title: Epidermal Langerhans cell-targeted gene expression by a dectin-2 promoter.
abstract: Despite their critical function as APCs for primary immune responses, dendritic cells (DC) and Langerhans cells (LC) have been rarely used as targets of gene-based manipulation because well-defined regulatory elements controlling LC/DC-specific expression have not been identified. Previously, we identified dectin-2, a C-type lectin receptor expressed selectively by LC-like XS cell lines and by LC within mouse epidermis. Because these characteristics raised the possibility that dectin-2 promoter may direct LC/DC-specific gene expression, we isolated a 3.2-kb nucleotide fragment from the 5'-flanking region of the dectin-2 gene (Dec2FR) and characterized its regulatory elements and the transcriptional activity using a luciferase (Luc) reporter system. The Dec2FR contains a putative TATA box and cis-acting elements, such as the IFN-stimulated response element, that drive gene expression specifically in XS cells. Dec2FR comprises repressor, enhancer, and promoter regions, and the latter two regions coregulate XS cell-specific gene expression. In transgenic mice bearing a Dec2FR-regulated Luc gene, the skin was the predominant site of Luc activity and LC were the exclusive source of such activity within epidermis. By contrast, other APCs (DC, macrophages, and B cells) and T cells expressed Luc activity close to background levels. We conclude that epidermal LC are targeted selectively for high-level constitutive gene expression by Dec2FR in vitro and in vivo. Our findings lay the foundation for use of the dectin-2 promoter in LC-targeted gene expression systems that may enhance vaccination efficacy and regulate immune responses.
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center and Dallas Veterans Affairs Medical Center, Dallas, TX 75390, USA.
authors.forename: M
authors.initials: M
authors.lastname: Bonkobara
authors.forename: P K
authors.initials: PK
authors.lastname: Zukas
authors.forename: S
authors.initials: S
authors.lastname: Shikano
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: P D
authors.initials: PD
authors.lastname: Cruz
authors.forename: K
authors.initials: K
authors.lastname: Ariizumi
mesh_terms: D024506:5' Flanking Region; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism; D000078404:Epidermal Cells; D018390:Gene Targeting / Q000379:methods*; D007801:Langerhans Cells / Q000276:immunology*; D037102:Lectins / Q000235:genetics*; D037181:Lectins, C-Type; D007962:Leukocytes / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D037102:Lectins; D037181:Lectins, C-Type; C445340:dectin-2, mouse; D008156:Luciferases