International archives of allergy and applied immunology最新文献

Intrathoracic injections of bradykinin (1-100 micrograms/cavity) induced a dose-dependent increase in the number of eosinophils recovered from the rat pleural cavity 24 h later. Eosinophilia by bradykinin was preceded by a marked pleural neutrophil influx within 6 h and was absent only 72 h following stimulation. Bradykinin (10(-9)-10(-5) M) failed to induce in vitro eosinophil chemotaxis, indicating that its in vivo effect must be mediated by an intermediate messenger. BW 755C (25 mg/kg) and the more selective lipoxygenase inhibitor BW A4C (20 micrograms/cavity) suppressed the pleural eosinophilia induced by bradykinin (50 micrograms/cavity), whereas the platelet-activating factor (PAF)-acether antagonist BN 52021 was inactive. We conclude that bradykinin is able to attract eosinophil in vivo by a mechanism independent of PAF-acether and sensitive to the blockage of the lipoxygenase pathway.

The platelet aggregation in the presence of 4 aggregation inducers was studied in 63 allergic patients, consisting of atopic and non-atopic asthmatics and aspirin-sensitive subjects, before and after inhalation tests or in vitro incubation with allergen. Basal platelet aggregation was decreased in 43% of the atopic patients for adrenaline and also in a smaller percentage for other agonists. A decreased aggregation was also observed in 3 out of 6 nonatopic patients and in aspirin-sensitive patients. In vivo or in vitro provocation tests decreased aggregation in some additional patients. These results point out to a compromise of platelets in allergic mechanisms.

The fibroblast proliferation activity (FPA) in pulmonary granulomatous lesions in rabbits which were exposed once (primary response) or twice (secondary response) to Trichosporon cutaneum was examined using R9ab, a rabbit fibroblast cell line cell, and fibroblasts from the lesions of the primary and secondary responses. The FPA in lung extracts and cell-free culture supernatants of bronchoalveolar lavage cells from the secondary response was more evident than that from the primary response. FPA from the primary response were recovered at about 60, 18, and 4.5 kD and those from secondary response at about 60, 26, 18, and 4.5 kD on Sephadex G-75 gel filtration. Among the FPA, the activity with a molecular weight of 26 kD and a pI of 7.0 was derived from lymphocytes, whereas the other activities were derived from macrophages. The macrophage-derived fibroblast proliferation factors (FPF) enhanced proliferation of fibroblasts from the lesions of both primary and secondary responses, while the lymphocyte-derived FPF enhanced only proliferation from the secondary response. It was further found that lymphocyte-derived FPF could chemotactically attract fibroblasts from the secondary but not the primary response, indicating functional specificity of lymphocyte-derived FPF on fibroblasts in the secondary response. The present results suggest that this lymphokine with fibroblast proliferation and chemotactic activity plays an important role in the granuloma formation in the secondary response to T. cutaneum.

Hemoglobins (Chi t I) of the dipteron species Chironomus thummi thummi are known to cause severe allergic diseases in humans. We tested the allergen-specific stimulation of human peripheral blood lymphocytes (PBL) by Chi t I and its nine main components. Further, we applied fragments of the well-analyzed component III, obtained by cleavage with trypsin as well as arginine protease. In this way, we screened the molecule in order to identify T-cell epitopes. The whole component was found to be immunogenic and to have regions demonstrating varying PBL stimulation. In addition, interindividual patterns of reactivity, probably due to genetic restriction, were found. A T-cell epitope could be shown to be within the site 98-111, as predicted by application of Rothbard's algorithms.

A cytokine, termed histamine-releasing factor (HRF) and produced by many cell types, has become the focus of research by many investigators due to its potential importance as a stimulus in chronic inflammation. We are producing and characterizing an HRF which causes IgE-mediated histamine release from human basophils. Following extensive purification procedures, the molecule will be sequenced and synthesized. A functional heterogeneity of IgE molecules was revealed by these studies. We are currently producing IgE antibody in vitro and testing the hypothesis that differential glycosylation is the basis for the heterogeneity. Knowledge of the structures and interactions of these molecules should advance our understanding of allergic and more chronic diseases.

Histamine-releasing factors (HRF) are cell-derived products which cause histamine release from basophils and/or mast cells. We have isolated HRF from human mononuclear cells and platelets and have purified 3 molecular species having molecular weights of 8-10, 15-17 and 35-41 kilodaltons (kDa). We prepared monoclonal antibodies to the 8- to 10-kDa form and have isolated it by affinity chromatography. A broad band was seen upon sodium dodecyl sulfate gel electrophoresis in 15% gels as well as immunoblotting, and the band was divided into an upper and a lower half. Amino acid sequence analysis of the upper half indicated that it is closely homologous to connective-tissue activating peptide III (CTAP III). The lower half also aligned with CTAP III beginning with amino acid 16; thus, proteolysis and occurred removing the N-terminal 15 amino acids. This corresponds to neutrophil-activating peptide 2. Both appear to be active on basophils with a dose-response between 250 ng up to 10 micrograms. Although interleukin-3 and granulocyte/macrophage-colony-stimulating factor have similar histamine-releasing capability at lower effective concentrations, they do not account for HRF activity in mononuclear cell/platelet supernatants, and the 15- to 17 and 40- to 41-kDa moieties appear to be unique gene products unrelated to previously described cytokines.

Biologically active molecules affecting basophil function can be divided into 4 groups according to their capacity to induce basophil degranulation and/or leukotriene generation: (1) full agonists such as anti-IgE or fMLP, which induce both histamine and leukotriene release; (2) partial agonists such as C5a, which induces degranulation only; (3) incomplete agonists such as neutrophil-activating peptide-1, platelet-activating factor or C3a, which induce mediator release only after cytokine preincubation, and (4) basophil response modifiers, such as interleukin-3, interleukin-5 and granulocyte/macrophage- colony-stimulating factor, which (a) enhance the releasability to all basophil agonists, (b) change the mediator profile, (c) enhance the rate of mediator release, (d) render basophils responsive to lower agonist concentrations and (e) render basophils responsive to incomplete agonists. We demonstrated that histamine release and de novo synthesis of lipid mediators are clearly separately regulated, and that combined actions of different molecules are of importance. In particular, the type(s), the time interval and the sequence of action of basophil-activating molecules are crucial for the final outcome of the basophil release reaction.

Gluten intolerance (coeliac disease) is characterised by the development of a small intestinal lesion following exposure to the gliadin fraction after consumption of wheat and related cereals. Cellular immune mechanisms are thought to be responsible for gliadin toxicity, but the toxic sequence/s within gliadin have not been clearly established. A panel of synthetic gliadin peptides was tested using peripheral blood mononuclear cells from coeliac patients and two assays for cell-mediated immunity. Using the indirect leucocyte migration inhibition factor and the macrophage procoagulant activity assays, gliadin peptides which were located in the aminoterminal or the proline-rich domain of the alpha/beta gliadin molecule were coeliac-active. Peptides predicted by T cell algorithms or on the basis of homology to adenovirus Ad12 Elb protein and which were located in the proline-poor gliadin domains were inactive. Protein sequence studies which indicate significant homology in the proline-poor gliadin domains with a number of non-coeliac-toxic seed proteins also supported the hypothesis that the proline-rich domains may be more important in the pathogenesis of coeliac disease.

To investigate neural events within the airways in asthma, endobronchial biopsies were obtained by fibre-optic bronchoscopy from 8 atopic asthmatic subjects and 8 non-atopic healthy controls. The biopsies were immediately fixed on sampling and subsequently analysed for nerves using specific indirect immunofluorescence with antisera to the neural marker PGP 9.5 and to the neuropeptides vasoactive intestinal peptide (VIP), substance P (SP) and calcitonin gene-related peptide (CGRP). Nerves were present in all the biopsies from both subject groups, with no significant difference between the asthmatic and non-asthmatics. VIP-immunoreactive nerves were equally present in both subject groups, being localized to smooth muscle and glandular sites. No immunoreactive nerves to SP or CGRP could be identified in any biopsy at any location. These in vivo findings do not identify an anatomical neuronal imbalance in asthma.

A study was carried out on 29 patients to investigate the amount of histamine liberation and release of platelet-activating factor and 6-keto-prostaglandin F1 alpha from gastric mucosa and whole blood or mononuclear cells by sodium benzoate. The patients suffered from asthma (10), atopic dermatitis (7) and chronic urticaria (4). 8 patients with unrelated, non-immunologic diseases served as controls. In the oral provocation test (OPT) 3 patients experienced a recurrence of their original disease, whilst 1 asthmatic patient reacted with abdominal disorder. The release of histamine and prostaglandin from mucosa was significantly increased by sodium benzoate in comparison to the spontaneous release observed in patients. The mucosa of the control persons did not react to sodium benzoate. Furthermore, there was a significant difference in prostaglandin release between patients with positive OPT and the control persons. No difference could be found between patients with negative OPT and those with positive OPT. Additionally, in the mediator release from whole blood or mononuclear cells there was no obvious difference apparent. These results suggest a possible involvement of prostacyclin and histamine in adverse reactions to benzoate. Due to the sensitivity of the method, a mediator release from mucosa can already be demonstrated in a preclinical state of the pseudoallergic reaction in the absence of clinical symptoms.