r-848

Resiquimod (R848) is an agonist of Toll-like receptors 7 and 8 (TLR7/TLR8) that induces the upregulation of cytokines including TNF-α, IL-6, and IFN-α. It possesses immunomodulatory, antitumor, and antiviral activities, and can be used to induce models of myocarditis and systemic lupus erythematosus (SLE).

CU-115 is a selective and potent TLR8 antagonist with IC50 of 1.04 µM and =>50 µM for TLR8 and TLR7, respectively. CU-115 decreases production of TNF-α and IL-1β activated by R-848 in THP-1 cells.

Lipid N2-3L is an ionizable cationic lipid with a pKa of 8.99, utilized in the formation of supramolecular lipid nanoparticles (SMLNPs) for enclosing mRNA in both in vitro and in vivo applications. Lipid N2-3L-containing SMLNPs accumulate at the injection site and draining lymph nodes in mice, featuring a luciferase reporter gene. Additionally, SMLNPs made with Lipid N2-3L that encapsulate ovalbumin mRNA and the Toll-like receptor 7/8 (TLR7/8) agonist R-848 serve as adjuvants. These enhance dendritic cell maturation and antigen presentation, reducing tumor volume and increasing survival rates in MC-38-OVA colon cancer mouse models.

CU-CPT9b (TLR8-specific antagonist 1) is an antagonist of toll-like receptor 8 (TLR8; Kd = 21 nM). It inhibits activation of NF- B induced by the TLR8 agonist R-848 in TLR8-overexpressing HEK-Blue cells with an IC50 value of 0.7 nM.

NCI 126224 is a Toll-like receptor 4 (TLR4) antagonist that selectively inhibits nitric oxide production induced by the TLR4 agonist LPS in RAW 264.7 macrophages (IC50 = 0.31 µM), while exhibiting weaker effects against the TLR7/8 agonist R-848, TLR1/2 agonist Pam3CSK4, and TLR3 agonist poly(I:C). NCI 126224 also inhibits FSL-1-induced NO production at 0.6 µM and suppresses LPS-induced NF-κB activity in BV-2 glial cells, while reducing IL-1β and TNF-α levels in RAW 264.7 cells (IC50s of 5.92 and 1.54 µM, respectively). 0.42, and 1.54 µM, respectively), demonstrating its significant value in studies of inflammatory and innate immune signaling pathways.