In Vitro Skin Sensitisation (ARE reporter gene assay)
Concept
The ARE reporter gene assay LuSens is a cell based animal free test system that helps to identify the skin sensitisation potential of substances in the context of hazard identification. The test system uses a transgenic HaCaT cell line which carries the luciferase reporter gene under control of an ARE-element (Antioxidative ResponseElement) from rat NADPH quinone oxidoreductase 1 gene. Sensitiser induced luciferase activity can be measured as luminescence and provides quantitative information about the sensitisation potential of a substance (Ramirez et al. 2014).
Context
LuSens is one part of a testing strategy that uses three assays aligned to different key events of the OECD Adverse Outcome Pathway (AOP).
- Key event 1: covalent interaction with skin proteins (DPRA, OECD 442C)
- Key event 2: keratinocyte response (e.g. LuSens, based on OECD 442D)
- Key event 3: dendritic cell activation (e.g. h-CLAT)
In a two out of three approach two of these tests with consistent positive outcome lead to rating the substance as skin sensitiser. Using this weight of evidence approach predictivities similar to the LLNA could be attained.
Conclusion
LAUS now offers the performance of the ARE reporter gene assay (LuSens) under GLP and non-GLP conditions. The test was established by BASF and is based on OECD 442D. Together with DPRA and h-CLAT the whole in vitroskin sensitisation package is available. This test strategy is an alternative for clients who intend or need to avoid animal testing with regard to skin sensitisation (OECD 406, 429, 442A), for example the cosmetic industry after the animal testing and marketing ban for cosmetic products in Europe.
Literature
Ramirez, Tzutzuy, Annette Mehling, Susanne N. Kolle, Christoph J. Wruck, Wera Teubner, Tobias Eltze, Alexandra Aumann, Daniel Urbisch, Ben van Ravenzwaay, and Robert Landsiedel. 2014. “LuSens: A Keratinocyte Based ARE Reporter Gene Assay for Use in Integrated Testing Strategies for Skin Sensitization Hazard Identification.”Toxicology in Vitro : An International Journal Published in Association with BIBRA 28 (8). Elsevier Ltd: 1482–97.
