Search results for " Hypersensitivity"
showing 10 items of 216 documents
The Development of Novel Approaches to the Identification of Chemical and Protein Respiratory Allergens
2008
In October 2006, the European Centre for theValidation of Alternative Methods (ECVAM) spon-sored and hosted a three-day workshop to consideropportunities and challenges in the development ofalternative methods for the identification and char-acterisation of chemical respiratory allergens. Theproceedings, conclusions and recommendations ofthat workshop were subsequently made available asECVAM Workshop Report 60 (1).In April 2008, a second meeting was convenedby ECVAM to consider what progress has beenmade in the light of the recommendations derivedfrom the 2006 Workshop and the publishedreport. This meeting had as a second objective —to consider whether new opportunities for theidentificatio…
Anti-inflammatory and analgesic activities of flavonoid and saponin fractions from Zizyphus lotus (L.) Lam.
2008
Abstract The effect of the flavonoid and saponin fractions from the leaves and root bark of Zizyphus lotus (200 mg/kg) was evaluated on carrageenan-induced paw edema in rats and on acetic acid-induced algesia in mice. In addition, two methanolic extracts from the plant (1 mg/ear) were tested on oxazolone-induced contact-delayed hypersensitivity (DTH) in mice. The effect of the different fractions was also evaluated in vitro on the nitrite production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages. The results showed that both the flavonoid and saponin fractions significantly inhibited paw edema, algesia, and nitrite production without affecting cell viability. Furthermore, the …
Multiple in vitro and in vivo regulatory effects of budesonide in CD4+ T lymphocyte subpopulations of allergic asthmatics.
2012
Abstract BACKGROUND: Increased activation and increased survival of T lymphocytes characterise bronchial asthma. OBJECTIVES: In this study the effect of budesonide on T cell survival, on inducible co-stimulator T cells (ICOS), on Foxp3 and on IL-10 molecules in T lymphocyte sub-populations was assessed. METHODS: Cell survival (by annexin V binding) and ICOS in total lymphocytes, in CD4+/CD25+ and in CD4+/CD25- and Foxp3 and IL-10 in CD4+/CD25+ and in CD4+/CD25-cells was evaluated, by cytofluorimetric analysis, in mild intermittent asthmatics (n = 19) and in controls (n = 15). Allergen induced T lymphocyte proliferation and the in vivo effects of budesonide in mild persistent asthmatics (n =…
Enhanced production of CCL18 by tolerogenic dendritic cells is associated with inhibition of allergic airway reactivity
2012
Background IL-10–treated dendritic cells (DCs) have been shown to inhibit T-cell responses through induction of anergy and regulatory T cells in various model systems, including allergic inflammation, but the factors being involved in this inhibition are still unclear. Objective This study set out to analyze such factors produced or induced by IL-10–treated DCs by using gene expression profiling and to explore their function. Methods CD4 + T cells from allergic donors were stimulated with autologous monocyte-derived allergen-pulsed mature DCs or IL-10–treated DCs. After 24 hours, the transcriptional profile was analyzed by using Affymetrix technology. Results were validated by using quantit…
Effects of glycation of the model food allergen ovalbumin on antigen uptake and presentation by human dendritic cells.
2010
Advanced glycation endproducts (AGEs) of food proteins resulting from the Maillard reaction after cooking or heating may have particular importance in food allergy. The underlying immunological mechanisms are only poorly understood. The aim of the study was to examine the effects of AGE derived from the model food allergen ovalbumin (AGE-OVA) on dendritic cells (DCs), their immunostimulatory capacity and the T-cell response compared with regular OVA. For this purpose, human immature DCs were exposed to fluorescein isothiocyanate (FITC)-labelled AGE-OVA and FITC-labelled regular OVA and uptake was analysed by flow cytometry and fluorescence microscopy. Furthermore, autologous CD4(+) T-cell p…
The Downside of an Effective cART: The Immune Restoration Disease
2013
The prognosis of patients infected with human immunodeficiency virus (HIV) type 1 has dramatically improved since the advent of the highly active antiretroviral therapy (HAART), which have enabled sustained suppression of HIV replication and recovery of CD4+ T cells count [1-3]. However, many patients in resource-poor settings still start HAART at a late stage of HIV infection when they already have advanced immunodeficien‐ cy [4,5]. Immune reconstitution in HIV infected patients is characterized by replenishment of immune cells depleted directly or indirectly by HIV infection, by regeneration of primary and secondary lymphoid organs, by restoration of pathogen-specific T, B and NK cells an…
Research in practice: Different dendritic cell types in skin with various functions - important implications for intradermal vaccines
2011
Summary It was long believed that epidermal Langerhans cells (LC) are responsible for the initiation of cellular immunity. Only recently it has been shown that in skin alone 5 different subtypes of dendritic cells (DC) can be identified. Among these, LC, but also two Langerin-expressing dermal DC populations and two more Langerin-negative DC subtypes exist. Novel findings in the model disease leishmaniasis, as well as evidence from research in contact hypersensitivity, have revealed that activation of LC in skin leads to induction of regulatory, immunosuppressive T cells, whereas the other skin DC subtypes stimulate effector T cells. Thus, when producing vaccines designed for intradermal us…
Advances in the understanding of mast cell function
2008
Mast cells were formerly thought to contribute mainly to, sometimes even, fatal allergic reactions through the release of biologically highly active cytokines, chemokines, lipid mediators, proteases and biogenic amines. This potential harmful response is triggered by crosslinking of cell-bound IgE by the respective allergen. This review updates our current understanding of the emerging roles of mast cells with an emphasis on their relevance in protective host immunity. The activation of mast cells independently of Immunoglobulin E can lead to the initiation of fast inflammatory reactions, which were shown to be life-saving in murine models of bacterial infections. Besides their critical fun…
Non-specific bronchial hyper-responsiveness in children with allergic rhinitis: relationship with the atopic status
2003
An increased prevalence of bronchial hyper-responsiveness (BHR) has been demonstrated in children from a general population, and in non-asthmatic adults with allergic rhinitis. Thus, also children with allergic rhinitis are expected to be at higher risk of BHR. We evaluated the prevalence of BHR in a sample of non-asthmatic children with allergic rhinitis by means of the methacholine (Mch) bronchial challenge, and by monitorizing the airway patency using the daily peak expiratory flow variability (PEFv). Fifty-one children (ranged 6-15 years of age) with allergic rhinitis, ascertained by skin prick test to inhalant allergens, underwent a 14-day peak expiratory flow monitoring, and a Mch bro…
Association of Blattella germanica sensitization with atopic diseases in pediatric allergic patients
2011
The extent to which the sensitization to the German cockroach Blattella germanica (BG) affects onset/presence of rhinoconjunctivitis (RC) in children is unknown.