TH2-Type Infiltrating T Cells in Nickel-Induced Contact Dermatitis

The T cell response to nickel-modified endogenous peptides is involved in the immunopathogenesis of nickel-induced contact dermatitis. Nickel-reactive T cells described so far display a TH1 lymphokine secretion pattern characterized by high amounts of IFNγ, but little or no IL-4 and IL-5. In this paper we demonstrate that nickel-reactive T cells can belong to the TH0 and even to the TH2 CD4+ T cell subset. Nickel-reactive T cell clones (TCC) were derived from the lesion of a patient with nickel contact dermatitis. These TCC responded to nickel with the production of high levels of IL-5 and variable amounts of IFN-γ, and IL-4 resembling a TH2- or TH0-like cytokine secretion pattern. None of the nickel-reactive TCC showed a clear cut TH1 profile. We show that IL-4 was a growth factor for the TH2 and some of the TH0 TCC. We conclude that nickel is able to induce TH2 cells and that in this patient with a typical nickel-induced contact dermatitis TH2 cells are prevalent and might contribute to the immunopathogenesis of contact dermatitis.