| 21. |
- Broos, Sissela, et al.
(författare)
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Immunomodulatory nanoparticles as adjuvants and allergen-delivery system to human dendritic cells: Implications for specific immunotherapy.
- 2010
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Ingår i: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 28, s. 5075-5085
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Tidskriftsartikel (refereegranskat)abstract
- Novel adjuvants and antigen-delivery systems with immunomodulatory properties that shift the allergenic Th2 response towards a Th1 or regulatory T cell response are desired for allergen-specific immunotherapy. This study demonstrates that 200-nm sized biodegradable poly(gamma-glutamic acid) (gamma-PGA) nanoparticles (NPs) are activators of human monocyte-derived dendritic cells (MoDCs). gamma-PGA NPs are efficiently internalized by immature MoDCs and strongly stimulate production of chemokines and inflammatory cytokines as well as up-regulation of co-stimulatory molecules and immunomodulatory mediators involved in efficient T cell priming. Furthermore, MoDCs from allergic subjects stimulated in vitro with a mixture of gamma-PGA NPs and extract of grass pollen allergen Phleum pratense (Phl p) augment allergen-specific IL-10 production and proliferation of autologous CD4(+) memory T cells. Thus, gamma-PGA NPs are promising as sophisticated adjuvants and allergen-delivery systems in allergen-specific immunotherapy.
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| 22. |
- Cervin, Anders, et al.
(författare)
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Acute exudative inflammation and nasally exhaled nitric oxide are two independent phenomena
- 2002
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Ingår i: ORL. - : S. Karger AG. - 0301-1569 .- 1423-0275. ; 64:1, s. 26-31
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Tidskriftsartikel (refereegranskat)abstract
- Background. Increased levels of nitric oxide (NO) and the exudations of plasma proteins to the airway lumen have both been considered characteristics of airway inflammation. The aim of the present study was to investigate a possible relationship between nasal NO concentrations and acutely induced exudative inflammation of the nasal mucosa. Methods: Twelve healthy non-allergic subjects participated. Nasal challenges with saline, histamine 40 mug/ml (M), histamine 400 mug/ml (H2), oxymethazoline, 0.25 mg/ml (OXY), and a combination of oxymethazoline 0.25 mg/ml and histamine 800 mug/ml (OXYH), were performed on separate occasions. Exhaled NO was measured after each challenge, and alpha(2)-macroglobulin (as a marker of plasma exudation) was measured in nasal lavage fluids after the H 1 and H2 challenges. Results: The mean baseline NO in all measurements was 164 +/- 10.3 ppb. Saline and H1 challenge did not change NO and a2-macroglobulin levels. H2 challenge showed a tendency to reduce NO levels, and the most pronounced decrease was seen after 10 min (-36.3 +/- 16.3%, p = 0.07). This reduction was sustained throughout the registration period. Simultanousley with the decrease in NO, alpha(2)-macroglobulin levels were increased significantly. OXY challenge alone reduced NO significantly throughout the whole registration period. Maximum decrease was seen at 40 min (-21.3 +/- 3.4%, p = 0.03). The OXYH challenge also reduced NO, with a maximal reduction recorded at 10 min (-29.4 +/- 6.4%, p = 0.03). The reduction of NO was sustained throughout the registration period (p < 0.01). Conclusion: Histamine 400 mug/ml induced a prompt plasma exudation response whereas a decrease in nasal NO was registered, suggesting that these two events are not necessarily linked. Furthermore it was shown that the vasoconstrictor oxymethazoline reduced nasal NO, which could be related to reduced mucosal blood flow, whereas the reduction of nasal NO after histamine challenge remains to be elucidated. Copyright (C) 2002 S. Karger AG, Basel.
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| 23. |
- Cervin, Anders, et al.
(författare)
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Effects of long-term clarithromycin treatment on lavage-fluid markers of inflammation in chronic rhinosinusitis
- 2009
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 29:2, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- Macrolides can be clinically effective in chronic rhinosinusitis (CRS). However, little is known about how these drugs affect pathophysiological features of CRS in vivo. In the present study, patients with CRS were subjected to long-term treatment with clarithromycin. Nasal lavages with and without histamine (40 and 400 mu g ml(-1)) were carried out prior to and late into the treatment period. Histamine was included as a tool to produce plasma exudation, a process known to move free cellular products from the mucosal tissue into the airway lumen thereby enriching nasal surface liquids with such products. Interleukin-8 (IL-8), myeloperoxidase (MPO), eosinophil cationic protein (ECP), alpha(2)-macroglobulin and fucose were monitored as indices of pro-inflammatory cytokine production, neutrophil and eosinophil granulocyte activities, plasma exudation and mucinous secretion, respectively. Clarithromycin reduced the lavage fluid levels of IL-8 at the low-dose histamine observation (P < 0.001). There was a trend towards reduced MPO by the treatment, whereas ECP was significantly reduced at the low-dose histamine observation (P < 0.05). alpha(2)-Macroglobulin was reduced by clarithromycin (saline lavages) (P = 0.05), whereas fucose was unaffected. The exudative responsiveness to high-dose histamine was significantly reduced by the treatment (P < 0.05). Furthermore, significantly lower levels of fucose were observed at the low-dose histamine observation (P < 0.01). We conclude that long-term clarithromycin treatment likely exerts an anti-inflammatory effect in CRS.
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| 24. |
- Cervin, Anders, et al.
(författare)
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Nasal Septal Perforations during Treatment with Topical Nasal Glucocorticosteroids Are Generally Not Associated with Contact Allergy to Steroids.
- 2003
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Ingår i: ORL. - : S. Karger AG. - 0301-1569 .- 1423-0275. ; 65:2, s. 103-105
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Mucosal ulcers and perforations of the nasal septum are very rare and may have several underlying causes. Contact allergy to steroids has been suggested as a possible aetiological factor in patients who develop perforations during topical steroid use. <i>Methods:</i> We have identified 13 subjects with perforations of their nasal septum and concomitant topical nasal steroid use. In order to evaluate whether these patients had developed contact allergy to steroids they underwent patch testing with an extended steroid series. <i>Results:</i> None of the subjects displayed any positive reaction to the steroids. <i>Conclusion:</i> Sensitivity to glucocorticoids is a well-described phenomenon and may in selected subjects also be associated with local side effects to nasal sprays. However, contact allergy to steroids does not seem to be a general explanation for septal perforations in patients using nasal steroids.
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| 25. |
- Erjefält, Jonas, et al.
(författare)
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Allergen-induced eosinophil cytolysis is a primary mechanism for granule protein release in human upper airways
- 1999
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1535-4970. ; 160:1, s. 304-312
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Tidskriftsartikel (refereegranskat)abstract
- Cytotoxic eosinophil granule proteins are considered important in the pathogenesis of allergic airway diseases such as rhinitis and asthma. To explore the cellular mechanisms behind eosinophil granule release in human allergic airways, 16 symptom-free patients with seasonal allergic rhinitis were challenged daily with allergen during 1 wk. Nasal lavage samples and biopsies, obtained before and 24 h after the last allergen exposure, were processed for immunohistochemical and electron microscopic analysis. The allergen challenges produced nasal symptoms, marked tissue eosinophilia, and an increase in lavage fluid levels of eosinophil cationic protein (ECP). The nasal mucosa areas with intense extracellular immunoreactivity for ECP were associated with abundant free eosinophil granules. Electron microscopy confirmed the free granules and revealed that all mucosal eosinophils were involved in granule release, either by cytolysis (33%) or piecemeal degranulation (PMD) (67%). Resting or apoptotic eosinophils were not observed. Cytolytic eosinophils had less signs of intracellular granule release (p < 0. 001) and a higher content of intact granules (p < 0.001) compared with viable eosinophils in the same tissue. This study demonstrates eosinophil cytolysis (ECL) as a distinct mechanism for granule mediator release in human allergic airway mucosa. The nature and extent of the ECL and its product (i.e., protein-laden extracellular granules) indicate that allergen-induced cytolysis is a primary and major mechanism for the release of eosinophil proteins in human allergic airway inflammation in vivo.
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| 26. |
- Erjefält, Jonas, et al.
(författare)
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Cytolysis and piecemeal degranulation as distinct modes of activation of airway mucosal eosinophils
- 1998
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Ingår i: Journal of Allergy and Clinical Immunology. - 1097-6825. ; 102:2, s. 286-294
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cytotoxic eosinophil granule proteins are considered important in the pathogenesis of inflammatory airway diseases, including asthma, rhinitis, and polyposis. However, little is known about the mechanisms involved in the deposition of these tissue-damaging granular products in vivo. OBJECTIVE: We sought to determine the occurrence of degranulating eosinophils, those with morphologic evidence of cytolysis with associated clusters of free eosinophil granules (Cfegs), and to identify the frequency of apoptotic eosinophils in inflamed upper airway tissue. METHODS: Eosinophil-rich nasal polyps were processed for transmission electron microscopy and for light microscopic evaluation of whole-mount preparations subjected to deep tissue staining for eosinophil peroxidase. RESULTS: The mean proportion of eosinophil subtypes were intact and resting (6.8%), intact but degranulating (83%), cytolytic or Cfegs (9.9%), and apoptotic (0.0%). All degranulating eosinophils exhibited piecemeal degranulation. The occurrence of Cfegs was confirmed in nonsectioned whole-mount preparations. Depending on the appearance of their core and matrix, the specific granules were divided into four subtypes, and a degranulation index (altered per total granules) was calculated for each eosinophil. Cytolytic eosinophils had a much lower degranulation index than intact eosinophils present in the same tissue (P < .001). CONCLUSIONS: These data indicate that eosinophil cytolysis is present in human airway mucosa, that its occurrence is not an artifact of the means of tissue handling, and that cytolysis of eosinophils may occur without prior extensive degranulation. We suggest that eosinophil cytolysis is a major activation mechanism, which occurs along with, but is distinct from, other types of degranulation.
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| 27. |
- Erjefält, Jonas, et al.
(författare)
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Degranulation patterns of eosinophil granulocytes as determinants of eosinophil driven disease
- 2001
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Ingår i: Thorax. - : BMJ. - 1468-3296 .- 0040-6376. ; 56:5, s. 341-344
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Degranulation of eosinophils in target tissues is considered a key pathogenic event in major chronic eosinophilic diseases. However, because of a lack of appropriate methods, little is known about degranulation of eosinophils in common eosinophilic diseases. METHODS: Using transmission electron microscopic (TEM) analysis, a novel approach has been devised and validated to quantify eosinophil degranulation in human tissues (assessed in individual cells as percentage granules with structural signs of protein release). Biopsy specimens from patients with inflammatory bowel disease, allergic rhinitis, asthma, and nasal polyposis were evaluated. RESULTS: All conditions displayed a similar degree of local tissue eosinophilia, with no differences being observed in eosinophil numbers in the airway mucosa of patients with airway diseases and the colonic mucosa of those with inflammatory bowel disease (IBD). In contrast, marked differences in the mean (SE) extent of eosinophil degranulation were observed between the patient groups; IBD 9.3 (1.4)% altered granules, artificial and natural allergen challenge induced allergic rhinitis 67.8 (6.8)% and 86.6 (3.0)%, respectively, asthma 18.1 (2)%, and nasal polyposis 46.6 (7.6)%. CONCLUSIONS: This study provides the first quantitative data which show that different eosinophilic conditions, despite having similar numbers of tissue eosinophils, may exhibit markedly different degranulation patterns. The present assessment of piecemeal degranulation would thus make it possible to delineate the conditions under which eosinophils are likely to contribute to disease processes. This novel type of analysis may also guide and validate anti-eosinophilic treatment options.
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| 28. |
- Evilevitch, Vladimir, et al.
(författare)
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Microvascular response in guinea pig skin to histamine challenge with and without application of skin window.
- 2004
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 24:5, s. 266-269
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Tidskriftsartikel (refereegranskat)abstract
- We measured the microvascular response to histamine in guinea pig skin. Histamine (40 mg ml-1) was given either as a skin prick test or applied topically onto a skin window. The skin window was prepared by applying suction and gentle warming to the skin so that a blister was formed, and by removing the top of the blister. The microvascular response was measured as the accumulation of radiolabelled transferrin in the skin in vivo, reflecting a combination plasma exudation and vasodilatation. In the control (saline) challenge, the response was slightly greater in the skin window than after skin prick challenge and the scatter was larger. Histamine challenge resulted in a significant microvascular response with respect to the control situation when measured immediately after provocation for both challenge techniques. Ten minutes after challenge, a smaller response was measured, which was still significantly greater than control for the skin prick challenge, but not for topical provocation using the skin window technique. We conclude that the microvascular response to histamine after provocation with the skin prick technique is similar to that after topical provocation using the skin window technique. The skin window technique may have a lower sensitivity than the skin prick technique owing to a higher scatter in the control situation. This difference should be considered when performing and interpreting studies of the microvascular reaction in the skin.
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| 29. |
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| 30. |
- Ferreira, Alexandra Gabriela, et al.
(författare)
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Restoring tumor immunogenicity with dendritic cell reprogramming
- 2022
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Ingår i: Cancer immunology research. - 2326-6074. ; 10:12 suppl
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Konferensbidrag (refereegranskat)abstract
- Immunotherapy is revolutionizing cancer treatment, but success is limited to a fraction of patients. Tumor immunosurveillance and immunotherapy relies on presentation of tumor-associated antigens by conventional dendritic cells type 1 (cDC1). However, tumors develop mechanisms to avoid immune recognition such as downregulation of antigen presentation and exclusion of cDC1. We have previously demonstrated that enforced expression of the transcription factors PU.1, IRF8 and BATF3 (PIB) imposes the lineage conversion of fibroblasts to cDC1 by direct cell reprogramming. Here, we hypothesize that PIB reprograms cancer cells directly into functional tumor-antigen presenting cells (tumor-APCs) with enhanced immunogenicity. First, we show that enforced expression of PIB in a wide range of murine and human cancer cells from different origins is sufficient to induce surface expression of hematopoietic and DC-lineage specific markers (CD45 and Clec9a). Moreover, reprogramming restored the expression of antigen presentation complexes (MHC-I and MHC-II) and activated the expression of the co-stimulatory molecules CD40, CD80 and CD86, required for productive T cell activation. Transcriptomic analysis using mRNA-sequencing showed that PIB imposes a global cDC1 gene signature and an antigen presentation program in tumor cells as early as day 3 of reprogramming, overriding the original cancer cell program. Furthermore, Assay for Transposase-Accessible Chromatin (ATAC) sequencing analysis revealed that PIB-mediated cDC1 reprogramming elicited rapid epigenetic remodeling followed by gradual rewiring of transcriptional program and stabilization of cDC1 identity. Functionally, tumor-APCs present endogenous antigens on MHC-I, prime naïve CD8+ T and become prone to CD8+ T cell mediated killing. Tumor-APCs secrete pro-inflammatory cytokines (IL-12) and chemoattractants (CXCL10), uptake and process exogenous antigens, phagocyte dead cells, and cross-present exogenous antigens to activate naïve T-cells. In addition, reprogrammed tumor cells harboring TP53, KRAS and PTEN mutations downregulated proliferation and showed impaired tumorigenicity in vitro and in vivo. Importantly, we show that intra-tumoral injection of reprogrammed tumor-APCs elicited tumour growth control in vivo alongside increasing infiltration of CD8+ T and NK cells in B16-OVA tumors. Finally, we showed that our approach can be employed to convert primary cancer cells derived from melanoma, lung, breast, pancreatic, urothelial, and head and neck carcinomas as well as cancer associated fibroblasts. In summary, we provide evidence for the direct reprogramming of tumor cells into immunogenic cDC1-like cells, with restored antigen presentation capacity and the ability to reinstate anti-tumor immunity. Our approach elicits the immune system against cancer and counteract major tumor evasion mechanisms including tumor heterogeneity and impaired antigen presentation, laying the foundation for developing immunotherapeutic strategies based on the cellular reprogramming of human cancer cells.
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