This review summarizes research with a focus on clinical translation of iPSC-derived immune cells, as well as highlights continued challenges and prospects of this field.
Abstract
The landmark derivation of induced pluripotent stem cells (iPSCs) sparked an enormous range of research on development of diverse cell populations. Perhaps no aspect of this work has been as productive as studies on blood and immune cell production. Indeed, essentially all human blood cell populations can be derived from human iPSCs. While derivation of transplantable hematopoietic stem cells (HSCs) from iPSCs has been relatively challenging, clinical translation of iPSC-derived immune cells has been particularly productive. Notably, more patients have been treated with iPSC-derived natural killer (NK) cells than any other iPSC-derived cell type. Use of iPSCs provides a key platform to incorporate multiplexed gene edits before differentiation, enabling NK cells to be engineered with tumor-targeting CARs, cytokine support for improved persistence, enhanced tumor trafficking, and resistance to host immune rejection, modifications uniformly expressed across the entire cellular product. While T cells, macrophages and other immune cells can be produced from human iPSCs, iPSC-derived NK cells have been the most widely used in clinical trials for treatment of refractory malignancies, as well as autoimmune disease. This review summarizes research with a focus on clinical translation of iPSC-derived immune cells, as well as highlights continued challenges and prospects of this field.
Key applications of iPSC technology in hemato-oncology are summarized, its major advantages and current limitations are discussed, and emerging directions are highlighted, including scalable iPSC-derived blood cell therapies for inherited and acquired bone marrow failure syndromes and leukemia.
Ivan Tesakov, M. Nasri, M. Klimiankou et al.· Frontiers in Immunology· 0 citations
The etiology of Kawasaki disease (KD) remains unclear. Hematopoietic stem and progenitor cells (HSPCs) serve as the precursor cells for a multitude of immune cells. Investigating their initial transcriptional status may help uncover the aberrant immune mechanisms underlying KD.
Induced pluripotent stem cells (iPSCs) were reprogrammed from peripheral blood mononuclear cells (PBMCs) isolated from patients with KD and febrile individuals, followed by directed differentiation into HSPCs. We performed bulk RNA-sequencing to compare transcriptomic profiles of iPSC-derived HSPCs between the two groups, with further comparison against integrated HSPC data from public KD single-cell datasets.
We recruited three patients with KD prior to Intravenous immunoglobulin (IVIG) therapy and three febrile control patients, and successfully established an iPSC-derived HSPCs disease model. Transcriptomic profiling revealed elevated immune and inflammatory response signatures in iPSC-derived HSPCs from patients with KD compared with those from febrile individuals. In addition,
in vitro
-generated KD iPSC-HSPCs exhibited partial transcriptional features similar to
in vivo
HSPCs isolated from PBMCs of patients with KD. Gene Set Enrichment Analysis (GSEA) further revealed that gene sets associated with B-cell developmental processes were transcriptionally downregulated in iPSC-derived HSPCs from patients with KD relative to febrile controls.
iPSC-derived HSPCs from patients with KD display altered immune-inflammatory transcriptional profiles and suppressed B-cell developmental signatures at the transcriptomic level. These preliminary findings suggest that early hematopoietic immune dysregulation may contribute to KD pathogenesis. We propose that these iPSC-derived HSPCs could be a good cellular model for studying the etiology of KD
in vitro
. These findings are preliminary, constrained by the small sample size and limited to transcriptomic analysis only. Further studies with larger cohorts and functional experiments are needed to verify these results.
Lianni Mei, Lei Gao, Ruizhi Zhang et al.· Frontiers in Pediatrics· 0 citations
Thymic stromal cells are essential for T-cell progenitor proliferation and differentiation. While thymic epithelial cells are well studied, non-epithelial stromal populations–particularly neural crest—derived mesenchymal cells–are increasingly recognized for their roles in thymus formation and function. Mesenchymal defects contribute to thymic abnormalities in congenital syndromes such as DiGeorge syndrome (DGS), CHARGE syndrome, and Trisomy 21 (T21), yet human studies are limited by the rarity of these conditions and restricted access to thymic tissue.
We generated iPSCs from individuals with TBX1, CHD7, HOXA3, and PAX1 mutations, as well as DGS and T21 patients. Control and patient iPSCs, derived from PBMCs or skin biopsies, were differentiated into mesenchymal stem cells (MSCs). Primary thymic mesenchymal cells (ThyMCs) were also isolated from human thymi. All cell populations were analyzed by flow cytometry and bulk RNA-seq. Tri-lineage differentiation assays (adipogenic, chondrogenic, osteogenic) were performed to assess functional pathway defects.
Flow cytometry confirmed robust expression of MSC markers (CD73, CD146, CD105) in all MSC and ThyMC samples, absent in undifferentiated iPSCs. Principal component analysis revealed clear segregation of iPSCs, MSCs, and ThyMCs. Transcriptomic profiling showed that all patient-derived MSCs acquired mesenchymal identity, but each disease group displayed distinct transcriptional changes. MSCs with TBX1, HOXA3, or PAX1 mutations had the highest number of differentially expressed genes, affecting pathways such as extracellular matrix and cartilage development.DGS-derived MSCs and ThyMCs showed marked upregulation of ECM and collagen genes (FBLN5, PCOLCE, EMILIN1, COL3A1, COL1A2).
Our findings reveal disease-specific mesenchymal defects underlying thymic abnormalities in congenital syndromes.This platform enables mechanistic studies of thymic stromal dysfunction and advances understanding of immune deficits in these disorders.
This work was supported by the Division of Intramural Research, NIAID, NIH.
Hematopoiesis and Immune System Development (HEM)
Giuseppe Sangiorgio, Francesca Pala, Kayla Amini et al.· Journal of Immunology· 0 citations
INTRODUCTION
Macrophages are essential components of innate immunity, serving as a frontline defense against pathogens and maintaining tissue homeostasis. Human induced pluripotent stem cell (iPSC)-derived macrophages (iMacs) provide a powerful platform for studying human innate immunity and macrophage biology. Here, we describe a robust, reproducible, efficient serum-free and feeder-free protocol for generating functional iMacs and characterizing their innate immune properties.
METHODS
A 30-day monolayer culture system was utilized to continually generate hematopoietic progenitor cells (HPCs) from iPSCs starting on day 9, followed by macrophage differentiation over 21 days. Macrophage identity was assessed by flow cytometry, while functional assays evaluated phagocytosis and cytokine production, including interferons (IFNs). Transcriptomic profiling was performed by RNAseq across differentiation stages and following IFN stimulation.
RESULTS
The optimized protocol consistently yielded iMacs with >99% purity, expressing canonical macrophage markers including CD14, CD16, CD163, HLA-DR, and CD11b. iMacs demonstrated robust phagocytic capacity and cytokine production in response to microbial stimuli. RNA sequencing revealed distinct gene signatures during differentiation, highlighting key transitions from pluripotency to progenitors, then to mature macrophages. iMac transcriptomes aligned with tissue-resident macrophage profiles, supporting their relevance for modelling tissue-specific immunity. iMacs displayed differential interferon responses, with a strong response to type I IFNs.
CONCLUSION
This study establishes a highly efficient and robust protocol for generating functional human iPSC-derived macrophages, providing a versatile model for investigating innate immunity, host-pathogen interactions, and interferon signaling.
Hani Hosseini Far, Le Ying, L. Gearing et al.· Journal of Innate Immunity· 0 citations
Induced pluripotent stem cells (also known as iPS cells or iPSCs) are a type of pluripotent stem cell that can be generated directly from a somatic cell. The iPSC technology was pioneered by Shinya Yamanaka’s lab in Kyoto, Japan, who showed in 2006 that the introduction of four specific genes (named Myc, Oct3/4, Sox2 and Klf4) encoding transcription factors could convert somatic cells into pluripotent stem cells. He was awarded the 2012 Nobel Prize along with Sir John Gurdon "for the discovery that mature cells can be reprogrammed to become pluripotent."
Pluripotent stem cells hold promise in the field of regenerative medicine. Because they can propagate indefinitely, as well as give rise to every other cell type in the body (such as neurons, heart, pancreatic, and liver cells), they represent a single source of cells that could be used to replace those lost to damage or disease.
Recognising the central role of VSELs/progenitors and their niche in maintaining tissue homeostasis in vivo could resolve existing roadblocks and guide more effective endogenous regenerative therapies for diseased tissues and age-related dysfunctions.
D. Bhartiya, N. Sharma, Anish Tripathi et al.· Stem Cell Reviews and Report...· 0 citations
