Function characterization of a glyco-engineered anti-EGFR monoclonal antibody cetuximab in vitro
Abstract
Chang-hong YI1, Can-ping RUAN2, Hao WANG3, Xin-yun XU2, Yun-peng ZHAO1, Meng FANG1, Jun JI1, Xing GU1, Chun-fang GAO1, *
1Department of Laboratory Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China; 2Department of General Surgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China; 3Department of Laboratory Medicine, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
Aim: To evaluate the biochemical features and activities of a glyco-engineered form of the anti-human epidermal growth factor receptor monoclonal antibody (EGFR mAb) cetuximab in vitro.
Methods: The genes encoding the Chinese hamster bisecting glycosylation enzyme (GnTIII) and anti-human EGFR mAb were cloned and coexpressed in CHO DG44 cells. The bisecting-glycosylated recombinant EGFR mAb (bisec-EGFR mAb) produced by these cells was characterized with regard to its glycan profile, antiproliferative activity, Fc receptor binding affinity and cell lysis capability. The content of galactose-α-1,3-galactose (α-Gal) in the bisec-EGFR mAb was measured using HPAEC-PAD.
Results: The bisec-EGFR mAb had a higher content of bisecting N-acetylglucosamine residues. Compared to the wild type EGFR mAb, the bisec-EGFR mAb exhibited 3-fold higher cell lysis capability in the antibody-dependent cellular cytotoxicity assay, and 1.36-fold higher antiproliferative activity against the human epidermoid carcinoma line A431. Furthermore, the bisec-EGFR mAb had a higher binding affinity for human FcγRIa and FcγRIIIa-158F than the wild type EGFR mAb. Moreover, α-Gal, which was responsible for cetuximab-induced hypersensitivity reactions, was not detected in the bisec-EGFR mAb.
Conclusion: The glyco-engineered EGFR mAb with more bisecting modifications and lower α-Gal content than the approved therapeutic antibody Erbitux shows improved functionality in vitro, and requires in vivo validations.
Keywords: EGFR mAb; Erbitux; glyco-engineering; antibody-dependent cellular cytotoxicity; antiproliferation; Fc receptor binding; galactose-α-1,3-galactose
This work was supported by National Natural Science Foundation of China (No 81301877 and 81271925); State Key Project on Infectious Diseases of China (No 2012ZX10002-016); Science and Technology Commission of Shanghai Municipality (No 11JC1416400).
* To whom correspondence should be addressed.
E-mail gaocf1115@163.com
Received 2014-03-12 Accepted 2014-07-05
Keywords:
1Department of Laboratory Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China; 2Department of General Surgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China; 3Department of Laboratory Medicine, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
Aim: To evaluate the biochemical features and activities of a glyco-engineered form of the anti-human epidermal growth factor receptor monoclonal antibody (EGFR mAb) cetuximab in vitro.
Methods: The genes encoding the Chinese hamster bisecting glycosylation enzyme (GnTIII) and anti-human EGFR mAb were cloned and coexpressed in CHO DG44 cells. The bisecting-glycosylated recombinant EGFR mAb (bisec-EGFR mAb) produced by these cells was characterized with regard to its glycan profile, antiproliferative activity, Fc receptor binding affinity and cell lysis capability. The content of galactose-α-1,3-galactose (α-Gal) in the bisec-EGFR mAb was measured using HPAEC-PAD.
Results: The bisec-EGFR mAb had a higher content of bisecting N-acetylglucosamine residues. Compared to the wild type EGFR mAb, the bisec-EGFR mAb exhibited 3-fold higher cell lysis capability in the antibody-dependent cellular cytotoxicity assay, and 1.36-fold higher antiproliferative activity against the human epidermoid carcinoma line A431. Furthermore, the bisec-EGFR mAb had a higher binding affinity for human FcγRIa and FcγRIIIa-158F than the wild type EGFR mAb. Moreover, α-Gal, which was responsible for cetuximab-induced hypersensitivity reactions, was not detected in the bisec-EGFR mAb.
Conclusion: The glyco-engineered EGFR mAb with more bisecting modifications and lower α-Gal content than the approved therapeutic antibody Erbitux shows improved functionality in vitro, and requires in vivo validations.
Keywords: EGFR mAb; Erbitux; glyco-engineering; antibody-dependent cellular cytotoxicity; antiproliferation; Fc receptor binding; galactose-α-1,3-galactose
This work was supported by National Natural Science Foundation of China (No 81301877 and 81271925); State Key Project on Infectious Diseases of China (No 2012ZX10002-016); Science and Technology Commission of Shanghai Municipality (No 11JC1416400).
* To whom correspondence should be addressed.
E-mail gaocf1115@163.com
Received 2014-03-12 Accepted 2014-07-05