Designing Human Antibodies by Phage Display

Abstract

With six approved products and more than 60 candidates in clinical testing, human monoclonal antibody discovery by phage display is well established as a robust and reliable source for the generation of therapeutic antibodies. While a vast diversity of library generation philosophies and selection strategies have been conceived, the power of molecular design offered by controlling the in vitro selection step is still to be recognized by a broader audience outside of the antibody engineering community. Here, we summarize some opportunities and achievements, e.g., the generation of antibodies which could not be generated otherwise, and the design of antibody properties by different panning strategies, including the adjustment of kinetic parameters.

Keywords: Human monoclonal antibodies; Immunotherapy; In vitro evolution; Panning; Phage display; scFv.

Fig. 1

Antibody phage display. a In an antibody phage particle, the antibody gene and the function it encodes (antigen binding) are physically linked. This allows the affinity selection of monoclonal human antibodies in the test tube (a process named ‘panning’). b Panning in the presence of soluble competitor to deplete cross-reacting antibodies. c Panning under defined biochemical conditions selects only antibodies that are functional at these conditions. d Sequential panning rounds on two different but homologous antigens allow to functionally select antibodies that bind to a structural feature common to the two proteins.

Fig. 2

Affinity maturation and variation of association and dissociation constants by light chain shuffling. a Heavy chain of an antibody candidate was re-shuffled with the entire light chain repertoire of the naïve library (right panel: summarized plasmon resonance data of antigen binding). After screening with optimized conditions, antibodies with higher affinities were obtained (green dots). The parameters of the original antibody are indicated by the red dot. b plasmon resonance analysis of antigen binding of two human antibodies with similar affinity but different binding kinetics, obtained by light chain shuffling.