Optimization of the mouse ear swelling test for in vivo and in vitro studies of weak contact sensitizers^*

Abstract

Murine models for the assessment of the contact sensitizing properties of chemicals rely on mouse ear swelling tests (Mest), which are not sensitive enough to detect weak sensitizers. The aim of the present study was to develop in mice an adjuvant-free Mest appropriate for in vivo detection of any type of sensitizer (weak to strong), and useful for in vitro assessment of contact sensitivity (CS). 3 haptens were tested: dinitrochlorobenzene (DNCB), para-phenylenediamine (pPD) and isoeugenol. We compared various protocols for induction of the CS reaction, differing by the site of induction, the number of applications and the concentrations of the 3 haptens. Comparison of the induction site for optimal CS reaction showed that, in Balb/c mice, the back was a better site of induction than the abdomen. Detection of the sensitizing properties of weak sensitizers (pPD, isoeugenol) was possible using an adjuvant-free protocol, provided that the induction phase comprised hapten applications on 3 consecutive days on the backs of animals. For DNCB, one application was sufficient to obtain optimal CS reaction. For all 3 haptens, a secondary response in vitro was obtained using semi-purified lymph node T cells from animals sensitized 5 days before with the optimized Mest. These results demonstrate that the Mest could be a useful experimental model for the study of all types of contact sensitizers.

Immunomodulation of Delayed-Type Hypersensitivity Responses by Mesenchymal Stem Cells Is Associated with Bystander T Cell Apoptosis in the Draining Lymph Node

“…The mouse ear-swelling test has been performed by the methods described elsewhere (24,25). Briefly, 2, 4-dinitro-1-fluorobenzene (DNFB) was used as a contact-sensitizing agent.…”

Th1 and Type 1 Cytotoxic T Cells Dominate Responses in T-bet Overexpression Transgenic Mice That Develop Contact Dermatitis

“…Induction of CHS was conducted using the methods described previously (21). Briefly, mice were sensitized to DNFB by painting the shaved abdomen with 50 l of 0.5% DNFB in acetone/olive oil (4:1) and each footpad with 5 l of the mixture on days 0 and 1.…”

CCR6-deficient mice have impaired leukocyte homeostasis and altered contact hypersensitivity and delayed-type hypersensitivity responses

“…The mouse ear-swelling test has been described elsewhere (28). Briefly, mice were sensitized topically by applying 25 µl of 0.5% 2,4-dinitrofluorobenzene (DNFB; Sigma Chemical Co.) solution in acetone/olive oil (4:1) to the shaved abdomen.…”