The role of budesonide on CD8⁺CD25⁺Foxp3⁺ Treg cells in neutrophilic nasal polyps

Abstract

Objective:CD8⁺CD25⁺Foxp3⁺regulatory T（Treg） cells are reduced in chronic rhinosinusitis with nasal polyps（CRSwNP）. However, the role of these cells in nasal polyps（NP） has not been fully investigated. The aim of this study was to evaluate the influence of budesonide treatment on these cells and to assess their roles in neutrophilic NP. Method:Eight neutrophilic CRSwNP patients were enrolled and received budesonide nasal spray treatment for three months. Nasal samples were obtained from normal mucosa or NP and cultured in vitro. CD8⁺CD25⁺Foxp3⁺Treg cells were isolated and purified from normal or NP tissues and cultured in vitro. Then transforming growth factor-β（TGF-β） and its mRNA were examined in those cell cultures. After that, those cells were administered into NP cultures. Finally, the concentrations of myeloperoxidase（MPO） and interferon（IFN） -γ were evaluated in those tissue cultures. Result:CD8⁺CD25⁺Foxp3⁺Treg cells were decreased in NP compared to normal tissues. Budesonide treatment did not increase the percentage of those cells in NP. TGF-β and its mRNA were enhanced in CD8⁺CD25⁺Foxp3⁺Treg cell cultures from NP versus those from normal tissues. In addition, levels of MPO and IFN-γ were reduced after CD8⁺CD25⁺Foxp3⁺Treg cells administration. Conclusion:These findings indicated that CD8⁺CD25⁺Foxp3⁺Treg cells may play a role in the regulation of neutrophilic inflammation, and budesonide treatment may not influence these Treg cells.