title: Nickel-induced proliferation of both memory and naive T cells in patch test-negative individuals.
abstract: Lymphocyte transformation test has often been used as an in vitro test for nickel allergy. We have previously demonstrated the presence of nickel-reactive T cells in individuals with no history of allergic disease and with a negative patch test towards NiSO4. In this study, we show that this proliferative response was mainly confined to T cells within the CD4+ subset. In contrast to conventional recall antigens such as tetanus toxoid, in vitro stimulation using NiSO4 activated both FACS-purified CD4+CD45RA+ 'naive' and CD4+CD45RO+ 'memory' T cells. To determine which cell population reacted with nickel to induce T cell activation, peripheral blood mononuclear cells were separated into macrophages and non-adherent, HLA-DR-depleted T cells. We found that preincubation of monocytes/macrophages but not T cells with NiSO4 resulted in subsequent T cell proliferation. This result demonstrated that nickel did not exhibit any direct effect on the T cell. Furthermore, the NiSO4-induced T cell proliferation could be blocked by antibodies towards MHC class II (HLA-DR) molecules. Our results substantiate the concept that individuals with a negative patch test towards NiSO4 contain in their peripheral blood T cells capable of recognizing nickel or nickel-modified peptides. In contrast to conventional recall antigens, both memory and naive T cells were activated. Thus, when compared with data obtained from nickel-allergic individuals, this study shows a comparable nickel-inducible T cell activation in non-allergic individuals.
authors.affiliation: Department of Dermatology, University of Copenhagen, Gentofte Hospital, Hellerup, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Lisby
authors.forename: L H
authors.initials: LH
authors.lastname: Hansen
authors.forename: T
authors.initials: T
authors.lastname: Menn
authors.forename: O
authors.initials: O
authors.lastname: Baadsgaard
mesh_terms: D000328:Adult; D017951:Antigen Presentation / Q000187:drug effects; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D001665:Binding Sites / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D003877:Dermatitis, Contact / Q000175:diagnosis / Q000276:immunology; D006684:HLA-DR Antigens / Q000096:biosynthesis; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D009532:Nickel / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D010328:Patch Tests; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
chemical_list: D006684:HLA-DR Antigens; C029938:nickel sulfate; D009532:Nickel; D017493:Leukocyte Common Antigens