Characterizing cell interactions at scale with made-to-order droplet ensembles (MODEs).

Cell-cell interactions are important to numerous biological systems, including tissue microenvironments, the immune system, and cancer. However, current methods for studying cell combinations and interactions are limited in scalability, allowing just hundreds to thousands of multicell assays per experiment; this limited throughput makes it difficult to characterize interactions at biologically relevant scales. Here, we describe a paradigm in cell interaction profiling that allows accurate grouping of cells and characterization of their interactions for tens to hundreds of thousands of combinations. Our approach leverages high-throughput droplet microfluidics to construct multicellular combinations in a deterministic process that allows inclusion of programmed reagent mixtures and beads. The combination droplets are compatible with common manipulation and measurement techniques, including imaging, barcode-based genomics, and sorting. We demonstrate the approach by using it to enrich for chimeric antigen receptor (CAR)-T cells that activate upon incubation with target cells, a bottleneck in the therapeutic T cell engineering pipeline. The speed and control of our approach should enable valuable cell interaction studies.

Solving time-dependent CYP3A4 inhibition for a series of indole-phenylacetic acid dual antagonists of the PGD(2) receptors CRTH2 and DP.

Based on their structural similarity to previously described compound AMG 009, indole-phenyl acetic acids were proposed to be potent dual inhibitors of chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2 or DP2) and prostanoid D receptor (DP or DP1). This series was equipotent to AMG 009 in binding assays against both receptors but exhibited decreased serum shift. We discovered early in the optimization of these indole-phenylacetic acid compounds that they demonstrated CYP3A4 time-dependent inhibition (TDI). Hypothesizing that the source of TDI was the indole core we modified the 1,2,3-substitution to eventually afford a highly potent modulator of CRTH2 and DP which did not exhibit TDI.

Optimization of phenylacetic acid derivatives for balanced CRTH2 and DP dual antagonists.

Our first generation CRTH2 and DP dual antagonists, represented by AMG 009, are more potent toward the CRTH2 receptor than to the DP receptor. Here we report our efforts in the discovery of CRTH2 and DP dual antagonists with more balanced potencies to both receptors, such as compound 15.

Optimization of a series of quinazolinone-derived antagonists of CXCR3.

The evaluation of the CXCR3 antagonist AMG 487 in clinic trials was complicated due to the formation of an active metabolite. In this Letter, we will discuss the further optimization of the quinazolinone series that led to the discovery of compounds devoid of the formation of the active metabolite that was seen with AMG 487. In addition, these compounds also feature increased potency and good pharmacokinetic properties. We will also discuss the efficacy of the lead compound 34 in a mouse model of cellular recruitment induced by bleomycin.

Optimization of the heterocyclic core of the quinazolinone-derived CXCR3 antagonists.

A series of six-six and six-five fused heterocyclic CXCR3 antagonists has been synthesized and their activities evaluated in an [(125)I]-IP-10 displacement assay and an ITAC mediated in vitro cell migration assay. The pharmacokinetic properties of several top compounds have also been studied. This effort led to the discovery of compounds with increased potency and improved pharmacokinetic properties that could serve as useful tools to study the role of the CXCR3 receptor in vivo.

Signaling property study of adhesion G-protein-coupled receptors.

Adhesion G-protein-coupled receptors (GPCR) are special members of GPCRs with long N-termini containing multiple domains. We overexpressed our collection of receptors together with G-proteins in mammalian cell lines and measured the concentrations of intracellular signaling molecules, such as inositol phosphate and cAMP. Our results show that a subset of tested adhesion GPCRs has constitutive activities and is capable of coupling to a variety of G-proteins. In addition, we have identified a small molecule compound that specifically activates one of the subfamily members, GPR97, and the activation was confirmed by an independent GTPγS assay. These findings suggest classical GPCR screening assays could be applied to de-orphanize these receptors, and provide pharmacological tools to improve understanding of the physiological functions of these receptors.

Discovery of AMG 853, a CRTH2 and DP Dual Antagonist.

Prostaglandin D2 (PGD2) plays a key role in mediating allergic reactions seen in asthma, allergic rhinitis, and atopic dermatitis. PGD2 exerts its activity through two G protein-coupled receptors (GPCRs), prostanoid D receptor (DP or DP1), and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2 or DP2). We report the optimization of a series of phenylacetic acid derivatives in an effort to improve the dual activity of AMG 009 against DP and CRTH2. These efforts led to the discovery of AMG 853 (2-(4-(4-(tert-butylcarbamoyl)-2-(2-chloro-4-cyclopropylphenyl sulfonamido)phenoxy)-5-chloro-2-fluorophenyl)acetic acid), which is being evaluated in human clinical trials for asthma.

Discovery and optimization of a series of quinazolinone-derived antagonists of CXCR3.

A series of quinazolinone-derived inhibitors of the CXCR3 receptor have been synthesized and their affinity for the receptor evaluated. Compounds were evaluated in a (125)I-IP10 displacement assay and in in vitro cell migration assays to IP10, ITAC, and MIG using human peripheral blood mononuclear cells.