IL-17-Producing T Lymphocytes In Lung Tissue and In the Bronchoalveolar Space After Exposure to Endotoxin From Escherichia Coli In Vivo-Effects of Anti-Inflammatory … (original) (raw)
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Interleukin-17-producing T-helper cells and related cytokines in human airways exposed to endotoxin
European Respiratory Journal, 2010
Previous studies on mouse models have indicated that interleukin (IL)-17 and IL-17producing T-helper (Th) cells are important for pulmonary host defence against Gram-negative bacteria. Human correlates to these findings have not yet been demonstrated. The aim of the present study was to determine whether or not IL-17-producing Th cells are present and whether IL-17 and other Th17-associated cytokines are involved in the immunological response to endotoxin in human airways. Segmental exposure to endotoxin and contralateral exposure to vehicle were performed in the lungs of healthy volunteers, with subsequent bronchoalveolar lavage 12 or 24 h after exposure to study local changes in cytokines and inflammatory cells. Endotoxin exposure increased concentrations of IL-17, IL-22 and their downstream effector molecules, human b-defensin-2 and IL-8/CXC chemokine ligand 8, in bronchoalveolar lavage fluid. Th cells with the capacity to produce IL-17 were found among the bronchoalveolar lavage cells, and expression of IL-17 mRNA correlated with expression of the transcription factor, retinoic-acidreceptor-related orphan receptor C variant 2. Moreover, endotoxin increased the numbers of neutrophils, macrophages and IL-17-producing T-cells, as well as the concentration of the Th17regulating cytokines, IL-21 and IL-23. In conclusion, IL-17-producing Th cells are present, and IL-17, as well as other Th17-associated cytokines, is involved in the immunological response to endotoxin in human airways.
Contribution of IL-17 to the pulmonary inflammatory response
Th 17 Cells: Role in Inflammation and Autoimmune Disease, 2009
ABSTRACT Airway exposure to endotoxin and other microbial Toll-like receptor (TLR) agonists induces a rapid production of mediators including IL-1, neutrophil recruitment and bronchoconstriction, which are abrogated in mice deficient for distinct TLRs or the common adaptor molecule myeloid differentiation factor 88 (MyD88). Intranasal IL-17 administration causes acute neutrophilic lung inflammation in a proinflammatory environment. Recent investigations revealed that IL-17 is up-regulated upon endotoxin aerosol exposure and neutralization of IL-17 diminished endotoxininduced inflammation, suggesting a role of endogenous IL-17 in endotoxin-induced lung inflammation. Furthermore, administration of IL-1β mobilizes neutrophils and induces IL-17 production in the lung. Therefore, IL-17 might participates in IL-1β-induced lung inflammation. Importantly, lung injury leads to NALP3 inflammasome activation, leading to IL-1β-dependent acute inflammation. The participation of IL-17 in this response is discussed. In conclusion, TLR-agonist and injury-induced lung inflammation depend in part on IL-1β and IL-17. The role of inflammasome activation cleaving pro-IL-1β leading to mature IL-1ß and IL-1β-dependent IL-17 production and inflammation need to be explored further.
Journal of immunology (Baltimore, Md. : 1950), 2003
We have previously demonstrated that administration of the recently described cytokine IL-17 in rat airways in vivo recruits and activates neutrophils locally. In the current study, we examined whether endogenous IL-17 is involved in mediating neutrophil recruitment caused by endotoxin exposure in mouse airways. Our in vivo data show that local endotoxin exposure causes the release of free, soluble IL-17 protein 6 h later. Systemic pretreatment with a neutralizing anti-IL-17 Ab almost completely inhibits neutrophil recruitment 24 h, but not 6 h, after endotoxin exposure in the airways. Pretreatment with neutralizing anti-IL-6 and anti-macrophage inflammatory protein (MIP)-2 Abs inhibits neutrophil recruitment caused by local endotoxin exposure and IL-17, respectively. Our in vitro data show that endotoxin exposure stimulates the release of soluble IL-17 protein in T lymphocytes harvested from lung and spleen, respectively, and that this cytokine release requires coculture with airwa...
Regulation of IL-17 in chronic inflammation in the human lung
Clinical Science, 2011
The regulation of human Th17 cell effector function by Treg cells (regulatory T-cells) is poorly understood. In the present study, we report that human Treg (CD4+CD25+) cells inhibit the proliferative response of Th17 cells but not their capacity to secrete IL (interleukin)-17. However, they could inhibit proliferation and cytokine production by Th1 and Th2 cells as determined by IFN-γ (interferon-γ) and IL-5 biosynthesis. Currently, as there is interest in the role of IL-17-producing cells and Treg cells in chronic inflammatory diseases in humans, we investigated the presence of CD4+CD25+ T-cells and IL-17 in inflammation in the human lung. Transcripts for IL-17 were expressed in mononuclear cells and purified T-cells from lung tissue of patients with chronic pulmonary inflammation and, when activated, these cells secrete soluble protein. The T-cell-specific transcription factors RORCv2 (retinoic acid-related orphan receptor Cv2; for Th17) and FOXP3 (forkhead box P3; for Treg cells...
Free, soluble interleukin-17 protein during severe inflammation in human airways
European Respiratory Journal, 2002
Free, soluble interleukin-17 protein during severe inflammation in human airways. M. Laan, L. Palmberg, K. Larsson, A. Lindén. #ERS Journals Ltd 2002. ABSTRACT: Studies in rodents indicate that the cytokine, interleukin (IL)-17, links the activation of T-lymphocytes to neutrophilic inflammation. The aim of the current study was to determine whether free, soluble IL-17 protein can be released during severe inflammation in human airways.
Modulation of bronchial epithelial cells by IL-17
Journal of Allergy and Clinical Immunology, 2001
Background: The induction of epithelial cytokines/chemokines is crucial in the migration of leukocytes, and its regulatory mechanisms remain incompletely defined. Objective: To determine the role of IL-17, a CD4 + T cell-derived cytokine, in modulation of primary bronchial epithelial cells, the expression of IL-6, IL-8, and intercellular adhesion molecule 1 (ICAM-1) and the potential involvement of mitogen-activated protein (MAP) kinases in IL-17-mediated signaling were examined. Methods: The levels of gene expression and protein production for IL-6 and IL-8 in IL-17-treated cells, in the presence or absence of MAP kinase inhibitors, were analyzed by RT-PCR and ELISA, respectively, and activation of MAP kinases was determined by Western blot analyses. Results: We showed first that IL-17 induced time-dependent expression of IL-6 and IL-8 but not of the chemokines eotaxin and RANTES. In addition, IL-17 induced activation of extracellular signal-regulated kinase 1/2 but not of p38 or JNK kinases. A selective MAP kinase kinase inhibitor, PD98059, inhibited IL-17-induced IL-6 and IL-8. A combination of IL-17 and each of the cytokines IL-4, IL-13, and IFN-γ further enhanced IL-8 expression. IL-17 alone did not induce ICAM-1 expression and showed no effect on IL-4-or IL-13-induced ICAM-1 expression. In contrast, a combination of IL-17 and IFN-γ augmented IL-6 and ICAM-1 expression. Conclusion: These findings suggest that IL-17, alone or in combination with other cytokines, modulates airway inflammation via-in part-the expression of epithelial IL-6, IL-8, and ICAM-1. (
Interleukin-17F Induces Pulmonary Neutrophilia and Amplifies Antigen-induced Allergic Response
American Journal of Respiratory and Critical Care Medicine, 2005
Interleukin (IL)-17F is a recently described human cytokine belonging to the IL-17 gene family, but its in vivo function remains to be determined. To this end, a full-length mouse IL-17F cDNA sequence with a 483-bp coding region sequence was first identified. Pulmonary gene transfer of an IL-17F expression construct (pcDNAmIL-17F) in mice was used to investigate its regulatory role. The results showed first that a significant increase in the number of neutrophils was seen in the bronchoalveolar lavage fluids of IL-17F-transduced mice, concomitant with increased expression of genes encoding C-X-C chemokines and inflammatory cytokines when compared with mock and phosphate-buffered saline control animals. Mucosal transfer of the IL-17F gene in ovalbumin (OVA)-sensitized mice before antigen (Ag) challenge enhanced the levels of Ag-induced pulmonary neutrophilia, but not eosinophilia, goblet cell hyperplasia, and mucin gene expression. However, no significant change in the levels of Th2 cytokine expression was noted. A significant enhancement of ventilatory timing in response to inhaled methacholine was also seen in IL-17F-transduced, Ag-sensitized mice, whereas a small but significant increase was found in IL-17F-transduced, naive mice. These results suggest a role for IL-17F in the induction of neutrophilia in the lungs and in the exacerbation of Ag-induced pulmonary inflammation.