Characterization of Nickel-Specific T Cell Clones.

Nickel is the major cause of metal-induced allergic dermatitis. Twelve nickel-specific T cell clones were used to investigate the cellular immune reactions occurring in nickel sensitivity. The selection between the alternative T cell receptors αβ and γδ and two alternative Vβ genes (Vβ5 and Vβ8) were studied to see if nickel induces a selective pressure for clones bearing particular genes. Cell surface markers were studied by monoclonal antibodies and flow cytometry. Soluble mediators were measured by an ELISA method. The clones used T cell receptor αβ genes but did not use Vβ5 or Vβ8. They were T helper clones with a primed memory marker (CD3⁺CD4⁺CD8^-CD45RO⁺) and carried HLA-DR. None of the clones secreted IL-1α, all of them secreted IL-2 receptor. Four clones secreted IL-1β, six IL-4 and seven IL-6, the peaks in IL-2R and IL-6 secretion preceding IL-4 secretion. The clones helped immunoglobulin synthesis. The clones from late effector phase of the nickel allergic reaction favours the use of T cell receptors αβ genes. Nickel-specific clones were phenotypically indistinguishable but differed in soluble mediators produced. [ABSTRACT FROM AUTHOR]