TREX1 enables viral entry in intestinal epithelia via immunity-independent control of endocytosis

The endocytic machinery is essential for viral entry and material absorption, yet its regulatory mechanisms remain incompletely understood. Here, we report an unexpected function of the host exonuclease three-prime repair exonuclease 1 (TREX1) in promoting enterovirus A71 (EV-A71) infection independently of immune modulation. Our results reveal that TREX1 deficiency in intestinal cells does not activate innate immunity but impairs EV-A71 replication, primarily by blocking viral entry. Mechanistically, TREX1 silencing downregulates key endocytic factors, including WASF1, thereby inhibiting viral internalization. Disease-associated TREX1 mutations were found to disrupt this pro-endocytic function. Furthermore, we demonstrate that TREX1-dependent endocytosis is critical for dextran uptake, highlighting its broader role in nutrient absorption. Subsequently, we employed a TREX1 inhibitor, TREX1-IN-1, which suppresses viral infection without eliciting innate immune responses. Our study uncovers an immunity-independent role for TREX1 in regulating endocytosis, provides insights into viral entry and intestinal nutrient uptake, and further establishes TREX1 as a druggable target for antiviral therapy.