Related Experiment Video
Updated: May 18, 2026

Three-Dimensional Cell Culture Models to Investigate the Epithelial Barrier in Eosinophilic Esophagitis
Published on: May 10, 2024
Dysregulated synthesis of protectin D1 in eosinophils from patients with severe asthma
Jun Miyata1, Koichi Fukunaga, Ryo Iwamoto
1Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
Background:
Protectin D1 (PD1) is an anti-inflammatory and proresolving lipid mediator biosynthesized from the omega-3 fatty acid docosahexaenoic acid (DHA). Exogenous PD1 conferred protection against eosinophilic inflammation in animals with experimental asthma, although its endogenous cellular source and functions in human airways are of interest.
Objective:
We sought to investigate the synthesizing capacity of PD1 in eosinophils from healthy subjects and patients with severe asthma and its direct effects on eosinophil functions.
Methods:
Human eosinophil-derived metabolites of arachidonic acid and DHA were analyzed with liquid chromatography-tandem mass spectrometry-based lipidomic analysis. The biological activities of PD1 on the function of human eosinophils, including chemotaxis, adhesion molecule expressions, degranulation, superoxide anion generation, or survival, were examined.
Results:
We identified PD1 as one of the main anti-inflammatory and proresolving molecules synthesized in human eosinophils. PD1, in nanomolar concentrations, suppressed the chemotaxis induced by CCL11/eotaxin-1 or 5-oxo-eicosatetraenoic acid and modulated the expression of the adhesion molecules CD11b and L-selectin, although it had no effects on the degranulation, superoxide anion generation, or survival of the eosinophils. Compared with the cells harvested from healthy subjects, we observed a prominent decrease in the biosynthesis of PD1 by eosinophils from patients with severe asthma, even in presence of DHA.
Conclusion:
These observations are a first indication that activated human eosinophils represent a major source of PD1, which can act as a self-resolving machinery in eosinophilic inflammation, whereas the production of PD1 is impaired in patients with severe asthma.
Related Concept Videos
Asthma I: Introduction
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Chronic Obstructive Pulmonary Disease II: Emphysema
