Validation of an Image-Based 3D Natural Killer Cell-Mediated Cytotoxicity Assay

Abstract

An in vitro model for natural killer (NK) cell-mediated cytotoxicity was developed using a collagen-based scaffold 3D cell culture technology. This technology induced HCT116 cells to aggregate into tumoroids over time, which became the target cells during the cytotoxicity assay. Cytotoxicity was assessed by both phosphatidyl serine exposure (apoptosis) and plasma membrane rupture (necrosis) using fully automated workflows. Cytotoxicity was quantified using NK cells alone and with IL-2 stimulation, where a significant increase of cytotoxicity was evident. Cytotoxicity with this model was compared to HCT116 cells adhered to microplates in a conventional two-dimensional (2D) format. The three-dimensional (3D) model was far superior in both maintaining cell health over time and accurately depicting cytotoxic events.