Th1/Th2 balance in mouse delayed-type hypersensitivity model with mercuric chloride via skin and oral mucosa

In order to compare delayed-type hypersensitivity (DTH) among different exposure sites, we evaluated the sensitization potency of mercuric chloride (HgCl(2)) via exposure to the skin, or oral or esophageal mucosa using the mouse ear swelling test. Furthermore, we investigated in vitro splenocyte proliferation reaction and cytokine profile in HgCl(2)-exposed and control mice. Sensitization with HgCl(2) was established via the skin and oral mucosa but not via the esophageal mucosa. The splenocyte proliferation reaction was significantly enhanced to a similar degree in skin and oral mucosa-sensitized mice compared with in the control mice. IL-10 levels from cultured splenocytes were significantly increased in skin and oral mucosa-sensitized mice compared with those in control mice, whilst IFN-γ significantly increased only in splenocytes from skin-sensitized mice. These results suggest that exposure of the skin or oral mucosa to HgCl(2) can induce DTH, but that Th1/Th2 balance differs according to the site of antigen exposure.