Generation of Natural Killer Cells from Human Expanded Potential Stem Cells

Area of Science:

• Immunology
• Stem Cell Biology
• Cell Therapy

Background:

• Natural killer (NK) cells are crucial for innate immunity and cancer immunotherapy.
• Generating clinical-grade NK cells from human pluripotent stem cells (hPSCs) is vital for therapeutic applications.
• Existing methods for NK cell differentiation often require complex culture conditions or animal-derived products.

Purpose of the Study:

• To develop a robust and scalable protocol for differentiating hPSCs into NK cells.
• To establish a serum-free method for generating NK cells for potential clinical use.
• To investigate the utility of both 3D and 2D culture systems in NK cell differentiation and validation.

Main Methods:

• Utilized a two-phase protocol involving serum-free commercial medium.
• Employed a cytokine cocktail including interleukin (IL)-3, IL-7, IL-15, stem cell factor (SCF), and FMS-like tyrosine kinase 3 ligand (Ftl3L).
• Applied both 3-dimensional (3D) and 2-dimensional (2D) culture technologies for differentiation and phenotypical validation.

Main Results:

• Consistently generated CD3-CD56+ or CD45+CD56+ NK cells from human expanded potential stem cells (hEPSCs).
• Differentiated NK cells exhibited mild cytotoxicity against tumor targets in vitro.
• The 3D culture preserved the differentiation microenvironment, facilitating niche interaction studies, while 2D culture allowed for routine validation.

Conclusions:

• The described protocol offers a reliable method for generating NK cell properties from hEPSCs.
• This serum-free approach supports the development of clinical-grade NK cells for immunotherapy.
• The combined 3D and 2D culture strategy enhances both the study and validation of NK cell differentiation.