How do greasy membrane proteins form stable complexes amidst the greasy lipid solvent of the cell membrane? Furthermore, how do changes in lipid composition affect the free energy of these assemblies? To investigate these questions, we have developed single-molecule microscopy methods for measuring the equilibrium free energies of membrane protein complexes in lipid bilayers and use these approaches to identify the thermodynamic driving forces underlying protein assembly in membranes.

As COVID-19 forced to pivot research activities, we rapidly focused on developing antibodies as potential diagnostic tools and therapeutics against SARS CoV-2. We rapidly implemented our synthetic antibody discovery platform to develop highly potent virus neutralizing antibodies. We demonstrate capability of rapidly developing fully human antibodies using phage displayed synthetic antibody libraries that have excellent drug-like properties.

Multipass membrane proteins (MPs) such as G-protein coupled receptors and ion channels represent an important family of protein targets for the development of monoclonal antibodies (mAbs) to fight a wide variety of diseases ranging from cancer to inflammation, but a great technical challenge exists in displaying these MP antigens at their physiologically relevant conformations to produce mAbs with target specificity. Lipid nanodiscs (LNDs), the discoidal lipid bilayers of nanometer sizes encased by two copies of membrane scafold proteins (MSPs), represent a potentially powerful membrane platform for the development of MP-targeting mAbs with high specificity, but their utility is limited by the instability of detergent-solubilized MPs prior to reconstitution into LNDs, the instability of LNDs themselves, and the undesirable immunogenicity against MSPs. We address these limitations by developing synthetic amphipathic polymers and block copolymer membranes that substitute MSPs and lipid bilayers, respectively.

Phage selections on whole cells ensures relevant presentation of membrane proteins in their native context. However, selections may be complicated by low target density, high background of irrelevant antigens, and structural features that limit accessibility of binding phage. A case study presents cell-based phage selections of two membrane proteins, which resulted in a highly successful antibody discovery effort and one that did not. Factors influencing discovery will be discussed.

Often in antibody discovery the goal is to find binders that target a specific epitope on an antigen. In a standard phage display technique, a specific epitope for each binder is not defined until later in the process when scFvs or FABs from phage display are reformatted into IgGs. In this presentation we will showcase techniques that help to enrich phage display hits towards specific target epitopes.

Multipass transmembrane proteins are difficult targets for antibody generation due to the challenge of making a protein with native conformation. I will present a discovery strategy that resulted in the identification of antibodies that bind to extracellular epitopes of multipass transmembrane proteins. This strategy replaces the conventional hybridoma platform with a primary B-cell platform that mines more of the B-cell repertoire, resulting in a broad panel of diverse antibodies.

High-throughput single-cell screening is enabling the rapid generation of large, diverse antibody sequence data. By combining immune repertoire sequencing with functionally validated single-cell data, we further expand antibody diversity accessible for lead identification. CeliumTm, AbCellera's interactive software, interprets these complex datasets using dynamic visual networks to guide selection.

Scholar Rock’s insights into growth factor activation has led to the development of a platform to discover new medicines designed to selectively regulate growth factor activity in the local microenvironment of tissues. In this presentation, we will discuss how structural insights have enabled design of engineered proteins antigens that have led to discovery of antibodies with high specificity and unique mechanism of action against the TGFß family proteins.

AlivaMab Discovery Services produces low picomolar, neutralizing, development-ready human antibodies against even toxic targets in exceptionally fast timelines. Combining Ablexis' AlivaMab Mouse with ADS' proprietary AMMPD immunizations and direct-to-function screening puts projects on the fastest, most de-risked path from discovery through development and to market.

Two cell therapy and T cell engager technologies are advancing for diverse cancer indications. We developed novel proteins designed to complement and extend the functionality of cell therapeutics called bridging proteins. These can be considered CAR-T cell engagers by MOA. We present examples of the creation and evaluation of these proteins, for delivery to the patient as a biologic for injection or for delivery within the CAR T cell itself.

The law is in chaos with respect to the patentability of medical diagnostics and therapies, DNA, RNA, and proteins. The PTO and courts are acting inconsistently. Last year Congress seemed close to passing clarifying legislation, but that effort died. This presentation addresses such questions as: Are existing patents that seem to restrict research really valid? Are new therapies likely to be patentable? If not, can they attract necessary capital?

CD20 is a B cell marker of unknown function targeted by monoclonal antibodies (such as Rituximab) for the treatment of B cell disorders. We obtained a structure of CD20 in complex with Rituximab, revealing CD20 as a dimer bound by two Fabs; each Fab engages a composite epitope and an homotypic Fab:Fab interface. Our data suggest that Rituximab crosslinks CD20 into circular assemblies, leading to a model for complement recruitment.

Integral membrane proteins represent a major class of therapeutic targets currently underserved by antibody-based drugs. Using a combination of immunization, single B cell isolation, and yeast-based cloning and expression, we have developed a high-throughput method to discover antigen-specific antibodies to a variety of membrane protein target classes. Here, we demonstrate the efficient and large-scale isolation of high-affinity antibodies against membrane protein targets, including CCR8, a class-A GPCR.

Successful biologic discovery requires development of comprehensive screening funnel. Introduction of functional assays early in the screening process enables effective selection of biologics with a desired mode of action and improves understanding of drug biology. This presentation will highlight benefits of the early implementation of functional assays into biologics screening funnel.