A novel anti-TNF scFv constructed with human antibody frameworks and antagonistic peptides

Abstract

The introduction of TNF inhibitors has revolutionized the treatment of some chronic inflammatory diseases, e.g., rheumatoid arthritis and Crohn's disease. However, immunogenicity is one of the important mechanisms behind treatment failure, and generally, switching to another TNF inhibitor will be the first choice for patients and doctors, which results in unmet need for novel anti-TNF agents. Small antibody molecules with less number of epitope may be valuable in less immunogenicity. In this study, with the help of computer-guided molecular design, single-chain variable fragment (scFv) TSA2 was designed using consensus frameworks of human antibody variable region as scaffold to display anti-TNF antagonistic peptides. TSA2 showed evidently improved bioactivity over TSA1 (anti-TNF scFv explored before) and almost similar activity as S-Remicade (the scFv form of Remicade, anti-TNF antibody approved by FDA), especially in inhibiting TNF-induced cytotoxicity and NF-κB activation. Human antibody consensus frameworks with less immunogenicity have been used in the designing of VH domain antibody, scFv TSA1 and TSA2. A serial of TNF-related works convinced us that the novel design strategy was feasible and could be used to design inhibitors targeting more other molecules than TNF-α. More importantly, these designed inhibitors derived from computer modeling may form a virtual antibody library whose size depends on the number of candidate antagonistic peptides. It will be molecular-targeted virtual antibody library because of the specific antagonistic peptides and the potential antibodies could be determined by virtual screening and then confirmed by biologic experiments.

Designing antibody against highly conserved region of dengue envelope protein by in silico screening of scFv mutant library

“…Consequently, the sequence of scFv antibody against fusion loop of DENV was created from a pre-existing antibody by homology modelling. Previously, a novel anti-TNF scFv was constructed from human antibody frameworks and antagonistic peptides [25] suggesting a common approach to enhance the specificity and binding efficiency of scFv [26–29]. Interaction analysis between scFv and DENV envelope protein showed a stable interaction which assured that after conversion from Fab to scFv fragment, scFv antibody retained the binding property of the original antibody [30].…”