Cancer immunotherapy based on image-guided STING activation by nucleotide nanocomplex-decorated ultrasound...

Area of Science:

• Immunology
• Oncology
• Nanotechnology

Background:

• The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is vital for initiating anti-tumor immune responses via antigen-presenting cells (APCs).
• Current therapeutic agonists for cGAS-STING face challenges including poor cellular uptake, instability, and rapid clearance, limiting their clinical use.

Purpose of the Study:

• To develop an innovative ultrasound-guided platform for targeted delivery of cGAMP to activate the cGAS-STING pathway within APCs.
• To enhance the priming of adaptive anti-tumor immunity and improve therapeutic outcomes in cancer models.

Main Methods:

• Engineered nanocomplexes of cGAMP bound to cationic biopolymers, conjugated onto microbubbles (MBs) targeting APCs.
• Utilized ultrasound (US) for targeted delivery and sonoporation to facilitate cytosolic entry of cGAMP into APCs.
• Evaluated the platform's efficacy in activating the cGAS-STING pathway and priming antigen-specific T cells in murine cancer models.

Main Results:

• The nanocomplex-conjugated MBs successfully delivered cGAMP into APCs, activating the cGAS-STING pathway and downstream inflammatory responses.
• Demonstrated effective priming of antigen-specific T cells, leading to significant inhibition of tumor growth in both localized and metastatic models.
• Showcased improved therapeutic efficacy when combined with checkpoint blockade therapy.

Conclusions:

• Targeted, localized activation of STING in APCs using US-guided delivery of cGAMP nanocomplexes can induce systemic anti-tumor immunity.
• This image-guided strategy holds promise for novel, effective cancer immunotherapy, particularly in combination with existing treatments like checkpoint blockade.