Fig 2. TLR4 agonist LPS and Cobalt-alloy particles in THP-1 Macrophages induce significantly elevated secretion of IL-1β, TNF-α and IL-10, while only Cobalt particles significantly increase IL-1β without concomitant IL-10 increase.

(A) IL-1β (B) TNF-α (C) and IL-10 cytokine production was assessed after THP-1 differentiated macrophages were challenged with Cobalt-alloy particles (particles:cell = 5:1), Cobalt-alloy/LPS+, and LPS (100ng/mL) for 20 h and was quantified by ELISA. (D) THP-1 macrophages were challenged with Co-alloy particles and incubated with 15μg/ml DQ ovalbumin simultaneously for 4 hrs and subsequently were fixed and evaluated for the presence of large pools of dispersed DQ ovalbumin fluorescence co-localized with particles, indicative of lysosomal destabilization. Note: * p<0.05 compared to control macrophages.