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 8

AOA synergizes with chemotherapy-mediated antitumor immunity.

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AOA synergizes with chemotherapy-mediated antitumor immunity. (A and B) ...
(A and B) Quantitative analysis of intracellular cGAMP in MC38 cells with or without gemcitabine or oxaliplatin treatment by ELISA. (C and D) MC38 tumor tissues were treated with gemcitabine (C) or oxaliplatin (D) combined with or without AOA for 24 hours, and the tissular protein expression of p-IRF3 and p-STAT1 was then detected by immunoblotting. (E and F) MC38 tumor tissues were treated as in C and D and the tissular mRNA expression of Ifnb, Ifit1, Ifi44, Isg15, and Ccl5 was detected. (G and H) Tumor volume (G) and Kaplan-Meier survival curves (H) for C57BL/6 mice inoculated with approximately 8 × 105 MC38 cells. Mice were treated with gemcitabine (50 mg/kg, i.p.) combined with daily injections of AOA (5 mg/kg, i.p.) or PBS on days 7, 10, 13, and 16 (n = 6). (I and J) Tumor volume (I) and Kaplan-Meier survival curves (J) for C57BL/6 mice inoculated with approximately 8 × 105 MC38 cells. Mice were treated with oxaliplatin (5 mg/kg, i.p.) combined with daily injections of AOA (5 mg/kg, i.p.) or PBS on day 8 and 12. Tumor volume and mouse survival were measured 2–3 times a week (n = 8). (K–N) MC38-bearing mice were treated as in G and I; lymphocyte infiltration was measured by FACS. Quantification analysis of the percentage of CD8+ T cells in living cells from MC38 tumors after indicated treatment (K and M) (n = 4–5). Representative data and quantification analysis of the percentage of TNF-α+CD8+ T cells from MC38 tumors after indicated treatment (L and N) (n = 4–5). Statistical analysis was performed by 1-way ANOVA followed by Tukey’s test (A, B, E–G, I, and K–N) or log-rank test (H and J). *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.