NaCl enhances CD8⁺ T cell effector functions in cancer immunotherapy

Area of Science:

• Immunology
• Oncology
• Metabolic Regulation

Background:

• CD8+ T-cells are crucial for anti-tumor immunity but often become dysfunctional within the tumor microenvironment.
• Tumor-induced T-cell dysfunction limits the efficacy of current cancer immunotherapies.

Purpose of the Study:

• To investigate the role of sodium chloride (NaCl) in counteracting CD8+ T-cell dysfunction.
• To explore the potential of NaCl as an adjuvant for cancer immunotherapy.

Main Methods:

• In vitro culture of CD8+ T-cells with NaCl supplementation.
• Adoptive transfer of modified T-cells into a humanized mouse model.
• High-salt diet administration in mice with experimental tumors.
• Analysis of T-cell transcriptional, epigenetic, and metabolic profiles (including glutamine consumption).
• Comparison of human tumor-infiltrating CD8+ T-cells with NaCl-treated cells.

Main Results:

• NaCl supplementation enhanced CD8+ T-cell effector differentiation, IFN-γ production, and cytotoxicity while preserving stem-like plasticity.
• Adoptive transfer of NaCl-treated T-cells led to superior anti-tumor immunity in mice.
• High-salt diet reduced tumor growth in mice via enhanced CD8+ T-cell effector function.
• NaCl-induced reprogramming was linked to increased glutamine consumption.
• Human tumor-infiltrating CD8+ T-cells associated with immunotherapy response resembled NaCl-treated cells.

Conclusions:

• Sodium chloride metabolism is a critical regulator of CD8+ T-cell effector function and anti-tumor immunity.
• NaCl can reprogram T-cells to overcome tumor-induced dysfunction, suggesting potential therapeutic applications in cancer immunotherapy.