Plant-Produced Trastuzumab Inhibits the Growth of HER2 Positive Cancer Cells

Abstract

To study the agricultural production of biosimilar antibodies, trastuzumab (Herceptin) was expressed in Nicotiana benthamiana using the magnICON viral-based transient expression system. Immunoblot analyses of crude plant extracts revealed that trastuzumab accumulates within plants mostly in the fully assembled tetrameric form. Purification of trastuzumab from N. benthamiana was achieved using a scheme that combined ammonium sulfate precipitation with affinity chromatography. Following purification, the specificity of the plant-produced trastuzumab for the HER2 receptor was compared with Herceptin and confirmed by western immunoblot. Functional assays revealed that plant-produced trastuzumab and Herceptin have similar in vitro antiproliferative effects on breast cancer cells that overexpress HER2. Results confirm that plants may be developed as an alternative to traditional antibody expression systems for the production of therapeutic mAbs.

In Vivo Neutralization of α-Cobratoxin with High-Affinity Llama Single-Domain Antibodies (VHHs) and a VHH-Fc Antibody

“…To express the V H H2-Fc antibody, Nicotiana benthamiana plants were vacuum infiltrated with Agrobacterium strains containing pICH20111, pICH14011 and pV H H2-Fc according to the protocol described by Grohs et al [44] with the following modification. A vacuum was applied for 2 min with pressure ranging from 0.5 to 0.9 bar and then slowly released [45].…”

“…A Bradford Assay was used to determine the quantity of total soluble protein (TSP) present in the crude plant extract (cpe) with bovine serum albumin (BSA) as a standard. The cpe was analyzed using standard SDS-PAGE and immunoblotting techniques as described by Grohs et al [44], with the following modifications. The immunoblot was probed with a 1∶5,000 dilution of protein A conjugated to HRP (Zymed Laboratories, San Francisco, CA, USA) and 1-Step™ TMB-Blotting substrate (Thermo Scientific, Fisher) was used to develop the immunoblot.…”

Plant-Made Trastuzumab (Herceptin) Inhibits HER2/Neu+ Cell Proliferation and Retards Tumor Growth

“…Trastuzumab is produced by recombinant DNA technology in a mammalian cell (Chinese Hamster Ovary) culture. Recently, the production of plant-made trastuzumab [PMT] was shown in plant using the magnICON viral-based transient expression system [19]. Functional assays revealed that plant-produced trastuzumab and Herceptin have similar antiproliferative effects in vitro on HER2+ breast cancer cells.…”

Glycoengineered Pichia produced anti-HER2 is comparable to trastuzumab in preclinical study

“…3 At the same time, alternative mAb platforms including plant and microbial expression systems [4][5][6] are being explored and show great promise. Grohs et al 7 and Komarova et al 8 demonstrated that plant-produced antibody (trastuzumab) was as functional as the CHO-produced counterpart. Among these alternative systems, Mammalian cell culture systems are used predominantly for the production of therapeutic monoclonal antibody (mAb) products.…”