Archives

  • 2026-05
  • 2026-04
  • 2026-03
  • 2026-02
  • 2026-01
  • 2025-12
  • 2025-11
  • 2025-10
  • 2025-09
  • 2025-03
  • 2025-02
  • 2025-01
  • 2024-12
  • 2024-11
  • 2024-10
  • 2024-09
  • 2024-08
  • 2024-07
  • 2024-06
  • 2024-05
  • 2024-04
  • 2024-03
  • 2024-02
  • 2024-01
  • 2023-12
  • 2023-11
  • 2023-10
  • 2023-09
  • 2023-08
  • 2023-07
  • 2023-06
  • 2023-05
  • 2023-04
  • 2023-03
  • 2023-02
  • 2023-01
  • 2022-12
  • 2022-11
  • 2022-10
  • 2022-09
  • 2022-08
  • 2022-07
  • 2022-06
  • 2022-05
  • 2022-04
  • 2022-03
  • 2022-02
  • 2022-01
  • 2021-12
  • 2021-11
  • 2021-10
  • 2021-09
  • 2021-08
  • 2021-07
  • 2021-06
  • 2021-05
  • 2021-04
  • 2021-03
  • 2021-02
  • 2021-01
  • 2020-12
  • 2020-11
  • 2020-10
  • 2020-09
  • 2020-08
  • 2020-07
  • 2020-06
  • 2020-05
  • 2020-04
  • 2020-03
  • 2020-02
  • 2020-01
  • 2019-12
  • 2019-11
  • 2019-10
  • 2019-09
  • 2019-08
  • 2019-07
  • 2019-06
  • 2019-05
  • 2019-04
  • 2018-07

    • 2'3'-cGAMP (sodium salt): Precision STING Agonist for Inn...

    2025-11-29

    2'3'-cGAMP (sodium salt): Precision STING Agonist for Innate Immunity Research

    Executive Summary: 2'3'-cGAMP (sodium salt) is a cyclic dinucleotide synthesized by cGAS upon detection of cytosolic double-stranded DNA, acting as a potent STING agonist with a dissociation constant (Kd) of 3.79 nM for human STING (APExBIO, product page). It induces type I interferon (IFN-β) via TBK1 and IRF3 activation, making it a cornerstone for studies on innate immune signaling. Recent evidence links the cGAS-STING axis and its modulation by 2'3'-cGAMP to tumor immunity and DNA damage responses (Luo et al., 2024, DOI). The compound is highly water-soluble (≥7.56 mg/mL), stable at -20°C, but insoluble in ethanol and DMSO. 2'3'-cGAMP (sodium salt) is essential for dissecting STING-mediated pathways in immunology, oncology, and antiviral research.

    Biological Rationale

    2'3'-cGAMP (sodium salt) is an endogenous second messenger generated by cyclic GMP-AMP synthase (cGAS) in mammalian cells upon sensing aberrant cytosolic double-stranded DNA. This detection triggers innate immune signaling, serving as a key defense against viral and tumor-derived DNA insults (Luo et al., 2024). The resulting cGAS-STING pathway activation leads to pro-inflammatory cytokine production, particularly type I interferons, which are critical for antiviral and antitumor responses. In cancer, dysregulation of this pathway can shape the tumor microenvironment and impact immune surveillance. Studies have shown that upregulation of DNA damage repair enzymes, such as topoisomerase I, can modulate the cGAS-STING axis and influence tumor progression in cervical and other solid cancers (Luo et al., 2024). As a potent, cell-permeable STING agonist, 2'3'-cGAMP (sodium salt) provides a robust experimental tool for interrogating these mechanisms in vitro and in vivo.

    Mechanism of Action of 2'3'-cGAMP (sodium salt)

    Upon detection of cytosolic double-stranded DNA, cGAS catalyzes the formation of 2'3'-cGAMP from ATP and GTP. 2'3'-cGAMP then binds directly to the endoplasmic reticulum-resident stimulator of interferon genes (STING) protein with nanomolar affinity (Kd = 3.79 nM for human STING, APExBIO). This binding event induces conformational changes in STING, promoting its trafficking from the ER to the Golgi apparatus. Activated STING recruits and activates TANK-binding kinase 1 (TBK1), which phosphorylates interferon regulatory factor 3 (IRF3). Phosphorylated IRF3 translocates to the nucleus, where it drives transcription of type I interferon (e.g., IFN-β) and other inflammatory genes (Luo et al., 2024). Compared to other cyclic dinucleotides (CDNs), 2'3'-cGAMP exhibits superior binding affinity and specificity for human STING, enabling more precise modulation of downstream immune responses. The sodium salt form ensures high aqueous solubility and compatibility with a range of biological assays.

    Evidence & Benchmarks

    • 2'3'-cGAMP binds human STING with Kd = 3.79 nM, outperforming bacterial CDNs such as c-di-GMP and c-di-AMP (APExBIO, product data).
    • Activation of STING by 2'3'-cGAMP induces robust type I IFN-β production in mammalian cells under physiological conditions (Luo et al., 2024, DOI).
    • TOP1-mediated DNA damage leads to increased cytosolic DNA, activating the cGAS-STING pathway and promoting tumor-associated inflammation (Luo et al., 2024, DOI).
    • 2'3'-cGAMP is water-soluble (≥7.56 mg/mL); insoluble in ethanol and DMSO, enabling compatibility with aqueous in vitro and in vivo systems (APExBIO, product page).
    • Storage at -20°C preserves compound stability for at least 12 months under desiccated conditions (APExBIO, product page).
    • Research demonstrates the role of 2'3'-cGAMP in modulating the tumor microenvironment and enhancing antitumor immunity through STING activation (internal review).

    Applications, Limits & Misconceptions

    2'3'-cGAMP (sodium salt) is widely employed in:

    • Dissecting the cGAS-STING pathway in cell-based and animal models.
    • Screening and validating STING-targeted compounds for cancer immunotherapy.
    • Probing antiviral innate immunity in primary and transformed cell lines.
    • Exploring the role of innate immunity in tumor microenvironment remodeling.
    • Evaluating type I interferon responses in the context of DNA damage and repair mechanisms.

    Compared to previous reviews, this article details updated guidance on storage, solubility, and experimental specificity, providing more granular benchmarks for translational research. For advanced translational strategies, see this in-depth article, which focuses on biochemical and clinical applications beyond innate immunity. This article clarifies the precise boundaries and best practices for experimental design with 2'3'-cGAMP (sodium salt).

    Common Pitfalls or Misconceptions

    • 2'3'-cGAMP (sodium salt) is not a universal STING agonist for non-mammalian systems; its specificity is optimized for human and murine STING isoforms.
    • It should not be dissolved in ethanol or DMSO due to complete insolubility and loss of activity.
    • In vivo, excessive dosing can trigger systemic inflammation; titration is required for dose-response studies.
    • It does not directly activate downstream effectors (e.g., IRF3 or IFN-β) in the absence of functional STING protein.
    • Storage above -20°C or repeated freeze-thaw cycles may degrade compound potency.

    Workflow Integration & Parameters

    2'3'-cGAMP (sodium salt) is supplied as a solid, disodium salt (MW = 718.37; C20H22N10Na2O13P2) by APExBIO. For cell culture, dissolve in sterile water to ≥7.56 mg/mL; filter-sterilize if required. Avoid ethanol or DMSO as solvents. For in vivo delivery, dilute with sterile PBS or other isotonic buffers. Store aliquots at -20°C under desiccation to maintain activity for at least 12 months. Typical working concentrations range from 0.1 to 10 μM for cell-based assays. Monitor cell viability and cytokine induction to optimize dosing. For further guidance on workflow integration, this technical overview provides best practices for reproducible experimental outcomes; this article updates those recommendations with new evidence and user parameters.

    Conclusion & Outlook

    2'3'-cGAMP (sodium salt) from APExBIO is a benchmark tool for precision activation of the cGAS-STING pathway, enabling high-fidelity dissection of innate immunity, cancer immunotherapy, and antiviral responses. Its high aqueous solubility, nanomolar STING affinity, and robust induction of type I interferon make it superior to other CDNs for translational research. With growing evidence linking the cGAS-STING axis to tumor immunology and DNA damage repair, 2'3'-cGAMP (sodium salt) will remain central to immunological and oncological discoveries. For extended discussion on endothelial mechanisms and the future of STING-targeted therapies, see this expert analysis, which this article complements by focusing on core workflows and empirical boundaries.