Neisseria meningitidis-Induced Caspase-1 Activation in Human Innate Immune Cells Is LOS-Dependent

Figure 2

Involvement of LOS in N. meningitidis-induced secretion of TNF and IL-6 and NLRP3 inflammasome/caspase-1/IL-1β axis-dependent IL-1β secretion. Isolated human neutrophils were challenged (MOI of 10) with the parental wild-type N. meningitidis FAM20 or its LOS-deficient mutant strain IpxA for 6 h after TNF (a), IL-6 (b), IL-1β (c) secretion was measured from culture supernatant by ELISA. Bars represent ; . In some experiments, the isolated human neutrophils were preincubated with the NLRP3 inhibitor MCC950 prior to FAM20 stimulation (MOI of 10) (d). THP1-wt, THP1-defNLRP3, and THP1-defCASP1 cells were challenged with FAM20 (MOI of 10) for 6 h (e), and IL-1β release was measured from culture supernatant by ELISA. Bars represent ; .

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