TLR7 and syphilis: In support of a similar role for phagosomal signaling in Tp-mediated induction of type I INFs, three endosomal TLRs (TLR7, 8 and 9), capable of sensing nucleic acids within phagosomes of macrophages and DCs [98]–[100], also were markedly up-regulated in syphilis lesions.