Antigen specific human T cell lines specific for cobalt chloride

T lymphocyte lines specific for cobalt (CoCl2) were established from one cobalt and nickel sensitive donor. The lines were generated by stimulating peripheral blood mononuclear cells (PBL) with CoCl2 for 7 days. The activated blasts were maintained in interleukin 2 containing media and every 7-10 day restimulated with antigen (CoCl2) and fresh irradiated PBL. The antigen specificity of the lines was attested by their capacity to proliferate and release of IL 2 under restimulation by CoCl2 and not by an antigen like NiSO4, towards which the donor was also sensitized. The cell lines were of the helper phenotype, T3/T4 positive subset, as determined by monoclonal antibodies. Analysis of the HLA class II restriction by using allogeneic PBL as antigen presenting cells and the capacity of anti HLA-D antibodies to effectively inhibit the specific response indicated that the antigen specific T cell response to contact allergens like cobalt chloride is restricted to HLA class II antigens.