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Critical role of CCL4 in eosinophil recruitment into the airway
Author(s) -
Kobayashi Yoshiki,
Konno Yasunori,
Kanda Akira,
Yamada Yoshiyuki,
Yasuba Hirotaka,
Sakata Yoshiko,
Fukuchi Mineyo,
Tomoda Koichi,
Iwai Hiroshi,
Ueki Shigeharu
Publication year - 2019
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/cea.13382
Subject(s) - eosinophil , ccl11 , eosinophilic pneumonia , bronchoalveolar lavage , eosinophil granule proteins , immunology , ccl4 , eotaxin , medicine , chemokine , infiltration (hvac) , ccl5 , airway , asthma , inflammation , pathology , major basic protein , lung , chemistry , immune system , t cell , il 2 receptor , carbon tetrachloride , thermodynamics , physics , organic chemistry , surgery
Summary Background Excessive eosinophil airway infiltration is a clinically critical condition in some cases. Eosinophilic pneumonia (EP) is a pulmonary condition involving eosinophil infiltration of the lungs. Although several chemokines, including eotaxin‐1 (CCL11), RANTES (CCL5) and macrophage inflammatory protein 1β (MIP‐1β or CCL4), have been detected in bronchoalveolar lavage fluid (BALF) from patients with EP, the pathophysiological mechanisms underlying EP, including potential relationships between eosinophils and CCL4, have not been fully elucidated. Objective To examine the involvement of CCL4 in eosinophilic airway inflammation. Methods We analysed supernatants of activated eosinophils and BALF from 16 patients with eosinophilic pneumonia (EP). Further, we examined the effects of CCL4 on eosinophil functions in vitro and those of anti‐CCL4 neutralizing antibody in an in vivo model. Results We found that purified human eosinophils stimulated with IL‐5 predominantly secreted CCL4 and that patients with EP had elevated CCL11 and CCL4 levels in BALF compared with samples from individuals without EP. Because CCL4 levels were more strongly correlated with eosinophil count and expression of eosinophil granule proteins than CCL11, in vitro experiments using purified eosinophils concentrated on the former chemokine. Interestingly, CCL4 acted as a chemoattractant for eosinophils. In a mouse model, administration of a CCL4‐neutralizing antibody attenuated eosinophilic airway infiltration and airway hyperresponsiveness. Conclusions and Clinical Relevance Overall, these findings highlight an important role of CCL4 in the mechanisms underlying eosinophil recruitment into the airway and may provide a novel insight into this potential therapeutic target.