FIG. 3.

Secretion of IL-8 by Hct-8 cells treated with Stx1, TNF-α, or both. For each concentration of Stx1 alone, TNF-α alone, or Stx1 plus TNF-α, IL-8 measured in cell culture supernatants is shown (mean amounts from three to six samples with SD). Inserted above each solid bar is protein synthesis expressed as a percentage of control levels, as determined by [³H]leucine incorporation (SD are reported in parentheses). Comparisons were made between TNF-α-induced IL-8 levels and Stx1-plus-TNF-α-induced IL-8 levels. P values are as follows: ∗, 0.0002; ∗∗, <0.0001; #, 0.001; ##, 0.0005.