Accelerated antibody discovery targeting the SARS-CoV-2 spike protein for COVID-19 therapeutic potential

Abstract

Background: Rapid deployment of technologies capable of high-throughput and high-resolution screening is imperative for timely response to viral outbreaks. Risk mitigation in the form of leveraging multiple advanced technologies further increases the likelihood of identifying efficacious treatments in an aggressive timeline. Methods: In this study, we describe two parallel, yet distinct, in vivo approaches for accelerated discovery of antibodies targeting the SARS-CoV-2 spike protein. Working with human transgenic Alloy-GK mice, we detail a single B-cell discovery workflow to directly interrogate antibodies secreted from plasma cells for binding specificity and ACE2 receptor blocking activity. Additionally, we describe a concurrent accelerated hybridoma-based workflow utilizing a DiversimAb™ mouse model for increased diversity. Results: The panel of antibodies isolated from both workflows revealed binding to distinct epitopes with both blocking and non-blocking profiles. Sequence analysis of the resulting lead candidates uncovered additional diversity with the opportunity for straightforward engineering and affinity maturation. Conclusions: By combining in vivo models with advanced integration of screening and selection platforms, lead antibody candidates can be sequenced and fully characterized within one to three months.

High-throughput analysis system of interaction kinetics for data-driven antibody design

“…Although BreviA does not have a throughput comparable to these systems, it is unique and useful because it can directly and quantitatively evaluate the affinity of each antibody. Although several systems utilizing LSA, a high-throughput SPR instrument, have been reported [26][27][28] , none have characterized antibodies in an antibody library, as shown here. In addition to SPR, microscale thermophoresis (MST) 35 and bio-layer interferometry (BLI) 36 are known high-throughput methods for measuring protein-protein interactions.…”

“…Recently, an SPR instrument capable of simultaneously measuring 384 interactions was launched by Carterra Inc. This instrument, LSA, can immobilize purified antibodies 26,27 and antibodies in crude solutions, such as hybridoma culture medium 28 , and allows high-throughput evaluation of many clones simultaneously. However, using this instrument for analyses that require prior cloning, such as mutational analysis, can be difficult since it is a time-consuming process.…”

Alpaca single B cell interrogation and heavy-chain-only antibody discovery on an optofluidic platform

“…VHH) antibody discovery, which is typically done using in vitro display approaches and subject to their limitations. For the first time, in this study, we established a novel platform for function-forward VHH discovery directly from a natural camelid immune repertoire by pairing high-resolution Beacon screening capabilities—which have been successfully used for immunized mice [ 27 , 29 ] and human donors [ 26 ]—with a newly developed upstream workflow for alpaca B cell enrichment, stimulation and screening. This platform was used to discover and validate a panel of 13 antibodies that bound PSMA with nanomolar affinity and exhibited a broad epitopic coverage and sequence diversity.…”

Alpaca Single B Cell Interrogation and Heavy-Chain-Only Antibody Discovery on an Optofluidic Platform

“…VHH) antibody discovery. For the first time, in this study, we established a novel platform for function-forward VHH discovery by pairing high-resolution Beacon screening capabilities— which have been successfully used for immunized mice 27,29 and human donors 26 —with a newly developed upstream workflow for alpaca B cell enrichment, stimulation, and screening. This platform was used to discover and validate a panel of 13 antibodies that bound PSMA with nanomolar affinity and exhibited a broad epitopic coverage and sequence diversity.…”

“…Compared with original approaches such as hybridoma and single B cell sorting, multiple next generation antibody discovery technologies have accelerated the discovery of therapeutic molecules. Single B cell screening platforms such as the Berkeley Lights Beacon combine relatively high throughput with complex screening strategies using multiplexed assays to enable antibody discovery against challenging targets [26][27][28][29] . There is a growing need for next-generation antibody discovery methods that can be applied to VHH campaigns.…”