(1109-B) Enabling High-throughput 3D Cell-based Assays with Commercially-available Sources of Human iPSC-derived Cell Types

Abstract: It is well established that drug screening in whole cells can reveal a great deal more about the target and mechanism of action for a compound as compared to biochemical assays with enzymes or proteins. Given this importance of biological context, new tools and techniques that can better reflect the in vivo environment are required during the drug discovery process. Introduction of induced pluripotent stem cell (iPSC) technology has helped to enhance physiological relevant by building a bridge between animal testing and human diseases. Furthermore, increased assay complexity can be achieved with three-dimensional (3D) culture systems. Different than “organoids”, however, that are traditionally generated from stem cells embedded in a hydrogel matrix over a long period of time, similar structures can be created by mixing individual cell types differentiated from iPSC at defined numbers and ratios and allowing them to self-assemble in co-culture. Such 3D spheroid products can also recapitulate many aspects of the complex structure and function of the corresponding in vivo tissue. Additionally, this approach enables a more flexible method (modular incorporation of defined cell types, including disease-specific lines) while also allowing more control over variability (individual components are well-defined and highly reproducible), both of which are critical to the success of incorporating such technologies into cell-based assay workflows.
Here we present several examples of enabling 3D cell-based assays with human iPSC-derived cell types in 384-well format. Generation of “cardiospheres” from cardiomyocytes, cardiac fibroblasts, and endothelial cells yields a system with improved myocardial maturity that demonstrates a positive inotropic response (increased calcium waveform amplitude) to compounds like isoproterenol and dobutamine. A diverse range of “neurospheres” can be created using healthy or diseased neurons and astrocytes, with the option of incorporating microglia, to model neurodegenerative disease or to study neuroinflammation. Other example data will be presented, including hepatocytes and macrophages together in 3D to yield a more complex liver co-culture system; and an alternative blood-brain barrier (BBB) model system composed of astrocytes, pericytes, and brain microvascular endothelial cells. Importantly, all of these systems described above are isogenic, meaning the cells are derived from the same iPSC donor background.
All of these iPSC-derived cell types are manufactured at scale, quality controlled, cryopreserved, and commercially available so that they are ready-to-use with confidence at any point in time. Implementation of these cells into modular 3D assay workflows is novel approach to complement current organoid research and enhance the biological complexity required in cell-based assays for drug discovery, toxicity screening, and disease modeling.