Cambridge Healthtech Institute’s Kent Simmons recently spoke with Yongliang Fang, a researcher at Dartmouth College’s Thayer School of Engineering, about his upcoming presentation “Ultra-High Throughput Screening of Soluble, Secreted mAbs against Intact Cancer Cells”, to be delivered in the Emerging Technologies for Antibody Discovery meeting at the 2017 Peptalk event.

Why have you chosen Pichia pastoris for antibody engineering?

Prokaryotic cells have limited capacities to secrete full-length immunoglobulin molecules. Mammalian cells are ideal for full-length antibodies production, however, multiple vector integrations have known to be a challenge to generate antibody libraries in mammalian cells. Furthermore, time and resources needed for mammalian cell culture also limits its application for the construction and screening of large combinatorial libraries. On contrast, eukaryotic yeast cells are able to express high-quality full-length IgGs with proper post-translational modifications. In addition, engineered Pichia cells can even process the human-like glycosylation. Therefore, Pichia pastoris can be a great choice for antibody engineering.

What are the advantages of isolating secreted and full-length IgG over antibody fragments?

Based on our previous experience, the physicochemical properties and expressibilities of single-chain variable fragment (scFv) or fragment antigen-binding (Fab) may not correlate with their cognate full-length formats. Therefore, isolating secreted and full-length IgG from antibody libraries can significantly advance further characterization of the lead candidates and accelerate downstream development.

What new techniques may aid into the antibody engineering methodology?

There are more and more emerging techniques that can help protein engineers to develop more and better screening methods for antibody engineering. For instance, the development of CRISPR Cas9 technology may be leveraged to solve the multiple vector integrations issues in generating antibody libraries with mammalian cells. Also new designs of microfluidic chips enable “on-chip” screening which may be applied for the development of high throughput screening of antibodies libraries beyond antigen binding. In this case, scientists can select antibodies leads based on their biological functions, like blocking receptors, triggering signal pathways and apoptosis.

Speaker Biography:

Yongliang Fang, Researcher, Thayer School of Engineering, Dartmouth College

Yongliang Fang is currently a graduate researcher in the Thayer School of Engineering at Dartmouth. He received his BE degree from China Pharmaceutical University. Under the supervision of Prof. Karl Griswold at Thayer, his work in the field of protein engineering has resulted in the development of engineered human lysozyme variants able to evade pathogen-derived inhibitory proteins, high throughput antibody screening technologies that combine microfluidics and flow cytometry, and development of deimmunized therapeutic proteins, including a next-generation anti-MRSA biotherapeutic.