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Late-phase Reactions (late-phase + reaction)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Early production of thymic stromal lymphopoietin precedes infiltration of dendritic cells expressing its receptor in allergen-induced late phase cutaneous responses in atopic subjects

ALLERGY, Issue 7 2009
C. J. Corrigan
Background:, Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine that triggers dendritic cell-mediated T helper (Th)2 inflammatory responses through a receptor consisting of a heterodimer of the IL-7 receptor alpha (IL-7R,) chain and the TSLP receptor (TSLPR), which resembles the cytokine receptor common gamma chain. Dendritic cells activated by TSLP prime development of CD4+ T cells into Th2 cells contributing to the pathogenesis of allergic inflammation. We hypothesized that allergen exposure induces expression of TSLP and results in recruitment of TSLPR bearing cells in the cutaneous allergen-induced late-phase reaction (LPR) in atopic subjects. Methods:, Skin biopsies were obtained from atopic subjects (n = 9) at various times after cutaneous allergen challenge. In situ hybridization and immunohistochemistry were used to determine TSLP mRNA expression and to measure infiltration of TSLPR+ DC in skin LPR. RT-PCR and flow cytometry were employed to analyse TSLPR expression on isolated blood DC. Results:, Allergen-induced skin TSLP expression occurred as early as 1 h after allergen challenge, whereas TSLPR+ and CD11c+ cells infiltrated relatively late (24,48 h). The majority of TSLPR+ cells were DC co-expressing blood DC antigen-1 (BDCA-1) or BDCA-2. Freshly isolated blood DC expressed both TSLPR and IL-7R, chains. Maturation and stimulation with TSLP or polyriboinosinic,polyribocytidylic acid in vitro upregulated the expression of both TSLPR and IL-7R, chains in DC but not in chemoattractant receptor-homologous molecule expressed on Th2 cells+ CD4+ T cells. Conclusion:, The data suggest that TSLP plays a role in augmenting, through DC recruitment and activation, the development of Th2-type T cells in allergic inflammation. [source]

The cells and mediators of allergic inflammation

CLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2002
A. B. Kay
Summary In sensitized atopic subjects allergen administration results in an immediate-type reaction and, depending on the dose of the allergen, an additional late-phase reaction. The early reaction results largely from the release of histamine, leukotrienes and other mediators from mast cells. The cutaneous late-phase reaction is probably also predominantly mast-cell-dependent. The late asthmatic reaction, however, also involves T-cell activation. T cells release a cascade of factors which evoke the migration of many cell types, including eosinophils, neutrophils and macrophages into the site of inflammation, under the influence of a complex combination of cytokines and chemokines. Neural inflammation (i.e. neuropeptides and neurotrophins) may also be involved. The identification of the processes underlying the inflammatory response to allergens, and their control mechanisms, provides specific targets for therapeutic measures (such as the use of monoclonal antibodies and soluble receptor molecules) which are designed to impede or abolish the allergic inflammatory cascade. [source]

The impact of pollen-related food allergens on pollen allergy

ALLERGY, Issue 1 2007
B. Bohle
Patients with birch pollen allergy frequently develop hypersensitivity reactions to certain foods, e.g. apples, celery, carrots and hazelnuts. These reactions are mainly caused by IgE-antibodies specific for the major birch pollen allergen, Bet v 1, which cross-react with homologous proteins in these foods. Analyzing the T-cell response to Bet v 1-related food allergens revealed that these dietary proteins contain several distinct T-cell epitopes and activate Bet v 1-specific T cells to proliferate and produce cytokines. Several of these cross-reactive T-cell epitopes were not destroyed by simulated gastrointestinal digestion of food allergens and stimulated Bet v 1-specific T cells despite nonreactivity with IgE antibodies. Similarly, cooked food allergens did not elicit IgE-mediated symptoms (oral allergy syndromes) but caused T-cell-mediated late-phase reactions (deterioration of atopic eczema) in birch pollen-allergic patients with atopic dermatitis because thermal processing affected their conformational structure and not the primary amino acid sequence. Thus, T-cell cross-reactivity between Bet v 1 and related food allergens occurs independently of IgE-cross-reactivity in vitro and in vivo. We speculate that symptom-free consumption of pollen-related food allergens may have implications for the pollen-specific immune response of allergic individuals. [source]

Macrophage inflammatory protein-1, and C,C chemokine receptor-1 in allergen-induced skin late-phase reactions: relationship to macrophages, neutrophils, basophils, eosinophils and T lymphocytes

CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2001
S. Ying
Background Macrophage inflammatory protein (MIP)-1, binds to C,C chemokine receptor (CCR)-1 with high affinity. CCR-1 is expressed on neutrophils, eosinophils, monocytes, T lymphocytes and basophils; cells characteristic of atopic allergic inflammation. In vitro, MIP-1, is chemotactic for monocytes, T cells and basophils and is also a potent histamine-releasing factor for basophils and mast cells. Although increased levels of MIP-1, were shown in atopic allergic disorders, the kinetics of expression of these CC chemokines in vivo is largely unknown. Objective To investigate the kinetics of expression of MIP-1, and receptor CCR-1 and the relationships between the expression and infiltration of inflammatory cells in allergen-induced cutaneous late-phase reactions in atopic subjects. Methods Cryostat sections, obtained from skin biopsies from 10 human atopic subjects at 6, 24, 48, 72 h and 7 days after allergen challenge, were processed for immunohistochemistry and in situ hybridization using 35S-labelled riboprobes. Results The peak expression of allergen-induced mRNA for MIP-1, and CCR-1 was 6 h. This was maintained at 24 h, and gradually returned to base line at 7 days. At 6 h, the number of cells expressing MIP-1, mRNA significantly correlated with elastase+ neutrophils and BB-1+ basophils. At 24 h, the MIP-1, mRNA+ cells significantly correlated with CD68+ macrophages. There were significant inverse correlations between the numbers of MIP-1, mRNA cells and the numbers of Tryptase+ mast cells at 6 and 24 h after allergen challenge. Conclusion Allergen-induced cutaneous late-phase reactions in humans were associated with increased expression of MIP-1, and CCR-1. This may be relevant to the infiltration of neutrophils, eosinophils, basophils and macrophages. [source]