Christian Doppler Labor für Antikörperengineering - Modul 3

Bispecific antibodies are of great interest for the development of new antibody-based therapeutic strategies. A number of ways on how to achieve bispecific binding of complete, Ig-like antibodies have been devised, as e.g. the knobs-into-holes method. Recently, the SEED technology has been developed that allows the heterodimerization of CH3 domains by strand-exchange engineering (Davis, Aperlo et al. 2010). This strategy is based on the observation of specific CH3 homodimerization properties of IgA and IgG, and consequently uses CH3 sequences that are composed of alternating exchanged sequence fragments of IgA and IgG. No matter what the mechanism of heavy chain heterodimerization is in an engineered antibody, the problem persists that the pairing of the light chains with the heavy chains in the Fab part can still, to a certain degree, occur at random, resulting in heterogeneous products secreted by the expressing cells, which make further downstream processing cumbersome. Main purpose of the project (Modul 3, Department of Biotechnology) is to devise a strategy that allows specific and controlled pairing between heavy and light chains in the Fab region of heterodimeric antibody constructs. More specifically, mutations should be introduced at the interface between VH and VL domains on the one hand, and at the CH1/CL interface on the other hand, that only allow selective pairing with the accordingly engineered second chain, but not with the corresponding wild type or otherwise engineered chain. A generic solution that can be applied to different antibodies is preferred over a solution that needs case by case engineering.