TLR7 and TLR8 are expressed on human cells with a distinct expression pattern. In human cells, plasmacytoid dendritic cell (pDCs) and B cells express predominantly TLR7, whereas TLR8 is mainly expressed on cells of the myeloid lineage, such as monocytes, macrophages, and myeloid dendritic cells (mDCs). In mice, TLR7 is also expressed on mDCs and monocytes whereas murine TLR8 is functionally impaired
1,2 . TLR7 and TLR8 recognize virally derived double- or singlestranded RNA as well as small molecules like R848 (Resiquimod), both leading to a strong Myd88-dependent activation of immune cells
3,4 . R848 (Resiquimod) is an imidazoquinoline compound, which possesses antiviral and antitumoral activity
3,4 . R848 (Resiquimod) is poorly soluble in water. Therefore, R848 (Resiquimod) is provided as its hydrochloride analog, which improves the solubility of R848 (Resiquimod) in aqueous solution without affecting potency.
