• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.390-394
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• 2011

BACKGROUND: Plant expression system for mass production of recombinant proteins has several advantages over other existing expression systems with economical and safety issues. Breast cancer is a cancer originating from breast tissue and comprises almost 25% of all cancers in women world widely. Lewis-Y antigen is difucosylated oligosaccharide and is carried by glycoconjugates at cancer cell surface. In this study, the anti-breast cancer mAb BR55, which recognizes the epitope Lewis-Y, was expressed in the plant expression system. METHODS AND RESULTS: We have developed plant system for production of mAb BR55 with or without KDEL (the ER retention signal). This ER retention signal was attached to C-terminus of protein to help retain the recombinant glycoprotein carrying oligomannose glycans and enhance glycoprotein accumulation. PCR analysis was performed and confirmed the presence of recombinant genes. Western blot validated that the recombinant proteins mAb BR55 with or without KDEL were expressed in transgenic plants, moreover, the expression level of the mAb BR55 with KDEL was higher compared to the mAb BR55 without KDEL. CONCLUSION: These results indicate that KDEL fusion is a good way to produce proteins and plant can be an ideal expression system to obtain proteins and enhance accumulation of proteins.

• Journal of Life Science
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• v.19 no.1
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• pp.123-128
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• 2009

Production of highly valuable immunotherapeutic proteins such as monoclonal antibodies and vaccines using plant biotechnology and genetic engineering has been studied as a popular research field. Plant expression system for mass production of such useful recombinant therapeutic proteins has several advantages over other existing expression systems with economical and safety issues. Immunotherapy of multiple monoclonal antibodies, which can recognize multiple targeting including specific proteins and their glycans highly expressed on the surface of cancer cells, can be an efficient treatment compared to a single targeting immunotherapy using a single antibody. In this study, we have established plant production system to express two different targeting monoclonal antibodies in a single transgenic plant through crossing fertilization between two different transgenic plants expressing anti-colorectal cancer mAbCO17-1A and anti-breast cancer mAbBR55, respectively. The F1 seedlings were obtained cross fertilization between the two transgenic parental plants. The presence, transcription, and protein expression of heavy chain (HC) and light chain (LC) genes of both mAbs in the seedlings were investigated by PCR, RT-PCR, and immunoblot analyses, respectively. Among all the seedlings, some seedlings did not carry or transcribe the HC and LC genes of both mAbs. Thus, the seedlings with presence and transcription of HC and LC genes of both mAbs were selected, and the selected seedlings were confirmed to have relatively stronger density of HC and LC protein bands compared to the transgenic plant expressing only each mAb. These results indicate that the F1 seedling plant with carrying both mAb genes was established. Taken together, plant crossing fertilization can be applied to generate an efficient production system expressing multiple monoclonal antibodies for immunotherapy in a single plant.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.339-346
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• 2007

Pollen germination viability is an essential factor to produce seeds from pollination and fertilization, which are required to maintain plant generation. In this study, we tried to identify the effect of boric acid on pollen germination and tube grouch in non-transgenic and transgenic plants expressing monoclonal antibodies (anti-colorectal cancer mAb CO17-1A, anti-breast cancer mAb BR55, and anti-rabies virus mAb57). The pollen of non-transgenic plant was treated with different concentration of boric acid (0, 5, 10, 15, 20, $40{\mu}g/mL$) in germination buffer to investigate its effect on in vitro pollen germination. At $20{\mu}g/mL$ of boric acid, tile pollen germination rate was the highest (49.5%) compared to other concentrations. In general, the germination rate significantly increased 3-10 folds in boric acid ($20{\mu}g/mL$) treated group in non-transgenic and transgenic plants. Also, the pollen tube length increased in boric acid ($20{\mu}g/mL$) treated groups. In the treated group, the pollen tube length increased until 3 h boric acid treatment and decreased after the 3 h, indicating that the 3 h is the most appropriate incubation time period. Western blot analysis showed that the mAb transgene expression was more stable in leaf than pollen in transgenic plants. This study suggested that $20{\mu}g/mL$ of boric acid is ideal concentration to induce in vitro pollen germination of transgenic plants expressing therapeutic monoclonal antibodies, indicating stable pollination and fertilization in transgenic plants.