β-Glucan-Induced Reprogramming of Human Macrophages Inhibits NLRP3 Inflammasome Activation in Cryopyrinopathies
Exposure of mononuclear phagocytes to β-glucan, a naturally occurring polysaccharide, contributes to the induction of innate immune memory, which is associated with long-term epigenetic, metabolic, and functional reprogramming. Although previous studies have shown that innate immune memory induced by β-glucan confers protection against secondary infections, its impact on autoinflammatory diseases, associated with inflammasome activation and IL-1β secretion, remains poorly understood. In particular, whether β-glucan-induced long-term reprogramming affects inflammasome activation in human macrophages in the context of these diseases has not been explored. We found that NLRP3 inflammasome-mediated caspase-1 activation and subsequent IL-1β production were reduced in β-glucan-reprogrammed macrophages. β-Glucan acted upstream of the NLRP3 inflammasome by preventing potassium (K+) efflux, mitochondrial ROS (mtROS) generation, and, ultimately, apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization and speck formation. Importantly, β-glucan-induced memory in macrophages resulted in a remarkable attenuation of IL-1β secretion and caspase-1 activation in patients with an NLRP3-associated autoinflammatory disease, cryopyrin-associated periodic syndromes (CAPS). Our findings demonstrate that β-glucan-induced innate immune memory represses IL-1β-mediated inflammation and support its potential clinical use in NLRP3-driven diseases.
Camilli, Giorgio; Bohm, Mathieu; Piffer, Alícia Corbellini; Lavenir, Rachel; Williams, David L.; Neven, Benedicte; Grateau, Gilles; Georgin-Lavialle, Sophie; and Quintin, Jessica. 2020. β-Glucan-Induced Reprogramming of Human Macrophages Inhibits NLRP3 Inflammasome Activation in Cryopyrinopathies. Journal of Clinical Investigation. Vol.130(9). 4561-4573. https://doi.org/10.1172/JCI134778 PMID: 32716363 ISSN: 0021-9738