Notes: CU-CPT8m is an antagonist of toll-like receptor 8 (TLR8; Kd = 220 nM; IC50 = 67 nM in a reporter assay).{35162} It is selective for TLR8 over a panel of all other human TLRs when used at a concentration of 1 μM. CU-CPT8m (1 μM) inhibits increases in TNF-α and IL-8 mRNA expression induced by the TLR8 agonist R-848 (Item No. 14806) in TLR8-overexpressing HEK-Blue cells. It also inhibits R-848-induced increases in TNF-α protein levels in differentiated THP-1 monocytes and human primary peripheral blood mononuclear cells (PBMCs) in a concentration-dependent manner. CU-CPT8m decreases TNF-α and IL-8 levels in synovial cells derived from patients with osteoarthritis and TNF-α levels in PBMCs derived from patients with rheumatoid arthritis.