Journal Article

OLT1177, a β-sulfonyl nitrile compound, safe in humans, inhibits the NLRP3 inflammasome and reverses the metabolic cost of inflammation

Neff, Charles P., Jones, Terry M., Skouras, Damaris B., Scribner, Curtis L., D’Alessandro, Angelo, Goodrich, Scott A., Marchetti, Carlo, Janciauskiene, Sabina, Gamboni, Fabia, Tengesdal, Isak, Swartzwelter, Benjamin, Gattorno, Marco, Azam, Tania, Richter, Katrin, Henry, Curtis, Altman, Roy D., Barrow, Robert B., Grau, Veronika, Nemkov, Travis, Joosten, Leo A. B., Dinarello, Charles A., Carta, Sonia, Jones, Gerald S., Rubartelli, Anna, St. Laurent, Joseph P.

2018

Overview

Activation of the NLRP3 inflammasome induces maturation of IL-1β and IL-18, both validated targets for treating acute and chronic inflammatory diseases. Here, we demonstrate that OLT1177, an orally active β-sulfonyl nitrile molecule, inhibits activation of the NLRP3 inflammasome. In vitro, nanomolar concentrations of OLT1177 reduced IL-1β and IL-18 release following canonical and noncanonical NLRP3 inflammasome activation. The molecule showed no effect on the NLRC4 and AIM2 inflammasomes, suggesting specificity for NLRP3. In LPS-stimulated human blood-derived macrophages, OLT1177 decreased IL-1β levels by 60% and IL-18 by 70% at concentrations 100-fold lower in vitro than plasma concentrations safely reached in humans. OLT1177 also reduced IL-1β release and caspase-1 activity in freshly obtained human blood neutrophils. In monocytes isolated from patients with cryopyrin-associated periodic syndrome (CAPS), OLT1177 inhibited LPS-induced IL-1β release by 84% and 36%. Immunoprecipitation and FRET analysis demonstrated that OLT1177 prevented NLRP3-ASC, as well as NLRP3-caspase-1 interaction, thus inhibiting NLRP3 inflammasome oligomerization. In a cell-free assay, OLT1177 reduced ATPase activity of recombinant NLRP3, suggesting direct targeting of NLRP3. Mechanistically, OLT1177 did not affect potassium efflux, gene expression, or synthesis of the IL-1β precursor. Steady-state levels of phosphorylated NF-κB and IkB kinase were significantly lowered in spleen cells from OLT1177-treated mice. We observed reduced IL-1β content in tissue homogenates, limited oxidative stress, and increased muscle oxidative metabolism in OLT1177-treated mice challenged with LPS. Healthy humans receiving 1,000 mg of OLT1177 daily for 8 d exhibited neither adverse effects nor biochemical or hematological changes.

• Publisher: National Academy of Sciences
• Subject: Activation / Adenosine triphosphatase / Biological Sciences / Blood / Caspase / Caspase-1 / Cryopyrin / Efflux / Fluorescence resonance energy transfer / Gene expression / Immunology and Inflammation / Immunoprecipitation / Inflammasomes / Inflammatory diseases / Interleukin 18 / Leukocytes (neutrophilic) / Lipopolysaccharides / Macrophages / Metabolic rate / Metabolism / Mice / Molecules / Monocytes / Muscles / NF-κB protein / Oligomerization / Oxidative metabolism / Oxidative stress / PNAS Plus / Spleen