ATP-fueled STING activation of manganese coordinated nanoagonist to boost antitumor immunity.

Abstract

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway represents a central driver of innate immune activation, and manganese ion (Mn²⁺) has recently been identified as a potent modulator of this signaling axis. However, the application of Mn²⁺ is limited by its rapid clearance, nonspecific distribution and potential neurotoxicity. Inspired by the unique chemical structure and biological functions of adenosine triphosphate (ATP), we herein propose an ATP-Mn coordination nanoparticle (ATP-Mn CNP) to fuel cGAS-STING activation and antitumor immunity. We demonstrated that the phosphate groups of ATP could coordinate with Mn²⁺ and form stable, well-defined nanoparticles after lipid coating. ATP-Mn CNP significantly increased the expression of cGAS-STING-associated genes and activated the corresponding signaling cascades, and thus effectively polarized macrophages from tumor-supportive M2 to antitumor M1 phenotype. <i>In vivo</i> antitumor studies indicated that ATP-Mn CNP treatment significantly suppressed tumor growth, and reprogramed macrophages in tumors and draining lymph nodes, which thus facilitated the tumor infiltration of cytotoxic lymphocytes. Combination of ATP-Mn CNP with immune checkpoint inhibitors achieved 37.5% tumor eradication in MC38 murine models, and significantly prolonged mice survival. This study establishes an ATP-fueled coordination strategy that harnesses ATP as both an assembly ligand and an immune stimulator to enhance Mn-mediated STING activation.