CD8 Tregs ameliorate inflammatory reactions in a murine model of allergic rhinitis.

BACKGROUND

CD8CD25fork-head box transcription factor (Foxp3) regulatory T cells (CD8 Tregs) play a role in immune tolerance. However, the role of these cells in allergic rhinitis (AR) has not been elucidated. The study aimed to evaluate influences of CD8 Tregs on inflammatory conditions in a murine model of AR.

METHODS

A murine model of AR was established. CD8 Tregs were isolated from mice nasal mucosa and cultured in vitro. We examined interleukin (IL)-10 and transforming growth factor (TGF)-β in cell cultures. Then, we administered CD8 Tregs into mice nasal mucosal cultures, and examined eosinophil cation protein (ECP), IL-4, IL-5 and IL-13 in these cultures. Finally, we adoptively transferred CD8 Tregs into mice models, and evaluated percentages of CD8 Tregs, numbers of sneezing and nasal rubbing, and counts of eosinophils and contents of ECP, IL-4, IL-5, IL-13, IL-10 and TGF-β in nasal lavage fluid (NLF) in mice.

RESULTS

The percentage of CD8 Tregs from AR mice was reduced. IL-10 and TGF-β were increased in cell cultures from AR mice. ECP, IL-4, IL-5 and IL-13 were decreased after the AR mice CD8 Tregs administration in mucosal cultures. However, their contents were not changed after normal CD8 Tregs treatment. Additionally, the adoptive transfer of AR CD8 Tregs enhanced the percentage of CD8 Tregs and levels of IL-10 and TGF-β in NLF, reduced numbers of sneezing and nasal rubbing, and counts of eosinophils and concentrations of ECP, IL-4, IL-5 and IL-13 in NLF. However, normal CD8 Tregs could not change above parameters.

CONCLUSION

These findings show that CD8 Tregs may inhibit inflammatory responses in the AR condition.