Chengdu High-tech Legion Once Again “Shows Its Sword”: ABLINK Has Screened the Therapeutic Antibody

ABLINK’s antibody library

Recently, it was learned from Chengdu Shengshi Junlian Biotechnology Co., Ltd. (referred to as "ABLINK"), located in the Tianfu Life Science Park in Chengdu Hi-tech Zone, that they have successfully screened neutralizing antibodies against SARS-CoV-2, the virus responsible for COVID-19, using their own billion-level fully synthetic human antibody library. These antibodies can be used to develop antibody drugs to treat COVID-19. The related research results have been published on BioRxiv, the largest preprint platform in the field of biology, and have entered peer review in overseas academic journals.

ABLINK was founded by Dr. Liu Jianghai in 2016 and successfully developed a new generation of "phage display antibody libraries" with independent intellectual property rights in 2017. They have now established multiple "fully human antibody libraries and fully synthetic antibody libraries" with independent intellectual property rights. And the diversity of their antibody libraries has reached hundred-billion level. 

Dr. Zeng Xin shows ABLINK’s antibody library

After the outbreak of COVID-19, ABLINK quickly screened detection antibodies against the virus using its antibody library technology platform. On one hand, ABLINK provided raw materials for antibody testing to assist downstream partners in developing testing kits and rapid detection methods. On the other hand, it produced a small number of kits to serve vaccine companies.

"It is easy to detect the coronavirus using antibody, but it is complex to screen therapeutic antibodies and develop them into drugs," said Dr. Zeng Xin, the Technical Director of ABLINK. With the changing domestic and international epidemic situation, the company has decided to adjust its strategy in the process of screening testing antibodies, and is currently working on screening antibodies with potential therapeutic effects against the coronavirus, in order to provide a "seed" for the development of future treatment drugs.

The COVID-19 detection kits produced by ABLINK’s self-developed antibodies

Put it simply, an antibody library is like a reservoir with many fish (antibodies). When using the antigen surface-specific protein (the therapeutic target of a disease) as bait for fishing, it is easy to obtain antibodies with high affinity and specificity. Compared with traditional hybridoma technology, phage display antibody library technology has the advantages of fast screening cycle, no need for animal use, and direct acquisition of fully human/humanized antibodies.

"The testing antibodies or antibodies isolated from patients generally have weak specificity and limited potential for drug development," explained Dr. Zeng Xin. In order to screen for therapeutic antibodies with potential for drug development from antibody libraries, Dr. Zeng Xin, as a PhD in structural biology from Tsinghua University, designed a unique "fishing strategy" after comparing and analyzing the protein structure information of the novel coronavirus, SARS virus, and known SARS antibodies in detail. This strategy uses the structural features of the surface S protein of the novel coronavirus that specifically binds to human receptors as bait, to fish out antibodies in the library that can block the virus from binding to receptors, thereby preventing the virus from entering human cells and achieving the goal of "keeping the enemy out."

After screening antibodies through a competitive strategy, we confirmed their medicinal value in treating COVID-19 through ELISA and pseudovirus validation. And we also hope that interested stakeholders can participate in collaborations to accelerate the development process.

Many well-known domestic and foreign research teams have previously announced the discovery of neutralizing monoclonal antibodies in the bodies of recovered patients. Currently, there are no reported cases in China of screening therapeutic antibodies of COVID-19 from a fully synthetic human antibody library. The discovery by ABLINK fills the gap in this field of utilizing a fully human antibody library for antibody screening in China.

Reprinted from Sohu News