Pattern-recognition receptors and scavenger receptors on antigen-presenting cells (PRRs and SRs on APCs)

Pattern-recognition receptors (PRRs) and scavenger receptors (SRs) are diverse groups of proteins primarily expressed on antigen-presenting cells (APCs), such as dendritic cells and macrophages, where they serve as the primary sensors of the innate immune system (Kumar et al., 2011) [1]. PRRs, including Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), identify conserved molecular structures known as pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) (Janeway & Medzhitov, 2002) [5]. Scavenger receptors facilitate the clearance of altered self-molecules, such as oxidized low-density lipoproteins, and play a critical role in phagocytosis and lipid metabolism (Zani et al., 2015) [2]. Upon ligand binding, these receptors initiate signaling pathways that lead to the maturation of APCs, the secretion of pro-inflammatory cytokines, and the subsequent activation of the adaptive immune system (Banchereau et al., 2000) [3]. In clinical practice, these receptors are targeted by agonists like Imiquimod and CpG oligonucleotides to enhance vaccine efficacy and anti-tumor immunity (Kaczanowska et al., 2013) [4]. Conversely, inhibiting these pathways is a strategy for treating chronic inflammatory conditions and autoimmune diseases where overactive innate signaling contributes to tissue damage (Zani et al., 2015) [2].

Other names

Innate immune receptorsPattern recognition moleculesPRRsScavenger receptorsSRs

Agonism of specific pattern-recognition receptors to stimulate innate and adaptive immunity; Antagonism of scavenger or pattern-recognition receptors to suppress pathological inflammation or lipid accumulation.