Host innate immune pattern-recognition receptors and associated antigen-presenting cells (PRRs and APCs)

Host innate immune pattern-recognition receptors (PRRs) and associated antigen-presenting cells (APCs) form the critical interface between innate and adaptive immunity. PRRs, including Toll-like receptors (TLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs), are germline-encoded sensors that detect conserved molecular signatures from pathogens or damaged host cells [1]. These receptors are highly expressed on professional APCs such as dendritic cells, macrophages, and B cells, where they orchestrate the uptake, processing, and presentation of antigens [2]. Activation of the PRR-APC axis leads to the upregulation of co-stimulatory molecules and the secretion of polarizing cytokines, which are essential for effective T-cell activation [3]. In drug development, this system is leveraged through the use of PRR agonists as vaccine adjuvants (e.g., Monophosphoryl lipid A) or as standalone immunotherapies for cancer (e.g., Imiquimod) [4]. However, dysregulated signaling within this axis is a primary driver of cytokine storms, chronic inflammatory diseases, and autoimmune pathologies, necessitating the development of targeted inhibitors [5].

Other names

Innate immune sensing systemPRR-APC axisPattern recognition receptorsProfessional antigen-presenting cells

Agonism of specific pattern-recognition receptors (e.g., TLRs, NLRs) on antigen-presenting cells to induce maturation, co-stimulatory molecule expression, and cytokine secretion, thereby enhancing T-cell priming and adaptive immunity.