Pluripotent stem cell-derived extracellular vesicles for systemic immune modulation in diabetes therapy

Embryos can achieve immune tolerance, yet the underlying mechanisms remain incompletely understood. Here, we demonstrate that pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), secrete extracellular vesicles (EVs) that markedly outperform mesenchymal stem cell (MSC)-derived EVs in suppressing pro-inflammatory cytokine secretion, inhibiting activated T-cell proliferation, and inducing regulatory T-cell (Treg) formation through CDK8 downregulation. Nuclear magnetic resonance (NMR) analysis reveals distinct molecular fingerprints of PSC EVs compared to those of MSC EVs. Moreover, comparative analyses show that PSC EVs contain unique proteins and microRNAs, such as the pluripotency-associated proteins ROR1 and CD133 and members of the miR-302 family, which are not found in MSC EVs, as determined by proteomic profiling and microRNA sequencing. Notably, the dynamic suspension culture of PSC aggregates significantly increases EV yield, offering a scalable and reproducible source superior to other cell sources. To evaluate their therapeutic potential, we employed an antigen-specific type 1 diabetes model and found that two local injections of iPSC EVs, particularly when delivered via a biomaterial scaffold, significantly enhanced diabetes-free survival. These treatments increased Treg populations in draining lymph nodes, induced systemic immunomodulation, and preserved β-cell mass from immune-mediated destruction. The immunomodulatory capability of PSC EVs suggests broad applications in treating autoimmune diseases and supporting stem cell-derived cell therapies by promoting immune tolerance. Their scalability, consistency, and superior therapeutic properties position PSC EVs as a compelling platform for next-generation immunotherapies and cell-based treatment strategies.