Research on the effects of chemical substances on children, elderly
people, and those with gene disorders
Title of Research:
15_S03-01-1

Establishment of in vitro evaluation system for the prediction ofrespiratory sensitizing potential of chemicals
Principal Investigator:
Takayuki Yoshimoto, PhD (Professor, Tokyo Medical University, Institute of Medical Science)
6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan(tel)+81-3-3351-6141 Ext. 431, (e-mail) yoshimot@tokyo-med.ac.jp
Collaborators:
Izuru Mizoguchi, PhD (Research Associate, Tokyo Medical University, Institute of MedicalScience) 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan(tel) +81-3-3351-6141 Ext. 448, (e-mail) imizo@tokyo-med.ac.jp
Summary of Research:
Although the number of patients with occupational asthma has recently been estimated to beas high as approximately 15-18% of that with adult asthma, there is no established diagnostic
methods for it and no standard, validated and regulatory-accepted methods to identify potential
respiratory sensitizers and distinguish them from skin sensitizers. This is in marked contrast to thesituation of contact hypersensitivity, where there are highly sophisticated, established diagnosticmethods. Testing assays for assessment of chemical sensitizers including GPMT and LLNA,
which utilize guinea pigs and mice, respectively, were previously developed. However, the use ofanimal models in safety testing will be significantly limited due to introduction of 3Rs principles ofrefinement, replacement, and reduction of animal experimentations in research wherever possible.
Therefore, several in vitro assays including DPRA, KeratinoSense, h-CLAT, and IL-8 Luc Assay
have been developed. However, these alternative methods cannot distinguish chemical
respiratory sensitizers and chemicalskin sensitizers, although the risk-management
countermeasure is markedly different between them.
Therefore in the present study, we aim at developing a novel in vitro assay, which candiscriminate chemical respiratory sensitizers from chemical skin sensitizers by taking advantage ofthe fundamental differences between their modes of function (AOP: Adverse outcome pathway);development of type 2 helper T (Th2) immune responses, which is critical for respiratory
sensitization.
Using the Alvetex® Scaffold from Reinnervate, we have established an immunocompetent 3D
co-culture system of human upper airway. It consists of a human airway epithelial cell line, humanimmature dendritic cells (DCs) derived from peripheral blood CD14+ monocytes, and a humanfibroblast cell line cultured in individual scaffolds and then assembled into a 3D multi-cell tissue
model, which more closely mimics the in vivo physiological situation. The present results indicatethat this 3D co-culture system has great potential to contribute to the establishment of in vitroevaluation system for the prediction of respiratory sensitizing potential of chemicals by means ofenhanced expression of molecules critical for induction of Th2 differentiation and immune
responses such as OX40L and IL-10 as markers.
Timeline:
March 1, 2015-Feberary 29, 2016
Topics:The 3th Annual Meeting of The Japan Chemical Industry Association LRI, poster presentation“Development of a novel method for in vitro assessment of chemical respiratory sensitizers”(Tokyo, August 28, 2015)
Publications:
The 28th Annual Meeting of The Japanese Society for Alternatives to Animal Experiments, Japan
Chemical Industry Association LRI Symposium, oral presentation “Development of a novel method
for in vitro assessment of chemical respiratory sensitizers” (Yokohama, December 11, 2015)17