TLR4 and temporal arteritis: In the experimental mouse model of GCA, systemic administration of ligands for Toll-like receptor (TLR)2 or TLR4 in human artery-SCID chimeras led to differentiation of adventitial dendritic cells into chemokine-producing effector cells with high-level expression of both CD83 and CD86 and mediated T-cell recruitment through release of interleukin (IL)-18 [4].