Research ArticleImmunology

p38α signaling in Langerhans cells promotes the development of IL-17–producing T cells and psoriasiform skin inflammation

See allHide authors and affiliations

Science Signaling  13 Mar 2018:
Vol. 11, Issue 521, eaao1685
DOI: 10.1126/scisignal.aao1685
  • Fig. 1 Deletion of p38α in DCs reduces IMQ-induced skin inflammation in mice.

    (A) Wild-type (WT) mice were topically treated with imiquimod (IMQ)–containing or control cream for two consecutive days, and the phosphorylation (p) of p38 in skin CD45+ cells was analyzed by flow cytometry (n = 6 mice per group). MFI, mean fluorescence intensity. (B and C) Tamoxifen-pretreated WT and p38αCreER mice were topically treated with IMQ for six consecutive days. Change in ear thickness (left) and disease severity score (right) were recorded (B) (n = 5 mice per group). Histopathological changes in skin tissue of WT (left) and p38αCreER (middle) mice were examined by hematoxylin and eosin (H&E) staining (n = 3 mice per group), and the marked area was magnified (right) (C). Scale bars, 200 μm. (D) p-p38 in skin dendritic cells (DCs) was analyzed by flow cytometry in WT mice topically treated with control or IMQ-containing cream for two consecutive days (n = 6 mice per group). (E to J) WT and p38αΔDC mice were treated with IMQ for six consecutive days. Change in ear thickness (left) and disease severity score (right) (E) (n = 5 mice per group), representative images of H&E staining of skin sections (n = 3 mice per group) (F), the percentages (G) and cell numbers (H) of neutrophils and macrophages in the epidermis (n = 4 mice per group), and the percentages (I) and cell numbers (J) of neutrophils and macrophages in the dermis (n = 4 mice per group). Scale bars, 200 μm. Two-sided Student’s t tests [right panels of (A), (B), (D), and (E); (G) to (J)] and two-way analysis of variance (ANOVA) [left panels of (B) and (E)] were performed, and data are means ± SEM. Data are representative of three (A to D) or four (E to J) independent experiments.

  • Fig. 2 p38α activity in DCs is required for the generation of IL-17–producing T cell in vivo.

    WT and p38αΔDC mice were topically treated with IMQ for six consecutive days. (A) Relative mRNA expression of inflammation-related genes in skin tissue was examined (n = 5 mice per group). ns, not significant. (B and C) The percentages (B) and cell numbers (C) of interleukin-17–positive (IL-17+) γδ T cells in the epidermis and dermis (n = 6 mice per group). γδTCR, γδ T cell receptor. (D and E) The percentages (D) and cell numbers (E) of IL-17+ CD4+ T cells in the epidermis and dermis (n = 6 mice per group). Two-sided Student’s t tests were performed, and data are means ± SEM. Data are representative of three independent experiments.

  • Fig. 3 p38α signaling in LCs is important for the development of IMQ-induced skin inflammation.

    Bone marrow (BM) cells of WT or p38αΔDC mice were transplanted into x-ray–irradiated WT or p38αΔDC mice, respectively, to make the WT→WT, WT→p38αΔDC, p38αΔDC→WT, and p38αΔDC→p38αΔDC chimeras. The chimeras were topically treated with IMQ for six consecutive days. (A) Change in ear thickness (n = 6 mice per group). (B) Representative images of H&E staining of skin section (n = 3 mice per group). Scale bars, 200 μm. (C) The percentages of neutrophils in the epidermis and dermis (n = 6 mice per group). (D) The percentages of IL-17+ γδ T cells and IL-17+ CD4+ T cells in the draining lymph nodes (DLNs) (n = 6 mice per group). (E) The relative expression of inflammation-related genes in skin tissue (n = 6 mice per group). Two-way ANOVA with Bonferroni post tests (A) and one-way ANOVA with Bonferroni post tests (C to E) were performed, and data are means ± SEM. Data are representative of two independent experiments.

  • Fig. 4 Signaling by p38α in LCs controls IL-17–producing T cell generation and skin inflammation by regulating the expression of IL-6 and IL-23.

    (A) IL-17 production in the supernatant of γδ T cells cocultured with R848-stimulated WT and p38αΔDC Langerhans cells (LCs) for 48 hours (n = 3 biological replicates). (B) The differentiation of TH17 cells in CD4+ T cells activated with R848-pulsed WT and p38αΔDC LCs for 5 days (n = 3 biological replicates). (C and D) Cytokine expression from WT and p38αΔDC LCs stimulated with R848 for 5 (C) and 24 hours (D) (n = 3 biological replicates). (E) IL-17 production from γδ T cells cocultured with WT and p38αΔDC LCs in the presence or absence of IL-23, IL-1β, or IL-6 (n = 3 biological replicates). (F) Relative mRNA expression of Il17 in CD4+ T cells cocultured with WT and p38αΔDC LCs in the presence or absence of IL-23, IL-1β, or IL-6 (n = 3 biological replicates). (G) Change in ear thickness of IMQ-treated WT and p38αΔDC mice subcutaneously injected with IL-23 or control phosphate-buffered saline (PBS) (n = 5 to 6 mice per group). (H) Change in ear thickness of IMQ-treated WT and p38αΔDC mice subcutaneously injected with IL-6 or control PBS (n = 5 to 8 mice per group). (I and J) Inflammation-related gene expression of IMQ-treated WT and p38αΔDC mice subcutaneously injected with IL-23 (I) or IL-6 (J) (n = 5 mice per group). Two-sided Student’s t tests (A to D and I and J) and two-way ANOVA with Bonferroni post tests (E to H) were performed, and data are means ± SEM. Data are representative of five (A and B), three (C and D and G to J), or four (E and F) independent experiments. Cells used in (A) to (F) were isolated from four to six mice per group.

  • Fig. 5 p38α MAPK in T cells is dispensable for the induction of psoriasiform inflammation.

    WT and p38αΔT mice were topically treated with IMQ cream for six consecutive days. (A) Change in ear thickness (left) and disease severity score (right) (n = 5 to 6 mice per group). (B) Representative images of H&E staining in skin section (n = 3 mice per group). Scale bars, 200 μm. (C and D) The percentages (C) and cell numbers (D) of neutrophils and macrophages in the epidermis (n = 5 to 6 mice per group). (E and F) The percentages (E) and cell numbers (F) of neutrophils and macrophages in the dermis (n = 5 to 6 mice per group). Two-way ANOVA [left panel of (A)] and two-sided Student’s t tests [right panel of (A); (C) to (F)] were performed, and data are means ± SEM. Data are representative of three independent experiments.

  • Fig. 6 Inhibition of p38 activity reduces disease severity in mice with established skin inflammation.

    WT mice were topically treated with IMQ for six consecutive days and received either the p38 inhibitor SB203580 or control vehicle daily by intraperitoneal injection from day 3. (A) Change in ear thickness (left) and disease severity score (right) (n = 6 mice per group). (B) Representative images of H&E staining in skin section (n = 3 mice per group). Scale bars, 200 μm. (C and D) The percentages (C) and cell numbers (D) of neutrophils and macrophages in the epidermis (n = 6 mice per group). (E and F) The percentages (E) and cell numbers (F) of neutrophils and macrophages in the dermis (n = 6 mice per group). (G) Relative expression of inflammation-related genes in skin tissue (n = 6 mice per group). Two-way ANOVA [left panel of (A)] and two-sided Student’s t tests [right panel of (A); (C) to (G)] were performed, and data are means ± SEM. Data are representative of three independent experiments.

Supplementary Materials

  • www.sciencesignaling.org/cgi/content/full/11/521/eaao1685/DC1

    Fig. S1. p38α deletion in mouse skin tissue and DCs.

    Fig. S2. Normal DC development and activation status in the epidermis and dermis of p38αΔDC mice.

    Fig. S3. Cell infiltration analysis in the skin and spleen of WT and p38αΔDC mice upon IMQ treatment.

    Fig. S4. Gene expression in KCs and cytokine production in skin tissue of WT and p38αΔDC mice upon IMQ treatment.

    Fig. S5. Decreased IL-17 production from γδ and CD4+ T cells in the skin and DLNs of p38αΔDC mice.

    Fig. S6. The proliferation and apoptosis of T cells in IMQ-treated WT and p38αΔDC mice.

    Fig. S7. p38α activity in LCs is important for psoriasiform skin inflammation.

    Fig. S8. LC p38α-mediated TH17 cell differentiation and IL-23, IL-1β, and IL-6 expression.

    Fig. S9. The effect of p38α signaling in DCs on skin inflammation is IL-1β–independent.

    Fig. S10. p38α in dDCs affects IL-17 production from CD4+ T cells but not γδ T cells.

    Fig. S11. p38α activity in T cells does not contribute to the IMQ-induced psoriasiform skin inflammation.

    Fig. S12. Decreased IL-17 production from γδ and CD4+ T cells in the DLNs upon SB203580 treatment.

    Fig. S13. Acute deletion of p38α reduces the severity of an ongoing psoriasiform skin inflammation.

  • Supplementary Materials for:

    p38α signaling in Langerhans cells promotes the development of IL-17–producing T cells and psoriasiform skin inflammation

    Tingting Zheng, Weiheng Zhao, Hongjin Li, Shuxiu Xiao, Ran Hu, Miaomiao Han, Heng Liu, Yeqiang Liu, Kinya Otsu, Xinguang Liu, Gonghua Huang*

    *Corresponding author. Email: gonghua.huang{at}shsmu.edu.cn

    This PDF file includes:

    • Fig. S1. p38α deletion in mouse skin tissue and DCs.
    • Fig. S2. Normal DC development and activation status in the epidermis and dermis of p38αΔDC mice.
    • Fig. S3. Cell infiltration analysis in the skin and spleen of WT and p38αΔDC mice upon IMQ treatment.
    • Fig. S4. Gene expression in KCs and cytokine production in skin tissue of WT and p38αΔDC mice upon IMQ treatment.
    • Fig. S5. Decreased IL-17 production from γδ and CD4+ T cells in the skin and DLNs of p38αΔDC mice.
    • Fig. S6. The proliferation and apoptosis of T cells in IMQ-treated WT and p38αΔDC mice.
    • Fig. S7. p38α activity in LCs is important for psoriasiform skin inflammation.
    • Fig. S8. LC p38α-mediated TH17 cell differentiation and IL-23, IL-1β, and IL-6 expression.
    • Fig. S9. The effect of p38α signaling in DCs on skin inflammation is IL-1β–independent.
    • Fig. S10. p38α in dDCs affects IL-17 production from CD4+ T cells but not γδ T cells.
    • Fig. S11. p38α activity in T cells does not contribute to the IMQ-induced psoriasiform skin inflammation.
    • Fig. S12. Decreased IL-17 production from γδ and CD4+ T cells in the DLNs upon SB203580 treatment.
    • Fig. S13. Acute deletion of p38α reduces the severity of an ongoing psoriasiform skin inflammation.

    [Download PDF]


    © 2018 American Association for the Advancement of Science

Stay Connected to Science Signaling

Navigate This Article