Altered Immune Regulation of Dendritic Cells and Enhanced Cytokine Production of T Cells in the Pathogenesis of Eosinophilic Chronic Rhinosinusitis

Abstract

<b><i>Introduction:</i></b> Eosinophilic chronic rhinosinusitis (ECRS) is a refractory chronic disease defined by recurrent nasal polyps with severe eosinophilic infiltration. This is mainly due to enhanced type 2-dominant immune responses, but the underlying mechanism is still not fully understood. <b><i>Objective and Methods:</i></b> In the present study, we aimed to determine the characteristics of dendritic cells (DCs) and cytokine profiles of T cells in the peripheral blood of individuals with ECRS and age- and sex-matched healthy controls (HC). <b><i>Results and Conclusion:</i></b> The ratios of myeloid (m)DC1s to DCs and PD-L1⁺ mDC1s to mDC1s were higher in ECRS patients than in HC. The proportions of plasmacytoid (p)DCs in DCs, and human leukocyte antigen-DR⁺ pDCs and ILT3⁺ pDCs in pDCs were lower in ECRS patients than in HC. In a characterization of T cells, IL-4⁺CD4⁺, IFN-γ⁺CD4⁺, IL-4⁺IFN-γ⁺CD4⁺, IL-4⁺Foxp3⁺CD4⁺, IFN-γ⁺Foxp3⁺CD4⁺, IFN-γ⁺IL-4⁻Foxp3⁻CD4⁺, IL-4⁺CD8⁺, IL-4⁺IFN-γ⁺CD8⁺, and IL-4⁺Foxp3⁺CD8⁺ T-cell populations were significantly higher in ECRS patients than in HC. These results suggest that the enhanced immune regulation of mDC1, diminished capacity of pDCs, and increased proportion of the T-cell phenotypes in peripheral blood might be factors in ECRS pathogenesis.