Sodium lauryl sulfate causes interleukin-1α release from normal human keratinocytes: dose-response and time-course curves

Interleukin 1alfa (IL-1 alfa) is involved in the biological response to irritants as one of the most important inflammatory mediators. The aim of the present study was to evaluate IL-1 alfa production after exposure of cultured human keratinocytes to Sodium Lauryl Sulfate (SLS), representing a model which enables assessment of the in vitro effects of SLS on epidermal cells independently from the skin immune system and barrier alteration.Normal human keratinocytes from plastic surgery were grown in serum free medium. At subconfuency cells were treated with SLS doses ranging from 0.00001 to 0.005% and after exposure for one hour, the medium was changed. At different time points the supernatant was collected for ELISA, and cells were harvested for Western blot analysis of pro-IL-1 alfa and IL-1 alfa. Extracellular secretion of IL-1 alfa from keratinocytes was increased in a dose dependent manner following SLS treatment. The release of IL-1alfa starts at 30 min after exposure (effective dose 50%) reaching a maximum at 3 h.Western blot analysis showed a down regulation of pro-IL-1alfa levels, while IL-1 alfa levels remained unchanged.