Multifunctional Nanoparticles Boost Cancer Immunotherapy Based on Modulating the Immunosuppressive Tumor...

Area of Science:

• Oncology
• Immunology
• Nanotechnology

Background:

• Cancer immunotherapy faces challenges due to immune tolerance and immunosuppressive tumor microenvironments (ITM).
• Overcoming these obstacles is crucial for developing effective cancer treatments.

Purpose of the Study:

• To develop a versatile nanoparticle system for co-delivering shikonin (SK) and PD-L1 knockdown siRNA (SK/siR-NPs).
• To remodel the ITM and enhance cancer immunotherapy efficacy.

Main Methods:

• Codelivery of shikonin and PD-L1 siRNA using nanoparticles.
• Induction of immunogenic cell death (ICD) in tumor cells.
• Inhibition of PD-L1 expression and PKM2.
• Repolarization of M2-tumor-associated macrophages (TAMs) to M1.
• Suppression of regulatory T lymphocytes.

Main Results:

• SK/siR-NPs effectively induced ICD and dendritic cell maturation.
• Significant inhibition of PD-L1 enhanced cytotoxic T lymphocyte responses.
• Restrained lactate production by downregulating PKM2 led to M2-TAM repolarization.
• Suppression of regulatory T lymphocytes contributed to fighting the ITM.

Conclusions:

• The developed SK/siR-NPs show significant potential for cancer immunotherapy.
• The system simultaneously induces ICD, repolarizes M2-TAMs, and relieves PD-L1-mediated immune tolerance.