Modifying interleukin-2 concentrations during culture improves function of T cells for adoptive immunotherapy

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• Adoptive immunotherapy using cytotoxic T cells shows promise for metastatic melanoma and viral infections.
• Ex vivo expansion of lymphocytes is crucial for cell transfer therapies.
• Interleukin-2 (IL-2) is a key cytokine for T-cell expansion and function.

Purpose of the Study:

• To investigate the impact of varying IL-2 concentrations on T-cell expansion and function.
• To determine optimal IL-2 dosing for generating effective T cells for immunotherapy.

Main Methods:

• Tumor-infiltrating lymphocytes (TIL) were cultured under GMP conditions for 14 days.
• Various IL-2 concentrations were tested to assess effects on cell growth, cytotoxicity, cytokine release (IFN-gamma), and surface markers.
• A two-phase IL-2 concentration strategy was evaluated.

Main Results:

• High IL-2 concentrations led to massive T-cell expansion and high IFN-gamma secretion but low cytotoxicity.
• Low IL-2 concentrations resulted in lower expansion and IFN-gamma secretion but high cytotoxicity.
• A phased approach (low IL-2 initially, then high) produced T cells with robust expansion, high IFN-gamma, and potent cytotoxicity.

Conclusions:

• Fine-tuning IL-2 concentration during ex vivo expansion is critical.
• A carefully controlled IL-2 regimen can generate optimal T cells for clinical immunotherapy.