A reference induced pluripotent stem cell line for large-scale collaborative studies

Abstract

Human induced pluripotent stem cells (iPSCs) are a powerful tool for studying development and disease. However, different iPSC lines show considerable phenotypic variation. The lack of common well-characterized cell lines that are used widely frustrates efforts to integrate data across research groups or replicate key findings. Inspired by model organism communities who addressed this issue by establishing a limited number of widely accepted strains, we characterised candidate iPSC lines in unprecedented detail to select a well-performing line to underpin collaborative studies. Specifically, we characterised the morphology, growth rates, and single-cell transcriptomes of iPSC lines in the pluripotent state and assessed their genomic integrity using karyotyping, DNA microarrays, whole genome sequencing, and functional assays for p53 activity. We further tested their ability to be edited by CRISPR/Cas9 and used single-cell RNA sequencing to compare the efficiency with which they could be differentiated into multiple lineages. We found that there was significant variability in the performance of lines across the tested assays that enabled the rational selection of a lead line, KOLF2.1J, which is a gene-corrected derivative of a publicly available line from the Human Induced Pluripotent Stem Cells Initiative (HipSci) resource. We are now using this line in an initiative from the NIH Center for Alzheimer's and Related Dementias to derive hundreds of gene-edited and functionalized sub-clones to be distributed widely through the research community along with associated datasets, with the aim of promoting the standardisation required for large-scale collaborative science in the stem cell field.