title: Molecular analysis of T-cell clonality with concomitant specific T-cell proliferation in vitro in nickel-allergic individuals.
abstract: BACKGROUND
  The peripheral blood mononuclear cells (PBMC) of individuals with nickel contact allergy are reported to proliferate to a varying degree upon nickel stimulation in vitro. Different phenotypes of the T cells involved are described. With regard to preferential use of the T-cell receptor (TCR), analysis of the several families of the TCR-gamma gene allows rearrangement evaluation of all T cells regardless of predominant surface expression of TCR alpha/beta.
  
  
  METHODS
  The PBMC of 10 nickel-allergic and five nonallergic individuals were cultured for 4 days in the presence of either medium, PHA, NiSO4, or tetanus toxoid (TT). Proliferation was measured by radioactive thymidine uptake and expressed as stimulation index (SI). T-cell clonality was assessed by analysis of the TCR-gamma chain gene, including the use of PCR with a primer combination covering the four main groups (Vgamma1-8, Vgamma9, Vgamma10, and Vgamma11) of the variable region of the TCR-beta chain gene.
  
  
  RESULTS
  In the allergic individuals, proliferation to NiSO4 was significantly (P<0.05) higher than in nonallergics (mean SI: 18.05/17.87 vs 0.67/2.27). In unstimulated and PHA-stimulated cultures, there was a random TCR spectrum in both groups. In contrast, in nickel-allergic individuals or individuals with recent TT-booster, oligoclonality could be observed in the correspondingly stimulated cultures.
  
  
  CONCLUSIONS
  In addition to proliferation assay, analysis of T-cell clonality may be a further means to characterize clinical hypersensitivity reactions on the basis of antigen-dependent oligoclonal T-cell expansion, as in the case of tissue-infiltrating lymphocytes.
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität München, Frauenlobstr. 9-11, D-80337 Munich, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Summer
authors.forename: C A
authors.initials: CA
authors.lastname: Sander
authors.forename: B
authors.initials: B
authors.lastname: Przybilla
authors.forename: P
authors.initials: P
authors.lastname: Thomas
mesh_terms: D000328:Adult; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002999:Clone Cells / Q000473:pathology; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D006967:Hypersensitivity / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009532:Nickel / Q000276:immunology* / Q000494:pharmacology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D013601:T-Lymphocytes / Q000473:pathology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; C029938:nickel sulfate; D009532:Nickel