Innate immune pattern recognition receptor (PRR)

Innate immune pattern recognition receptors (PRRs) are a diverse class of germline-encoded receptors that serve as the primary sensors of the host immune system (Janeway and Medzhitov, 2002). These receptors are highly expressed on professional antigen-presenting cells such as dendritic cells, monocytes, and peripheral blood mononuclear cells (PBMCs), where they detect pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) (Takeuchi and Akira, 2010). The major families include Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and C-type lectin receptors (CLRs). Upon ligand binding, PRRs activate intracellular signaling pathways, such as NF-κB and IRF, leading to the production of pro-inflammatory cytokines and type I interferons, which are essential for initiating adaptive immunity (Kawai and Akira, 2011). In drug development, PRR agonists like imiquimod and mifamurtide are used to enhance immune responses in cancer and viral infections, while PRR antagonists are being explored to treat chronic inflammatory and autoimmune diseases. However, systemic activation of these receptors carries the risk of severe side effects, including cytokine release syndrome and systemic inflammation.

Other names

Pattern recognition receptorsPRRsPathogen recognition receptorsInnate immune sensorsHost innate immune receptors

Agonism of specific PRR families (e.g., TLRs, NLRs) to stimulate innate immune signaling and cytokine production for immunotherapy; or antagonism to inhibit pathological inflammatory signaling in autoimmune disorders.