title: Anti-EGFR scFv tetramer (tetrabody) with a stable monodisperse structure, strong anticancer effect, and a long in vivo half-life.
abstract: The development of single-chain variable fragments (scFvs) as therapeutic agents has the potential to reduce the high cost of antibody production, but the development process often impairs scFv functions such as binding affinity and pharmacokinetics. Multimerization is one strategy for recovering or enhancing these lost functions. Previously, we constructed several antiepidermal growth factor receptor (EGFR) scFv multimers by modifying linker length and domain order. Antitumor effects comparable with those of the currently approved anti-EGFR therapeutic antibodies were observed for scFv trimers. In the present study, we fractionated an anti-EGFR scFv tetramer from the intracellular soluble fraction of an Escherichia coli transformant. Compared with the trimer, the tetramer showed higher affinity, greater cancer cell growth inhibition, and prolonged blood retention time. Furthermore, the tetramer did not dissociate into the trimer or other smaller species during long-term storage (up to 33 weeks). Thus, our developed scFv tetramer is an attractive candidate next-generation anti-EGFR therapeutic antibody that can be produced via a low-cost bacterial expression system.
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan; Present address: Department of Biotechnology and Life Science Graduate School of Engineering Tokyo University of Agriculture and Technology Tokyo 184-8588 Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Asano
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Koyama
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Hagiwara
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Masakari
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Orimo
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Arai
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ogata
authors.affiliation: Department of Radiopharmaceutical Chemistry Graduate School of Pharmaceutical Sciences Tohoku University Sendai Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Furumoto
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Umetsu
authors.affiliation: Department of Biomolecular Engineering Graduate School of Engineering Tohoku University Sendai Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Kumagai
keywords: EGFR; ScFv; ScFv multimer; anticancer effect; tetrabody