https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Is alveolar macrophage phagocytic dysfunction in children with protracted bacterial bronchitis a forerunner to bronchiectasis? https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29360 Thu 27 Jan 2022 15:58:57 AEDT ]]> Multiple inflammasomes may regulate the interleukin-1-driven inflammation in protracted bacterial bronchitis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32993 Haemophilus influenzae (NTHi). The mechanisms responsible for IL-1-driven inflammation in PBB are poorly understood. We hypothesised that the inflammation in PBB involves the NLRP3 and/or AIM2 inflammasome/IL-1ß axis. Lung macrophages obtained from bronchoalveolar lavage (BAL), peripheral blood mononuclear cells (PBMCs), blood monocytes and monocyte-derived macrophages from patients with PBB and age-matched healthy controls were cultured in control medium or exposed to live NTHi. In healthy adult PBMCs, CD14⁺ monocytes contributed to 95% of total IL-1ß-producing cells upon NTHi stimulation. Stimulation of PBB PBMCs with NTHi significantly increased IL-1ß expression (p<0.001), but decreased NLRC4 expression (p<0.01). NTHi induced IL-1ß secretion in PBMCs from both healthy controls and patients with recurrent PBB. This was inhibited by Z-YVAD-FMK (a caspase-1 selective inhibitor) and by MCC950 (a NLRP3 selective inhibitor). In PBB BAL macrophages inflammasome complexes were visualised as fluorescence specks of NLRP3 or AIM2 colocalised with cleaved caspase-1 and cleaved IL-1ß. NTHi stimulation induced formation of specks of cleaved IL-1ß, NLRP3 and AIM2 in PBMCs, blood monocytes and monocyte-derived macrophages. We conclude that both the NLRP3 and AIM2 inflammasomes probably drive the IL-1ß-dominated inflammation in PBB.]]> Mon 08 Jul 2019 11:29:52 AEST ]]>