Evaluation of intercellular cross-linking abilities correlated with cytotoxicities of bispecific antibodies with domain rearrangements using AFM force-sensing.

Atsushi Maejima, Kenta Ishibashi, Hyonchol Kim, Izumi Kumagai, Ryutaro Asano

Biosensors & bioelectronics 2021 Apr 15

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Bispecific antibodies (bsAbs) are a promising engineered antibody format; thus, technologies for the fabrication and evaluation of functional bsAbs are attracting increasing attention. Here, based on atomic force microscopy (AFM) force-sensing integrated with a metal cup-attached AFM chip (cup-chip) to ensure efficient capture of a target cell on a cantilever, we established a novel method for measuring cross-linking ability that is correlated with the cytotoxicities of bsAbs targeting two cells. We previously reported that domain rearrangements of bsAbs affected their cytotoxicities; however, no differences in cross-linking ability for soluble antigens were observed by surface plasmon resonance. We predicted that there would be differences in molecular configurations to avoid steric hindrance in the cross-linking of the two whole target cells. A picked-up T cell lymphoma cell on the cantilever using a cup-chip was moved to approach a cancer cell adhered to a dish, and force-curve measurements were performed. The resulting forces mediated by the cross-linking of bsAbs with different domain orders were well-correlated with their cytotoxicities. The AFM force-sensing method established herein may reflect steric hindrance of intercellular cross-linking, and thus has the potential to evaluate the net function of bsAbs and contribute to the generation of functional bsAbs. Copyright © 2021 Elsevier B.V. All rights reserved.

Citation

Atsushi Maejima, Kenta Ishibashi, Hyonchol Kim, Izumi Kumagai, Ryutaro Asano. Evaluation of intercellular cross-linking abilities correlated with cytotoxicities of bispecific antibodies with domain rearrangements using AFM force-sensing. Biosensors & bioelectronics. 2021 Apr 15;178:113037