Distinct immunohistochemical localization of IL-4 in human inflamed airway tissues. IL-4 is localized to eosinophils in vivo and is released by peripheral blood eosinophils
| Autor: | M Nonaka, R Nonaka, K Woolley, E Adelroth, K Miura, Y Okhawara, M Glibetic, K Nakano, P O'Byrne, J Dolovich |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 155:3234-3244 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.155.6.3234 |
| Popis: | Nasal polyposis and asthma are inflammatory conditions of the airways characterized by infiltration of activated inflammatory cells, particularly eosinophils. IL-4 is a multifunctional cytokine considered to play an important role in eosinophilic inflammation. We examined the cellular distribution of immunoreactive IL-4 in nasal polyps, as well as in the bronchial mucosa of both nonasthmatic control subjects (n = 6) and patients with well-characterized mild asthma (n = 6) subjected to a diluent or an allergen challenge. To determine eosinophilic contribution, tissue sections were counterstained with FITC after IL-4 immunostaining. No eosinophils were observed in the bronchial mucosa of nonasthmatic subjects. Nasal polyp tissues contained approximately 15 times more eosinophils per mm2 compared with bronchial tissues from asthmatics after a diluent challenge. Allergen challenge resulted in a marked increase in eosinophil density in bronchial tissues. A negligible number of cells immunostaining IL-4 was observed in bronchial tissues from nonasthmatic control subjects. The density of IL-4-positive cells in nasal polyp tissues was almost three times greater compared with asthmatics bronchial tissues after a diluent challenge. Approximately 90% of the IL-4-positive cells in bronchial tissues did not exhibit fluorescence after FITC counterstaining; in contrast, about 80% of the IL-4-positive cells in nasal polyp tissues did. We also show that peripheral blood eosinophils from allergic subjects express IL-4 mRNA by Northern blot analysis, particularly on stimulation with secretory IgA immune complexes. Finally, the supernatant of stimulated eosinophils contained approximately 50 pg/10(6) cells of IL-4 as determined by ELISA. These data demonstrate that eosinophils express the message and release IL-4 in vitro, and that these cells are the primary source of immunoreactive IL-4 in tissues undergoing chronic severe mucosal inflammation. |
| Databáze: | OpenAIRE |
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