The role of CD4+ T cells in the induction of contact hypersensitivity to mercury in a murine model.

BACKGROUND

The exact immunopathogenesis of contact hypersensitivity (CH) to mercury remains unclear.

OBJECTIVE

The aim of the present study was to assess the role of CD4+ T cells in mercury-induced CH in mice.

METHODS

Splenic CD4+ T cells obtained from nonsensitized and mercury-sensitized Balb/c mice were adoptively transferred to groups I and II of the syngeneic recipients, respectively. All recipients were ear-challenged with mercury. The next experiments were to transfer nonsensitized CD4+ T cells to group A of the recipients, whereas mercury-sensitized CD4+ T cells were transferred to groups B and C. Groups A and B were ear-challenged with mercury, whereas group C was ear-challenged with chromium. The ear swelling 24 hours and 48 hours after challenge was used to assess CH.

RESULTS

The results of the present study showed that mercury-sensitized but not nonsensitized CD4+ T cells could transfer CH in mice. Furthermore, mercury-sensitized CD4+ T cells could transfer the induction of CH only in the recipients that were challenged with mercury, but not those that were challenged with chromium.

CONCLUSION

The results of the present study suggest that mercury-induced CH may be mediated by mercury-specific CD4+ T cells.