The h-CLAT addresses Dendritic Cell Activation, a key Adverse Outcome Pathway event of dermal sensitization.
The h-CLAT test method is an in vitro toxicology assay that evaluates cell surface marker expression - CD86 and CD54 on THP-1 cells, a human monocytic leukemia cell line following a 24 hrs exposure to a test substance. CD86 and CD54 are surface molecules that are typical markers of Dendritric Cell(DC) activation and play an important role in T cell priming. The cell surface marker expression is measured by flow cytometry following fluorescent staining with fluorochrome-tagged antibodies. Assessment of surface markers expression at sub-cytotoxic concentrations is also asses concurrently. The relative fluorescence intensity of the surface markers are calculated by comparing results to vehicle control are calculated and used in the h-CLAT prediction model, allowing for discrimination between sensitizers and non-sensitizers.
OECD Test Guideline is in draft, pending approval/acceptance. Previously, the h-CLAT has been evaluated in a European Union Reference Laboratory for Alternatives to Animal Testing (EURL-ECVAM) and was considered scientifically valid to be used as part of an intergrated approach to testing and assessment (IATA) for discrimination between sensitizers and non-sensitizers for hazard classification and labelling.
MB Research is internally validating the h-CLAT testing procedures and will be offering the h-CLAT as a Good Laboratory Practices (GLP) assay.
MB Research has developed a non-animal Integrated Testing Strategy (ITS) for chemical-induced contact hypersensitivity (skin sensitization). This ITS provides a completely non-animal alternative to traditional testing methods. Together, our three assays address three key events on the skin sensitization adverse outcome pathway (AOP).