CXCL8 and escherichia coli infection: However, at 12 and 24 h post-infection, PGD2 significantly downregulated the secretion of TNF-α, IL-1β, and IL-8 compared to the E. coli infection group, while the secretion of IL-6 and IL-10 remained elevated (Figures 3B–F, P < 0.01).