“Affinity and Kinetic screening of Antibodies and Fab fragments: The art of selecting therapeutic antibody candidates.”

CANZIANI GA

Madrid

Workshop; Surface Plasmon Resonance: Analyzing INteractions Inside and Outside de Cell; 2006

Centro Nacional de Biotecnología, CSIC

Therapeutic proteins, such antibodies or antibody fragments, have quickly become the focus of the biopharmaceutical industry. The potential of the so-called “biologicals” hinges on the fact that proteins are effectors in known body-function disorders and that proteins are involved in recognition and binding events. The key advantage of mAb or Fab therapeutics is in their high specificity for the relevant disease targets with minimum or controllable side effects. Grafting the minimal antigen recognition domains into frameworks that match human germ-line sequences is now routine. In addition, advances in the area of recombinant antibody technology have allowed the production of antibodies to any antigen. Screening of vast libraries of recombinant antibody fragments displayed on phage involves submitting the antigen-bound phage to “stringent” or destabilizing environments. However, the resulting Fab candidates typically display affinities that may not be resolved and ranked in high-throughput, automated assays. There are currently ten approved antibodies in the market, two submitted for approval, and hundreds in development. In the past five years, surface plasmon resonance (SPR) was the leading detection technology employed in the selection of best target-binders from hybridoma and recombinant sources. This presentation will review how not only observing interactions directly without the use of labels but the microfluidics, robotics, assay design, and data processing allow us to rank crude antibody/Fab preps with high precision using SPR. Very recently, we have witnessed to the optimization of software for the simultaneous analysis of multiple interactions. However, useful data are obtained from excellent reagents. We will review how biochemical and biophysical properties of the target (antigen), purity, and active concentrations impact the interpretation of the results. .