title: Modulation of Ia+ Langerhans cell numbers in vivo by cultured epidermis derived supernatants and by GM-CSF.
abstract: This paper demonstrates that epidermal cells in culture produce an activity which can increase the frequency of Ia+ epidermal Langerhans cells (LC). This was achieved by treating mice topically with a mixture containing supernatant derived from primary culture of murine epidermis (ES) and a synthetic corticosteroid, triamcinolone acetonide (TAC). The presence of the supernatant in the mixture partially protected the Ia+ LC from depletion by the steroid. The Ia+ LC frequency increasing activity was measured as the difference between the Ia+ LC frequency due to treatment with steroid mixed with supernatant and the Ia+ LC frequency due to treatment with steroid mixed with negative control medium. The mean frequency of Ia+ LC in epidermis treated with TAC mixed with ES was 606(SD 43) cells/mm2, as compared with 486 (SD 68) cells/mm2 in the epidermis treated with TAC mixed with control medium. The activity appeared to be caused by (a) proteinaceous factor(s). A fraction of ES which was retained above a > or = 10 KDa molecular weight cut-off membrane was capable of partially protecting Ia+ LC frequency from TAC depletion. Supernatants from cultured lymph nodes, dermis as well as the squamous cell carcinoma lines T7 and T79, but not the human osteosarcoma cell-line 143B, also contained similar activities. We demonstrate that GM-CSF also increased the number of Ia+ epidermal LC when applied topically to mouse skin in this system. Therefore, using this Ia+ LC frequency modulation system, we propose that GM-CSF is one example of a cytokine which may be involved in the regulation of Ia+ LC numbers in epidermis and that epidermal cells produce factors which can increase the number of Ia+ LC.
authors.affiliation: Department of Dermatology, University of Sydney, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
authors.forename: G M
authors.initials: GM
authors.lastname: O'Sullivan
authors.forename: R
authors.initials: R
authors.lastname: Sluyter
authors.forename: C M
authors.initials: CM
authors.lastname: Boswell
authors.forename: R S
authors.initials: RS
authors.lastname: Barnetson
authors.forename: G M
authors.initials: GM
authors.lastname: Halliday
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D002452:Cell Count / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D000949:Histocompatibility Antigens Class II; D007801:Langerhans Cells / Q000187:drug effects*; D008198:Lymph Nodes / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology; D011994:Recombinant Proteins / Q000494:pharmacology; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology; D014222:Triamcinolone Acetonide / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D017077:Culture Media, Conditioned; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D014222:Triamcinolone Acetonide