Abstract
A variety of Fc domain engineering approaches for abrogating the effector functions of mAbs exists. To address some of the limitations of the current Fc domain silencing approaches, we are exploring a less commonly considered option which relies on the deletion of the hinge. Removal of the hinge domain in humanized IgG1 and IgG4 mAbs obliterates their ability to bind to activating human Fc gamma receptors I and IIIA, while leaving their ability to engage their target antigen intact. Deletion of the hinge also reduces binding to the Fc neonatal receptor, although Fc engineering allows partial recovery of affinity. Engineering of the CH3 domain, stabilizes hinge deleted IgG4s and prevents Fab arm exchange. The faster clearing properties together with the pacified Fc make modality of the hinge deleted mAb an appealing solution for therapeutic and diagnostic applications.
Highlights
Gamma Immunoglobulins are key components of innate and acquired immunity
The purified hinge deleted IgG1 and IgG4 mAbs were tested by size exclusion chromatography (SEC) with online UV and Multi Angle Laser Light Scattering (MALS) detectors
As for most mAbs expressed in Chinese hamster ovary (CHO), the primary species attached to the hinge deleted antibody was G0F (Figures 2d and 3d)
Summary
Gamma Immunoglobulins are key components of innate and acquired immunity. Their central role in controlling pathogen infections relies on two specialized functional modules: the antigen binding fragment (Fab) and the crystallizable fragment (Fc) [1]. The four human gamma chains subclasses show over 90% amino acid sequence homology, with most of the sequence variations concentrated in the hinge and amino terminus of the CH2 domain [1] These sequence differences have important functional implications. The engineering solutions include insertion of point mutations in the CH2 domain or complete removal of the conserved Fc N-Glycan by modifying the consensus glycosylation site [14] While these strategies may reduce ADCC, they do not necessarily abolish binding to complement or other Fc receptors to the same magnitude, and they may contribute to potential immunogenicity or thermodynamic instability of the Fc domain. Hinge (IgG1 HC, IgG4 HC) and resulting sequence after deletion (IgG1 Δhinge and IgG4 Δhinge)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
