Human eosinophils express and release IL-13 following CD28-dependent activation.
Human eosinophils produce a large number of cytokines, including immunoregulatory cytokines. Given that eosinophils store and release interleukin (IL)-4, a key cytokine in the pathogenesis of allergic inflammation, and that IL-4 and IL-13 share common biological functions, we investigated the possibility that IL-13 may be synthesized by these cells. Using flow cytometry and immunocytochemistry, we show that eosinophils synthesize and store IL-13. Granule localization was demonstrated after subcellular fractionation, and IL-13 immunoreactivity was localized to crystalloid, granule-enriched fractions. Furthermore, electron microscopic analyses specifically localized IL-13 to the dense cores of bicompartmental secondary granules. Upon CD28 ligation, IL-13 was released by eosinophils, whereas a combination of CD28 and immunoglobulin A complexes resulted in decreased IL-13 secretion. Furthermore, eosinophil-derived IL-13 exerts a biological effect, inducing CD23 expression on B cells. By having the capacity to synthesize and release IL-13, eosinophils may participate in the development and maintenance of the T helper cell type 2 response, a prominent feature of allergic diseases.
Woerly
Gaetane
G
Centre d'Immunologie et Biologie Parasitaire, Unité INSERM U547 and IFR17, Institut Pasteur, Lille, France.
Lacy
Paige
P
Younes
Amena Ben
AB
Roger
Nadine
N
Loiseau
Sylvie
S
Moqbel
Redwan
R
Capron
Monique
M
D018106:CD28 Antigens / Q000276:immunology*; D002478:Cells, Cultured; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000097:blood / Q000276:immunology*; D018793:Interleukin-13 / Q000235:genetics / Q000276:immunology*; D015847:Interleukin-4 / Q000096:biosynthesis; D007424:Intracellular Fluid / Q000276:immunology; D008854:Microscopy, Electron
D018106:CD28 Antigens; D018793:Interleukin-13; D015847:Interleukin-4