| dc.identifier.citation | Moghaddas, F., Zeng, P., Zhang, Y., Schuetzle, H., Brenner, S., Hofmann, S. R., Berner, R., Zhao, Y., Lu, B., Chen, X., Zhang, L., Cheng, S., Winkler, S., Lehmberg, K., Canna, S. W., Czabotar, P. E., Wicks, I. P., De Nardo, D., Hedrich, C. M. ,... Masters, S. L. (2018). Autoinflammatory mutation in NLRC4 reveals a leucine-rich repeat (LRR)-LRR oligomerization interface. JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY, 142 (6), pp.1956-+. https://doi.org/10.1016/j.jaci.2018.04.033. | |
| dc.description.abstract | BACKGROUND: Monogenic autoinflammatory disorders are characterized by dysregulation of the innate immune system, for example by gain-of-function mutations in inflammasome-forming proteins, such as NOD-like receptor family CARD-containing 4 protein (NLRC4). OBJECTIVE: Here we investigate the mechanism by which a novel mutation in the leucine-rich repeat (LRR) domain of NLRC4 (c.G1965C, p.W655C) contributes to autoinflammatory disease. METHODS: We studied 2 unrelated patients with early-onset macrophage activation syndrome harboring the same de novo mutation in NLRC4. In vitro inflammasome complex formation was quantified by using flow cytometric analysis of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 techniques and lentiviral transduction were used to generate THP-1 cells with either wild-type or mutant NLRC4 cDNA. Cell death and release of IL-1β/IL-18 were quantified by using flow cytometry and ELISA, respectively. RESULTS: The p.W655C NLRC4 mutation caused increased ASC speck formation, caspase-1-dependent cell death, and IL-1β/IL-18 production. ASC contributed to p.W655C NLRC4-mediated cytokine release but not cell death. Mutation of p.W655 activated the NLRC4 inflammasome complex by engaging with 2 interfaces on the opposing LRR domain of the oligomer. One key set of residues (p.D1010, p.D1011, p.L1012, and p.I1015) participated in LRR-LRR oligomerization when triggered by mutant NLRC4 or type 3 secretion system effector (PrgI) stimulation of the NLRC4 inflammasome complex. CONCLUSION: This is the first report of a mutation in the LRR domain of NLRC4 causing autoinflammatory disease. c.G1965C/p.W655C NLRC4 increased inflammasome activation in vitro. Data generated from various NLRC4 mutations provides evidence that the LRR-LRR interface has an important and previously unrecognized role in oligomerization of the NLRC4 inflammasome complex. | |
