Abstract | BACKGROUND: Following consistent demonstrations of the clinical relevance of fluctuations in eosinophil-basophil (Eo-B) progenitors in the blood of patients with a variety of allergic airway disorders, we have turned our attention recently to hemopoietic events occurring in the bone marrow of allergic asthmatic subjects, utilizing a model of airway allergen challenge. METHODS: Flow-cytometric analyses of CD34/45+ progenitors for coexpression of surface alpha-receptor subunits for IL-3, IL-5 and GM-CSF, as well as in situ hybridization and in situ PCR methodologies to detect mRNA for IL-5 and GM-CSF in developing Eo-B in colony and liquid culture assays were employed before and after in vivo allergen challenge. RESULTS: An early, specific upregulation of IL-5R alpha expression on CD34/45 progenitors was observed after allergen challenge, concomitant with the development of the late-phase asthmatic response. Protein and mRNA for both GM-CSF and IL-5 were expressed in a time-dependent manner ex vivo, in developing (beta 7-integrin-positive), colony-derived Eo-B after allergen challenge in vivo. Both retinoic acid and corticosteroids were able to downregulate IL-3- and IL-5-induced expression of IL-5R on cord-blood-derived as well as HL-60 cloned Eo-B progenitors. CONCLUSION: These studies indicate the critical involvement of IL-5 and IL-5R in the induction of Eo-B differentiation and eosinophilic airway inflammation in allergic asthmatics, and point to these events as potential targets for long-term therapy of atopic disease.
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Authors | J A Denburg, R Sehmi, J Upham, L Wood, G Gauvreau, P O'Byrne |
Journal | International archives of allergy and immunology
(Int Arch Allergy Immunol)
1999 Feb-Apr
Vol. 118
Issue 2-4
Pg. 101-3
ISSN: 1018-2438 [Print] Switzerland |
PMID | 10224351
(Publication Type: Journal Article)
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Chemical References |
- Interleukin-5
- Receptors, Interleukin
- Receptors, Interleukin-5
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Topics |
- Asthma
(immunology, pathology)
- Bone Marrow Cells
(immunology, pathology)
- Cell Differentiation
(immunology)
- Eosinophils
(immunology, pathology)
- Humans
- Interleukin-5
(biosynthesis, immunology)
- Receptors, Interleukin
(biosynthesis, immunology)
- Receptors, Interleukin-5
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