Frucose removal results in enhancement of ADCC

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Journal of Biochemistry, doi:10.1093/jb/mvj157

This Article

© 2006 The Japanese Biochemical Society.

Received May 9, 2006

Accepted June 14, 2006

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Regular Paper

Fucose Removal from Complex-Type Oligosaccharide Enhances the

Antibody-Dependent Cellular Cytotoxicity of Single-Gene-Encoded

Bispecific Antibody Comprising of Two Single-Chain Antibodies Linked

to the Antibody Constant Region

Akito Natsume 1, Masako Wakitani 1, Naoko Yamane-Ohnuki 1, Emi Shoji-

Hosaka 1, Rinpei Niwa 1, Kazuhisa Uchida 1, Mitsuo Satoh 1, and Kenya

Shitara 1 *

1 Department of Antibody Research, Pharmaceutical Research Center,

Kyowa Hakko Kogyo Co., Ltd., 3-6-6 Asahi-machi, Machida-shi, Tokyo

194-8533, Japan

* To whom correspondence should be addressed.

Kenya Shitara, E-mail: kshitara@...

Abstract

Bispecific antibodies (bsAbs) have the potential to extend binding

selectivity, increase avidity and exert potent cytotoxicity due to

the combination of dual specificities. scFv2-Fc type of single-gene-

encoded bispecific antibody, composed of two different single-chain

Fvs and an Fc, has been reported to be capable of binding to

different antigens. The aim of this study was to determine the effect

of fucose removal on effector functions of scFv2-Fc since fucose

depletion from oligosaccharide of human IgG1 and scFv-Fc results in

significant enhancement of ADCC. We generated novel single-gene-

encoded bsAb with dual specificity against tumor associated

glycoprotein (TAG)-72 and MUC1 mucin as fucose-negative scFv2-Fc

from -1,6-fucosyltransferase knock-out CHO cells and a highly

fucosylated scFv2-Fc comparator from parental CHO cells. Expression,

assembly and the antigen-binding activity of the scFv2-Fc were not

influenced by removal of fucose. The fucose negative scFv2-Fc bound

with higher avidity to FcRIIIa and enhanced ADCC compared to the

highly fucosylated scFv2-Fc. These results demonstrate that ADCC-

enhancement by removal of fucose is effective in not only whole IgG1

and scFv-Fc, but also scFv2-Fc targeting two different antigens, and

thus increases the potential of fucose-negative scFv2-Fcs as novel

therapeutic candidates.

Keywords: Antibody-dependent cellular cytotoxicity; Bispecific

antibody; Cancer therapy; Glyco-modification; single-chain Fv.