Relationship between CCR5+FoxP3+ Treg cells and forced expiratory volume in 1 s, peak expiratory flow in patients with severe asthma
Łukasz Kraszula, Makandjou-Ola Eusebio, Piotr Kuna, Mirosława Pietruczuk
Abstract
Introduction: Severe asthma is a special clinical problem. CD4 + CD25 high CD127 low Foxp3 + Tregs play a role in maintaining appropriate immunological response. It is a known fact that Treg cells with CCR5 expression represent strong suppressive activity. It has been shown that a low number or altered function of FoxP3 + Tregs is associated with the inflammatory process and airway obstruction in asthma. Aim: To evaluate whether CCR5 Tregs expression and surface density on FoxP3 + Treg cells depend on the severity of asthma. Material and methods: The study included 50 patients with asthma (25 with severe and 25 with mild-to-moderate asthma). The control group comprised 25 healthy volunteers. The phenotype of CD4 + CD25 high CD127 low Foxp3 + CCR5 + cells was evaluated by multicolour flow cytometry. The degree of airflow obstruction was assessed by spirometry as forced expiratory volume in 1 s (FEV 1 ) and peak expiratory flow (PEF). Results: The absolute count of FoxP3 + Treg cells in patients with severe asthma was significantly decreased in comparison with the control group. MFI (median fluorescence intensity) of CCR5 expression on FoxP3 + Treg cells was significantly decreased in severe asthma compared to the mild-to-moderate asthma and control groups. CCR5 expression on FoxP3 + Treg cells as MFI positively correlated with lung function parameters FEV 1 % and PEF% in patients with severe asthma. Conclusions: High CCR5 Tregs expression as MFI is associated with improved in lung function parameters: FEV 1 % and PEF% in patients with severe asthma. The measurement of CCR5 expression on the surface of peripheral blood FoxP3 + Treg cells as MFI could be an additional tool to estimate the severity of asthma.