title: T lymphocyte dynamics in methylisothiazolinone-allergic patients.
abstract: BACKGROUND
  Methylisothiazolinone (MI), a preservative that is commonly used in personal care products, is now recognized as an important contact allergen in both cosmetic and occupational settings.
  
  
  OBJECTIVE
  To analyse T lymphocyte responses to MI, in order to provide important information regarding the relationship between the nature of such responses and skin sensitization potency.
  
  
  METHODS
  Proliferative responses to free MI and to an MI-human serum albumin (HSA) conjugate were measured according to [(3) H]thymidine incorporation (n = 56 donors; patch test scores of + in 20, ++ in 29, and +++ in 7). Peripheral blood mononuclear cells were cultured in the presence of MI (0.001-1 µg/ml) or MI-HSA (0.001-100 µg/ml). Proliferating CD4(+) and CD8(+) T lymphocytes were identified by flow cytometry with the intracellular marker Ki-67.
  
  
  RESULTS
  For free MI, modest positive responses were recorded for 7 of 31 donors. In contrast, MI-HSA stimulated more marked responses in 17 of 31 donors. Characterization of positive proliferative responses showed variable patterns of proliferating CD4(+) and CD8(+) T lymphocytes from donors with the same patch test scores and similar maximal values.
  
  
  CONCLUSIONS
  MI-HSA is able to induce secondary responses in lymphocytes drawn from sensitized subjects, and provides a more effective source of antigen than free MI. Furthermore, individual donors show differential activity profiles with respect to T lymphocyte subsets.
authors.affiliation: Faculty of Life Sciences, University of Manchester, M13 9PT, Manchester, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Popple
authors.affiliation: Contact Dermatitis Investigation Unit, Salford Royal NHS Foundation Trust, Salford M6 8HD, Salford, UK.
authors.forename: Jason
authors.initials: J
authors.lastname: Williams
authors.affiliation: Unilever Safety and Environmental Assurance Centre, Sharnbrook, Bedford MK44 1LQ, Sharnbrook, UK.
authors.forename: Gavin
authors.initials: G
authors.lastname: Maxwell
authors.affiliation: Unilever Safety and Environmental Assurance Centre, Sharnbrook, Bedford MK44 1LQ, Sharnbrook, UK.
authors.forename: Nichola
authors.initials: N
authors.lastname: Gellatly
authors.affiliation: Faculty of Life Sciences, University of Manchester, M13 9PT, Manchester, UK.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Dearman
authors.affiliation: Faculty of Life Sciences, University of Manchester, M13 9PT, Manchester, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Kimber
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D016022:Case-Control Studies; D049109:Cell Proliferation; D017449:Dermatitis, Allergic Contact / Q000209:etiology / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D019394:Ki-67 Antigen; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013844:Thiazoles / Q000009:adverse effects / Q000494:pharmacology*; D013936:Thymidine; D014316:Tritium
chemical_list: D019394:Ki-67 Antigen; D011310:Preservatives, Pharmaceutical; D013844:Thiazoles; D014316:Tritium; C011506:2-methyl-4-isothiazolin-3-one; D013936:Thymidine
keywords: CAS no. 2682-20-4; T lymphocytes; allergic contact dermatitis; methylisothiazolinone; patch testing and skin sensitization