Abstract 92: Assessment of an in vitro potency assay for evaluation of immune cell-mediated cytotoxicity using the Omni Pro 12 automated imaging platform

Abstract

Abstract The development of immunotherapies relies on the use of in vitro potency assays—which are key for understanding complex interactions between immune cells and cancer cells. Immune effector T-cells are a promising cancer therapy due to their innate cytotoxicity. In particular, CAR T-cell therapy uses genetically engineered T-cells that express a chimeric antigen receptor that binds to a specific antigen on tumor cells. Assessing the efficacy and potency of CAR T-cell therapies in vitro and at high throughputs is vital for the preclinical development of these promising therapies. Here, we describe an in vitro potency assay that uses an automated imaging platform to quantify immune cell-mediated cytotoxicity of cancer target cells by immune effector cells. A GFP fluorescent and HER-2 expressing lung cancer cell line, A549, was seeded into a 96-well cell culture plate. Then, HER-2 CAR T-cells were added at 24 hours post target cell seeding at various E:T ratios (1:10, 1:5, 1:2, 1:1, and 5:1). Fluorescent images of the target cells were captured every 6 hours by the Omni Pro 12, an automated, high-throughput, live-cell analysis platform designed for continuous multi-well imaging inside an incubator. Automated image analysis was performed using the Confluency Module in the Axion Portal to view attachment and proliferation and quantify cytolysis of fluorescent A549 target cells. Percent cytolysis of the target cells was calculated by comparing the green fluorescent confluency of treated wells to no treatment control wells. A549-GFP cells showed a dose-dependent decrease in confluency over time that correlated with increasing amounts of CAR T-cells. At 92 hours post HER-2 CAR T-cell addition, the 5:1 ET group demonstrated approximately 91.8% +/- 2.0% cytolysis of A549-GFP cells, while the 1:10 group demonstrated approximately 69.2% +/- 3.0% cytolysis. Future work will evaluate differences in CAR T-cell potency when co-cultured with target cells that express different levels of HER-2. Overall, the Omni Pro 12 platform enables continuous quantification of the potency and kinetics of immune cell-mediated cytolysis. Citation Format: Denise Sullivan, Lieke Stemkens, Inge Thijssen, Svenja Meiler, Danielle Califano, Stacie Chvatal, Daniel Millard. Assessment of an in vitro potency assay for evaluation of immune cell-mediated cytotoxicity using the Omni Pro 12 automated imaging platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 92.