Lactylation: a novel post-translational modification for cGAS-STING pathway

Lysine lactylation (Kla) is a lactate-derived post-translational modification that has emerged as a critical metabolic-epigenetic regulator linking cellular metabolic states to innate immune signaling. The cGAS-STING pathway, a central cytosolic DNA-sensing mechanism essential for antiviral defense, antitumor immunity, and inflammatory regulation, is profoundly influenced by the metabolic milieu. However, the precise role of lactylation in modulating this pathway remains to be systematically synthesized.

This review aims to comprehensively analyze the molecular mechanisms by which lysine lactylation regulates the cGAS-STING signaling axis, and to discuss the pathophysiological implications and therapeutic potential of targeting this modification in diseases ranging from autoimmunity and neuroinflammation to cancer.

A comprehensive review of the relevant literature was conducted to summarize the biochemical basis of lactylation (including writers, erasers, and readers) and to systematically examine emerging evidence demonstrating direct and indirect regulation of cGAS-STING components by lactylation. Studies involving site-specific modifications, disease models, and therapeutic interventions were collated and analyzed.

Lactylation directly targets core pathway components-cGAS at residues such as K21, K131, K156, K162, K275, and K409, and STING-altering their stability, enzymatic activity, DNA-binding capacity, phase separation, and downstream signaling outputs. Depending on context, lactylation exerts dual effects: it stabilizes cGAS and amplifies type I interferon responses in autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis) and hypoxic-ischemic encephalopathy, but promotes cGAS degradation or suppresses STING activity in cancer (lung adenocarcinoma, glioblastoma) and neuropathic pain, thereby facilitating immune evasion or pain sensitization. Indirectly, lactylation modulates cytosolic DNA ligand availability by influencing mitochondrial DNA release (via HMGB1, VDAC1, Arg1, DRP1) or DNA repair (via KU70). The discovery of specific lactyltransferases (AARS1/2, p300) and delactylases (SIRT1-3, HDAC1-3) establishes lactylation as a dynamic, enzymatically controlled process.

Lactylation functions as a pivotal metabolic-immune checkpoint that fine-tunes cGAS-STING signaling in a cell-type- and disease-specific manner. Targeting the lactylation regulatory axis-by inhibiting pathogenic lactylation to restore anti-tumor immunity or enhancing it to dampen deleterious inflammation-offers a novel immunometabolic therapeutic strategy for autoimmune disorders, chronic infections, neurodegeneration, and cancer.