Epithelial SLPI expression in severe inflammatory bowel disease relates to high IL-17 and neutrophil programming
Sandrine Nugteren, Beatriz Calado, Ytje Simons-Oosterhuis, Daniëlle H. Hulleman-van Haaften, Willem K. Smits, Renz C.W. Klomberg, Bastiaan Tuk, Mohammed Charrout, Dicky J. Lindenbergh-Kortleve, Michail Doukas, Mathijs A. Sanders, Gregory van Beek, Johanna C. Escher, Lissy de Ridder, Maria Fernanda Pascutti, Janneke N. Samsom
Sandrine Nugteren, Beatriz Calado, Ytje Simons-Oosterhuis, Daniëlle H. Hulleman-van Haaften, Willem K. Smits, Renz C.W. Klomberg, Bastiaan Tuk, Mohammed Charrout, Dicky J. Lindenbergh-Kortleve, Michail Doukas, Mathijs A. Sanders, Gregory van Beek, Johanna C. Escher, Lissy de Ridder, Maria Fernanda Pascutti, Janneke N. Samsom
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Research Article Gastroenterology Immunology

Epithelial SLPI expression in severe inflammatory bowel disease relates to high IL-17 and neutrophil programming

Abstract

Heterogeneity in disease severity and treatment response in inflammatory bowel disease (IBD) likely evolves from individual differences in host-microbiota-immune interactions. Histological evaluation of intestinal biopsies is central to diagnosis, but histological parameters that define underlying immune mechanisms are limited. We investigated histological features that distinguish individual patient immune profiles in therapy-naive pediatric IBD patients (age 6–18 years) using biopsy immunohistochemistry and transcriptomics and plasma proteomics across two cohorts. High colonic epithelial expression of secretory leukocyte protease inhibitor (SLPI), a microbiota-induced regulator of epithelial function, occurred in IBD patients with high clinical disease activity and more severe endoscopic and microscopic disease activity. SLPI expression was related to increased neutrophil infiltration, transcriptomic signatures of activation, and genes known to associate with therapeutic resistance. High SLPI colocalized with high densities of IL-17–secreting cells and was associated with high plasma concentrations of Th17-related immune proteins. Additionally, patients with high intestinal SLPI had an intrinsically different immunotype, in which circulating neutrophils exhibited altered transcription of genes involved in neutrophil granule formation, phagocytosis, oxidative phosphorylation, and interferon signaling. Thus, high colonic SLPI expression at diagnosis associates with severe IBD, increased IL-17A–neutrophil pathway responses, and altered transcriptomic wiring of circulating neutrophils.

Authors

Sandrine Nugteren, Beatriz Calado, Ytje Simons-Oosterhuis, Daniëlle H. Hulleman-van Haaften, Willem K. Smits, Renz C.W. Klomberg, Bastiaan Tuk, Mohammed Charrout, Dicky J. Lindenbergh-Kortleve, Michail Doukas, Mathijs A. Sanders, Gregory van Beek, Johanna C. Escher, Lissy de Ridder, Maria Fernanda Pascutti, Janneke N. Samsom

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Figure 5

Colonic epithelial SLPI protein expression is associated with IL-17–positive cells in the tissue and IL-17A production in peripheral blood.

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Colonic epithelial SLPI protein expression is associated with IL-17–posi...
(A) H&E staining and IHC for SLPI, calprotectin, and IL-17 on colonic biopsies from patients with CD (n = 41) or UC (n = 22) and IBD-negative (IBD-neg) controls (n = 15). Representative images acquired at ×20 magnification. (B) The GHAS parameter “infiltration by mononuclear cells in the lamina propria” scored on H&E-stained sections for the 3 categories of SLPI IHC scores (total n = 114 biopsies). Fisher’s exact test. (C) The number of IL-17–positive cells in the lamina propria was classified into 3 categories and plotted for the 3 categories of SLPI IHC scores (total n = 114 biopsies). Fisher’s exact test. For additional statistical comparisons, see Supplemental Table 2. (D–F) SLPI IHC scores were used to classify patients as SLPIlow (negative IHC, n = 25) or SLPIhigh (weak/strong IHC, n = 45). Protein concentrations in plasma were compared between the 2 groups (2-tailed independent t test; Benjamini-Hochberg correction). (D) Differentially abundant proteins (log2FC < –0.5 or > 0.5, adjusted P value < 0.05) between the SLPIhigh and SLPIlow groups are shown in red. (E) Z scores of the normalized protein expression (NPX) values of increased proteins in IBD; zero represents the NPX of non-IBD control. Ward’s clustering criterion (67, 68). (F) NPX values for differentially abundant proteins (log2FC < –0.5 or > 0.5, adjusted P value < 0.05) in the SLPIhigh compared with the SLPIlow group. (G and H) TR146 buccal epithelial cells were cultured and serum-starved for 4–24 hours (G) or 24 hours (H) and subsequently stimulated with IL-1β, TNF-α, IFN-γ, or IL-17A or unstimulated for 16 hours. (G) Relative expression of SLPI mRNA compared between unstimulated and stimulated cells measured by qPCR. (H) Concentrations of SLPI protein in the supernatant measured by ELISA. (G and H) Bars represent the mean of multiple culture wells. Wilcoxon’s rank sum test.