Skin sensitizer identification by IL-8 secretion and CD86 expression on THP-1 cells

• We use myelomonocytic THP-1 cell line to establish an in vitro predictive allergenic test.
• We found that 48-h chemical exposure was necessary to identify sensitizers by the analyses of CD86 expression.
• The CD54 expression analyses presented a poor efficiency to discriminate sensitizers from non-sensitizers in our conditions.
• The IL-8 secretion analyses after 24-h chemical incubation seemed to be an alternative for CD54 expression assessing.

Substantial progress has been made in the development of alternative methods for skin sensitization in the last decade in several countries around the world. Brazil is experiencing an increasing concern about using animals for product development, since the publication of the Law 9605/1998, which prohibits the use of animals when an alternative method is available. In this way, an in vitro test to evaluate allergenic potential is a pressing need.This preliminary study started setting the use of myelomonocytic THP-1 cell line, according to the human cell line activation test (h-CLAT), already under validation process. We found that 48-h chemical exposure was necessary to identify 22 out of 23 sensitizers by the analyses of CD86 expression. In addition, the CD54 expression analyses presented a poor efficiency to discriminate sensitizers from non-sensitizers in our conditions. In view of these results, we looked for changes of pro-inflammatory interleukin profile. The IL-8 secretion analyses after 24-h chemical incubation seemed to be an alternative for CD54 expression assessing.Altogether, our findings showed that the combination of the analyses of CD86 expression and IL-8 secretion allowed predicting allergenicity.