Increased ROS levels of trained monocytes do not contribute to their enhanced pro-inflammatory cytokine production. (A) ROS levels at 2 h, 24 h, and 6 days after exposure of monocytes to β-glucan and BCG (n = 6/9 donors, pooled from 2/3 independent experiments. Fridman test Dunn’s multiple comparisons test). (B) Expression levels of genes involved in the antioxidant defense in monocytes exposed to β-glucan for 24 h in comparison to unstimulated cells. Expression presented as log10(ratio). TNFα and IL-6 produced by β-glucan-trained macrophages after a 1 h pretreatment with (C) 0.5µM DPI (n = 6 donors, pooled from 2 independent experiments) and (D) 1 mM NAC, 50 µM AT or 0.5 µM AA (n = 6 donors, pooled from two independent experiments, two-way ANOVA, Sidak’s multiple comparisons test). (mean ± SEM, * p < 0.05).