Inhibiting Neutrophil Extracellular Trap Formation through Iron Regulation for Enhanced Cancer Immunotherapy

Area of Science:

• Biomedical Engineering
• Immunology
• Cancer Research

Background:

• Neutrophil extracellular trap (NET) formation is a key immunosuppressive mechanism in the tumor microenvironment.
• Dysregulated iron metabolism in neutrophils contributes to NET formation and hinders anti-tumor immune responses.

Purpose of the Study:

• To develop a transformable iron nanochelator (TIN) for targeted regulation of neutrophil iron metabolism.
• To investigate the efficacy of TIN in inhibiting NET formation and enhancing anti-tumor immunity.
• To evaluate the synergistic effects of TIN with other cancer immunotherapies.

Main Methods:

• Development of a peptide-drug conjugate (PDC)-based transformable iron nanochelator (TIN).
• Investigation of TIN's morphological transformation and iron(II) chelation capabilities.
• Assessment of TIN's impact on neutrophil extracellular trap (NET) formation in vitro and in vivo.
• Evaluation of TIN's therapeutic efficacy in combination with protein arginine deiminase 4 inhibitors and anti-PD-L1 therapy.

Main Results:

• The TIN demonstrated neutrophil elastase-mediated transformation from nanoparticles to nanofibers, enabling specific iron(II) chelation.
• TIN effectively inhibited neutrophil extracellular trap (NET) formation, thereby reducing immunosuppression in the tumor microenvironment.
• Combination therapy with TIN synergistically enhanced the anti-tumor effects of protein arginine deiminase 4 inhibitors and anti-PD-L1 treatment.

Conclusions:

• Targeting neutrophil iron metabolism with TIN is a viable strategy to inhibit NET formation and overcome tumor-induced immunosuppression.
• TIN holds promise as an innovative therapeutic agent for cancer immunotherapy, particularly in combination regimens.
• This study provides a novel approach for immune modulation by targeting the iron metabolism of neutrophils in cancer treatment.