombinant antibody, 
 the vector further comprising at least one element able to reduce the expression level of said recombinant antibody, the at least one element being selected from
 a) a suppressed stop codon inside either the leader peptide or the recombinant antibody coding sequence; 
 b) a low-efficient promoter driving transcription of said recombinant antibody coding sequence; or 
 c) an inhibitor of the promoter driving transcription of said recombinant antibody coding sequence; and 
 
 
       wherein
 the vector comprises a further element able to provide an efficient display of said recombinant antibody, the further element comprising:
 a) a sequence coding for a carboxy-terminal part of a minor coat protein pill fused to the recombinant antibody coding sequence; 
 b) a sequence coding for a leader peptide of the alkaline phosphatase of E. coli comprised as the leader peptide of the recombinant antibody sequence; and 
 c) a coding sequence for the minor coat protein pill fused to the recombinant antibody coding sequence with no amber codon therebetween. 
 
 
     
     
       2. The vector according to  claim 1  wherein the recombinant antibody includes: ScFv, active fragments of Abs, or humanized sequences of Abs. 
     
     
       3. The vector according to  claim 1  wherein the vector is a plasmid, a phagemid or a phage. 
     
     
       4. The vector according to  claim 1 , said vector being a phagemid vector having the nucleotide sequence of SEQ ID NO: 1. 
     
     
       5. An in vitro host cell transformed with the vector according to  claim 1 . 
     
     
       6. A non-human host cell transformed with the vector according to  claim 1 . 
     
     
       7. The non-human host cell of  claim 6 , wherein the non-human host cell is a bacterial cell. 
     
     
       8. The vector of  claim 1 , wherein the vector is a DNA vector. 
     
     
       9. The in vitro host cell of  claim 5 , wherein the host cell is a bacterial cell. 
     
     
       10. A method for improving selection and/or maturation of a recombinant antibody, the method comprising
 cloning and expressing sequences encoding for recombinant antibodies with the vector according to claim 1; and   selecting a cloned and expressed recombinant antibody having an affinity for an antigen or target protein thus improving the selection and/or maturation of the recombinant antibody.   
     
     
       11. The method of claim 10, wherein the cloning and expressing comprises
 constructing a phage display library for the recombinant antibody with the vector of claim 1 comprising the sequences encoding for the recombinant antibodies.    
     
     
       12. The method of claim 11, wherein the phage display library is selected from a synthetic or semi-synthetic antibody library, or a library mutated for affinity maturation of antibodies. 
     
     
       13. The method of claim 11, wherein the selecting comprises
 performing affinity selection of the recombinant antibodies from the phage display library to obtain an affinity selected recombinant antibody having high affinity for the antigen or target protein.   
     
     
       14. The method of claim 11, wherein the phage display library -is a library mutated for affinity maturation of antibodies; and the selecting comprises
 selecting a maturated recombinant antibody from the library mutated for affinity maturation of antibodies, the maturated recombinant antibody having an affinity for an antigen or target protein.   
     
     
       15. The method of claim 11, wherein the phage display library is a library mutated for affinity maturation of antibodies; and the selecting comprises
 performing affinity selection of maturated recombinant antibodies from the library mutated for affinity maturation of antibodies to obtain an affinity maturated recombinant antibody having high affinity for an antigen or a target protein.   
     
     
       16. The method of claim 10, wherein the antigen or target protein is displayed on a cell. 
     
     
       17. The method of claim 10, wherein the sequences encoding for the recombinant antibodies comprise mutagenized sequences from an original sequence encoding for an original recombinant antibody. 
     
     
       18. The method of claim 10, wherein the sequences encoding for recombinant antibodies are derived from antibody producing cells. 
     
     
       19. The method of claim 18, wherein the antibody producing cells are Tumor Infiltrating Lymphocytes (TILs) or Peripheral Blood Lymphocytes (PBLs). 
     
     
       20. The method of claim 18, wherein the antibody producing cells are isolated from a tumor affected subject. 
     
     
       21. The method of claim 20, wherein the tumor affected subject is a breast cancer affected subject.