The expression of TSLP in monocyte derived dendritic cells in the interactions between respiratory epithelium and macrophages in asthma, COPD and healthy controls

Abstract

Background: The epithelium derived cytokine thymic stromal lymphopoietin (TSLP) is an important mediator of allergic reaction. The study was aimed to evaluate the expression of TSLP in human monocyte derived dendritic cells (moDC) co-cultured with respiratory epithelium and monocyte derived macrophages (moMφ) in asthma, COPD and healthy controls.

Material and Methods: The study used a triple-cell co-culture model: 1) the epithelial cells (ECs) cultured in the air–liquid interface (ALI); 2) macrophages located on top of the epithelium; 3) the subepithelial dendritic cells (DCs). In vitro model consisted primary nasal ECs from 6 asthma, 4 COPD patients and 4 healthy controls. moMφ and moDCs were specialized from PBMC monocytes by stimulation with M-CSF (moMφ) or GM-CSF, IL-4, IL-1β and TNF-α (moDCs). ECs were stimulated with IL-13 (50 ng/ml) and poly I:C (10 µg/ml) for 24 hours. The changes in mRNA expression of TSLP in moDCs were evaluated with real time PCR.

Results: MoDC were characterized as CD45+, CD14-, CD206+, CD83+, CD11b+ cells. The TSLP receptor was expressed only on CD83+ high/CD11b+ high cells. The expression of TSLP in unstimulated moDC was not different between evaluated groups. In control co-culture model IL-13 and poly I:C stimulation decreased TSLP expression. TSLP expression in moDC co-cultured was significantly lower in COPD than in controls. We observed higher TSLP expression in moDC co-cultured and stimulated with poly I:C of asthma compared to COPD group.

Conclusion: TSLP expression in moDC differs between asthma, COPD and healthy subjects, may be influenced by ECs and macrophages interactions.