title: Immunomodulatory effects of mono-, di-, and trimethylphenols in mice.
abstract: The relationship of air pollutants with the increasing prevalence of allergic diseases is a matter of concern in developed countries. In this study, the immunomodulatory effects of mono-, di-, and trimethylphenols in mice were examined as regards two aspects. First, whether or not these chemicals act as sensitizers was evaluated by local lymph node assay. Of the 13 methylphenols tested, three dimethylphenol isomers (2,4-DMP, 2,5-DMP, and 3,4-DMP) were found to induce auricular lymphocyte proliferation after dermal application on both ears of mice. Cytokine production patterns in the supernatants of cultured auricular lymphocytes from mice showed these methylphenols to be contact sensitizers. Second, the effects of methylphenols on cytokine production profiles were examined using cultured splenocytes from immunologically naive mice. Under subtoxic conditions, eight methylphenols inhibited interferon-gamma (IFN-gamma) production significantly, while the effect on intreluekin-4 (IL-4) production was moderate, resulting in higher IL-4/IFN-gamma ratios in all of the tested chemicals, with the most prominent effect shown by 2,6-DMP. These results suggest that several methylphenols, especially dimethylphenol isomers, have potencies that affect the immune system, being immunogens themselves or modulators of the Th1/Th2 cytokine balance.
authors.affiliation: Osaka City Institute of Public Health and Environmental Sciences, Osaka, Japan. tetsuo.yamano@iphes.city.osaka.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yamano
authors.forename: Masako
authors.initials: M
authors.lastname: Ichihara
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shimizu
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Noda
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D048708:Cell Growth Processes / Q000187:drug effects; D007155:Immunologic Factors / Q000276:immunology / Q000494:pharmacology*; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D023441:Local Lymph Node Assay; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010636:Phenols / Q000276:immunology / Q000494:pharmacology*; D013154:Spleen / Q000187:drug effects* / Q000276:immunology*; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology; D014992:Xylenes / Q000276:immunology / Q000494:pharmacology*
chemical_list: D007155:Immunologic Factors; D010636:Phenols; D014992:Xylenes; D015847:Interleukin-4; D007371:Interferon-gamma