Interaction with Secretory Component Stimulates Effector Functions of Human Eosinophils But Not of Neutrophils This information is current as Youichi Motegi and Hirohito Kita of September 23, 2021. J Immunol 1998; 161:4340-4346; ; http://www.jimmunol.org/content/161/8/4340 Downloaded from References This article cites 49 articles, 20 of which you can access for free at: http://www.jimmunol.org/content/161/8/4340.full#ref-list-1 Why The JI? Submit online. http://www.jimmunol.org/ • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication *average by guest on September 23, 2021 Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 1998 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. Interaction with Secretory Component Stimulates Effector Functions of Human Eosinophils But Not of Neutrophils1 Youichi Motegi and Hirohito Kita2 Eosinophils and their products are important in the pathophysiology of allergic inflammation in mucosal tissues. Secretory component bound to IgA mediates transepithelial transport of IgA and confers increased stability on the resultant secretory IgA; however, the effect of secretory component on the biologic activity of IgA is unknown. Here, we report that secretory IgA and secretory component preferentially activate human eosinophils. When eosinophils were stimulated with immobilized secretory IgA, degranulation and su- peroxide production were two- to threefold greater than when stimulated with serum IgA. In contrast, neutrophils responded similarly to secretory IgA and serum IgA. Flow cytometric analysis showed that eosinophils bound to purified secretory component. The binding of 125I-labeled secretory component was inhibited by unlabeled secretory component or secretory IgA but not by serum IgA. Superoxide production by eosinophils stimulated with cytokines or IgG was enhanced synergistically by immobilized secretory component; secre- Downloaded from tory component showed no effect on neutrophil activation. Finally, anti-CD18 mAb abolished eosinophil superoxide production stim- b ulated with secretory IgA or secretory component but not with serum IgA, suggesting a crucial role for 2 integrins in eosinophil interactions with secretory IgA or secretory component. Thus, secretory component plays important roles in activating eosinophil functions but not neutrophil functions. This preferential interaction between secretory component and eosinophils may provide a novel mechanism to regulate mucosal tissue inflammation. The Journal of Immunology, 1998, 161: 4340–4346. http://www.jimmunol.org/ osinophils play important roles in the pathophysiology of Secretory IgA (S-IgA)3 is the main Ab secreted by the mucosa allergic diseases, such as bronchial asthma and allergic rhi- of the airways, gastrointestinal tract, and other mucosal tissues E nitis, and in host immunity to parasitic infections (reviewed (reviewed in Ref. 8). A high proportion of Ig-producing cells in the in Ref. 1). During such inflammatory reactions, eosinophils release mucosal lymphoid tissue is committed to the IgA isotype, and the toxic granule proteins, which act as cytotoxins on a variety of cell majority of IgA in mucosa is derived from local synthesis (9). types, including tracheal epithelial cells, pneumocytes, and parasites Receptors for the Fc portion of IgA (FcaR) have been established (reviewed in Ref. 1). In humans, eosinophils are tissue-resident cells on a variety of cell types, including lymphocytes (10, 11), mono- with .99% residing in tissues, especially in the mucosal tissues (2). cytes/macrophages (12, 13), neutrophils (14, 15), and eosinophils by guest on September 23, 2021 In healthy individuals, eosinophils are normally found only in the (16). The importance of IgA in mucosal immunity is further sup- intestine (2). In specimens from patients with bronchial asthma, eo- ported by the presence of secretory component (SC) in S-IgA (17). Epithelial cells express the polymeric Ig receptor, which binds and sinophils and released toxic granule proteins are found in the damaged mediates the transepithelial transport of IgA from the basolateral epithelium of bronchial tissues (3–5). In specimens from patients with side of the cells into the lumen (8, 18). The SC is a soluble pro- intestinal parasitic diseases, with allergic gastroenteritis or with celiac teolytic cleavage fragment of the extracellular domain of mem- disease, eosinophils are detected in large numbers in the lamina pro- brane-bound polymeric Ig receptor (19). Addition of SC to IgA pria of the small and large intestines (1). Furthermore, eosinophil in- confers increased stability on the resultant S-IgA by helping to filtration and degranulation are also observed in nasal epithelium of hold the IgA monomers together (20) and by masking proteolytic patients with upper respiratory allergy (6) and in biliary tracts of pa- sites from proteases present in mucosal secretions (21); however, tients with obstructive hepatic diseases (7). Thus, the association be- the effect of the addition of SC on the biologic activity of IgA is tween eosinophils and mucosal tissues in both healthy individuals and unknown. Recent studies showed that SC did not modify the abil- patients led us to speculate on the specific role(s) of eosinophils in ity of IgA to mediate hemagglutination inhibition and to neutralize mucosal inflammation and/or immunity. influenza virus in vitro (22). The SC consists of five Ig-like domains (23); this structure is used commonly as a cell surface receptor and an adhesion mole- cule. Furthermore, S-IgA immobilized onto Sepharose 4B beads potently stimulates eosinophil degranulation (24). These observa- tions lead us to hypothesize that SC directly interacts with human eosinophils and plays an important role in activation of this leu- Department of Immunology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905 kocyte. In this report, we demonstrate a unique function of SC as Received for publication April 6, 1998. Accepted for publication June 17, 1998. a costimulatory molecule for effector functions of human eosino- The costs of publication of this article were defrayed in part by the payment of page phils. This interaction between SC and eosinophils may provide a charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. 1 Supported in part by Grants AI 34577 and AI 34486 from the National Institutes of Health and by the Mayo Foundation. 3 Abbreviations used in this paper: S-IgA, secretory IgA; FcaR, receptor for the Fc 2 Address correspondence and reprint requests to Dr. Hirohito Kita, Department of portion of IgA; DCS, defined calf serum; EDN, eosinophil-derived neurotoxin; GM, Immunology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail ad- granulocyte-macrophage; HSA, human serum albumin; PE, phycoerythrin; SC, se- dress: [email protected] cretory component. Copyright © 1998 by The American Association of Immunologists 0022-1767/98/$02.00 The Journal of Immunology 4341 novel mechanism to regulate the magnitude of mucosal tissue eosinophil degranulation, the concentration of an eosinophil granule pro- inflammation. tein, eosinophil-derived neurotoxin (EDN), in the sample supernatants was measured by double Ab competition assay using radioiodinated EDN, rab- bit anti-EDN Ab, and burro anti-rabbit IgG, as previously reported (27). Materials and Methods Total cellular EDN was measured in supernatants from cells lysed with Reagents 0.5% Nonidet P-40 detergent. To quantify neutrophil degranulation, the concentration of elastase in the sample supernatants was measured by col- Human S-IgA was obtained from Organon Teknika-Cappel (Malvern, PA) orimetric assay (28, 29). Twenty microliters of samples or serial dilutions or Accurate Chemical & Scientific (Westbury, NY). Purified human serum of elastase standards were mixed with 130 ml of HBSS with 10 mM IgA and IgG were purchased from ICN Pharmaceuticals (Costa Mesa, CA). HEPES in 96-well culture plates, and 50 ml of 2.5 mM elastase substrate Purified human SC was kindly provided by Dr. Michael W. Russell (Uni- (MeOSuc-Ala-Ala-Pro-Val-pNA) (30) was added. Reaction mixtures were versity of Alabama, Birmingham, AL) (25). The IgG fraction of goat anti- 9 incubated at 37°C for 1 h. After incubation, the absorbance at 405 nm in human SC Ab and phycoerythrin (PE)-conjugated F(ab )2 fragments of each well was measured with a microplate reader (Thermomax; Molecular donkey anti-goat IgG Ab were purchased from INCSTAR (Stillwater, MN) Devices), and the elastase concentration was calculated using an elastase and Jackson Immunoresearch Laboratories (West Grove, PA), respectively. a standard curve made in the same assay. Total cellular elastase was mea- mAb against human Fc R (My43, mouse IgM) and control mAb (anti-ox sured in supernatants from cells lysed with 0.5% Nonidet P-40 detergent. erythrocytes,