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Interleukin-19: a constituent of the regulome that controls antigen presenting cells in the lungs and airway responses to microbial products - PubMed

Interleukin-19: a constituent of the regulome that controls antigen presenting cells in the lungs and airway responses to microbial products

Carol Hoffman et al. PLoS One. 2011.

Abstract

Background: Interleukin (IL)-19 has been reported to enhance chronic inflammatory diseases such as asthma but the in vivo mechanism is incompletely understood. Because IL-19 is produced by and regulates cells of the monocyte lineage, our studies focused on in vivo responses of CD11c positive (CD11c+) alveolar macrophages and lung dendritic cells.

Methodology/principal findings: IL-19-deficient (IL-19-/-) mice were studied at baseline (naïve) and following intranasal challenge with microbial products, or recombinant cytokines. Naïve IL-19-/- mixed background mice had a decreased percentage of CD11c+ cells in the bronchoalveolar-lavage (BAL) due to the deficiency in IL-19 and a trait inherited from the 129-mouse strain. BAL CD11c+ cells from fully backcrossed IL-19-/- BALB/c or C57BL/6 mice expressed significantly less Major Histocompatibility Complex class II (MHCII) in response to intranasal administration of lipopolysaccharide, Aspergillus antigen, or IL-13, a pro-allergic cytokine. Neurogenic-locus-notch-homolog-protein-2 (Notch2) expression by lung monocytes, the precursors of BAL CD11c+ cells, was dysregulated: extracellular Notch2 was significantly decreased, transmembrane/intracellular Notch2 was significantly increased in IL-19-/- mice relative to wild type. Instillation of recombinant IL-19 increased extracellular Notch2 expression and dendritic cells cultured from bone marrow cells in the presence of IL-19 showed upregulated extracellular Notch2. The CD205 positive subset among the CD11c+ cells was 3-5-fold decreased in the airways and lungs of naïve IL-19-/- mice relative to wild type. Airway inflammation and histological changes in the lungs were ameliorated in IL-19-/- mice challenged with Aspergillus antigen that induces T lymphocyte-dependent allergic inflammation but not in IL-19-/- mice challenged with lipopolysaccharide or IL-13.

Conclusions/significance: Because MHCII is the molecular platform that displays peptides to T lymphocytes and Notch2 determines cell fate decisions, our studies suggest that endogenous IL-19 is a constituent of the regulome that controls both processes in vivo.

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Conflict of interest statement

Competing Interests: The authors have the following competing interests: RdWM is employed by Merck Research Laboratories, Palo Alto, formerly Schering Plough Biopharma, formerly DNAX Research Institute. CE and JL were employed by Schering Plough Biopharma while being members of RdWM's research group. In the future, patents and products might be developed. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials, as detailed online in the guide for authors. The other authors have no conflicting financial interests.

Figures

Figure 1
Figure 1. Decreased abundance of CD11c+ cells in the BAL of naïve IL-19-/- 129xBL6 mice.

(A) Bar graphs (white – wild-type, striped – IL-19-/-) show means and SEM of numbers of total cells and CD11c+ cells in the BAL. One representative independent experiment of 5 is shown (n = 4-5 per group per study), *p<0.05, Mann-Whitney-U test. (B) Dot plots show CD11c versus MHCII staining of BAL cells. The percentages of the gated CD11c+ cells are indicated. One representative of 20 independent experiments is shown. (C) Electron micrographs of marker negative cells in IL-19-/- mice. The marker negative cells were purified by cell sorting from a pool of BAL samples from groups of 20 to 25 mice of each genotype: wild type or IL-19-/-. Note that cells from the BAL of IL-19KO mice were eosinophils. Only debris was harvested from the BAL of wild type mice (not shown).

Figure 2
Figure 2. Strain-dependent decreased abundance of CD11c+ cells in the BAL of naive IL-19-/- 129xBL6 mice.

The abundance of CD11c+ cells in the BAL (%) from individual mice is shown for the following parental and offspring strains: (A) IL-19-/- 129xBL6 (blue diamonds); IL-19-/- C57BL/6 (yellow upright triangles); second generation, intercross F2 offspring from a cross between IL-19-/- 129xBL6 and IL-19-/- C57BL/6 parental lines (green circles); and for comparison, wild-type C57BL/6 (red squares). (B) Backcross N2 offspring originating from a cross between IL-19-/- 129xBL6 and wild-type C57BL/6 mice. The mice were genotyped and found to be wild type (il19 +/il19 + purple squares), heterozygous (il19 +/il19 - yellow downward triangles) or IL-19-/- (il19 -/il19 - blue diamonds). Data from individual mice are shown. Horizontal lines indicate means. Data were pooled from 4-6 experiments. Statistical analysis was with ANOVA followed by Dunnett multiple comparison test, * p<0.05 for comparison between N2-wild type and N2-IL-19 -/-.

Figure 3
Figure 3. Decreased expression of MHCII in antigen presenting cells from the lungs of IL-19-/- mice.

MHCII expression was determined by flow cytometry in CD11c+ cells from the BAL (A-C), in CD11bint cells from the lungs (D), or in B cells (CD19+, B220+) from the lungs (E). The gating strategy is shown in Figure S2. Cells were analyzed from primed animals that were challenged with Aspergillus antigen (A, Asp. Ag, shaded symbols) and from naïve animals that were challenged with LPS (B, at 1 or 5 µg/dose as indicated, shaded symbols) or IL-13 (C-E, shaded symbols). Control animals (open symbols) were given saline (PBS) intranasally or saline containing bovine serum albumin (BSA), the carrier protein used to stabilize IL-13. The experimental schedules are outlined in Figure S1. Wild type and IL-19-/- mice were of the BALB/c (A), or C57BL/6 (B-E) strains. Points represent data for mean fluorescence intensity measured in cells that were harvested from individual wild type (circles), or IL-19-/- (diamonds) mice pooled from 2 experiments each. Horizontal lines indicate medians. Significance levels were calculated with the Mann-Whitney-U test.

Figure 4
Figure 4. IL-19 regulates Notch2 expression in lung monocytes and bone marrow derived dendritic cells.

(A) The density plot of lung cells shows the electronic gate used to identify CD11bint/Ly6Cint lung monocytes. Extracellular (B) or transmembrane/intracellular (C) Notch2 expression (mean fluorescence intensity) by lung CD11bint/Ly6Cint monocytes is shown from groups of individual wild type (circles) and IL-19-/- (gray diamonds) mice. The data were pooled from two independent experiments. Horizontal lines indicate medians. (B) The mice were given intranasally control protein (bovine serum albumin, BSA) solution or IL-19 (Figure S1). (C) Naïve mice were analyzed. The two experiments had different baseline mean fluorescence intensity for Notch2 expression. Therefore, mean fluorescence intensities were plotted relative to the respective median value of wild type mice for each of the experiments and then the data were pooled. (D) Extracellular Notch2 expression by bone marrow derived CD205+ dendritic cells. Bone marrow cells were isolated from 8 individual IL-19-/- mice and cultured in the presence of granulocyte-macrophage colony stimulating factor (GM-CSF), with or without the addition of IL-19 at 1 or 10 ng/ml as indicated. CD205+ cells were electronically gated and Notch2 expression was determined by flow cytometry. The lines connect the data from each individual mouse. The data were pooled from two independent experiments. Statistical analysis was with the Friedman test for non-parametric repeated measures (overall p = 0.0009) and Wilcoxon matched-pairs signed rank test (* p<0.01).

Figure 5
Figure 5. IL-19 regulates the relative size of the CD205+ subset of CD11c+ cells in the airways and lungs of naïve mice.

(A-D) The dot plots show CD11c (y-axis) vs. CD205 (x-axis) staining of BAL (A, B), and lung (C, D) cells. Representative plots from naïve wild type (A, C, n = 21) and IL-19-/- (B, D, n = 16) C57BL/6 mice are shown. The percentage of cells that express CD11c and CD205 at high levels is indicated. (E, F) Group comparisons of naïve C57BL/6 wild type (circles) and IL-19-/- (gray diamonds) mice for percentages of CD11c+ CD205+ cells in the BAL (E) or in cell suspensions prepared from the lung parenchyma (F). Individual data points that were pooled from two experiments are shown. Horizontal lines indicate medians. Significance levels were calculated with the Mann-Whitney-U test. Note that the numbers of CD11c+ cells in the BAL and lungs of wild type and IL-19-/- mice were similar (Table S2).

Figure 6
Figure 6. IL-19-/- mice have a decreased inflammatory response to a T cell-dependent challenge of the airways.

(A) Groups of IL-19-/- (diamonds) and wild type (circles) mice were primed with Aspergillus antigen and challenged with antigen intranasally (Asp. Ag, shaded symbols). (B, C) Groups of naïve mice were given lipopolysaccharide (B, LPS, 1 or 5 µg/dose as indicated) or IL-13 (C) intranasally shown as shaded symbols. Control animals received saline (PBS) or control protein (bovine serum albumin, BSA) intranasally (A-C, open symbols). Figure S1 shows the experimental schedules; Figure S2 the technique for the determination of eosinophils, neutrophils, and CD11c+ cells in the BAL by flow cytometry. IL-19-/- and wild type mice were of the BALB/c (A), or C57BL/6 (B, C) background strains. Groups of mice were pooled from 2-3 independent experiments. Individual data are shown. Horizontal lines represent medians. Significance levels were calculated with the Mann Whitney U test.

Figure 7
Figure 7. Histological changes in the lungs of wild type and IL-19-/- mice primed and challenged with Aspergillus fumigatus antigen.

Wild type and IL-19-/- mice were of the BALB/c background strain. Priming and challenge with Aspergillus antigen was as indicated in Figure S1. Control animals were given saline (PBS) intranasally. (A) Photomicrographs of lung sections from wild type or IL-19-/- mice. The sections were stained with periodic acid schiff and digitally scanned. The software was used to generate the scale bar (50 µm). Perivascular/peribronchial inflammation (arrows), pulmonary arterial remodeling (stars) and mucus cell hyperplasia (arrow heads) are indicated. (B) Scores for perivascular/peribronchial inflammation, arterial remodeling and mucus cell hyperplasia in the lungs of wild-type (circles) or IL-19-/- (diamonds) mice. The gray boxes outline the values from the groups of control animals depicting the scores spanning the 25% and the 75% quartiles. Dots represent individual data from Aspergillus antigen primed and challenged mice. Horizontal lines show medians. Three independent experiments were performed during a time span of 6 years. Therefore, scores needed to be standardized. For this reason, scores were plotted relative to the respective median scores of primed and antigen-challenged wild-type mice for each experiment and then the data were pooled. Significance levels were calculated with the Mann-Whitney-U test.

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References

    1. Liao SC, Cheng YC, Wang YC, Wang CW, Yang SM, et al. IL-19 induced Th2 cytokines and was up-regulated in asthma patients. J Immunol. 2004;173:6712–6718. - PubMed
    1. Zhong H, Wu Y, Belardinelli L, Zeng D. A2B adenosine receptors induce IL-19 from bronchial epithelial cells, resulting in TNF-alpha increase. Am J Respir Cell Mol Biol. 2006;35:587–592. - PubMed
    1. Huang F, Wachi S, Thai P, Loukoianov A, Tan KH, et al. Potentiation of IL-19 expression in airway epithelia by IL-17A and IL-4/IL-13: important implications in asthma. J Allergy Clin Immunol. 2008;121:1415–1421, 1421, e1411-1413. - PMC - PubMed
    1. Gallagher G, Eskdale J, Jordan W, Peat J, Campbell J, et al. Human interleukin-19 and its receptor: a potential role in the induction of Th2 responses. Int Immunopharmacol. 2004;4:615–626. - PubMed
    1. Romer J, Hasselager E, Norby PL, Steiniche T, Thorn Clausen J, et al. Epidermal overexpression of interleukin-19 and -20 mRNA in psoriatic skin disappears after short-term treatment with cyclosporine a or calcipotriol. J Invest Dermatol. 2003;121:1306–1311. - PubMed

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