Glycomodification and characterization of anti-colorectal cancer immunotherapeutic monoclonal antibodies in transgenic tobacco

• Published in: Plant cell, tissue and organ culture Vol. 113; no. 1; pp. 41 - 49
• Main Authors: So, Yangkang, Lee, Kyung-Jin, Kim, Deuk-Su, Lee, Jeong-Hwan, Oh, Doo-Byoung, Hwang, Kyung-A, Ko, Kinarm, Choo, Young-Kug, Ko, Kisung
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2013; Springer Nature B.V
• Subjects: Anticancer properties; Antigens; Binding; Biological activity; Biomedical and Life Sciences; C-Terminus; Colorectal cancer; Colorectal carcinoma; Cytotoxicity; Domains; Endoplasmic reticulum; Enzyme-linked immunosorbent assay; Fc receptors; Flow cytometry; Glycan; Glycosylation; Immunoglobulin G; Life Sciences; Monoclonal antibodies; Original Paper; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Plants; Polysaccharides; Tobacco; Toxicity; Transgenic plants; Human colorectal carcinoma; Glycosylation; Transgenic plant; ADCC; Anti-cancer antibody; Oligomannose
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-012-0249-z

Anti-colorectal cancer mAb CO17-1A (IgG 2a ) recognizes the antigen GA733, which is highly expressed on the surface membrane of human colorectal carcinoma cells. In this study, a transgenic tobacco system for the production of mAb CO17-1A was developed. The mAb construct included a KDEL sequence, an endoplasmic reticulum (ER) retention signal attached to the C-terminus of the heavy chain, to target accumulation of mAb into ER. An immunoblot showed significantly enhanced levels of expression of the plant-derived mAbK (mAb P K) CO17-1A compared to mAb P CO17-1A mAb without the KDEL sequence. An ELISA assay using human colorectal carcinoma cells confirmed that expression of mAb P K was also significantly higher than that of mAb P . Glycosylation analysis revealed that mAb P had plant-specific glycans; whereas, mAb P K primarily had oligomannose glycans. FACS showed that the Fc domains of both mAb P K and mammalian-derived mAb (mAb M ) had similar binding activity to the FcγRI receptor (CD64). However, the Fc domains of the mAb P had slightly lower binding activity to the Fc γ RI receptor than both mAb P K and mAb M . The antibody-dependent cell cytotoxicity of mAb P K, against human colorectal cancer cells, was as efficient as mAb M ; whereas mAb P was very low. These results suggest that KDEL localized and accumulated mAb P in the ER and eventually enhanced the expression of mAb P with oligomannose glycan and similar anti-cancer biological activity to the parental mAb M .