Cytokine release from dendritic cells in vitro is a useful marker to discriminate between sensitizing and irritant haptenic chemicals. Unfortunately, pro-haptens, which gain reactivity following metabolic/auto activation, yield negative results. To overcome this, we exposed human neutrophils and THP-1 cells to haptens/pro-haptens and measured IL-8 release. Haptenic compounds stimulated IL-8 release in neutrophils and THP-1 cells. In contrast, the pro-haptens eugenol, isoeugenol, and 2-aminophenol stimulated high levels of IL-8 release from neutrophils alone. Neutrophil cytokine release was reduced when glutathione was added. Cyp1A1/1B1/3A4 were not detectable in THP-1 cells or neutrophils; however, neutrophils expressed high levels of myeloperoxidase.
