title: Adaptation of the KeratinoSens™ skin sensitization test to animal-product-free cell culture
abstract: Skin sensitization is the process by which a substance induces an allergic reaction following skin contact. The process has been described as an adverse outcome pathway (AOP), including several key events, from skin penetration and covalent protein binding, to keratinocyte activation, dendritic cell activation and T-lymphocyte proliferation. The in vitro assay KeratinoSens™ measures the activation of keratinocytes. It is fully accepted at a regulatory level (OECD TG 442d) and complies with a range of legislation including the EU Cosmetics Regulation, REACH, and the CLP Regulation. Currently, many in vitro methods use animal-derived components in their cell culture systems. Many stakeholders in the cosmetics industry have both scientific and ethical concerns relating to this issue and have stated a strong preference for fully human in vitro test systems. We have adapted the KeratinoSens™ method to animal product-free condi­tions, and carried out an in-house validation with 21 reference substances, including those listed in the Performance Standards associated with OECD TG442d. The modified method was shown to be equivalent to the Validated Ref­erence Method (VRM), with comparable values for accuracy (85.7%), sensitivity (84.6%) and specificity (87.5%), and all acceptance criteria being met. In Europe, data generated by the adapted method may be used in REACH submissions, and we are now seeking approval to list the adaptation in OECD TG 442d, enabling formal compliance with a range of global regulations.
authors.affiliation: XCellR8 Ltd, The Innovation Centre, Sci-Tech Daresbury, Daresbury, Cheshire, UK.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Belot
authors.affiliation: XCellR8 Ltd, The Innovation Centre, Sci-Tech Daresbury, Daresbury, Cheshire, UK.
authors.forename: Bushra
authors.initials: B
authors.lastname: Sim
authors.affiliation: XCellR8 Ltd, The Innovation Centre, Sci-Tech Daresbury, Daresbury, Cheshire, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Longmore
authors.affiliation: XCellR8 Ltd, The Innovation Centre, Sci-Tech Daresbury, Daresbury, Cheshire, UK.
authors.forename: Lottie
authors.initials: L
authors.lastname: Roscoe
authors.affiliation: XCellR8 Ltd, The Innovation Centre, Sci-Tech Daresbury, Daresbury, Cheshire, UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Treasure
mesh_terms: D000826:Animal Testing Alternatives / Q000379:methods*; D018929:Cell Culture Techniques; D002460:Cell Line; D003358:Cosmetics; D005060:Europe; D006801:Humans; D066298:In Vitro Techniques / Q000379:methods; D015603:Keratinocytes / Q000187:drug effects*; D023441:Local Lymph Node Assay; D023422:Skin Irritancy Tests / Q000379:methods*
chemical_list: D003358:Cosmetics
keywords: skin sensitization; KeratinoSens; alternatives to animal testing; 3R; in vitro