Tumor cell AMPK activation enhances NK cell anti-tumor immunity and synergizes with PD-L1 blockade therapy

Area of Science:

• Immunology
• Cancer Biology
• Metabolic Signaling

Background:

• Immune checkpoint blockade (ICB) targeting PD-1/PD-L1 improves cancer treatment but benefits only a subset of patients.
• Mechanisms of resistance to ICB therapy are not fully understood.
• AMP-activated protein kinase (AMPK) regulates cellular energy and is implicated in cancer development.

Purpose of the Study:

• To investigate the role of tumor cell-intrinsic AMPK activation in mediating sensitivity to PD-L1 immunotherapy.
• To explore the impact of AMPK on natural killer (NK) cell-mediated antitumor immunity.
• To identify molecular mechanisms linking AMPK activation to ICB response.

Main Methods:

• Analysis of AMPK phosphorylation in tumors responsive and non-responsive to PD-L1 blockade.
• Pharmacological inhibition and activation of AMPK in cancer cells.
• Assessment of NK cell-mediated cytotoxicity and tumor growth in mouse models.
• Transcriptomic analysis to identify gene expression changes induced by AMPK activation.

Main Results:

• PD-L1 blockade increased AMPK phosphorylation in responsive tumors.
• Inhibition of AMPK reduced the efficacy of PD-L1 blockade.
• AMPK activation sensitized cancer cells to NK cell killing and synergized with PD-L1 blockade to inhibit tumor growth.
• AMPK activation upregulated pattern recognition receptor and chemokine genes associated with improved patient survival.

Conclusions:

• Tumor cell-intrinsic AMPK activation is a key determinant of sensitivity to PD-L1 immunotherapy.
• AMPK enhances antitumor immunity through NK cell-dependent mechanisms.
• Targeting AMPK may represent a strategy to overcome resistance to ICB therapy.