Nucleic acid sensing in the tumor vasculature

Endothelial cells form a powerful interface between tissues and immune cells. In fact, one of the underappreciated roles of endothelial cells is to orchestrate immune attention to specific sites. Tumor endothelial cells have a unique ability to dampen immune responses and thereby maintain an immunosuppressive microenvironment. Recent approaches to trigger immune responses in cancers have focused on activating nucleic acid sensors, such as cGAS‐STING, in combination with immunotherapies. In this review, we present a case for targeting nucleic acid‐sensing pathways within the tumor vasculature to invigorate tumor‐immune responses. We introduce two specific nucleic acid sensors—the DNA sensor TREX1 and the RNA sensor RIG‐I—and discuss their functional roles in the vasculature. Finally, we present perspectives on how these nucleic acid sensors in the tumor endothelium can be targeted in an antiangiogenic and immune activation context. We believe understanding the role of nucleic acid‐sensing in the tumor vasculature can enhance our ability to design more effective therapies targeting the tumor microenvironment by co‐opting both vascular and immune cell types.