title: Antigen presentation by keratinocytes directs autoimmune skin disease.
abstract: The antigen-presenting cells that initiate and maintain MHC class II-associated organ-specific autoimmune diseases are poorly defined. We now describe a new T cell antigen receptor (TCR) transgenic (Tg) model of inflammatory skin disease in which keratinocytes activate and are the primary target of autoreactive CD4(+) T cells. We previously generated keratin 14 (K14)-A(beta)b mice expressing MHC class II only on thymic cortical epithelium. CD4(+) T cells from K14-A(beta)b mice fail to undergo negative selection and thus have significant autoreactivity. The TCR genes from an autoreactive K14-A(beta)b CD4 hybridoma were cloned to produce a TCR Tg mouse, 2-2-3. 2-2-3 TCR Tg cells are negatively selected in WT C57BL6 mice but not in 2-2-3K14-A(beta)b mice. Interestingly, a significant number of mice that express both the K14-A(beta)b transgene and the autoreactive 2-2-3 TCR spontaneously develop inflammatory skin disease with mononuclear infiltrates, induction of MHC class II expression on keratinocytes, and T helper 1 cytokines. Disease can be induced by skin inflammation but not solely by activation of T cells. Thus, cutaneous immunopathology can be directed through antigen presentation by tissue-resident keratinocytes to autoreactive TCR Tg CD4(+) cells.
authors.affiliation: The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Lian
authors.initials: L
authors.lastname: Fan
authors.forename: Brian W
authors.initials: BW
authors.lastname: Busser
authors.forename: Traci Q
authors.initials: TQ
authors.lastname: Lifsted
authors.forename: Mohamed
authors.initials: M
authors.lastname: Oukka
authors.forename: David
authors.initials: D
authors.lastname: Lo
authors.forename: Terri M
authors.initials: TM
authors.lastname: Laufer
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D002454:Cell Differentiation; D003872:Dermatitis / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D019672:Genes, T-Cell Receptor; D006825:Hybridomas / Q000276:immunology; D015603:Keratinocytes / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology