Robust and Reproducible Monoclonal Antibody Production Using a Transgenic Silkworm System.

Area of Science:

• Biotechnology
• Protein Engineering
• Entomology

Background:

• Transgenic silkworms offer advantages for recombinant protein production, including high synthesis capacity and human-like posttranslational modifications.
• Monoclonal antibodies (mAbs) are crucial therapeutics, but their production can be complex and costly.

Purpose of the Study:

• To develop and evaluate transgenic silkworms for the production of a recombinant human monoclonal antibody (mAb) targeting the gp120 protein of human immunodeficiency virus (HIV).
• To assess the scalability, consistency, and quality of mAb production using the silkworm system.

Main Methods:

• Generation of transgenic silkworms secreting an anti-gp120 mAb into cocoons.
• Pilot-scale production involving rearing large numbers of silkworms across multiple batches.
• Extraction and purification of the mAb from cocoon shells.
• Characterization of mAb properties, including N-glycosylation, oligomeric content, and host protein contamination.

Main Results:

• Rearing conditions (temperature, humidity) had minimal impact on mAb N-glycosylation.
• Pilot-scale production yielded 4-8 kg of cocoon shells per batch from 22,000-45,000 larvae.
• Purification yielded 6.1-7.6 g of mAb per kg of cocoons with high batch-to-batch consistency.
• Purified mAb exhibited low levels of oligomeric antibodies (<0.2%) and host proteins (<10 ppm).

Conclusions:

• Transgenic silkworms provide a robust and reproducible platform for the large-scale production of high-quality therapeutic monoclonal antibodies.
• The silkworm system is a viable alternative for manufacturing complex biologics like anti-HIV mAbs.