Eosinophils contribute to the resolution of lung-allergic responses following repeated allergen challenge

Katsuyuki Takeda, Yoshiki Shiraishi, Shigeru Ashino, Junyan Han, Yi Jia, Meiqin Wang, Nancy A. Lee, James J. Lee, Erwin W. Gelfand

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

Background Eosinophils accumulate at the site of allergic inflammation and are critical effector cells in allergic diseases. Recent studies have also suggested a role for eosinophils in the resolution of inflammation. Objective To determine the role of eosinophils in the resolution phase of the response to repeated allergen challenge. Methods Eosinophil-deficient (PHIL) and wild-type (WT) littermates were sensitized and challenged to ovalbumin (OVA) 7 or 11 times. Airway inflammation, airway hyperresponsiveness (AHR) to inhaled methacholine, bronchoalveolar lavage (BAL) cytokine levels, and lung histology were monitored. Intracellular cytokine levels in BAL leukocytes were analyzed by flow cytometry. Groups of OVA-sensitized PHIL mice received bone marrow from WT or IL-10-/- donors 30 days before the OVA challenge. Results PHIL and WT mice developed similar levels of AHR and numbers of leukocytes and cytokine levels in BAL fluid after OVA sensitization and 7 airway challenges; no eosinophils were detected in the PHIL mice. Unlike WT mice, sensitized PHIL mice maintained AHR, lung inflammation, and increased levels of IL-4, IL-5, and IL-13 in BAL fluid after 11 challenges whereas IL-10 and TGF-β levels were decreased. Restoration of eosinophil numbers after injection of bone marrow from WT but not IL-10-deficient mice restored levels of IL-10 and TGF-β in BAL fluid as well as suppressed AHR and inflammation. Intracellular staining of BAL leukocytes revealed the capacity of eosinophils to produce IL-10. Conclusions After repeated allergen challenge, eosinophils appeared not essential for the development of AHR and lung inflammation but contributed to the resolution of AHR and inflammation by producing IL-10.

Original languageEnglish (US)
Pages (from-to)451-460.e5
JournalJournal of Allergy and Clinical Immunology
Volume135
Issue number2
DOIs
StatePublished - Feb 1 2015

Keywords

  • Eosinophils
  • IL-10
  • resolution of inflammation

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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