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

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.

Prospective cross-sectional study.

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.

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.

The findings demonstrate that CD8⁺ Tregs may alleviate inflammatory responses in AR condition.

3 Laryngoscope, 131:E316-E323, 2021.