|A Simple Plate Based Assay Using pH Sensor Dye to Screen for Internalizing Antibody|
Nidhi Nath, Becky Godat, Cesear Corona, Chad Zimprich, Mark McDougall, Poncho Meisenheimer, Marjeta Urh
Receptor mediated internalization is a key mechanism of action (MOA) for antibody drug conjugates (ADCs). However, current methods of studying antibody internalization have several limitations including: 1) A multistep process not suitable for screening; 2) Low signal-to-background ratios; 3) Not suitable for kinetic measurements. We have developed a method that mitigates problems associated with traditional internalization assays.
|An IgG Cleaving Protease from S equi with Improved Activity Against Mouse IgGs|
Chris Hosfield, Philip Compton, Luca Fornelli, Paul Thomas, Neil L. Kelleher, Michael Rosenblatt & Marjeta Urh
Here we have expressed and purified a modified recombinant IdeZ, and show that it has significantly improved activity against mouse IgG2a and IgG3 subclasses when compared to IdeS. We also demonstrate the use of IdeZ in LC-MS workflows for human and mouse IgG characterization.
|Better Cell-Based Assays for Anti-CTLA-4, Anti-PD-1/PD-L1, and Bispecific Immunotherapy Drug Studies|
Richard Somberg, Mei Cong, Pete Stecha, Natasha Karassina, Jim Hartnett, Zhi-Jie Jey Cheng, and Frank Fan
Here we report the development of a panel of robust reporter assays to measure the potencies for biologics in immunotherapy. These assays reflect mode of action and can serve as valuable tools in immunotherapy drug development and discovery.
|CellTiter-Glo® 2.0: A Novel Luminescent Cell Viability Assay with Greatly Enhanced Storage Stability|
Michael P. Valley, James Unch, Poncho L. Meisenheimer, James J. Cali, and Dan F. Lazar
Here we report on the attributes of a novel ATP detection reagent for cell viability with all of the assay performance of the previous CellTiter-Glo® Reagent, but now with markedly enhanced stability as a single component in a liquid format. These new features provide for much greater ease-of-use in that storage of the reagent at 4°C eliminates the requirement for reagent thawing and minimizes temperature equilibration time.
|Design and Validation of Bioluminescent Assays for 3D Cell Culture Models Poster|
Terry L. Riss, Michael P. Valley, Chad A. Zimprich, Andrew L. Niles, Kevin R. Kupcho and Dan F. Lazar
Cells cultured in 3D model systems often acquire relatively large in vivo-like structures compared to the thickness of a 2D monolayer of cells grown on standard plastic plates.
|Development of a Robust Reporter-based T cell Activation Assay for Therapeutic Biologics in Immunotherapy |
Zhi-jie Jey Cheng, Pete Stecha, Jim Hartnett, Frank Fan, and Mei Cong
Jurkat T-cells stably expressing luciferase reporter driven by IL2 promoter or NFAT-RE, are used as effector cells. Tumor cell lines endogenously expressing cancer antigen are used as antigen presenting cells (APC). By co-cultivating the two cell lines in the presence of CD3 bispecific antibody, TCR/CD3 is activated in Jurkat effector cells. Luciferase activity is up regulated through IL-2 promoter or NFAT-RE activation.
|iPSC-Derived Cardiomyocytes and Luciferase Reporters: A Robust Reporting Platform for Monitoring Cardioprotection and Pathway Biology in Endogenous Human Tissue Cells|
Fiene, S., Thompson, A., Niles, A., Robers, M., Anson, B.
Pathophysiological conditions, medical interventions, and off-target toxicities can all result in cellular oxidative stress. In cardiac myocytes, prolonged and/or excessive oxidative stress can lead to cardiotoxicity: a primary cause of developmental delays, black-box warnings, and post-launch withdrawal of pharmaceuticals.
|Reporter Bioassays to Assess Therapeutic Antibodies for Immunotherapy Programs|
Mei Cong, Zhi-Jie Jey Cheng, Pete Stecha, Jun Wang, Jamison Grailer, Natasha Karassina, Jim Hartnett, and Frank Fan
Immunotherapy, also called biologic therapy or biotherapy, stimulates certain parts of the immune system to fight diseases such as cancer. Important drug targets in immunotherapy include: Co-inhibitory receptors, such as PD-1/PD-L1, CTLA-4, LAG3, Tim3; and co-stimulatory receptors, such as GITR, CD40, OX40, 4-1BB.
Current approaches to assaying these targets are cumbersome and variable. Here we offer an improved in vitro bioassay approach.
|ROS-Glo™ H2O2 Assay: A Luminescent Assay for Detection of Reactive Oxygen Species Poster|
Gediminas Vidugiris, Sarah Duellman, John Shultz, Jolanta Vidugiriene, Hui Wang, Jean Osterman, Wenhui Zhou, Poncho Meisenheimer and James J. Cali
H2O2 is a reactive oxygen species (ROS) that is measured in cells as a marker of oxidative stress. It is also measured as a marker of enzyme activities that either consume or produce H2O2. It is desirable to screen chemical compounds for their capacity to alter H2O2 levels in cultured cells or for their effects on H2O2 levels in enzyme reactions.