R848, 50 mg

From STEMCELL Technologies, this immune-response modifier is an imidazoquinoline that acts as an agonist of Toll-like receptors (TLRs) 7 and 8. It mimics pathogen-associated molecular patterns that activate immune cells through TLR7 and TLR8, and demonstrates potent anti-tumor and anti-viral properties, with an IC₅₀ of 4.2 µM (Seganish et al.). These effects appear to be mediated predominantly through the induction of cytokines, including interferon (IFN)-α and interleukin (IL)-12, resulting from stimulation of monocytes, macrophages, and dendritic cells (Bernstein et al.; Hattermann et al.; Nian et al.).

The compound is supplied as a crystalline solid with a chemical formula of C₁₇H₂₂N₄O₂ and a molecular weight of 314.4 g/mol, and has a purity of ≥ 98% (CAS Number 144875-48-9; alternative names: Resiquimod; S 28463). It has low solubility in aqueous media; recommended working solubilities are ≤ 35 mM in DMSO and ≤ 10 mM in absolute ethanol. For use as a cell culture supplement, stock solution should be diluted into culture medium immediately before use, with final DMSO concentration kept below 0.1% due to potential cell toxicity. The product is stable at -20°C as supplied and should be protected from prolonged exposure to light; for long-term storage, store with a desiccant.

Published applications reported in immunology include triggering activation of human B cells, inducing proliferation and cytokine production by human CD4+ T cells, priming human neutrophils for leukotriene B4, prostaglandin E2, and platelet-activating factor biosynthesis, suppressing HIV-1 replication in monocytes, and inducing expression of IL-12 and IFN-ɣ in mouse and human peripheral blood cell cultures. Differentiation-related applications include targeting osteoclast precursors and inhibiting their differentiation into osteoclasts via TLR7, as well as inducing myeloid differentiation of CD34+ hematopoietic progenitor cells, with upregulated expression of cytokines (IL-1β, TNF-α, IL-6, GM-CSF) and the CD11c surface marker. Products from STEMCELL Technologies are for research use only and not intended for human or animal diagnostic or therapeutic uses unless otherwise stated.