Hydrolysis of 2'3'-cGAMP by ENPP1 and design of nonhydrolyzable analogs.

Abstract

Agonists of mouse STING (TMEM173) shrink and even cure solid tumors by activating innate immunity; human STING (hSTING) agonists are needed to test this therapeutic hypothesis in humans. The endogenous STING agonist is 2'3'-cGAMP, a second messenger that signals the presence of cytosolic double-stranded DNA. We report activity-guided partial purification and identification of ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP1) to be the dominant 2'3'-cGAMP hydrolyzing activity in cultured cells. The hydrolysis activity of ENPP1 was confirmed using recombinant protein and was depleted in tissue extracts and plasma from Enpp1(-/-) mice. We synthesized a hydrolysis-resistant bisphosphothioate analog of 2'3'-cGAMP (2'3'-cG(s)A(s)MP) that has similar affinity for hSTING in vitro and is ten times more potent at inducing IFN-β secretion from human THP1 monocytes. Studies in mouse Enpp1(-/-) lung fibroblasts indicate that resistance to hydrolysis contributes substantially to its higher potency. 2'3'-cG(s)A(s)MP is therefore improved over natural 2'3'-cGAMP as a model agonist and has potential as a vaccine adjuvant and cancer therapeutic.

• Authors: Lingyin Li, Qian Yin, Pia Kuss, Zoltan Maliga, José L Millán, Hao Wu, Timothy J Mitchison
• Journal: Nature chemical biology (Nat Chem Biol) Vol. 10 Issue 12 Pg. 1043-8 (Dec 2014) ISSN: 1552-4469 [Electronic] United States
• PMID: 25344812 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Membrane Proteins
• Nucleotides, Cyclic
• Organothiophosphorus Compounds
• Recombinant Proteins
• STING1 protein, human
• Sting1 protein, mouse
• cyclic guanosine monophosphate-adenosine monophosphate
• Interferon-beta
• Phosphoric Diester Hydrolases
• ectonucleotide pyrophosphatase phosphodiesterase 1
• Pyrophosphatases

Topics

• Animals
• Antineoplastic Agents (chemical synthesis, pharmacology)
• Cell Line, Tumor
• Gene Expression Regulation, Neoplastic
• Humans
• Hydrolysis
• Interferon-beta
• Membrane Proteins (agonists, deficiency, genetics, metabolism)
• Mice
• Monocytes (drug effects, metabolism, pathology)
• Nucleotides, Cyclic (chemistry, metabolism, pharmacology)
• Organothiophosphorus Compounds (chemical synthesis, pharmacology)
• Phosphoric Diester Hydrolases (genetics, metabolism)
• Pyrophosphatases (antagonists & inhibitors, genetics, metabolism)
• Recombinant Proteins (genetics, metabolism)
• Second Messenger Systems (genetics)
• Signal Transduction