ICCVAM Biennial Report 2014-2015

ICCVAM Biennial Report 2014-2015

Immunotoxicity Testing: ICCVAM and NIEHS Activities

Development of an Integrated Testing Strategy for Prediction of Skin Sensitization Hazard

NICEATM and ICCVAM scientists developed an integrated testing strategy that uses data from three in vitro tests (the direct peptide reactivity assay, human cell line activation test, and KeratinoSensTM assay), six physicochemical properties, and an in silico read-across prediction of skin sensitization hazard as inputs to machine-learning approaches to predict murine local lymph node assay (LLNA) outcomes and human skin sensitization hazard. Using a particular combination of inputs and machine-learning approaches (computer algorithms that can make predictions or decisions about sets of data) yielded more accurate predictions of LLNA or human skin sensitization hazard than any of the in chemico, in vitro, or in silico methods alone. Three manuscripts describing different strategies and targets will result from these efforts. One has been accepted for publication in the Journal of Applied Toxicology; the other two will be submitted in 2016.

ICCVAM Evaluation of the Electrophilic Allergen Screening Assay

The electrophilic allergen screening assay, an in chemico method, was nominated to ICCVAM in 2012 for evaluation of its usefulness to identify potential skin sensitizers. NICEATM has been working with the test method sponsor to address technical issues with the assay prior to advancing to a validation study.