Influences of CD8 + Tregs on Peripheral Blood Mononuclear Cells from Allergic Rhinitis Patients

Objectives CD8+(or CD4+) CD25+fork‐head box transcription factor (Foxp3)+ regulatory T cells (CD8+ or CD4+ Tregs) all play a significant role in immune homeostasis and tolerance. However, the role of CD8+ Tregs in allergic rhinitis (AR) have not been clearly elucidated. The present study was aimed to assess the influence of CD8+ Tregs on peripheral blood mononuclear cells (PBMCs) from AR patients. Study Design Prospective cross‐sectional study. Methods Patients with AR were enrolled. PBMCs were obtained, and CD4+ and CD8+ Tregs were separated from PBMCs and cultured in vitro. We examined percentages of these Tregs in total CD4+ or CD8+ T cells, respectively. After that, we evaluated levels of interleukin (IL)‐10 and transforming growth factor (TGF)‐β in Tregs cultures. Finally, we administered CD4+ and CD8+ Tregs from AR patients into PBMCs cultures and examined contents of IL‐4 and IL‐5. Results The percentages of CD4+ or CD8+ Tregs in the total CD4+ or CD8+ T cells from PBMCs in AR patients were reduced compared to normal subjects. However, IL‐10 and TGF‐β and their mRNAs were increased in CD4+ and CD8+ Tregs cultures from AR patients, and there were no significant differences in their levels between these two Tregs cultures. IL‐4 and IL‐5 were increased in AR subjects’ PBMCs compared to normal ones and decreased after the AR CD4+ or CD8+ Tregs administration. However, there were no statistical differences in IL‐4 and IL‐5 concentrations between these two Tregs treatments. Conclusions The findings demonstrate that CD8+ Tregs may alleviate inflammatory responses in AR condition. Level of Evidence 3 Laryngoscope, 131:E316–E323, 2021