Toll-like receptor (with specific members: Toll-like receptor 2, Toll-like receptor 3, Toll-like receptor 4, Toll-like receptor 7, Toll-like receptor 9) (TLR (with TLR2, TLR3, TLR4, TLR7, TLR9 as standard subtypes))

Toll-like receptors (TLRs) are a family of type I transmembrane, pattern recognition receptors crucial for the detection of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) derived from microbes and host tissue. TLR2, TLR4, and TLR5 are located on the cell surface and mainly recognize microbial lipids, lipoproteins, and proteins, while TLR3, TLR7, TLR8, and TLR9 are predominantly found in endolysosomal compartments and recognize microbial nucleic acids. Upon ligand binding, TLRs dimerize and activate intracellular signaling cascades via adaptor proteins like MyD88 and TRIF, resulting in the activation of transcription factors (NF-κB, IRF family) that induce cytokine production and shape the innate and adaptive immune responses. Members of the TLR family have been implicated in a variety of infectious, inflammatory, autoimmune, and neoplastic diseases, making them important targets for therapeutic intervention and vaccine development.

Other names

Toll like receptorToll/interleukin-1 receptor familytype I transmembrane protein receptors

Agonists mimic pathogen ligands to stimulate innate immune responses and cytokine/chemokine production Antagonists block ligand binding or downstream signaling, suppressing inflammation Adjuvant effect (for vaccine enhancement)