title: A critical role for dermal mast cells in cis-urocanic acid-induced systemic suppression of contact hypersensitivity responses in mice.
abstract: Many studies have implicated cis-urocanic acid (cis-UCA) in UVB-induced immunomodulation. The strongest evidence came from studies in mice whereby a cis-UCA antibody blocked UVB-induced suppression of delayed-type hypersensitivity responses. Furthermore, in several studies, the cis-UCA antibody at least partially reversed UVB suppression of contact hypersensitivity responses. Previous reports suggested that cis-UCA was immunomodulatory through its effects on keratinocytes, Langerhans cells, fibroblasts, T lymphocytes, natural killer cells and monocytes/macrophages. As dermal mast cells were recently demonstrated to be critical to UVB-induced systemic suppression of certain delayed-type and contact hypersensitivity responses, we investigated whether they were involved in the processes by which cis-UCA was immunomodulatory. Not only was there a correlation between dermal mast cell prevalence and the degree of susceptibility of different strains of mice to the immunomodulatory effects of cis-UCA, there was also a functional link. Mast cell-depleted Wf/Wf mice were rendered susceptible to immunomodulation by cis-UCA injected subcutaneously only after their dorsal skin had been reconstituted with bone marrow-derived mast cell precursors. These studies suggest that mast cells are critical to the processes by which cis-UCA suppresses systemic contact hypersensitivity responses to the hapten, trinitrochlorobenzene, in mice.
authors.affiliation: Department of Microbiology & Infectious Diseases, School of Medicine, Flinders University, Adelaide, Australia. prue.hart@flinders.edu.au
authors.forename: P H
authors.initials: PH
authors.lastname: Hart
authors.forename: M A
authors.initials: MA
authors.lastname: Grimbaldeston
authors.forename: G J
authors.initials: GJ
authors.lastname: Swift
authors.forename: E K
authors.initials: EK
authors.lastname: Hosszu
authors.forename: J J
authors.initials: JJ
authors.lastname: Finlay-Jones
mesh_terms: D000818:Animals; D003877:Dermatitis, Contact / Q000276:immunology / Q000517:prevention & control; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D014560:Urocanic Acid / Q000494:pharmacology*
chemical_list: D007166:Immunosuppressive Agents; D014560:Urocanic Acid