cGAS-STING pathway mediates activation of dendritic cell sensing of immunogenic tumors.

Type I interferons (IFN-I) play pivotal roles in tumor therapy for three decades, underscoring the critical importance of maintaining the integrity of the IFN-1 signaling pathway in radiotherapy, chemotherapy, targeted therapy, and immunotherapy. However, the specific mechanism by which IFN-I contributes to these therapies, particularly in terms of activating dendritic cells (DCs), remains unclear. Based on recent studies, aberrant DNA in the cytoplasm activates the cyclic GMP-AMP synthase (cGAS)- stimulator of interferon genes (STING) signaling pathway, which in turn produces IFN-I, which is essential for antiviral and anticancer immunity. Notably, STING can also enhance anticancer immunity by promoting autophagy, inflammation, and glycolysis in an IFN-I-independent manner. These research advancements contribute to our comprehension of the distinctions between IFN-I drugs and STING agonists in the context of oncology therapy and shed light on the challenges involved in developing STING agonist drugs. Thus, we aimed to summarize the novel mechanisms underlying cGAS-STING-IFN-I signal activation in DC-mediated antigen presentation and its role in the cancer immune cycle in this review.

A modified HSV-1 oncolytic virus reconciles antiviral and antitumor immunity via promoting IFNß expression and inhibiting PKR.

Type I interferon (IFN-I) is a potent immune modulator intricately involved in regulating tumor immunity. Meanwhile, the integrity of the IFN-I signaling pathway is essential for radiotherapy, chemotherapy, targeted therapy, and immunotherapy. However, the clinical application of IFN-I remains challenging due to its non-specific cytotoxicity and limited half-life. To overcome these limitations, we developed a gene delivery platform, CRISPR-V, enabling the rapid creation of novel HSV-1 oncolytic viruses. Utilizing this platform, we created an oncolytic virus, OVH-IFNß, in which the IFNß gene was incorporated into the HSV-1 genome. However, exogenous IFNß expression significantly inhibited OVH-IFNß replication. Through transcriptome data analyses, we identified several ISG genes inhibiting OVH-IFNß replication. By gene knockout and functional studies of the downstream effectors, we confirmed the prominent antiviral activities of protein kinase R (PKR). To balance the antitumor and antiviral immunity of IFNß, we developed a novel HSV-1 oncolytic virus, OVH-IFNß-iPKR, which can express IFNß while inhibiting PKR, leading to a potent antitumor immunity while reducing the antiviral capacity of IFNß. OVH-IFNß-iPKR shows a strong ability to induce immunogenic cell death and activate tumor-specific CD8+ T cells, leading to de novo immune responses and providing a novel strategy for tumor immunotherapy.