Unlocking the Therapeutic Potential of the cGAS-STING Pathway through TREX1 Targeting

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Stimulator of Interferon Gene (STING) agonists face development challenges for cancer immunotherapy.
• Cytosolic cyclic dinucleotides activate STING, and the enzyme TREX1 degrades these molecules.
• Identifying alternative pathways to boost interferon (IFN) signaling and antitumor immunity is crucial.

Purpose of the Study:

• To discover and evaluate a novel TREX1 inhibitor for its potential to enhance IFN signaling and antitumor immunity.
• To assess the efficacy of TREX1 inhibition in preclinical tumor models.
• To explore TREX1 targeting as a strategy to activate the cGAS-STING pathway.

Main Methods:

• Discovery and immunologic testing of a novel small-molecule TREX1 inhibitor.
• Utilizing an engineered inducible Trex1 knockout mouse model.
• Evaluating the inhibitor's effect on IFN signaling, CD8+ T-cell immunity, and tumor progression in vivo.
• Assessing the enhancement of anti-PD-1 therapy efficacy.

Main Results:

• The novel TREX1 inhibitor augments IFN signaling in situ.
• TREX1 inhibition promotes CD8+ T-cell immunity.
• Systemic TREX1 ablation in mice resulted in modest inflammatory pathology.
• The TREX1 inhibitor enhanced anti-PD-1 efficacy in preclinical tumor models.

Conclusions:

• TREX1 inhibition is a viable strategy for augmenting IFN signaling and antitumor immunity.
• Targeting TREX1 may overcome limitations of STING agonists in cancer therapy.
• Systemic delivery of TREX1 inhibitors shows potential for clinical application in cancer immunotherapy.