PMC

TLR1, TLR2, TLR4, TLR5 and TLR6 are located on the cell surface. TLR2 forms a heterodimer with TLR1 or TLR6. TLR3, TLR7, and TLR9 translocate from the endoplasmic reticulum to endolysosomal compartments following cell stimulation. The CLRs are cell surface receptors whereas the NLRs and RLRs reside in cytoplasm. The interaction of a PRR with its cognate ligand results in initiation of a signaling cascade leading to inflammatory responses.