The Role of Cytosolic Sensors in Host Defense to Intracellular Pathogens

Download or read book The Role of Cytosolic Sensors in Host Defense to Intracellular Pathogens written by Sergio C. Oliveira and published by Frontiers Media SA. This book was released on 2024-11-07 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innate immunity is the first arm of the immune system to be triggered in host defense against intracellular pathogens. Some pathogens during evolution have developed stealthy strategies to bypass innate surface receptors but when they reach host cell cytosol they are recognized by cytosolic receptors. Professional phagocytes, such as macrophages, neutrophils, or dendritic cells, have the specialized ability to internalize pathogens into membrane-bound compartments, termed phagosomes. Additionally, pathogen phagocytosis effectively guarantees the concentrated delivery of pathogen-associated molecular patterns (PAMPs) inside cells. Some pathogens can exit phagosomes and survive and replicate in the cytosolic space. Several pattern recognition receptors (PRR) have been described over the years. A diverse repertoire of PRRs exists, localized freely in the cytosol or associated with or integrated into cytoplasmic membranes, to detect these organisms. Among these intracellular sensors, several molecules have been identified such as cGAS/STING pathway, the inflammasome platforms (eg: NLRP3, NLRC4, AIM2), caspase-11/4/5, RIG-I, among others. Host cell activation through these receptors leads to cell signaling pathways resulting in inflammatory and anti-inflammatory reactions.