Quantitative activation suppression assay to evaluate human bone marrow-derived mesenchymal stromal cell potency

Area of Science:

• Cellular immunology
• Immunotherapy
• Regenerative medicine

Background:

• Increasing use of immune modulatory cell therapies necessitates standardized potency assays.
• Current methods for evaluating cell product suppressive capacity lack standardization.

Purpose of the Study:

• To develop a standardized assay for quantifying immune-modulatory capacity.
• To use the Karpas 299 (K299) cell line as a reference suppressor for assay development.
• To evaluate the immune-modulatory capacity of bone marrow-derived mesenchymal stromal cells (BM-MSCs).

Main Methods:

• Co-culture of healthy donor CD4 T cells with K299 cells or BM-MSCs.
• Stimulation with anti-CD3/CD28 beads.
• Measurement of CD154 activation and proliferation of CD4 T cells to calculate suppression.

Main Results:

• K299 cells reproducibly suppressed CD4 T cell activation and proliferation in a dose-dependent manner.
• A rapid 16-hour assay based on activation-suppression was developed.
• Suppression potency of BM-MSCs was defined in K299 Suppression Units, accounting for inter-donor variability and manufacturing factors.

Conclusions:

• The developed assay provides a standardized platform for measuring suppressor function.
• This method facilitates comparisons of cell products across laboratories.
• The assay can be utilized as a cell product release assay for quality control.