title: Cytokine induction in human epidermal keratinocytes exposed to contact irritants and its relation to chemical-induced inflammation in mouse skin.
abstract: In response to exogenous stimuli such as phorbol-12-myristate 13-acetate, ultraviolet B radiation, and lipopolysaccharide, human keratinocytes produce soluble mediators that are important in primary contact irritancy including cytokines that are associated with proinflammatory properties (interleukin-1 alpha [IL-1 alpha], tumor necrosis factor alpha), chemotaxis (IL-8), and growth activation (granulocyte/macrophage colony stimulating factor, IL-6, transforming growth factor alpha). We examined qualitative and quantitative changes in selected intracellular and secreted cytokines in human keratinocyte cultures in response to non-sensitizing contact irritants (croton oil, sodium lauryl sulfate, methyl salicylate, ethyl phenylpropiolate), sensitizing irritants (oxazolone, dinitrofluorobenzene), and ulcerative agents (phenol, benzalkonium chloride, chromium trioxide). The chemicals were also applied to mouse skin to assess whether the chemical-specific pattern of inflammation correlated with the in vitro production of keratinocyte-derived cytokines. Although all agents elicited neutrophils to the site of chemical application, time dependent and chemical-specific patterns of inflammation could be detected. Sodium lauryl sulfate, phenol, and croton oil induced increases in IL-8 production at non-cytotoxic concentrations in semi-confluent human keratinocyte cultures. Phenol and croton oil stimulated tumor necrosis factor alpha production, whereas croton oil was the only agent found to induce granulocyte/macrophage colony-stimulating factor production. Croton oil, phenol, benzalkonium chloride, and dinitrofluorobenzene induced the intracellular production of IL-1 alpha without a concomitant release into the medium. The release of cytokines occurred in parallel with a relative increase in cytokine-specific mRNA transcripts. Studies using neutralizing antibodies to tumor necrosis factor alpha and IL-1 alpha demonstrated that IL-8 induction by croton oil and phenol occurred directly rather than through autocrine circuits. These data suggest that a given pattern of cytokine production is chemical-specific and may predict the contribution of keratinocytes to skin inflammation.
authors.affiliation: Environmental Immunology and Neurobiology Section, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
authors.forename: J L
authors.initials: JL
authors.lastname: Wilmer
authors.forename: F G
authors.initials: FG
authors.lastname: Burleson
authors.forename: F
authors.initials: F
authors.lastname: Kayama
authors.forename: J
authors.initials: J
authors.lastname: Kanno
authors.forename: M I
authors.initials: MI
authors.lastname: Luster
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003436:Croton Oil / Q000009:adverse effects*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D003877:Dermatitis, Contact / Q000209:etiology* / Q000378:metabolism / Q000473:pathology*; D005260:Female; D015870:Gene Expression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis / Q000235:genetics / Q000502:physiology; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis / Q000235:genetics / Q000502:physiology; D016209:Interleukin-8 / Q000032:analysis / Q000235:genetics / Q000502:physiology; D015603:Keratinocytes / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010081:Oxazolone / Q000009:adverse effects*; D010636:Phenols / Q000009:adverse effects*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012867:Skin / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000235:genetics / Q000502:physiology
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D016209:Interleukin-8; D010636:Phenols; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D010081:Oxazolone; D003436:Croton Oil; D016178:Granulocyte-Macrophage Colony-Stimulating Factor