Antibody Structure and Function: The Basis for Engineering Therapeutics

Abstract

Antibodies and antibody-derived macromolecules have established themselves as the mainstay in protein-based therapeutic molecules (biologics). Our knowledge of the structure–function relationships of antibodies provides a platform for protein engineering that has been exploited to generate a wide range of biologics for a host of therapeutic indications. In this review, our basic understanding of the antibody structure is described along with how that knowledge has leveraged the engineering of antibody and antibody-related therapeutics having the appropriate antigen affinity, effector function, and biophysical properties. The platforms examined include the development of antibodies, antibody fragments, bispecific antibody, and antibody fusion products, whose efficacy and manufacturability can be improved via humanization, affinity modulation, and stability enhancement. We also review the design and selection of binding arms, and avidity modulation. Different strategies of preparing bispecific and multispecific molecules for an array of therapeutic applications are included.

Novel single-domain antibodies against the EGFR domain III epitope exhibit the anti-tumor effect

“…Second, mAbs for cancer therapy are normally isolated from mouse and are mouse antibodies against human proteins. Mouse antibody is recognized as a foreign antigen in human and can be rejected by human immune system, which can result in rapid mouse antibody clearance, low anti-tumor efficacy or hypersensitivity reactions in human body [12]. As the development of genetic engineering, humanized antibody or chimeric antibody were developed to reduce the antigenicity of mouse antibody [13].…”

“…However, mAbs used for cancer therapy have many disadvantages. Mouse-derived mAbs can result in rapid antibody clearance, loss of efficacy or hypersensitivity reactions in cancer patients [12]. Along with the development of genetic engineering, chimeric antibodies or humanized antibodies were developed and reduced only some of their antigenicity [13].…”

Exploration and Modulation of Antibody Fragment Biophysical Properties by Replacing the Framework Region Sequences

“…In the present study, the S1A0 scFv was developed from the variable sequences extracted from the 4F11E12 monoclonal antibody. S1A0 and its variants were all designed in the VH-VL orientation and linked by the peptide (Gly 4 Ser) 3 . Globally, S1A0 exhibited poor biophysical qualities.…”

“…A scFv fragment resulted from the association of the heavy and light variable domains of an antibody via the (Gly 4 Ser) 3 peptide link and the inclusion of peptide flag Gly 3 AlaSerHis 6 in the C-terminal portion. The pSW1 plasmid was used in the expression of all scFv constructs.…”

“…Over recent years, various alternative antibody formats have been designed [1]. Converting these molecules into therapeutic drugs remains a challenge since therapeutic antibodies must satisfy several developability criteria [2,3]. Antigen recognition activity is carried by antibody fragments mainly represented by monovalent Fabs or single-chain variable fragments (scFv) [4].…”