ADU-S100 ammonium salt is an activator of stimulator of interferon genes (STING). ADU-S100 ammonium salt leads to potent and systemic tumor regression and immunity.

METHODS: BMDCs were treated with free ADU-S100 (0.5 μg/mL) or liposomal ADU-S100 (0.1 μg/mL) for 24 hours, and IFNβ (A) and TNFα (B) levels in the cell culture medium were measured using ELISA.
RESULTS ADU-S100 enhanced the production of TNFα and IFNβ in BMDCs. [1]
METHODS: Mouse cDC2 and human cDC2 were cultured in 12.5-200 μM ADU-S100 for 24 hours, and the effects of ADU-S100 on cDC2 were observed.
RESULTS 25 μM ADU-S100 increased the expression of Tim-3 on DC, showing a significant upregulation of Tim-3. [3]

METHODS: After a 50 μg bolus injection of ADU-S100 on day 14 after intracranial implantation of GL261 mice, brain infiltrating leukocytes (BILs) were analyzed in detail by flow cytometry using a panel of 13 immune markers.
RESULTS Three days after treatment of ADU-S100, suppression of microglia, CD4+ and CD8+ T cell populations, and infiltration of NK and CD11b/Gr1 inflammatory immune cells were observed, and 7 days after treatment, the proportion of T cells recovered and increased compared to baseline levels. CD45-negative cells decreased shortly after treatment. [2]
METHODS: B16F1-OVA cells/100 μL PBS were injected into the right groin of C57BL/6 mice, and tumor-bearing mice were treated intratumorally with saline and 50 μg ADU-S100 every 2 days during the first week. Then, the dose of S100 was reduced to 30 μg, while the frequency of administration remained unchanged.
RESULTS Mice treated with ADU-S100 lost weight and had smaller tumors. [3]