ABSTRACT
Cholera toxin (CT), a bacterial exotoxin composed of one A subunit (CTA) and five B subunits (CTB), functions as an immune adjuvant. CTB can induce production of interleukin-1ß (IL-1ß), a proinflammatory cytokine, in synergy with a lipopolysaccharide (LPS), from resident peritoneal macrophages (RPMs) through the pyrin and NLRP3 inflammasomes. However, how CTB or CT activates these inflammasomes in the macrophages has been unclear. Here, we clarify the roles of inositol-requiring enzyme 1 alpha (IRE1α), an endoplasmic reticulum (ER) stress sensor, in CT-induced IL-1ß production in RPMs. In RPMs, CTB is incorporated into the ER and induces ER stress responses, depending on GM1, a cell membrane ganglioside. IRE1α-deficient RPMs show a significant impairment of CT- or CTB-induced IL-1ß production, indicating that IRE1α is required for CT- or CTB-induced IL-1ß production in RPMs. This study demonstrates the critical roles of IRE1α in activation of both NLRP3 and pyrin inflammasomes in tissue-resident macrophages.
Subject(s)
Cholera Toxin , Endoplasmic Reticulum Stress , Endoribonucleases , Interleukin-1beta , Protein Serine-Threonine Kinases , Interleukin-1beta/metabolism , Animals , Endoribonucleases/metabolism , Protein Serine-Threonine Kinases/metabolism , Endoplasmic Reticulum Stress/drug effects , Mice , Cholera Toxin/pharmacology , Cholera Toxin/metabolism , Inflammasomes/metabolism , Mice, Inbred C57BL , Macrophages/metabolism , Macrophages/drug effects , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/immunology , Lipopolysaccharides/pharmacology , Endoplasmic Reticulum/metabolismABSTRACT
This study aims to clarify the clinical significance of dupilumab-induced elevation of blood eosinophil in Japanese patients with atopic dermatitis (AD). Eosinophil elevation was defined as ≥ 5% increase of eosinophil percentage within one year after dupilumab initiation. Seven patients (15.7%) were shown to have eosinophil elevation, six of whom developed dupilumab-associated conjunctivitis (DAC) and were accompanied with DAC more frequently than those without eosinophil elevation, with statistically significant difference. Eosinophil percentage resolved spontaneously in all seven patients, including the one without DAC, despite the continuation of dupilumab treatment. None of the patients with eosinophil elevation had cardiac or pulmonary complications attributable to the hypereosinophilia. The patients with eosinophil elevation were all male. Furthermore, none of four patients in whom efficacy of dupilumab was < 25% showed eosinophil elevation. Childhood onset tended to be more common in patients with the elevation of eosinophil. This study suggests that most eosinophil elevation is associated with DAC, and that the eosinophil ratio is a biomarker for DAC.
