Switchable assembly and function of antibody complexes in vivo using a small molecule.

The antigen specificity and long serum half-life of monoclonal antibodies have made them a critical part of modern therapeutics. These properties have been coopted in a number of synthetic formats, such as antibody-drug conjugates, bispecific antibodies, or Fc-fusion proteins to generate novel biologic drug modalities. Historically, these new therapies have been generated by covalently linking multiple molecular moieties through chemical or genetic methods.

Targeting a proteolytic neoepitope on CUB domain containing protein 1 (CDCP1) for RAS-driven cancers.

Extracellular proteolysis is frequently dysregulated in disease and can generate proteoforms with unique neoepitopes not found in healthy tissue. Here, we demonstrate that Abs that selectively recognize a proteolytic neoepitope on CUB domain containing protein 1 (CDCP1) could enable more effective and safer treatments for solid tumors. CDCP1 is highly overexpressed in RAS-driven cancers, and its ectodomain is cleaved by extracellular proteases.

Engineering luminescent biosensors for point-of-care SARS-CoV-2 antibody detection.

Current serology tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies mainly take the form of enzyme-linked immunosorbent assays, chemiluminescent microparticle immunoassays or lateral flow assays, which are either laborious, expensive or lacking sufficient sensitivity and scalability. Here we present the development and validation of a rapid, low-cost, solution-based assay to detect antibodies in serum, plasma, whole blood and to a lesser extent saliva, using rationally designed split luciferase antibody biosensors. This new assay, which generates quantitative results in 30 min, substantially reduces the complexity and improves the scalability of coronavirus disease 2019 (COVID-19) antibody tests.

Theranostic Targeting of CUB Domain Containing Protein 1 (CDCP1) in Pancreatic Cancer.

Purpose: The recent emergence of radioligand therapies for cancer treatment has increased enthusiasm for developing new theranostic strategies coupling both imaging and cytotoxicity in the same entity. In this study, we evaluated whether CUB domain containing protein 1 (CDCP1), a single-pass transmembrane protein highly overexpressed in diverse human cancers, might be a target for cancer theranostics.

Experimental Design: The ectodomain of CDCP1 was targeted using radiolabeled forms of 4A06, a potent and specific recombinant human antibody that we developed.

Engineering Improved Antiphosphotyrosine Antibodies Based on an Immunoconvergent Binding Motif.

Phosphotyrosine (pY) is one of the most highly studied posttranslational modifications that is responsible for tightly regulating many signaling pathways in eukaryotes. Pan-specific pY antibodies have emerged as powerful tools for understanding the role of these modifications. Nevertheless, structures have not been reported for pan-specific pY antibodies, greatly impeding the further development of tools for integrating this ubiquitous posttranslational modification using structure-guided designs.

Highly multiplexed and quantitative cell-surface protein profiling using genetically barcoded antibodies.

Human cells express thousands of different surface proteins that can be used for cell classification, or to distinguish healthy and disease conditions. A method capable of profiling a substantial fraction of the surface proteome simultaneously and inexpensively would enable more accurate and complete classification of cell states. We present a highly multiplexed and quantitative surface proteomic method using genetically barcoded antibodies called phage-antibody next-generation sequencing (PhaNGS).

Targeting RAS-driven human cancer cells with antibodies to upregulated and essential cell-surface proteins.

While there have been tremendous efforts to target oncogenic RAS signaling from inside the cell, little effort has focused on the cell-surface. Here, we used quantitative surface proteomics to reveal a signature of proteins that are upregulated on cells transformed with KRAS, and driven by MAPK pathway signaling. We next generated a toolkit of recombinant antibodies to seven of these RAS-induced proteins.

Human antibody-based chemically induced dimerizers for cell therapeutic applications.

Chemically induced dimerizers (CIDs) have emerged as one of the most powerful tools for artificially regulating signaling pathways in cells; however, currently available CID systems lack the properties desired for use in regulating cellular therapies. Here, we report the development of human antibody-based chemically induced dimerizers (AbCIDs) from known small-molecule-protein complexes by selecting for synthetic antibodies that recognize the chemical epitope created by the bound small molecule. We demonstrate this concept by generating three antibodies that are highly selective for the BCL-xL-ABT-737 complex compared to BCL-xL alone.

Saccharin derivatives as inhibitors of interferon-mediated inflammation.

A series of novel, saccharin-based antagonists have been identified for the interferon signaling pathway. Through in vitro high-throughput screening with the Colorado Center for Drug Discovery (C2D2) Pilot Library, we identified hit compound 1, which was the basis for extensive structure-activity relationship studies. Our efforts produced a lead anti-inflammatory compound, tert-butyl N-(furan-2-ylmethyl)-N-{4-[(1,1,3-trioxo-2,3-dihydro-1λ(6),2-benzothiazol-2-yl)methyl]benzoyl}carbamate CU-CPD103 (103), as a potent inhibitor using an established nitric oxide (NO) signaling assay.

Development of β-amino alcohol derivatives that inhibit Toll-like receptor 4 mediated inflammatory response as potential antiseptics.

Toll-like receptor 4 (TLR4) induced proinflammatory signaling has been directly implicated in severe sepsis and represents an attractive therapeutic target. Herein, we report our investigations into the structure-activity relationship and preliminary drug metabolism/pharmacokinetics study of β-amino alcohol derivatives that inhibit the TLR4 signaling pathway. Lead compounds were identified from in vitro cellular examination with micromolar potency for their inhibitory effects on TLR4 signaling and subsequently assessed for their ability to suppress the TLR4-induced inflammatory response in an ex vivo whole blood model.

Selection, Preparation, and Evaluation of Small- Molecule Inhibitors of Toll-Like Receptor 4.

Toll-like receptor 4 (TLR4), a membrane spanning receptor protein that functions in complex with its accessory protein MD-2, is an intriguing target for therapeutic development. Herein we report the identification of a series of novel TLR4 inhibitors and the development of a robust, enantioselective synthesis using an unprecedented Mannich-type reaction to functionalize a pyrazole ring. In silico and cellular assay results demonstrated that compound 1 and its analogues selectively block TLR4 activation in live cells.

Development of agents that modulate protein-protein interactions in membranes.

Membrane proteins account for approximately one third of all proteins in eukaryotic and prokaryotic cells. These proteins are critical in a diverse array of cellular functions. Despite their obvious importance, the effectiveness of research tools to study the structure and function of integral membrane proteins lags behind that of water-soluble proteins.

A peptide antagonist of the TLR4-MD2 interaction.

Toll-like receptors are an integral part of innate immunity in the central nervous system (CNS); they orchestrate a robust defense in response to both exogenous and endogenous danger signals. Recently, toll-like receptor 4 (TLR4) has emerged as a therapeutic target for the treatment of CNS-related diseases such as sepsis and chronic pain. We herein report a chemical biology approach by using a rationally designed peptide inhibitor to disrupt the TLR4-MD2 association, thereby blocking TLR4 signaling.