Integration of MUTZ-Langerhans cells into a 3D full-thickness skin equivalent and influences of serum reduction and undefined medium supplements on differentiation.

The MUTZ-3 cell line is a surrogate for Langerhans cells (LCs) employed in New Approach Methodologies for assessing the skin sensitizing potential of chemicals. However, MUTZ-3 cells must first be differentiated to achieve the LC-typical phenotype. As all protocols use high fetal calf serum (FCS) concentrations, we aimed at reducing, or even replacing FCS, while maintaining MUTZ-LC characteristics.

Performance of the DASF compared to other combinations of OECD NAMs for eye hazard identification of surfactants.

Currently, the OECD has adopted three defined approaches (DAs) for eye hazard identification of non-surfactant liquids and solids (TG 467) according to the three UN GHS categories. We are now expanding the applicability domain with a new DA for chemicals having surfactant properties (DASF). It is based on a combination of recombinant human cornea-like epithelium test methods (TG 492: EpiOcular™ EIT or SkinEthic™ HCE EIT) and a modification of the Short Time Exposure (TG 491) method.

Significance of melanin distribution in the epidermis for the protective effect against UV light.

Melanin, the most abundant skin chromophore, is produced by melanocytes and is one of the key components responsible for mediating the skin's response to ultraviolet radiation (UVR). Because of its antioxidant, radical scavenging, and broadband UV absorbing properties, melanin reduces the penetration of UVR into the nuclei of keratinocytes. Despite its long-established photoprotective role, there is evidence that melanin may also induce oxidative DNA damage in keratinocytes after UV exposure and therefore be involved in the development of melanoma.

A human 3D immune competent full-thickness skin model mimicking dermal dendritic cell activation.

We have integrated dermal dendritic cell surrogates originally generated from the cell line THP-1 as central mediators of the immune reaction in a human full-thickness skin model. Accordingly, sensitizer treatment of THP-1-derived CD14, CD11c immature dendritic cells (iDCs) resulted in the phosphorylation of p38 MAPK in the presence of 1-chloro-2,4-dinitrobenzene (DNCB) (2.6-fold) as well as in degradation of the inhibitor protein kappa B alpha (IκBα) upon incubation with NiSO (1.