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Eosinophil Recruitment (eosinophil + recruitment)
Selected AbstractsFunction of Siglec-8 on human eosinophilsCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 2004E. Nutku Summary Eosinophil recruitment and activation are regarded as central to the pathophysiology of allergic diseases, including asthma. An improved understanding of the mechanisms involved in these responses is therefore of great relevance to asthma pathogenesis and the development of new therapeutics. As part of ongoing efforts to discover novel eosinophil-specific molecules, we recently cloned Siglec-8 (formerly called sialoadhesin family member-2) from a human eosinophil cDNA library. Siglecs (sialic acid binding Ig-like lectins) are a family of transmembrane, I-type lectins characterized by an N-terminal V-set Ig domain that binds sialic acid. We now know that Siglec-8 is expressed only on human eosinophils, basophils and mast cells, giving it a unique expression pattern on effector cells of allergic disease. We have determined that in eosinophils, Siglec-8 exists in two isoforms, one of which contains two putative cytoplasmic tyrosine-based signalling motifs, including an ITIM (immunoreceptor tyrosine-based inhibitory motif) sequence. Because of the ITIM sequence, we hypothesized that Siglec-8 ligation would inhibit eosinophil functions. Initial studies found that incubation of eosinophils with Siglec-8 binding monoclonal antibodies under cross-linking conditions caused rapid and profound caspase-dependent apoptosis, and this response could not be rescued by the survival-promoting cytokine interleukin (IL)-5. In fact, IL-5 enhanced the ability of Siglec-8 cross-linking to induce eosinophil apoptosis. Activation via Siglec-8 could potentially be used to inhibit eosinophil survival in vivo, providing a novel strategy for reducing or inhibiting these cells in allergic and other diseases. [source] The allergen specificity of the late asthmatic reactionALLERGY, Issue 3 2010M. Hatzivlassiou To cite this article: Hatzivlassiou M, Grainge C, Kehagia V, Lau L, Howarth PH. The allergen specificity of the late asthmatic reaction. Allergy 2010; 65: 355,358. Abstract Background:, Allergen inhalation challenge in asthma may induce both early (EAR) and late (LAR) asthmatic reactions. The EAR is IgE and mast cell dependent. The mechanism of the LAR is less well defined and we have hypothesized may be allergen dependent. The aim of this study was to investigate the allergen specificity of the LAR to allergen inhalation in asthma. Methods:, In a randomized, double-blind, crossover design six asthmatic volunteers with dual sensitization to house dust mite (HDM) allergen and grass pollen (GP) allergen underwent inhalation allergen challenge with these separate allergens on two occasions separated by 14 days. Lung function changes were followed for 8-h postchallenge. Bronchial reactivity (histamine PC20) and airway inflammation, assessed by induced sputum differential cell count, were measured 24-h pre and postallergen challenge. The allergen inhalation challenges were matched to achieve the same magnitude of EAR. Results:, Despite comparable group mean EAR percent falls in FEV1 (25.8% following GP and 28.0% following HDM (P = 0.917), the LAR was statistically greater on the HDM challenge day (13.0%vs 22.8% [P = 0.046]) and was associated with a significant airway eosinophil recruitment (mean (SD) of 5.4 (4.8)% to 22.1 (18.2)% (P = 0.028) that was not evident on the GP allergen challenge day. Conclusions:, These findings identify the allergen specificity of the LAR and indicate that factors independent of IgE contribute to the LAR. Such findings have relevance both to the understanding of the allergen-induced airway responses in asthma and the need for homogeneity in inhaled-allergen challenge studies in asthma. [source] Cytokine-regulated accumulation of eosinophils in inflammatory diseaseALLERGY, Issue 8 2004M. Lampinen The role of cytokines in the accumulation of eosinophil granulocytes in inflamed tissue has been studied extensively during recent years, and these molecules have been found to participate throughout the whole process of eosinophil recruitment. Haematopoietic cytokines such as IL-3, IL-5 and GM-CSF stimulate the proliferation and differentiation of eosinophils in the bone marrow, and the release of mature eosinophils from the bone marrow into the blood is probably promoted by IL-5. Priming of eosinophils in the blood following, for example, allergen challenge is performed mainly by IL-3, IL-5 and GM-CSF. An important step in the extravasation of eosinophils is their adhesion to the vascular endothelium. Adhesion molecules are upregulated by, e.g. IL-1, IL-4, TNF- , and IFN- , and the same cytokines may also increase the affinity of adhesion molecules both on eosinophils and endothelial cells. Finally, a number of cytokines have been shown to act as eosinophil chemotactic factors, attracting the cells to the inflammatory focus in the tissue. Some of the most important eosinophil chemoattractant cytokines are IL-5, IL-8, RANTES, eotaxin, eotaxin-2, eotaxin-3, MCP-3, MCP-4 and TNF- ,. Th2 cells, mast cells and epithelial cells are important sources of proinflammatory cytokines, but in recent years, the eosinophils have also been recognized as cytokine-producing and thereby immunoregulatory cells. The aim of this paper is to review the role of cytokines in the process of eosinophil recruitment in asthma, allergy and ulcerative colitis. [source] Chemokine responses in schistosomal antigen-elicited granuloma formation,PARASITE IMMUNOLOGY, Issue 6 2002Bo-Chin Chiu Summary Host immune systems have evolved specialized responses to multicellular parasites. This is well represented by the type 2 granulomatous response to Schistosoma mansoni egg antigens, which is an eosinophil-rich inflammatory response mediated by Th2-associated cytokines. Using Ag-bead models of pulmonary granuloma formation in mice, we defined characteristic chemokine (CK) profiles in the granulomatous lungs. Our findings point to a role for C-C chemokine receptor-2 (CCR2) and CCR3 agonists such as monocyte chemotactic proteins (MCPs) 1/CCL2, 3/CCL7 and 5/CCL12 as important participants that are subject to regulation by Th2 cytokines interleukin (IL)-4 and IL-13. CCR4 and CCR8 agonists are also likely contributors. Analysis of CK receptor knockout mice revealed that CCR2 ligands (e.g. MCP-1 and 5) promoted early phase granuloma macrophage accumulation, whereas anti-MCP-3 (CCL7) antibody treatment abrogated eosinophil recruitment. CCR8 knockout mice also demonstrated impaired eosinophil recruitment but this appeared to be related to impaired Th2 cell function. Transcript analysis of CD4+ T cells generated during schistosome granuloma formation failed to show biased CCR8 expression but, having a more limited receptor repertoire, these cells were likely more dependent on CCR8 ligands. Together, these studies indicate an intricate involvement of chemokines in various stages and aspects of schistosomal egg Ag-elicited granuloma formation. [source] Nasal Interleukin-5, Immunoglobulin E, Eosinophilic Cationic Protein, and Soluble Intercellular Adhesion Molecule-1 in Chronic Sinusitis, Allergic Rhinitis, and Nasal PolyposisTHE LARYNGOSCOPE, Issue 6 2000Matthias F. Kramer MD Abstract Objective To compare concentrations of interleukin-5 (IL-5), immunoglobulin E (IgE), eosinophilic cationic protein (ECP), and soluble intercellular adhesion molecule-1 (sICAM-1) in nasal secretion and serum of patients with chronic nonallergic sinusitis, allergic rhinitis, and nonallergic nasal polyposis to obtain information about the pathogenesis of these diseases. Methods Nasal secretion and serum were analyzed by routine enzyme-linked immunosorbent assay techniques. Nineteen patients with chronic nonallergic sinusitis, 24 patients with seasonal allergic rhinitis, and 18 patients with nonallergic nasal polyposis were included in the study. Eight healthy, nonallergic probands served as control subjects. Results Significantly elevated concentrations of IL-5 (5-fold, P < .05) and IgE (15-fold, P < .01) were detected in nasal secretion of patients with allergic rhinitis (IL-5, 51.8 ± 13.2 pg/mL; IgE, 41.9 ± 20.9 kU/L) or nonallergic nasal polyposis (IL-5, 57.9 ± 36.9 pg/mL; IgE, 40.5 ± 20.2 kU/L) compared with controls (IL-5, 10.6 ± 7.8 pg/mL; IgE, 2.8 ± 0.5 kU/L) or with patients with chronic nonallergic sinusitis (IL-5, 16.5 ± 13.2 pg/mL; IgE, 5.4 ± 3.1 kU/L). There were no significant differences between patients with allergic rhinitis and those with nonallergic nasal polyposis. Concentrations of ECP were significantly elevated (sixfold, P < .01) in patients with allergic rhinitis (297.8 ng/mL ± 173.1) compared with controls (52.4 ± 28.0 ng/mL) or patients with chronic nonallergic sinusitis (44.8 ± 40.1 ng/mL), whereas twofold higher concentrations (not significant) of ECP were observed in patients with nonallergic nasal polyposis (107.1 ± 26.6 ng/mL). Significantly elevated concentrations of sICAM-1 in nasal secretion (threefold, P < .05) were detected only in patients with chronic nonallergic sinusitis (79.4 ± 45.6 ng/mL). The elevated sICAM-1 nasal secretion values in this group correlated significantly (P < .05) to the serum values. Conclusions Equally elevated concentrations of IL-5 and IgE in patients with allergic rhinitis and nonallergic nasal polyposis implicated similar pathogenic processes in both diseases. Whereas the pathogenesis of allergic rhinitis is IgE-specific, the pathogenesis of nasal polyps is not as clear. IL-5 was suggested to play a pivotal role in tissue eosinophilia, which was confirmed by data in the present study. Elevated concentrations of ECP were suggested to result from tissue eosinophilia,a characteristic of both diseases. Elevated concentrations of sICAM-1 in patients with chronic nonallergic sinusitis pointed to its key role in the recruitment of neutrophils into the inflamed tissue, whereas an important role in eosinophil recruitment was ruled out. [source] Eosinophil infiltration of the oesophageal mucosa in patients with pollen allergy during the seasonCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2005K. Onbasi Summary Background The oesophagus is normally devoid of eosinophils. There are some disorders accompanying with eosinophil infiltration. Food allergy has been reported as a common reason, especially in children but some other studies have also indicated that aeroallergens might have a role in oesophageal eosinophil accumulation. Objective In this study we investigated whether there is any eosinophil recruitment in the oesophagus of pollen-allergic patients who had respiratory symptoms during the season. Methods Thirty-eight symptomatic patients (allergic rhinitis (AR) with or without asthma) who had sensitization to grass pollen were included in the study during the pollen season. Controls were composed of 25 healthy non-atopics and 24 patients diagnosed as having gastro-oesophageal reflux disease. Reflux was excluded in allergic and non-atopic groups, whereas the presence of allergy was eliminated in control groups. Gastrointestinal endoscopy was performed in all participants, and biopsy specimens were taken from both the proximal and the distal oesophagus to evaluate eosinophil accumulation. At the same time, blood eosinophil numbers were counted. Results Oesophageal eosinophil accumulation was found in 10 allergic patients (26%) and in five patients (21%) with gastro-oesophageal reflux disease but none of the healthy controls had eosinophils (0%) (P<0.05). Blood eosinophils were higher in these 10 patients than the rest of the 28 patients without infiltration. In this group, blood eosinophils were also correlated with the number of accumulated eosinophils in the oesophagus (P<0.001). There was more intense eosinophil infiltration at the distal part of the oesophagus in the reflux group when compared with the allergic group (mean 7.6±5.6 vs. 3.2±3.7). Nevertheless, eosinophils were found to be concentrated (mean 5.5±7.3) in the proximal oesophagus of allergic patients, although it was 1.7±1.5 in reflux patients (P>0.05). Conclusion Our results showed that eosinophil infiltration might be observed in oesophageal tissue of patients with respiratory tract allergy during the symptomatic period. This finding may possibly reflect the systemic and common mucosal aspects of allergic inflammation. [source] Fibroblasts: a cell type central to eosinophil recruitment?CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2000Minshall No abstract is available for this article. [source] | ||||||||||