Interleukin-8 production by human monocytic cells in response to staphylococcal exotoxins is direct and independent of interleukin-1 and tumor necrosis factor-α

Staphylococcal exotoxins have been implicated as major virulence factors responsible for toxic shock syndrome. To elucidate further the cellular mechanisms contributing to shock, human monocytic cells were stimulated with the staphylococcal toxic shock syndrome toxin-1, enterotoxin A, or enterotoxin B, and the production of the chemokine interleukin-8 (IL-8) was examined. All three exotoxins were potent inducers of IL-8. IL-8 induction occurred rapidly, within 2 h after stimulation, independent of IL-1 and tumor necrosis factor-alpha produced by these cells. This study suggests that IL-8 is one of the earliest mediators produced by monocytic cells in direct response to staphylococcal exotoxins. IL-8 may serve as the first proinflammatory signal for neutrophil recruitment to tissue and may contribute to staphylococcal superantigen-mediated shock and multiorgan failure characteristic of toxic shock.