Observation of hapten-induced sensitization responses for the development of a mouse skin sensitization test, including the elicitation phase

Abstract

The only official method that can detect the skin sensitizing potential of chemicals, including the elicitation response, is the OECD test guideline (TG) 406. However, this guideline uses guinea pigs, which requires complex procedures. Since a simple and complete test method for evaluating skin sensitization is needed, especially for mechanistic studies of skin sensitization, this study confirmed the reactivity of mice to skin sensitizing substances. We set up a protocol involving one induction exposure of the test substance to the back skin, followed by three challenge exposures to the auricle (Protocol 2), and compared their skin sensitization responses with the results of two exposures to the auricle and back skin every 2 weeks (Protocol 1) and a local lymph node assay (TG442B). A hapten 2,4-dinitrofluorobenzene caused significant auricular thickening, skin inflammation, and enlarged auricular lymph nodes in Protocols 1 and 2. These changes were more pronounced in Protocol 2. Plasma IgE and IgG1 and gene expression of IL4, IFNγ, and perforin were significantly increased in Protocol 2. Cell proliferation in the auricular lymph nodes was observed in both protocols as in TG442B. These results indicate that Protocol 2 can be a good candidate for a relatively simple skin sensitization test.

Toxicity Assessment of Mixed Exposure of Nine Perfluoroalkyl Substances at Concentrations Relevant to Daily Intake

“…The gene expression levels of eight genes representing pathways that varied in the transcriptome analysis were confirmed via quantitative PCR (qPCR), according to our previous report [ 24 ]. Briefly, reverse transcription from mRNA was performed using the LunaScript ® RT SuperMix Kit (New England BioLabs), following standard protocols.…”

Subchronic Toxicity Assessment of Perfluoroalkyl Substances by Mixed Exposure of Nine Substances at Daily Intake Relevant Concentration

“…The copyright holder for this preprint this version posted May 19, 2023. ; https://doi.org/10.1101/2023.05.17.541082 doi: bioRxiv preprint previous report (Kamata et al, 2022). Briefly, reverse transcription from mRNA was performed using the LunaScript® RT SuperMix Kit (New England BioLabs) following standard protocols.…”