Establishment of nickel-specific T cell lines from patients with allergic contact dermatitis: comparison of different protocols.

Allergic contact dermatitis is a delayed-type hypersensitivity reaction, secondary to hapten-specific T lymphocyte activation in sensitized individuals. The present study reports on the establishment of T cell lines from peripheral blood mononuclear cells (PBMC) of nickel-allergic patients, initially cultured with nickel, IL-2, or PHA and IL-2. It was possible to derive hapten-specific T cell lines from the three protocols, and the best proliferative responses to nickel were observed when PBMC were cultured in the presence of nickel in vitro. T cell lines initially cultured with IL-2 always gave better specific proliferative responses to nickel than those derived with PHA and IL-2. Phenotypical analysis of the nickel-specific T cell lines showed that they were mainly composed of activated CD8+ TcR alpha beta + T lymphocytes. These results emphasize the importance of initial culture conditions for the generation of hapten-specific T cell lines and suggest that CD8+ lymphocytes could play an important role in the pathogenesis of allergic contact dermatitis.