Posters
The PARP family catalyzes the ADPribosylation of proteins, playing a key role in the response to DNA damage, and is therefore highly relevant to cancer therapy. Several inhibitors are clinically approved, with newer generations focusing on increased specificity. Here, we describe complementary assays for evaluating the potency and selectivity of candidates against the PARP family, including enzymatic assays for catalytic inhibitors, DNA-trapping, and olaparib competition assays. We also discuss a cellular PARylation assay that measures drug activity in cells to obtain information on parameters not captured in biochemical assays.
Bispecific antibodies engage two targets simultaneously to enhance specificity and efficacy across cancer and immune-related applications. Here we present a portfolio of control bispecific antibodies with supporting validation tools, including γδ T cell engagers and AbTAC-based assays enabling targeted degradation of membrane proteins such as EGFR. Together, these platforms provide robust and reliable tools for evaluating next-generation bispecific therapeutics, including approaches to previously undruggable targets.
We have developed a series of cell lines to interrogate various receptor-signaling pathways for drug screening and characterization. These cells respond to agonists by displaying a dose-dependent increase in luciferase activity. For example, Muscarinic Acetylcholine Receptor NFAT Luciferase reporter cell lines were generated by expressing mAChR M1, M3, or M5, together with a firefly luciferase reporter under the control of an NFAT response element. Similarly, cell lines expressing various incretin receptors were generated to assess the effectiveness of incretin agonists. In addition, we successfully developed cell lines to measure the activation of thyroid receptors α and β (TRα/β).
Inhibitors of interleukin signaling have transformed the treatment of immune-related diseases and represent a rapidly expanding area of research. Development of these biologics is supported by engineered interleukin receptor-expressing cells quantifying cytokine responses through inducible luciferase reporter activity, and ligand–receptor assay kits allowing the screening and profiling of neutralizing antibodies by directly measuring a cytokine binding to its receptor. Functionality was validated by measuring agonist activity of the respective interleukin in reporter cells and determining IC₅₀ values of novel therapeutics using both ELISA and reporter cell assays. Together, these platforms provide versatile tools for assessing the effects of agonists, antagonists, and neutralizing antibodies.
A suite of biological tools was generated to support research on HLA-conscious adoptive cell therapies or biologics. First, B2M-KO target cells were developed to enable HLA allele-specific screening. Then, a B2M-KO lung cancer cell line was engineered to re-express B2M together with specific HLAs, creating an HLA-informed panel of cell lines to use as target cells in the assessment of HLA-targeted TCR molecules or bispecific T cell engagers. These engineered platforms offer versatile, physiologically relevant systems for TCR or bispecific molecule screening, assay optimization, and functional characterization, and support the development of novel HLA-informed therapeutics.
WRN, BLM, and DHX9 are DNA/RNA helicases with ATPase activity that play central roles in maintaining genome stability and are linked to a range of human diseases, including several types of cancer. To facilitate drug discovery and development efforts targeting these enzymes, we have developed robust high-throughput ATPase and helicase assay kits. Experimental protocols were optimized to account for their dual enzymatic activities and for differences in substrate preferences. These quantitative assays allow determination of candidate drug efficacy on both helicase and ATPase activity and target selectivity.
The global rise in obesity has increased cases of type 2 diabetes, cardiovascular disease, and cancers, making weight and comorbidity management essential. Incretin agonists like GLP-1 improve glucose control, satiety, weight loss, and reduce cardiovascular risk. Dual or triple agonists targeting GLP-1R, GCGR, and GIPR show greater promise. Amylin and leptin receptors also regulate energy balance and metabolism, with agonists under development to enhance outcomes. However, these therapies can cause muscle loss, prompting exploration of Activin/Myostatin inhibitors to preserve muscle. To support drug discovery, we developed luciferase reporter cell lines for GLP-1R, GLP-2R, GIPR, GCGR, Activin/Myostatin, leptin, and amylin receptors.
Bispecific antibodies that recognize two distinct antigens represent a promising class of next-generation biologics. Evaluating their ability to bind both targets simultaneously is critical for advancing their therapeutic use. CD3-bispecific antibodies activate T cells by binding a tumor antigen and CD3 on T cells, resulting in tumor cell destruction. This poster presents dual-target bridging ELISAs designed to engage T cells via CD3 binding. These assays are simple, cost-effective, and require no specialized equipment, making them accessible to most labs. They are compatible with purified proteins, human serum, or cell culture medium.
TCR-T cell-based immunotherapy leverages genetically engineered T cells that recognize specific antigens via T cell receptors (TCRs). When TCRs bind to target antigens presented by MHC molecules, they activate T cells, triggering an immune response that kills abnormal cells. This approach allows for precision treatment by engineering T cells to target specific cancer-related antigens. This poster highlights the utility of a new suite of tools supporting TCR-T cells development projects.
Antibodies represent a cornerstone of modern therapeutics, demonstrating remarkable efficacy in oncology and immunology. The rapid progress in therapeutic antibody development requires robust analytical methods to evaluate critical characteristic. In this study, we discuss methods to assess key aspects of antibody characterization, including target engagement, binding kinetics, and Fc domain functional activity. These assays provide the depth of characterization essential for the identification and validation of antibody candidates with optimal target engagement and effector functions.
T cell lymphocytes are composed of two sub-populations, αβ T cells and γδ T cells, which are distinguished by the expression of either an αβ TCR (T Cell Receptor) or a γδ TCR, respectively. The γδ T cells are less abundant than αβ T cells and recognize antigens independently of MHC (Major Histocompatibility Complex) presentation. Both αβ T cells and γδ T cells contribute to cell cytotoxicity through distinct mechanisms to target and eliminate infected or abnormal cells. However, transplanted γδ T cells have a lower risk of causing GvHD (Graft-versus-Host Disease) and induce cytotoxicity against a wide range of tumor types. We demonstrate the successful isolation, activation, and expansion of αβ T cells and γδ T cells. Functional validations by two different cytotoxicity assays (flow cytometry and luciferase-based assays) showed that T cells can effectively kill cancer cells in vitro. Furthermore, we demonstrate BPS Bioscience’s T Cell Engagers can activate αβ T cells to kill tumor cells in vitro, while expanded γδ T cells kill target cells without needing t cell engagers.
Inhibitors of poly (ADP-ribose) polymerases (PARPs) have revolutionized cancer therapy by highlighting the potential of synthetic lethal drugs to target the DNA damage response (DDR) network. More recently, the development of PARG inhibitors was spurred by the discovery that inhibiting PARG (poly (ADP-ribose) glycohydrolase) results in the accumulation of poly (ADP-ribose) on DDR proteins and induces cell death.
Adding PARG or PARP inhibitors to a cell of interest and quantifying the resulting levels of PARylation can provide valuable insight on compound membrane permeability and target engagement in a cellular context. Nevertheless, assessing PARylation in cells is difficult, impeding the progress of candidate drug development. A sandwich ELISA was developed to analyze the total protein PARylation present in cellular extracts. Experimental protocols were optimized to discern differences in cellular PARylation levels resulting from activating the DDR or from exposure to PARP and/or PARG inhibitors.
Adenosine Deaminase Acting on RNA (ADAR) enzymes perform adenosine to inosine base editing in RNA, particularly targeting adenosines located within a specific double-stranded stem-loop motif. ADAR editors are promising therapeutic targets and are used as tools in experiment treatments for genetic diseases. We describe the design and optimization of three cell lines generated to support different aspects of ADAR1 research:
ADAR1 Responsive Luciferase Reporter Cell Line is designed to compare the effect of ADAR1 modifications and mutations on ADAR1 activity, for example when studying structure/function relationships, or when designing ADAR1 variants for RNA editing.
ADAR1 Activity Luciferase Reporter Cell Line stably expresses ADAR1 and is suitable to assess the efficacy of ADAR1 modulators such as small molecule inhibitors. This assay is amenable to high-throughput screening.
ADAR1 Activity Two-Luciferase Cell Line allows the multiplexing of efficacy measurements in parallel with toxicity determination of ADAR1-directed compounds such as small molecule inhibitors.
Better control of blood glucose levels in diabetic patients has been achieved with GLP-1R (glucagon-like peptide-1 receptor) agonists, which also promote a sense of satiety, helping patients with weight loss and reducing cardiovascular risks. Dual or triple receptor agonists targeting GLP-1R, GCGR (glucagon receptor) and GIPR (glucose-dependent insulinotropic polypeptide receptor) may provide even better options to improve metabolism and health outcomes.
To support multi-receptor agonist development, we generated and characterized three cell lines that respond to GCGR, GIPR, or GLP-1R activation by inducing luciferase activity which can be measured using a simple luminometer and is directly proportional to receptor activation. These cells express GCGR, GIPR, or GLP-1R, and a firefly luciferase reporter under the control of CRE (cAMP response elements). They produce a robust luciferase readout upon agonist stimulation (up to 40 to 300-fold stimulation depending on the cell line) and are ideal for screening candidate molecules and determining their EC50.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates circulating cholesterol levels by binding to low-density lipoprotein receptor (LDLR) on the cell surface. Gain-of-function (GOF) mutations in PCSK9 increase the risk of cardiovascular disease, and PCSK9 has become a promising therapeutic target for the treatment of inherited or sporadic cardiovascular disease. Two assays were designed to evaluate the effect of candidate drugs on PCSK9/LDLR binding. Experimental parameters and buffer compositions were optimized to detect conformational effects of pH and PCSK9 mutations. Our experimental findings are consistent with existing literature on PCSK9 mutations, demonstrating the utility of these assays. Optimizing drug candidates to function effectively across a range of pH conditions enhances their potential clinical applicability. Thus, measuring PCSK9-LDLR binding at different pH levels is crucial for understanding the physiological relevance, optimizing drug development, unraveling intracellular trafficking mechanisms, exploring disease mechanisms, and gaining basic biological insights into this important molecular interaction.
Poly-(ADP-ribose) glycohydrolase (PARG) degrades ribosylation chains generated by PAR polymerases PARPs) in response to DNA damage and has been implicated in cancer. PARG is a promising therapeutic target as its inhibition may potentiate the effect of chemotherapy and radiation. This study describes the optimization of two biochemical assays measuring PARG enzymatic activity for inhibitor screening & profiling. The PARG Fluorogenic Assay uses a straightforward, fast, no-wash method to study enzyme kinetics, and is ideal for high-throughput screening applications. However, test compounds with intrinsic fluorescence will interfere with the assay, requiring a non-fluorescent method. The PARG Chemiluminescent Assay, although inappropriate for kinetic studies, offers a convenient alternative to the fluorogenic assay.
Casitas B-lineage lymphoma (CBL) is a family of RING-type E3 ligases that target proteins for degradation via the proteasomal pathway. CBL-b specifically functions as a negative effector of T cell activation by down regulating the T cell receptor, whereas c-CBL interacts with various receptor tyrosine kinases involved in cell signaling and activation, targeting them for degradation. In this study, we used TR-FRET to uncover new mechanistic aspects of CBL activation. Our data indicates that no significant difference in the parameters of substrate ubiquitination exists between CBL-b and c-CBL, and that ubiquitination of receptor tyrosine kinase Tyro3 by either c-CBL or CBL-b depends on the kinase binding to CBL but not on the phosphorylation of CBL.
Poly (ADP-ribose) polymerase (PARP) inhibitors are currently used in the clinic for the treatment of tumors with a defective DNA damage response. The continuous presence of PARP at the site of damage prevents repair and blocks replication, leading to cell death. Therefore, drugs that trap PARP1/2 to the DNA tend to be significantly more cytotoxic than other PARP inhibitors, which is highly desirable. This study describes the design and optimization of novel PARPtrap assays to specifically assess the ability of a drug to trap PARP onto DNA.
Drug discovery and development projects require reliable assays to screen and evaluate new small molecules that potentially inhibit RAS isoforms. We describe the development of two types of assays for high-throughput screening applications and titration of candidate compounds. One assay is based on AlphaScreen® technology, while the other takes advantage of BODIPY®-GDP in fluorophore GDP/GTP exchange assay kits.
Designing new therapeutic strategies requires the generation of appropriate tools, which can use considerable time and resources. BPS Bioscience has generated a varied portfolio of validated immuno-oncology tools to support drug development efforts as well as basic research projects, allowing the scientific community to focus on critical questions. These tools include anti-BCMA antibodies for BCMA detection, BiTEs (Bispecific T cell Engagers) and TriTEs, BCMA cell lines with or without reporter genes, biochemical assays, and BCMA lentivirus. Thus, BPS supports researchers at all phases of drug discovery to accelerate the development of new treatments for human diseases.
PROTACs® (Proteolysis Targeting Chimeras) are heterobifunctional molecules that bind a target protein of interest (POI) and a specific E3 ligase, triggering the target for degradation through the ubiquitin-proteasome system. This therapeutic approach provides advantages over classical drug therapy enabling targeting of otherwise undruggable proteins, while requiring relatively low amounts of compound. To support the advancement of therapeutic PROTACs, we have developed biochemical assays using AlphaScreen™ technology, providing a simple, rapid, and sensitive no-wash system for high throughput-screening.
