1. An Alternative Pathway of Imiquimod-Induced Psoriasis-Like Skin Inflammation in the Absence of Interleukin-17 Receptor A Signaling 
Khalifa El Malki, Susanne H. Karbach, Jula Huppert, Morad Zayoud, Sonja Reißig, Rebecca Schüler, Alexej Nikolaev, Khalad Karram, Thomas Münzel, Christoph R.W. Kuhlmann, Heiko J. Luhmann, Esther von Stebut, Simone Wörtge, Florian C. Kurschus, Ari Waisman 
Journal of Investigative Dermatology 
Volume 133, Issue 2, Pages (February 2013)
DOI: /jid
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2. Figure 1
IL-17RAdel mice show a milder form of imiquimod (IMQ)-induced psoriasis in comparison with control mice. (a) Construction of the IL-17RAdel mouse strain: exons 4–7 of the mouse IL-17RA gene are flanked by LoxP sites, indicated by blue triangles (IL-17RAFl). After crossing this mouse strain with a Deleter Cre mouse, exons 4–7 (red boxes) are deleted. Exons are indicated as boxes. The small oval indicates the Flippase Recognition Target site, which flanked the neomycin resistance cassette during the generation process of this mouse line and is removed in the IL-17RAFl and the IL-17RAdel mice. (b) IL-17RAdel mice express no wild-type (WT) IL-17RA messenger RNA (mRNA) in reverse transcriptase (RT)–PCR: IL-17RAFl mice show normal levels of IL-17RA mRNA (lanes 1 and 2) compared with WT (lane 4). In contrast, IL-17RAdel mice (lane 3) do not express IL-17RA mRNA. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as internal control. (c) Phenotypical presentation of mouse back skin of 8-week-old WT and IL-17RAdel mice that were treated with IMQ on the shaved and depilated back skin and on the right ear over 7 days. The photo was taken on day 4. Mouse one was the internal sham-treated control in each group, which shows no disease development. (d) Daily scoring of scaling, skin thickness, and erythema of IL-17RAdel and control mice under IMQ treatment over 8 days. The cumulative psoriasis area and severity index (PASI) includes scaling, skin thickness, and erythema of IMQ-treated animals. Scale from 0 to 4. Shown is the mean±standard deviation (SD; n=4 per experiment, representing three independent experiments with comparable results; the statistical analysis of significance is described in the methods section). (e) Microscopical quantification of epidermal hyperplasia after 5 days of treatment (n=3, blinded measurements were performed at three different regions and do not include the stratum corneum to avoid measurement falsification due to fixation artifacts). (f) Ears of WT and IL-17RAdel mice were injected intradermally for 8 days with 20μl phosphate-buffered saline (PBS), alone or containing 500ng IL-23. Ear thickness was measured daily and shows percentagewise increase of the starting values (n=3, significance is shown in comparison with the PBS-treated WT control).
Journal of Investigative Dermatology  , DOI: ( /jid )
Copyright © 2013 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Invasion of neutrophilic granulocytes and macrophages to the skin of imiquimod (IMQ)-treated mice. IL-17RAdel and control mice in comparison with sham-treated controls after 8 days of treatment. (a) Flow cytometric analysis of the ear skin using the indicated antibodies. Right: CD11b+ gated cells showing GR1+ granulocytes and F4/80+ monocytes/macrophages. Panels are representative for three independent experiments including 3–4 mice each with comparable results. (b) CD11b+ cells invading the ears of IMQ- and sham-treated wild-type (WT) and IL-17RAdel mice shown as percentage of acquired cells of the live gate (analyzed with one-way analysis of variance (ANOVA)). (c) Total number of CD11b+ cells and GR1+ granulocytes in the ears of IMQ- and sham-treated WT and IL-17RAdel mice (analyzed with one-way ANOVA). (d, e) Immunofluorescence of back skin crysosections of IL-17RAdel and control mice after 9 days of sham or IMQ treatment: (d) Red=myeloperoxidase (MPO), blue=4′,6-diamidino-2-phenylindole (DAPI). (e) Red=F4/80, blue=DAPI. Different magnifications are presented. Bar=100μm; in highest original magnification bar=50μm.
Journal of Investigative Dermatology  , DOI: ( /jid )
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4. Figure 3
Invasion of Th17– and IL-17A–producing γδT cells in the back skin upon imiquimod (IMQ) treatment of IL-17RAdel and control mice in comparison with the sham-treated controls after day 7. (a) Flow cytometric analysis of cells isolated from the skin and stained with the indicated antibodies. Cells were pregated on B220−, CD3+, and on CD4+ cells (for Th17) or on γδ-TCRlo for dermal γδ T cells. Panels are representative for three independent experiments each including 3–4 mice with comparable results. (b) Percentages of CD4+ and γδ-TCRlo cells invading the skin of IMQ-treated WT and IL-17RAdel mice (left) and percentage of IL-17A+ CD4+ T cells (Th17) and IL-17A–producing γδT cells invading the skin of the indicated groups (right). (c) Total number of CD4+ and γδ-TCRlo cells invading the skin of IMQ-treated WT- and IL-17RAdel mice (left) and Th17– and IL-17A–producing dermal γδ T cells (right). (d) Immunofluorescence of skin crysosections of IL-17RAdel and control mice with sham and IMQtreatment: red=CD4, green=IL-17A, blue=4′,6-diamidino-2-phenylindole (DAPI). Bar=100μm.
Journal of Investigative Dermatology  , DOI: ( /jid )
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5. Figure 4
Expression of cytokines in the back skin of imiquimod (IMQ)-treated IL-17RAdel control mice after 7 days of treatment. Quantitative real-time reverse transcriptase (RT)–PCR analysis of the indicated genes in the skin of IMQ-treated IL-17RAdel mice in comparison with IMQ-treated control mice. Expression level shown relative to the housekeeping gene HPRT (n=4 from two independent experiments with comparable results).
Journal of Investigative Dermatology  , DOI: ( /jid )
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6. Figure 5
Elevated IL-6 production of T cells in the skin of imiquimod (IMQ)-treated IL-17RAdel and wild-type (WT) mice. (a) Flow cytometric analysis of IL-6–producing dermal γδ-TCRlo and epidermal γδ-TCRhi cells in the skin of IMQ- or sham-treated IL-17RAdel and WT mice. (b) IL-6–producing T cells. All cells are pregated on CD11b− and CD3+.
Journal of Investigative Dermatology  , DOI: ( /jid )
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7. Figure 6
IL-22 production of T cells in the ear skin of imiquimod (IMQ)-treated IL-17RAdel and wild-type (WT) mice. (a) CD3+ T cells in the skin: cells were pregated on CD3+, CD11b−, and CD19−. (b, c) Flow cytometric analysis of IL-22–producing dermal γδ-TCRlo and CD4+ T cells in the skin of IMQ- or sham-treated IL-17RAdel and WT mice. (d) Statistical analysis of IL-22–producing γδ-TCRlo and CD4+ T cells shown as percentage of total cells. Bars represent n=3 per group; Student's t-test was used for statistical analysis.
Journal of Investigative Dermatology  , DOI: ( /jid )
Copyright © 2013 The Society for Investigative Dermatology, Inc Terms and Conditions