Host immune recognition pathways

Host immune recognition pathways represent the fundamental biological systems used by the innate immune system to detect foreign pathogens and endogenous cellular stress. These pathways utilize a variety of germline-encoded pattern recognition receptors (PRRs), including Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and C-type lectin receptors (CLRs), to sense pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) [1, 2]. Activation of these receptors initiates complex intracellular signaling cascades, often involving key adapter proteins like MyD88, TRIF, or MAVS, which ultimately lead to the activation of transcription factors such as NF-κB and Interferon Regulatory Factors (IRFs) [2, 3]. This process results in the production of pro-inflammatory cytokines, chemokines, and type I interferons, which are essential for orchestrating both innate and adaptive immune responses [1]. Dysregulation of these pathways is a hallmark of many diseases, including autoimmune disorders, chronic inflammatory conditions, and sepsis [3]. In modern pharmacology, these pathways are targeted either to stimulate immune activity, such as using TLR or STING agonists in cancer immunotherapy, or to suppress overactive responses in inflammatory diseases using specific PRR antagonists [4, 5]. Citations: [1] Janeway CA Jr, Medzhitov R. Innate immune recognition. Annu Rev Immunol. 2002;20:197-216. [2] Takeuchi O, Akira S. Pattern recognition receptors and inflammation. Cell. 2010;140(6):805-820. [3] Thompson SR, et al. Pattern recognition receptors and the host response to infectious diseases. Virulence. 2011;2(3):179-189. [4] Li T, Chen ZJ. The cGAS-cGAMP-STING pathway connects DNA sensing to innate immunity and inflammation. Immunity. 2018;49(3):401-419. [5] Fitzgerald KA, Kagan JC. Toll-like Receptors and the Control of Immunity. Cell. 2020;180(3):444-466.

Other names

Innate immune sensingPattern recognition receptor pathwaysPAMP/DAMP recognitionInnate immune recognition

Modulation of pattern recognition receptors (PRRs) to either stimulate or inhibit innate immune signaling cascades and cytokine production.