ArticleAnnals of laboratory medicine2026
Optimization of Natural Killer Cell Expansion with K562-mbIL-18/-21 Feeder Cells and Assurance of Feeder Cell-free Products.
Article in Annals of laboratory medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.
What it found
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Who cites it
5 citing papers in PubMed.
- PTPN22 as a novel therapeutic target: a key intracellular checkpoint for NK cell therapy.Journal for immunotherapy of cancer · 2026Article
- Donor NKG2A/NKG2C Immunophenotype Influences the GMP-Compliant Manufacturing Potential of NK Cells for Adoptive Immunotherapy.Cancers · 2026Article
- Natural Killer Cell Assays: Clinical Applications and Future Directions.Annals of laboratory medicine · 2026Review
- BaEV-pseudotyped lentiviral vectors enable stable CAR expression and cytotoxic function in NK cells.PloS one · 2026Article
- Antibody-Mediated In Vitro Activation and Expansion of Blood Donor-Derived Natural Killer Cells with Transient Anti-Tumor Efficacy.Biomedicines · 2025Article
Corrections and comments
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Authors and funding
9 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Background: Cancer cell line-derived feeder cells enhance natural killer (NK) cell expansion; however, concerns regarding viable residual feeder cells in the final product limit their use. Evidence supporting the safety of NK-sensitive K562-based feeders, even when irradiated, is scarce. We optimized an NK cell expansion protocol using genetically engineered K562-mbIL-18/-21 (GE-K562) feeder cells and clinical-grade media and confirmed the absence of residual feeder cells. Methods: NK cell expansion efficiency was compared between feeder-free and feeder-based systems using CTS NK-Xpander Medium. To achieve optimal NK expansion, various peripheral blood mononuclear cell (PBMC)-to-feeder ratios and re-stimulation frequencies were tested over 21 days. Flow cytometry and Results: Feeder-based systems showed superior NK cell fold expansion compared with that of feeder-free systems. Among feeder-based conditions, NK cells expanded 5,224-fold at a 2:1 PBMC-to-feeder ratio after 3 weeks, relative to 1,450-fold at a 6:1 ratio ( Conclusions: Our optimized NK cell expansion protocol using irradiated GE-K562 feeder cells and clinical-grade media offers a safe and scalable approach to generating large numbers of NK cells, supporting its potential use in clinical immunotherapy applications.
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