NLRP3 inflammasome activation triggers IL-1β and IL-18 production in HMPV-infected THP-1 and J774.2 cells but has no effect on the viral replication.

THP-1 cells were differenciated into macrophages using PMA (100 ng/ml). THP-1 or J774.2 cells were treated with 10 μM of MCC950 or DMSO (control) and then infected or not with HMPV at a MOI of 0.001 (THP-1) or 0.01 (J774.2). (A) The viral titers were determined by immunostaining. Data were collected from three independent experiments. Values were shown as mean ± S.E.M (unpaired Student t-test, n = 5 per group per experiment). (B & C) Cytokine levels were determined in the cell supernatants by ELISA assay. Values are shown as mean ± S.E.M (Kruskal-Wallis test, ** P vs HMPV, n = 5 per group).