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| 2. |
- Andreasson, Ulrika, et al.
(författare)
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The human IgE-encoding transcriptome to assess antibody repertoires and repertoire evolution
- 2006
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 1089-8638 .- 0022-2836. ; 362:2, s. 212-227
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Tidskriftsartikel (refereegranskat)abstract
- Upon encounter with antigen, the B lymphocyte population responds by producing a diverse set of antigen-specific antibodies of various isotypes. The vast size of the responding populations makes it very difficult to study clonal evolution and repertoire composition occurring during these processes in humans. Here, we have explored an approach utilizing the H-EPSILON-encoding transcriptome to investigate aspects of repertoire diversity during the season of antigen exposure. We show through sequencing of randomly picked transcripts that the sizes of patients' repertoires are relatively small. This specific aspect of the transcriptome allows us to construct evolutionary trees pinpointing features of somatic hypermutation as it occurs in humans. Despite the small size of the repertoires, they are highly diverse with respect to VDJ gene usage, suggesting that the H-EPSILON-encoding transcriptome is a faithful mimic of other class-switched isotypes. Importantly, it is possible to use antibody library and selection technologies to define the specificity of clonotypes identified by random sequencing. The small size of the H-EPSILON-encoding transcriptome of peripheral blood B cells, the simple identification of clonally related sets of genes in this population, and the power of library and selection technologies ensure that this approach will allow us to investigate antibody evolution in human B lymphocytes of known specificity. As H-EPSILON repertoires show many of the hallmarks of repertoires encoding other isotypes, we suggest that studies of this type will have an impact on our understanding of human antibody evolution even beyond that occurring in the IgE-producing B cell population.
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| 3. |
- Korsgren, Magnus, et al.
(författare)
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Clinical efficacy and pharmacokinetic profiles of intranasal and oral cetirizine in a repeated allergen challenge model of allergic rhinitis.
- 2007
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Ingår i: Annals of Allergy, Asthma & Immunology. - 1081-1206. ; 98:4, s. 316-321
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Tidskriftsartikel (refereegranskat)abstract
- Background: Intranasal and oral antihistamines are effective in treating allergic rhinitis. Studies comparing these routes of administration of an antihistamine regarding efficacy and pharmacokinetic profile are lacking. Objective: To compare topical and oral routes of administration of cetirizine regarding efficacy, plasma exudation, and systemic drug levels in a repeated allergen challenge model of allergic rhinitis. Methods: Oral cetirizine dihydrochloride, 10 mg once daily, and topical cetirizine dinitrate in a dose corresponding to 4.4 mg of the dihydrochloride salt twice daily were given to grass pollen-sensitive individuals for 12 days in a double-blind, placebo-controlled, crossover design. Timothy grass pollen allergen challenges were given once daily for 7 days using a nasal spray device. Nasal symptoms and peak inspiratory flow were recorded in the morning, 10 minutes after allergen challenge, and in the evening. The pharmacokinetics of the treatments was monitored in 8 patients. The remaining 28 patients were challenged topically with histamine 12 and 24 hours after the final topical and oral cetirizine doses, respectively. Nasal lavage levels of alpha(2)-macroglobulin were determined to evaluate histamine-induced mucosal plasma exudation. Results: During the last 3 days of the repeated allergen challenge model, chronic symptoms were established. Both treatments reduced symptoms 10 minutes after allergen challenge (P < .001 vs placebo). Neither treatment reduced morning and evening symptoms or nasal peak inspiratory flow. Topical, but not oral, cetirizine reduced histamine-induced plasma exudation (P < .01 vs placebo) when systemic drug levels were similar in the 2 treatment regimens. Conclusions: Topical and oral cetirizine reduced acute nasal symptoms produced by allergen challenges in patients with established chronic symptoms. There were also antihistaminic effects of topical cetirizine not related to systemic drug levels.
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| 4. |
- Korsgren, Magnus, et al.
(författare)
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Inhalation of LPS induces inflammatory airway responses mimicking characteristics of chronic obstructive pulmonary disease.
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 32:1, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Inhalation of lipopolysaccharide (LPS) produces both systemic and pulmonary inflammatory responses. The aim of this study was to further characterize the response to LPS in order to develop a human model suitable for early testing of drug candidates developed for the treatment for chronic obstructive pulmonary disease (COPD). Materials: Blood and induced sputum were obtained 4, 24 and 48 h following inhalation of saline and LPS (5 and 50 μg). Blood was analysed for C-reactive protein (CRP), α(1) -antitrypsin and neutrophils/leucocytes, and sputum was analysed for biomarkers of neutrophil inflammation and remodelling activities, i.e. neutrophil elastase (NE) protein/activity and α(1) -antitrypsin. Levels of tumour necrosis factor-α (TNFα) were measured in both blood and sputum. Urine was collected 0-24 and 24-48 h postchallenge, and desmosine, a biomarker of elastin degradation, was measured. Results: Lipopolysaccharide inhalation induced dose-dependent flu-like symptoms and increases in plasma CRP and α(1) -antitrypsin as well as increases in blood neutrophil/leucocyte numbers. Furthermore, LPS produced increases in sputum TNFα and sputum NE activity. Urine levels of desmosine were unaffected by the LPS challenge. All subjects recovered 48 h postchallenge, and indices of inflammatory activity were significantly lower at this observation point cf 24 h postchallenge. Conclusion: Inhalation of LPS in healthy volunteers can be used as a safe and stable model of neutrophil inflammation. Blood/plasma and sputum indices can be employed to monitor the response to LPS. We suggest that this model may be used for initial human studies of novel COPD-active drugs.
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| 5. |
- Korsgren, Magnus, et al.
(författare)
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Neural expression and increased lavage fluid levels of secretoneurin in seasonal allergic rhinitis.
- 2003
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1535-4970. ; 167:11, s. 1504-1508
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Tidskriftsartikel (refereegranskat)abstract
- Secretoneurin is a neuropeptide potentially involved in migration of eosinophils, monocytes, and dendritic cells. Whether secretoneurin is present in the human airway mucosa and whether it is released at ongoing allergic airway inflammation is currently unknown. In patients with allergic rhinitis, we have explored the occurrence of secretoneurin in nasal mucosal biopsies and lavage fluids before and during natural allergen exposure. Immunohistochemical analysis revealed an abundance of nerves displaying secretoneurin immunoreactivity, which were distributed predominantly around blood vessels and submucosal glands. A majority of nerve fibers containing vesicular acetylcholine transporter, tyrosine hydroxylase, calcitonin gene–related peptide, and vasoactive intestinal peptide were also secretoneurin-immunoreactive, indicating a localization of secretoneurin in cholinergic, adrenergic, and sensory nerves. Lavage fluid levels of secretoneurin were increased at allergen exposure (p < 0.01–0.05). Levels of secretoneurin did not correlate with eosinophil cationic protein ({rho} = 0.1, p = 0.7). We conclude that secretoneurin has a widespread occurrence in nasal mucosal nerves of patients with seasonal allergic rhinitis and that increased nasal lavage fluid levels of secretoneurin may characterize ongoing allergen exposure. These data favor a role of secretoneurin in the local traffic of immune cells in human airway mucosa.
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| 8. |
- Larsson, Kristina, et al.
(författare)
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CD4+ T-cells have a key instructive role in educating dendritic cells in allergy
- 2009
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1423-0097 .- 1018-2438. ; 149:1, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dendritic cells (DCs) are central in allergy as regulators of the Th1/Th2 balance. We have recently demonstrated a unique transcriptional profile of DCs in patients with ongoing allergy compared with healthy subjects and shown that crosstalk between DCs and memory T cells affects the transcriptional profile of T cells. However, the transcriptional profile of DCs educated by T cells in allergy is unknown. Methods: In the present study, we have examined the transcriptional profiles of DCs after stimulation with grass pollen allergens, Phleum pratense and coculture with autologous CD4+ memory T cells using high-density microarray. Protein analysis was performed using flow cytometry and recombinant antibody protein microarrays. Patients with allergic rhinitis and healthy subjects were compared. Results: The results reveal a distinct T-cell-induced DC profile in atopic individuals. Accordingly, about 170 genes were upregulated and 40 genes downregulated. For example, the chemokine receptor CXCR4 and the tumor necrosis factor receptor CD30 were upregulated in DCs derived from atopic donors, and this could also be verified at the protein level. Conclusion: We conclude that crosstalk between CD4+ memory T cells and autologous DCs induces transcriptional reprogramming in DCs. This finding suggests that T cells have a key instructive role in educating DCs in Th2-type responses.
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| 9. |
- Lindstedt, Malin, et al.
(författare)
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Genomic and functional delineation of dendritic cells and memory T cells derived from grass pollen-allergic patients and healthy individuals.
- 2005
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377 .- 0953-8178. ; 17:4, s. 401-409
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCIs) possess a potent ability to modulate and activate specific T-cell responses to allergens, which play a pivotal role in allergic inflammation by secreting cytokines and other mediators. However, the molecular mechanisms by which allergen-challenged DCs regulate specific T-cell responses are still not well characterized. This study aims at elucidating the molecular mechanisms underlying the DC–T-cell interaction during an allergic immune response to grass pollen, using a genomic and functional approach. Transcriptional analysis was performed on grass allergen Phleum pratense-stimulated DCs and on autologous memory CD4+ T cells co-cultured with allergen-challenged DCs from healthy and allergic donors. DCs from the allergic donors were potent inducers of T-cell proliferation and Th2 polarization, as demonstrated by high IL-4, IL-5 and IL-13, and low IFN- production. A gradual up-regulation of activation markers on both DCs and T cells was evident during the co-culture period, demonstrating an educational element of the DC–T-cell interaction. The global transcriptional analysis revealed a differential gene regulation in DCs and T cells derived from allergic donors after stimulation with allergen, as compared with the healthy donors. Peripheral memory CD4+ T cells from healthy and allergic donors also responded differently after stimulation with allergen-loaded DCs with respect to cytokine production, proliferation, surface marker expression and gene transcription. We found up-regulated genes involved in Th2 cell biology, such as genes important for homing, adhesion, signaling and transcription, in addition to genes previously not described in the context of allergy. The panel of differentially expressed genes in the allergic group will form the basis for an increased understanding of the molecular mechanisms in allergy.
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