title: Upregulated interleukin-21 receptor on B cells associated with the downregulation of IgE in patients with allergic rhinitis.
abstract: Allergic diseases, such as allergic rhinitis, caused by an immunoglobulin E (IgE)-mediated reaction to specific allergens are a common chronic condition worldwide. Interleukin-21 (IL-21), a type I cytokine that is produced by T cells, exerts regulatory effects on a variety of immune cells. In our previous study, we found that serum levels of IL-21 were significantly decreased in patients with severe atopic dermatitis, suggesting that IL-21 might play a role in allergic reactions. In this study, we investigated the role of IL-21/IL-21 receptor (IL-21R) in patients with allergic rhinitis. Our results demonstrated that there was no difference in IL-21 serum levels between allergic rhinitis patients and controls. However, allergic patients had significantly increased expression of IL-21R on naive and memory B cells. IL-21R was upregulated through stimulation by the combination of CD40 ligand (CD40L) and IL-4. IL-21 alone neither induced nor inhibited IgE secretion from CD40L-stimulated B cells. However, IL-21 inhibited IgE secretion of B cells that were induced by the combination of CD40L and IL-4 in allergic patients. Moreover, a negative correlation between the expression of IL-21R and serum levels of IgE was found in patients with allergy. These results suggest that the role of IL-21 in an ongoing allergic reaction is to downregulate the IgE level by binding to IL-21R on B cells, which increases the expression in allergic patients.
authors.affiliation: 1 Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University , Taipei, Taiwan .
authors.forename: Hsiao-Yu
authors.initials: HY
authors.lastname: Jen
authors.forename: Yao-Hsu
authors.initials: YH
authors.lastname: Yang
authors.forename: Bor-Luen
authors.initials: BL
authors.lastname: Chiang
authors.forename: Ya-Hui
authors.initials: YH
authors.lastname: Chuang
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand / Q000276:immunology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D053738:Interleukin-21 Receptor alpha Subunit / Q000096:biosynthesis* / Q000276:immunology; D007378:Interleukins / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D050830:L-Amino Acid Oxidase / Q000276:immunology; D008297:Male; D011485:Protein Binding; D065631:Rhinitis, Allergic / Q000276:immunology*; D015854:Up-Regulation; D055815:Young Adult; D000098546:Interleukin-21
chemical_list: C508117:IL21R protein, human; D053738:Interleukin-21 Receptor alpha Subunit; D007378:Interleukins; D023201:CD40 Ligand; D007073:Immunoglobulin E; C105158:IL4I1 protein, human; D050830:L-Amino Acid Oxidase; D000098546:Interleukin-21