Immunologic mechanisms in COPD and asthma

Abstract

printing supported by . Visit Chiesi at Stand B2.10 TUESDAY, SEPTEMBER 4TH 2012 that lung DCs of COPD patients express low levels of co-stimulatory molecules, respond poorly to stimulation and display low ability to prime autologous lung T cells and allogeneic naive T cells. Importantly, naïve T cells primed with lung DCs from patients with COPD inhibit T cell proliferation. Here, we have characterized the gene and protein expression profile of these regulatory cells and investigated the mechanism of their suppressive function. Naïve CD4+ T cells primed with lung DCs from patients with COPD showed increased gene expression for Foxp3, Ahr and GATA3 (assessed by qRT-PCR) compared to T cells primed with lung DCs from smokers without COPD. Accordingly, flow cytometry analysis showed higher IL-10 and Foxp3 intracellular protein expression. These findings suggest that the induced regulatory cells are Tregs type 1. Type 1 Tregs suppress immune responses primarily through IL-10. Indeed, naïve T cells that had been primed with COPD lung DCs failed to inhibit T cell proliferation in the presence of blocking IL-10 receptor antibody. Our findings show that lung DCs from patients with COPD induce type 1 Tregs. 3114 Lung B cell-derived CXCL13 is critical for lymphoid follicle formation in chronic obstructive pulmonary disease Eleni Litsiou1, Maria Semitekolou2 , Ioannis Morianos2, Aikaterini Tsoutsa1, Panagiota Kara3, Dimitra Rontogianni3, Ion Belenis4, Maria Konstantinou5, Konstantinos Potaris5, Georgina Xanthou2, Spyros Zakynthinos1, Maria Tsoumakidou1,2. 1Critical Care Medicine and Pulmonary Services, Evangelismos General Hospital, Athens, Greece; 2Cellular Immunology, Biomedical Research Foundation of the Academy of Athens, Greece; 3Pathology, Evangelismos General Hospital, Athens, Greece; 4Thoracic Surgery, Evangelismos General Hospital, Athens, Greece; 5Thoracic Surgery, Sotiria Chest Hospital, Athens, Greece Lymphoid follicles (LFs) that have a similar organization to lymph nodes are found in small airways and alveoli in Chronic Obstructive Pulmonary Disease (COPD), but the mechanism of their development is unclear. During lymph node ontogeny lymphotoxin (LT)-expressing lymphoid-tissue inducer cells induce lymphokine production (mainly CXCL13) to LT-receptor-expressing stromal cells. Lymphokines attract haemopoietic cells leading to lymphoid organ development. We examined peripheral lung tissue from COPD patients with LFs (COPD-LF+), without LFs (COPD-LF-) and never-smokers. Lung CXCL13 was significantly increased in COPD-LF+ compared to COPD-LFand never-smokers and positively correlated to surface area of LFs. Immunostaining showed CXCL13 expression in B cell areas of LFs. Flow cytometry indicated that among lung cells, B cells have the highest expression for LT receptors. Ex-vivo, lipopolysaccharide (LPS) and a LT-receptor agonist induced CXCL13 production to whole lung cell cultures from COPD-LF+. The LPS induction of CXCL13 was decreased by neutralizing LT. Depletion of B cells from the cultures significantly decreased CXCL13 and LT. Isolated lung B cells showed high migration towards lung tissue homogenates from COPD-LF+ that was significantly decreased by CXCL13 neutralization. When isolated lung B cells were exposed to CXCL13, LT was significantly increased, indicating a positive feedback loop between LT and CXCL13. We propose that the initiating event to LF formation in CODP is B cell stimulation, leading to LT expression and CXCL13 production. CXCL13 positively feeds back LT, amplifying its levels and attracting more B cells that organize themselves into LFs. 3115 Dendritic cells-nerve interaction in allergic airway inflammation Duc Dung Le1,2,4 , Sabine Rochlitzer4, Ulrike Funck2, Hendrik Suhling2, Robert Bals3, Armin Braun4, Tobias Welte2, Quoc Thai Dinh1,3. 1Department of Experimental Pneumology and Allergology, Saarland University Hospital, Homburg/Saar, Germany; 2Department for Respiratory Medicine, Hannover Medical School, Hannover, Germany; 3Department of Pneumology, Allergology, Respiratory and Environmental Medicine, Saarland University Hospital, Homburg/Saar, Germany; 4Department of Airway Immunology, Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany Introduction: Dendritic cells (DC) play as antigen-presenting cells a decisive role within the allergic airway inflammation. The colocalisation of DC in sensory airway ganglia has been not explored so far. The aim of the present study is to evaluate possible interactions of DC in sensory ganglia concerning calcitonin gene-related-peptides (CGRP)-expression during allergic airway inflammation. Methods: The BALB/c mice were treated with intranasal house dust mite (HDM) extract (25μg/50μl) for 5 days a week within a total period of 7 weeks. The jugular-nodose ganglion complex was removed 24 hours after final allergen challenge and histological slices were prepared. Immunohistology was performed to detect the colocalisation of DC by MHC-II and CD11c and neurons by neuronal marker PGP 9.5. Results: Under physiological conditions dendritic cells are found in the vagal sensory airway ganglia of the mouse and that they were significantly increased during an allergic airway inflammation (DCs/neurons: control 23.48±7.613% vs. HDM 49.75±4.194%, p = 0.0003). Additionally, an increased number of CGRP positive neurons in vagal sensory airway ganglia during allergic airway inflammation was found (CGRP positive neurons/total neurons: HDM 52.07±3.040% vs. control 21.63±3.799%, p = 0.0001). Conclusion: The finding of the presence of DC in the airway jugular-nodose ganglion indicates a role of the DC in these ganglia under physiological conditions. The increased numbers of DC and CGRP-positive neurons in these ganglia suggest the involvement of these cells the pathogenesis of allergic airway inflammation. However, the exact functions of DC and CGRP in allergic airway inflammation remain to be explored in future studies. 3116 LSC 2012 Abstract – The protective role of Pim1 in cigarette smoke induced damage of airway epithelium M. de Vries, R. Gras, L.E. den Boef, M. van der Toorn, A.J.M. van Oosterhout, M.C. Nawijn. Pathology and Medical Biology, Allergology and Pulmonary Disease, UMCG, Groningen, Netherlands Rationale: The main risk factor of developing COPD is exposure to cigarette smoke. CS exposure induces airway epithelial cell damage, release of DAMPs and an innate inflammatory response. We previously observed increased expression of Pim1 in vivo after sub-chronic CS exposure in mice. Pim1 is a serine/threonine kinase involved in cell growth and survival by preventing apoptosis induction through the mitochondrial pathway. We hypothesize that Pim1 plays a protective role in the airway epithelium after CS exposure by phosphorylating BAD and enhancing cell survival. Methods: Pim1-KO mice were exposed to CS twice a day for 4 days. Inflammatory cells and KC levels in BAL were determined. Beas-2b cells were treated with CS extract (CSE) for 4 hours with(out) Pim-inhibitor. Mitochondrial membrane potential ( M) and apoptosis/necrosis induction were measured by flowcytometry. BAD phosphorylation was determined by Western Blotting. Results: CS exposure induces neutrophilic airway inflammation and increases KC levels in Pim1-KO mice, but not in WT controls. CSE induces a dose-dependent loss of BAD phosphorylation, loss of M and necrotic cell death in Beas-2b cells. All of these CSE-induced effects are aggravated by inhibition of Pim1. Conclusion: Pim1 protects airway epithelial cells from CS-induced damage and cell death by phosphorylating BAD and increasing the threshold for apoptosis. In vivo, this protective effect suffices to prevent CS-induced neutrophilic airway inflammation. 3117 LSC 2012 Abstract – Role of ADAM19 and neuregulin-1 in Muc5ac expression in lungs of cigarette smoke-exposed mice Lisa Dupont, Guy Joos, Guy Brusselle, Ken Bracke. Respiratory Medicine, Ghent University Hospital, Ghent, Belgium Mucus hypersecretion is an important feature of COPD, resulting in chronic cough and contributing to dyspnea by obstructing the airway lumen. Signalling through the epidermal growth factor receptor (EGFR) plays an ubiquitous role in the production of mucins. We hypothesize that A Disintegrin And Metalloproteinase 19 (ADAM19) stimulates mucin production by shedding of the EGFR-ligand neuregulin-1. C57BL/6 mice were exposed to air or cigarette smoke (CS) for 4 or 24 weeks. IHC for ADAM19 on lung tissue sections showed intense staining in bronchial and vascular smooth muscle cells, as well as in endothelium, and a faint staining in bronchial and alveolar epithelial cells. Quantification of ADAM19 protein expression in the airway wall showed a significant increase upon 4 weeks of CS-exposure, but not upon 24 weeks. Accordingly, protein levels of neuregulin-1 were significantly elevated in BAL fluid of mice exposed to CS for 4 weeks, but not for 24 weeks. Finally, pulmonary Muc5ac mRNA expression was significantly increased upon both 4 and 24 weeks of CS-exposure, while we found no differences in the mRNA expression of Muc5b. These data demonstrate that 4 weeks of CS-exposure leads to increased expression of ADAM19 and enhanced shedding of neuregulin-1. Binding of neuregulin-1 to EGFR may contribute to the increased expression of Muc5ac. However, especially upon chronic CS-exposure, other EGFR-ligands or alternative mechanisms may be involved in mucin production. 3118 The IL-2-dependent Th1 response to bacterial infections is suppressed in COPD Juergen Knobloch, Sarah Chikosi, David Jungck, Andrea Koch. Medical Clinic III for Pneumology, Allergology, Sleepand Respiratormedicine, University Hospital Bochum-Bergmannsheil, Bochum, NRW, Germany Susceptibility to bacterial infections is enhanced in COPD, which promotes exacerbations. IL-2 triggers proliferation of Th1 cells important for infection defence. We elucidated modulation of IL-2 release from Th1 cells by LPS and in COPD. Peripheral blood CD4+ cells of n=10 age-/gender-matched never-smokers (NS), smokers without (S) and with COPD were ex vivo activated towards Th1 by αCD3/αCD28 antibodies and IL-12. IL-2 release (ELISA) and cell count/death was analyzed after 24-96h of cultivation. Activation towards Th1 increased IL-2 release and cell count. IL-2 release was increased in COPD and negatively correlated to FEV1 [% pred.]. Nonetypeable H. influenzae extract suppressed IL-2 release from Th1 cells of NS, which was abolished by Polymyxin B or CLI095 (LPS/TLR4 inhibitors). LPS reduced IL-2 553s Oral Presentation Room Lehar 1-2 08:30 10:30 Abstract printing supported by . Visit Chiesi at Stand B2.10printing supported by . Visit Chiesi at Stand B2.10 TUESDAY, SEPTEMBER 4TH 2012 release and cell count of Th1 cells, these effects were enhanced in COPD. LPS effect on IL-2 negatively correlated with FEV1 [% pred.] and was abolished by CLI095. In the presence of LPS, blocking MyD88/IRAK was more efficient in restoring IL-2 release in NS vs. COPD, whereas blocking TRIF/IKKε was more efficient in COPD, and moxifloxacin (MXF) increased IL-2 release and cell count of Th1 cells. MXF effect on IL-2 was enhanced in COPD and correlated to the IL-2-inducing effect of p38MAPK inhibitor SB203580. All effects were p<0.05. LPS and MXF did not induce Th1 cell death. Th1 response to bacterial infections is impaired in COPD due to a shift from MyD88/IRAK to TRIF/IKKε signalling, which enhances suppression of IL-2 and Th1 growth by LPS. MXF might reinforce IL-2 expression and Th1 growth by blocking p38MAPK signalling. Targeting TLR4 signalling combined with MXF might reduce exacerbation rates. 3119 LSC 2012 Abstract – FOXO transcription factors regulate innate immune mechanisms in respiratory epithelial cells during bacterial infection Christoph Beisswenger, Frederik Seiler, Philipp Lepper, Robert Bals, Christian Herr. Department of Internal Medicine V, Saarland University Hospital, Homburg/Saar, Germany Bacterial pathogens are a leading cause of lung infections and contribute to acute exacerbations in patients with respiratory tract diseases. The innate immune system of the lung controls and prevents colonization of the respiratory tract with bacterial pathogens. Here, we show that FOXO transcription factors regulate innate immune mechanism of respiratory epithelial cells in response to bacterial pathogens such as Haemophilus influenzae and Pseudomoas aeruginosa. Infection with bacterial pathogens led to the activation of FOXO transcription factors in respiratory epithelial cells in vivo and in vitro. siRNA mediated knock down of FOXO3 in bronchial epithelial cells resulted in reduced expression of factors of the innate immune system such as antimicrobial peptides and factors involved in a proinflammatory response. In addition, FOXO3 plays a role in the internalization of bacterial pathogens. These data show that FOXO transcription factors are involved in the cellular response to bacterial stimuli and have a central role in regulating innate immune functions of respiratory epithelial cells. 554s Oral Presentation Room Lehar 1-2 08:30 10:30 Abstract printing supported by . Visit Chiesi at Stand B2.10printing supported by . Visit Chiesi at Stand B2.10

Cite this paper

@inproceedings{Mordacq2012ImmunologicMI, title={Immunologic mechanisms in COPD and asthma}, author={Cl{\'e}mence Mordacq and Antoine Deschildre and Isabelle Tillie-Leblond and Anny Dewilde and Muriel Pichavant and Caroline Thumerelle and David Romero and Philippe Gosset and Maria Tsoumakidou and Sofia Tsousa and Maria Semitekolou and Panagiota Panagiotou and Anna Panagiotou and Eleni Litsiou and Ioannis Morianos and Maria I Konstantinou and Konstantinos Potaris and Spyros G. Zakynthinos and Georgina Xanthou}, year={2012} }