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Updated: Jun 9, 2026
Contact Hypersensitivity as a Murine Model of Allergic Contact Dermatitis
Published on: September 26, 2022
Allergy-inducing nickel concentration is lowered by lipopolysaccharide at both the sensitization and elicitation
M Kinbara1, N Sato, T Kuroishi
1Department of Molecular Regulation, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. kinbara@dent.tohuku.ac.jp
Background:
Nickel (Ni) is the major cause of contact allergy. We previously found that lipopolysaccharide (LPS, a cell-surface component of gram-negative bacteria) markedly promotes Ni allergy in a murine model. Establishing the minimum concentration or amount of Ni needed to induce allergic responses may help us to prevent or reduce such responses.
Objectives:
Using the above murine model, we examined the influence of LPS on the minimum allergy-inducing concentrations of Ni (Ni-MAICs) at the sensitization step and at the elicitation step.
Methods:
BALB/c mice were sensitized by intraperitoneal injection of a mixture containing various concentrations of LPS and NiCl(2). Ten days later, their ear pinnas were challenged intradermally with a mixture containing various concentrations of LPS and NiCl(2), and ear swelling was measured.
Results:
Without LPS, the Ni-MAICs at the sensitization and elicitation steps were around 1×10(-2) mol L(-1) and 1×10(-5) mol L(-1) , respectively. Sensitization with NiCl(2) + LPS did not alter the value at elicitation. Surprisingly, LPS markedly reduced these Ni-MAICs (to around 1×10(-6) molL(-1) at sensitization, with 25 μg mL(-1) LPS, and 1×10(-12) mol L(-1) at elicitation, with 0·5 μg mL(-1) LPS). The effect of LPS depended on its concentration and the timing of its injection.
Conclusions:
Our findings suggest that: (i) Ni-MAIC is higher at sensitization than at elicitation; (ii) once sensitization is established, Ni allergy can easily be induced by a low concentration of Ni; and (iii) a bacterial milieu or infection may greatly facilitate the establishment and elicitation of Ni allergy.
