International archives of allergy and applied immunology最新文献

Availability of reproducible mouse models for allergic contact dermatitis (ACD) to the metal allergens nickel, mercury and chromium, would be of great value for pathogenetic and preventive studies. We explored epicutaneous sensitization to nickel, mercury and chromium in mice in which oral grooming of the sensitization site was prevented by a plaster cast around the abdomen and lower thorax. This procedure was based on earlier findings that oral ingestion of allergen could prevent contact sensitization. The present results show that BALB/c mice can be readily sensitized to mercury and chromium using this epicutaneous casting method, without the further use of adjuvants. With nickel, however, neither this method, nor conventional methods involving the use of Freund's complete adjuvant (FCA) were effective.

Mononuclear phagocytes have been investigated in biopsies taken from the nasal mucosa and in epithelial cell samples from 22 grass-pollen-allergic subjects before season, after allergen challenge and during season by means of immunohistochemistry and electron microscopy. The cells were positive for CD68/EBM11 and HLA-DR, but failed to react with CD1 and CD23/BB10. The cells increased in number during season as well as after allergen challenge, especially in the upper part of the mucosa. Heteromorphy of macrophages, as seen by transmission electron microscopy, confirmed the presence of diverse macrophage subpopulations in the nasal mucosa of allergic subjects. Using brush sampling techniques, CD68-positive and HLA-DR-positive cells significantly increased in epithelial cell samples 4-8 h after allergen challenge, indicating a central role of these cells not only in antigen processing but also in late phase reactions of allergic rhinitis.

Peripheral blood mononuclear cells from 8 normals and 8 patients with atopic dermatitis (AD) were cultured with recombinant interleukin-4 (IL-4) and the IgE and IgG subclass levels in the culture supernatants measured by radioimmunoassays. IL-4 induced IgE and IgG4 secretion by B cells from both normals and AD patients whereas it has no consistent effect on IgG1, IgG2 and IgG3 secretion. The IL-4 dose response was similar for IgE and IgG4 secretion by cells from both normals and AD patients. On the average, the patients' cells secreted more IgE and less IgG4 than the cells from normals, but because of a large variation, the differences were not significant. However, the ratio of IgG4:IgE secretion was significantly greater for normals than AD patients (mean +/- SEM 7.1 +/- 1.6:1 vs. 1.5 +/- 0.4:1; p less than 0.01). The data demonstrate that IL-4 induces IgE and IgG4 secretion by B cells from both normals and AD patients and suggest that the IL-4 induced switch from IgM to IgG4 or IgE secretion may proceed preferentially to IgE in AD patients as compared to normals.

A long-term co-culture of mononuclear cells of human umbilical cord blood with mouse embryo-derived 3T3 fibroblasts resulted in the development of human mast cells. These mast cells are morphologically and functionally mature cells, containing 1.4-2.8 micrograms histamine per 10(6) cells and bear approximately 10(5) Fc epsilon RI per cell. The mast cells sensitized with human IgE released histamine upon challenge with anti-IgE. Electron-microscopic analysis of the cells showed that these cells were mature human mast cells, and clearly different from basophilic granulocytes. Most of the mast cells contained some granules with regular crystalline arrays and both tryptase and chymase, resembling human skin mast cells. When mononuclear cells of cord blood were seeded in a millicell insert which was placed on 3T3 fibroblasts monolayer, the number of mast cells developed in the millicell inserts was comparable to those developed in the co-culture of the same cord blood cells with 3T3 fibroblasts. Recent observations that mast cells developed in the presence of concentrated culture supernatants of 3T3 fibroblasts without fibroblasts feeder layers, confirmed that soluble factors released from 3T3 fibroblasts are essential and sufficient for the differentiation of human mast cell progenitors in vitro. Analysis of functional characteristics of cultured mast cells revealed that they respond to anti-IgE, Ca2+ ionophore A23187 and substance P for histamine release, but failed to respond to compound 48/80 and FMLP. Upon anti-IgE challenge, sensitized mast cells generated approximately 80 ng PGD2 per 10(6) cells, and approximately 50 ng of LTC4 per 10(6) cells but no detectable generation of LTB4.(ABSTRACT TRUNCATED AT 250 WORDS)

To further define the role of histamine in the nasal mucosa, we studied the possible effect of histamine provocation on the generation of prostanoids and leukotrienes, and on the induction of hyperresponsiveness to methacholine. In separate experiments, we performed nasal challenges with histamine and measured by gas chromatography negative ion mass spectrometry and by radioimmunoassay after high-performance liquid chromatography the levels of prostanoids and leukotrienes, respectively, in recovered nasal lavages 10 min after challenge. Hyperresponsiveness to methacholine was tested in both nostrils 24 h after unilateral provocation with histamine. Our data suggest that histamine induced an immediate symptomatic response, but neither led to the generation of prostaglandins or leukotrienes nor induced hyperresponsiveness to methacholine. These results differ from those achieved after antigen stimulation and emphasize the importance of mediators in addition to histamine in the allergic reaction.

Air samples taken from the clean air over Bristol were examined using scanning, transmission and X-ray probe micro-analysis. A diversity of material was identified demonstrating the importance of man-made pollutants which have the potential to produce lung damage in addition to pollen moulds.

Because the secretions of asthma and rhinitis contain toxic eosinophil granule proteins and because secretory IgA is the most potent immunoglobulin stimulus for eosinophil degranulation, we measured eosinophil-derived neurotoxin and ragweed-specific IgA and IgE antibodies in nasal lavage before and during the ragweed pollen season in 44 hay fever patients. We found IgA antibody in nanogram/milliliter concentrations before the season and rising 20-fold by the end of the season. IgE antibody was present in picogram/milliliter concentrations and did not change. Eosinophils and eosinophil-derived neurotoxin also increased. We conclude that IgA is the predominant antibody in allergic nasal secretions and increases with allergen exposure. The hypothesis that secretory IgA antibody-allergen complexes contributes to allergic inflammation by stimulating eosinophil degranulation warrants further study.

We investigated the capacity of excretory and secretory antigen (ES) derived from living filarial worms in the induction of CD23 expression on human peripheral blood T cells by using flow cytometry. ES (10 micrograms/ml) significantly induced the expression of CD23 on human T cells. Moreover, increased CD23 expression was completely abolished by preincubation with specific antibody to ES. The results suggest that ES might play a certain role in IgE antibody production by induction of CD23 expression on T cells.

Abnormalities of peripheral-blood lymphocyte subsets and activation markers were detected in patients with both allergic and nonallergic asthma. Most allergic asthmatics were characterized by increased numbers of IL-2R+ helper T cells and CD23+ B cells. In contrast, nonallergic asthmatics showed increased numbers of IL-2R+ and HLA-DR+ helper and cytotoxic T cells, and a clear redistribution from naive (CD45RA+) to memory (CD45RO+) cells. The number of IL-2R+ T cells correlated with the number of CD23+ B cells in allergic asthma. These changes in the distribution and activation state of T cells suggest an active role for T cells in the pathogenesis of both allergic and nonallergic asthma.