Involvement of CCL18 in allergic asthma

Area of Science:

• Immunology
• Pulmonology
• Allergy Research

Background:

• Allergic asthma involves pulmonary immune cell recruitment, particularly Th2 cells, basophils, and eosinophils, driven by chemokine production.
• CCL18, a human-specific chemokine found in the lungs and induced by Th2 cytokines, is a potential factor in allergic asthma.

Purpose of the Study:

• To investigate the role of chemokine CCL18 in allergic asthma.
• To determine if CCL18 is produced by asthmatic patients' cells upon allergen exposure.
• To assess the functional effects of CCL18 on immune cells relevant to asthma.

Main Methods:

• Peripheral blood mononuclear cells (PBMCs) from house dust mite-allergic asthmatics and healthy donors were stimulated with Dermatophagoides pteronyssinus 1 (Der p 1).
• CCL18 levels were measured in cell cultures and bronchoalveolar lavage fluids.
• In vitro chemotaxis assays and histamine/calcium release assays were performed using polarized Th2 cells and basophils.

Main Results:

• PBMCs from allergic asthmatics produced CCL18 after Der p 1 stimulation, unlike those from healthy donors.
• CCL18 was found in bronchoalveolar lavages of untreated allergic asthmatics at higher levels than controls.
• CCL18 demonstrated preferential in vitro attraction of Th2 cells and basophils, inducing histamine and calcium release from basophils.

Conclusions:

• CCL18 is produced in response to allergen in allergic asthma.
• CCL18 attracts Th2 cells and basophils, suggesting a significant role in allergic asthma pathophysiology.
• CCL18 represents a novel therapeutic target for allergic asthma.