Variation in the differentiation capacity of induced pluripotent stem cells (iPSCs) to specific lineages is a significant concern for their use in clinical applications and disease modeling. To identify factors that affect differentiation capacity, we performed integration analyses between hematopoietic differentiation performance and molecular signatures such as gene expression, DNA methylation, and chromatin status, using 35 human iPSC lines and four ESC lines. Our analyses revealed that hematopoietic commitment of PSCs to hematopoietic precursors correlates with IGF2 expression level, which in turn depends on signaling-dependent chromatin accessibility at mesendodermal genes. Maturation capacity for conversion of PSC-derived hematopoietic precursors to mature blood associates with the amount and pattern of DNA methylation acquired during reprogramming. Our study therefore provides insight into the molecular features that determine the differential capacities seen among human iPSC lines and, through the predictive potential of this information, highlights a way to select optimal iPSCs for clinical applications.

Limited T cell availability and proliferative exhaustion present major barriers to successful T cell-based immunotherapies and may potentially be overcome through the use of "rejuvenated" induced pluripotent stem cells derived from antigen-specific T cells (T-iPSCs). However, strict antigen specificity is essential for safe and efficient T cell immunotherapy. Here, we report that CD8αβ T cells from human T-iPSCs lose their antigen specificity through additional rearrangement of the T cell receptor (TCR) α chain gene during the CD4/CD8 double positive stage of in vitro differentiation. CRISPR knockout of a recombinase gene in the T-iPSCs prevented this additional TCR rearrangement. Moreover, when CD8αβ T cells were differentiated from monocyte-derived iPSCs that were transduced with an antigen-specific TCR, they showed monoclonal expression of the transduced TCR. TCR-stabilized, regenerated CD8αβ T cells effectively inhibit tumor growth in xenograft cancer models. These approaches could contribute to safe and effective regenerative T cell immunotherapies.

Oligomeric forms of amyloid-β peptide (Aβ) are thought to play a pivotal role in the pathogenesis of Alzheimer's disease (AD), but the mechanism involved is still unclear. Here, we generated induced pluripotent stem cells (iPSCs) from familial and sporadic AD patients and differentiated them into neural cells. Aβ oligomers accumulated in iPSC-derived neurons and astrocytes in cells from patients with a familial amyloid precursor protein (APP)-E693Δ mutation and sporadic AD, leading to endoplasmic reticulum (ER) and oxidative stress. The accumulated Aβ oligomers were not proteolytically resistant, and docosahexaenoic acid (DHA) treatment alleviated the stress responses in the AD neural cells. Differential manifestation of ER stress and DHA responsiveness may help explain variable clinical results obtained with the use of DHA treatment and suggests that DHA may in fact be effective for a subset of patients. It also illustrates how patient-specific iPSCs can be useful for analyzing AD pathogenesis and evaluating drugs.