Aspartate deficiency amplifies cGAS-STING signaling in antitumor immunity
Yuheng Liao, Hanze Wang, Hengxin Liu, Xi Chen, Renqiang Sun, Xie Li, Zhen Yang, Chenying Liu, Wei Wu, Ziqian He, Yuzheng Zhao, Ying Mao, Dan Ye, Hui Yang
Yuheng Liao, Hanze Wang, Hengxin Liu, Xi Chen, Renqiang Sun, Xie Li, Zhen Yang, Chenying Liu, Wei Wu, Ziqian He, Yuzheng Zhao, Ying Mao, Dan Ye, Hui Yang
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Research Article Metabolism Oncology

Aspartate deficiency amplifies cGAS-STING signaling in antitumor immunity

Abstract

Metabolic signals critically shape innate immune responses. Through pharmacological screening of metabolic pathways, we identified aspartate metabolism as a key regulator of cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) signaling. Genetically or aminooxyacetic acid–mediated (AOA-mediated) pharmacologically reducing aspartate levels markedly potentiated the cGAS-STING pathway, leading to stronger upregulation of type I interferons and interferon-stimulated genes. Mechanistically, disruption of de novo pyrimidine synthesis, a major downstream pathway of aspartate, induced mtDNA replication stress and increased mtDNA double-strand breaks, promoting mtDNA release into the cytosol. Cytosolic mtDNA synergized with cGAS-STING agonists to upregulate Z-DNA binding protein 1 (ZBP1), which recruits RIPK1/3 to sustain IRF3 phosphorylation, forming a positive feedback loop that amplifies innate immune signaling. In immunocompetent mouse models, AOA enhanced the antitumor efficacy of STING agonists, chemotherapy, or radiotherapy, whereas aspartate supplementation abrogated these effects. Consistently, aspartate levels negatively correlated with antitumor immunity in colorectal cancer patient samples. Together, our study identifies aspartate–pyrimidine metabolism as a critical metabolic checkpoint that licenses STING signaling by enabling mtDNA stress to cooperate with agonist stimulation, driving type I interferon–dependent ZBP1 induction and feed-forward amplification of STING signaling, thus offering a promising strategy to enhance antitumor immunity.

Authors

Yuheng Liao, Hanze Wang, Hengxin Liu, Xi Chen, Renqiang Sun, Xie Li, Zhen Yang, Chenying Liu, Wei Wu, Ziqian He, Yuzheng Zhao, Ying Mao, Dan Ye, Hui Yang

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Figure 6

AOA augments low-dose cGAMP–mediated antitumor immunity.

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AOA augments low-dose cGAMP–mediated antitumor immunity. (A–F) Tumor vol...
(A–F) Tumor volume (A, C, E) and Kaplan-Meier survival curves (B, D, and F) for C57BL/6 mice inoculated with approximately 2 × 105 B16-F10 cells (A, n = 5), 2 × 105 LLC cells (C, n = 5), or 8 × 105 MC38 cells (E, n = 6). Mice were treated with 3 μg/mouse cGAMP combined with daily injections of AOA (5 mg/kg, i.p.) or PBS on days 7, 10, and 13. (G) AOA enhances cGAMP-mediated antitumor response. Quantification analysis of the percentage of CD8+ T cells in gated CD3+ T cells. (H and I) TNF-α (H) and IFN-γ (I) production on CD8+ T cells isolated from tumors of MC38 tumor–bearing mice. FACS analysis was performed 6 hours after the last cGAMP injection (n = 5). (J) MC38 tumor–bearing mice were administered Asp (100 mg/kg) on days 7–13 by intraperitoneal injection, with cGAMP and AOA treatment as mentioned before. Serum IFNB and CXCL10 levels were measured 6 hours after the last cGAMP injection (n = 4–5). (K and L) MC38 cells were subcutaneously transplanted into C57BL/6J mice (n = 5). AOA (5 mg/kg) and aspartate (100 mg/kg) were administered intraperitoneally daily along with 3 doses of cGAMP as mentioned above. Tumor volumes (K) were measured every 2–3 days, and intratumoral aspartate levels (L) were quantified. Data are represented as means ± SEM. Representative data are shown from 2 or 3 independent experiments. Statistical analysis was performed by 1-way ANOVA followed by Tukey’s or Bonferroni’s test (A, C, E, and G–L) or log-rank test (B, D and F). *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.