| 1. |
- Bodahl, Sara, et al.
(författare)
-
LL-37 and Double-Stranded RNA Synergistically Upregulate Bronchial Epithelial TLR3 Involving Enhanced Import of Double-Stranded RNA and Downstream TLR3 Signaling
- 2022
-
Ingår i: Biomedicines. - : MDPI AG. - 2227-9059. ; 10:2
-
Tidskriftsartikel (refereegranskat)abstract
- The human host defense peptide LL-37 influences double-stranded RNA signaling, but this process is not well understood. Here, we investigate synergistic actions of LL-37 and synthetic double-stranded RNA (poly I:C) on toll-like receptor 3 (TLR3) expression and signaling, and examine underlying mechanisms. In bronchial epithelial BEAS-2B cells, LL-37 potentiated poly I:C-induced TLR3 mRNA and protein expression demonstrated by qPCR and Western blot, respectively. Interestingly, these effects were associated with increased uptake of rhodamine-tagged poly I:C visualized by immunocytochemistry. The LL-37/poly I:C-induced upregulation of TLR3 mRNA expression was prevented by the endosomal acidification inhibitor chloroquine, indicating involvement of downstream TLR3 signaling. The glucocorticoid dexamethasone reduced LL-37/poly I:C-induced TLR3 expression on both mRNA and protein levels, and this effect was associated with increased IκBα protein expression, suggesting that dexamethasone acts via attenuation of NF-κB activity. We conclude that LL-37 potentiates poly I:C-induced upregulation of TLR3 through a mechanism that may involve enhanced import of poly I:C and that LL-37/poly I:C-induced TLR3 expression is associated with downstream TLR3 signaling and sensitive to inhibition of NF-κB activity.
|
|
| 2. |
|
|
| 3. |
- Cerps, Samuel, et al.
(författare)
-
House dust mite sensitization and exposure affects bronchial epithelial anti-microbial response to viral stimuli in patients with asthma
- 2022
-
Ingår i: Allergy: European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538. ; 77:8, s. 2498-2508
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Allergen exposure worsens viral-triggered asthma exacerbations and could predispose the host to secondary bacterial infections. We have previously demonstrated that exposure to house dust mite (HDM) reduced TLR-3-induced IFN-β in human bronchial epithelial cells (HBECs) from healthy donors. We hypothesize that HDM sensitization in different ways may be involved in both viral and bacterial resistance of HBECs in asthma. In this study, the role of HDM sensitization and effects of HDM exposure on viral stimulus-challenged HBECs from asthmatic donors have been explored with regard to expression and release of molecules involved in anti-viral and anti-bacterial responses, respectively. Methods: HBECs from HDM-sensitized (HDM+) and unsensitized (HDM-) patients with asthma were used. HBECs were exposed to HDM or heat inactivated (hi)-HDM (20 μg/ml) for 24 h prior to stimulation with the viral infection mimic, Poly(I:C), for 3 or 24 h. Samples were analyzed with ELISA and RT-qPCR for β-defensin-2, IFN-β, TSLP, and neutrophil-recruiting mediators: IL-8 and TNF-⍺. NFκB signaling proteins p105, p65, and IκB-⍺ were analyzed by Western blot. Results: Poly(I:C)-induced IFN-β expression was reduced in HBECs from HDM + compared to HDM- patients (p = 0.05). In vitro exposure of HBECs to HDM furthermore reduced anti-microbial responses to Poly(I:C) including β-defensin-2, IL-8, and TNF-⍺, along with reduced NFκB activity. This was observed in HBECs from asthma patients sensitized to HDM, as well as in non-sensitized patients. By contrast, Poly (I:C)-induced release of TSLP, a driver of T2 inflammation, was not reduced with exposure to HDM. Conclusion: Using HBECs challenged with viral infection mimic, Poly(I:C), we demonstrated that allergic sensitization to HDM was associated with impaired anti-viral immunity and that HDM exposure reduced anti-viral and anti-bacterial defense molecules, but not TSLP, across non-allergic as well as allergic asthma. These data suggest a role of HDM in the pathogenesis of asthma exacerbations evoked by viral infections including sequential viral-bacterial and viral-viral infections.
|
|
| 4. |
- Porsbjerg, Celeste, et al.
(författare)
-
Phenotype and severity of asthma determines bronchial epithelial immune responses to a viral mimic
- 2022
-
Ingår i: The European respiratory journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 60:1
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Asthma is characterised by an aggravated immune response to respiratory viral infections. This phenomenon is a clinically well-recognised driver of acute exacerbations, but how different phenotypes of asthma respond immunologically to viruses is unclear. OBJECTIVES: To describe the association between different phenotypes and severity of asthma and bronchial epithelial immune responses to viral stimulation. METHODS: In the Immunoreact study, healthy subjects (n=10) and 50 patients with asthma were included; 30 (60%) were atopic, and 34 (68%) were eosinophilic; 14 (28%) had severe asthma. All participants underwent bronchoscopy with collection of bronchial brushings. Bronchial epithelial cells (BECs) were expanded and stimulated with the viral replication mimic poly (I:C) (Toll-like receptor (TLR)3 agonist) in vitro. The expression of TLR3-induced pro-inflammatory and antiviral responses of BECs were analysed using reverse transcriptase quantitative PCR and multiplex ELISA and compared across asthma phenotypes and severity of disease. RESULTS: Patients with atopic asthma had increased induction of interleukin (IL)-4, interferon (IFN)-β, IL-6, tumour necrosis factor-α, and IL-1β after poly (I:C) stimulation compared to non-atopic patients, whereas in patients with eosinophilic asthma only IL-6 and IL-8 induction was higher than in non-eosinophilic asthma. Patients with severe asthma displayed a decreased antiviral IFN-β, and increased expression of IL-8, most pronounced in atopic and eosinophilic asthmatics. Furthermore, induction of IL-33 in response to poly (I:C) was increased in severe atopic and in severe eosinophilic asthma, but thymic stromal lymphopoietin only in severe eosinophilic asthma. CONCLUSIONS: The bronchial epithelial immune response to a viral mimic stimulation differs between asthma phenotypes and severities, which may be important to consider when targeting novel asthma treatments.
|
|
| 5. |
- Sverrild, Asger, et al.
(författare)
-
The effect of tezepelumab on airway hyperresponsiveness to mannitol in asthma (UPSTREAM)
- 2022
-
Ingår i: The European respiratory journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 59:1
-
Tidskriftsartikel (refereegranskat)abstract
- RATIONALE AND OBJECTIVES: Thymic stromal lymphopoietin (TSLP), an epithelial upstream cytokine, initiates production of type-2 (T2) cytokines with eosinophilia and possibly airway hyperresponsiveness (AHR) in asthma.This study aimed to determine whether tezepelumab (a human monoclonal antibody targeting TSLP) decreases AHR and airway inflammation in patients with symptomatic asthma on maintenance treatment with inhaled corticosteroids.METHODS AND MEASUREMENTS: In this double-blind, placebo-controlled randomised trial adult patients with asthma and AHR to mannitol received either 700 mg tezepelumab or placebo intravenously at 4-week intervals for 12 weeks. AHR to mannitol was assessed, and a bronchoscopy was performed at baseline and after 12 weeks. The primary outcome was the change in AHR from baseline to week-12 and secondary outcomes were changes in airway inflammation.RESULTS: Forty patients were randomised to receive either tezepelumab (n=20) or placebo (n=20). The mean change in PD15 with tezepelumab was 1.9 DD (95% CI 1.2 to 2.5) versus 1·0 (95% CI 0.3 to 1.6) with placebo; p=0.06. Nine (45%) tezepelumab and three (16%) placebo patients had a negative PD15 test at week-12, p=0.04. Airway tissue and BAL eosinophils decreased by 74% (95% CI -53 to -86) and 75% (95% CI -53 to -86) respectively with tezepelumab compared with an increase of 28% (95% CI -39 to 270) and a decrease of 7% (95% CI -49 to 72) respectively with placebo, p=0.004 and p=0.01.CONCLUSIONS: Inhibiting TSLP-signalling with tezepelumab reduced the proportion of patients with AHR and decreased eosinophilic inflammation in BAL and airway tissue.
|
|
| 6. |
- Voss, Ulrikke, et al.
(författare)
-
Airway exposure to urban aerosolized PM2.5 particles induces neuroinflammation and endothelin-mediated contraction of coronary arteries in adult rats
- 2022
-
Ingår i: Environmental Advances. - : Elsevier BV. - 2666-7657. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Ambient airborne particles with an aerodynamic diameter of <2.5 µm (PM2.5), which contain particles from combustion processes, are linked to increased risks for cardiovascular and respiratory diseases. In this experimental study, the short-term and long-term physiologic consequences of PM2.5 inhalation were investigated with the focus on inflammatory parameters and vascular tonus. PM2.5 collected from urban environments in southern Sweden were aerosolized with a nebulizer and delivered to male Sprague Dawley rats. The rats were divided into two treatment groups (n=8 in each): short-term exposed (8 h with an estimated lung exposure rate of 90 μg PM2.5/h); and long-term exposed (3 h/day, 5 days/week, for 8 weeks, with an estimated lung exposure rate of 30 μg PM2.5/h). A group of non-particle-exposed control animals (n=8) was run in parallel with each test group. The results showed that short-term exposure increased the numbers of lymphocytes in the bronchoalveolar lavage fluids. Long-term exposure led to impaired substance P-induced relaxation and increased endothelin-1-induced contraction of the coronary arteries. The contractile response was found to be mediated by endothelin receptor A. Long-term exposure led to increased interleukin-6 levels in brain tissues, as compared to the controls. In summary, this explorative study reveals that exposure to aerosolized, ambient PM2.5 leads to impaired coronary artery function and neuroinflammation. Further investigations into the impacts on health effects of short-term and long-term exposures to urban air pollution are warranted.
|
|
