Title: Properdin Contributes to Allergic Airway Inflammation through Local C3a Generation.
Authors: Wang, Yuan; Miwa, Takashi; Ducka-Kokalari, Blerina; Redai, Imre G; Sato, Sayaka; Gullipalli, Damodar; Zangrilli, James G; Haczku, Angela; Song, Wen-Chao
Published In J Immunol, (2015 Aug 01)
Abstract: Complement is implicated in asthma pathogenesis, but its mechanism of action in this disease remains incompletely understood. In this study, we investigated the role of properdin (P), a positive alternative pathway complement regulator, in allergen-induced airway inflammation. Allergen challenge stimulated P release into the airways of asthmatic patients, and P levels positively correlated with proinflammatory cytokines in human bronchoalveolar lavage (BAL). High levels of P were also detected in the BAL of OVA-sensitized and challenged but not naive mice. Compared with wild-type (WT) mice, P-deficient (P(-/-)) mice had markedly reduced total and eosinophil cell counts in BAL and significantly attenuated airway hyperresponsiveness to methacholine. Ab blocking of P at both sensitization and challenge phases or at challenge phase alone, but not at sensitization phase alone, reduced airway inflammation. Conversely, intranasal reconstitution of P to P(-/-) mice at the challenge phase restored airway inflammation to wild-type levels. Notably, C3a levels in the BAL of OVA-challenged P(-/-) mice were significantly lower than in wild-type mice, and intranasal coadministration of an anti-C3a mAb with P to P(-/-) mice prevented restoration of airway inflammation. These results show that P plays a key role in allergen-induced airway inflammation and represents a potential therapeutic target for human asthma.
PubMed ID: 26116506
MeSH Terms: Animals; Asthma/chemically induced; Asthma/immunology*; Asthma/pathology; Bronchoalveolar Lavage Fluid/chemistry; Bronchoalveolar Lavage Fluid/cytology; Complement C3a/biosynthesis*; Complement C3a/immunology; Eosinophils/immunology; Humans; Inflammation/immunology; Leukocyte Count; Lung/immunology; Lung/pathology; Methacholine Chloride/pharmacology; Mice; Mice, Inbred C57BL; Properdin/genetics; Properdin/immunology*; Th17 Cells/immunology*; Th2 Cells/immunology*